Chapter 3. Mine Pumps f1l3h

Chapter 3. Mine Pumps

ROBERTW. LAWSON INTRODUCTION

Prior to 1705, underground mining was limited to mineral deposits located above or a very small distance below the water table. The development of the steamdriven mining pump was motivated by the need to extract minerals from deposits considerably lower than the water table. Today, the majority of mine pumps are driven by electric motors, although some small utility pumps are driven by compressed air. Of the numerous types of pumps that might be applied to mine service, the two types used most frequently underground are the centrifugal and plunger pumps. Each of these types has its proper application. In most instances, plunger pumps are best for handling low water volumes against high heads, while centrifugal pumps effectively handle either low or high water volumes against low heads or high water volumes against high heads. This chapter describes pumps applied to underground mine service, where the mine service consists of mine drainage (removing mine water as it accumulates), mine dewatering (removing water from a flooded mine), and pumping for special applications such as hydraulic mining and hydraulic hoisting. -

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CENTRIFUGAL AND PLUNGER PUMPS

Modern mine pumps are classified as either centrifugal (kinetic) or plunger (positive-displacement) pumps. The following paragraphs describe each of these classifications. Centrifugal Pumps Centrifugal pumps may be grouped into various types, depending upon their various features: Number of Stages: In a single-stage pump, the total head is developed by one impeller, while a multistage pump utilizes two or more impellers acting in one casing to develop the total head. Fig. 1 shows a cutaway view of a single-stage horizontal split-case double-

Fig. 1. Cutaway view of a single-stage horizontal split-

case double-section centrifugal pump (courtesy of Ingersoll-Rand Co.). section centrifugal pump. Fig. 2 shows a cutaway view of a six-stage medium-pressure split-case diff-type centrifugal pump. Type of Casing: A volute pump has a casing in the form of a spiral or volute. A circular-casing pump has a casing of constant cross section concentric with the impeller. A diff pump is equipped with a diff that converts velocity head to pressure head. Shaft Position: A horizontal pump normally has the shaft in a horizontal position, while a vertical pump normally has the shaft in a vertical position. Fig. 3 illustrates a vertical turbine-type slurry pump. Suction: A single-suction pump equips the first stage with a single-suction impeller, with fluid entering the impeller on only one side. A double-suction pump equips

Fig. 2. Cutaway view of a medium-pressure split-case six-stage diffusor-type centrifugal pump (courtesy of IngersollRand Co.).

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ANCILLARY EQUIPMENT

Fig. 7. Cross section of a Mitsubishi-MarsTM plunger-type slurry-pump system (courtesy of Mitsubishi Co.).

gravity of the mine water, H is the total dynamic head in feet, E, is the efficiency of the pump, and E , is the efficiency of the motor. Suction Sump: The suction sump serves two important functions. First, the suction sump provides storage capacity in the event of a power outage or a mechanical failure of the pumping equipment. Many mines have established definite minimum storage limits. For example, Butte copper mines require that no pump installation have less than 4 hr storage of water inflow in the sump. In other mines, 45 to 90 min of storage is considered adequate, with local conditions dictating the storage capacity. Furthermore, the capacity of the storage sump should be adequate to accommodate any sudden inrush of water. The second function of the suction sump is to provide adequate residence time for the suspended solids to settle, and the sump must be designed to allow removal of the residue. Many arrangements are in use, and Fig. 8 illustrates one possible arrangement. The horizontal sump is the most prevalent, and it requires minimum shaft depth. It accommodates a horizontally split pump located in a dry well with flooded suction. The vertical sump, commonly used in South Africa, permits the residue to be drained by gravity from the bottom of the sump directly into a mud skip used to hoist the residue to the surface. However, a vertical sump. requires a greater shaft depth than does a horizontal sump. It is well suited to the use of a vertical mine pump. To determine the proper residency time in the sump, a number of mine-water samples should be placed in a laboratory graduate where the settling can be observed and timed. As a general approximation, a sump should have approximately 0.09 m2 (1.0 sq ft) of surface area for each 3.79 L (1.0 gal) pumped. This calculates to a settling rate of 0.68 mm/s (1.6 ipm). In deg either a vertical or a horizontal sump, an effort normally is made to direct the incoming water toward the bottom of the sump, taking the effluent from the top. The up-

ward rate of water flow should be less than the measured settling rate. In a horizontal sump, submerged weirs improve the effectiveness of solids removal, but such weirs should be designed so they do not hamper cleaning the residue from the bottom of the sump. The cost of providing adequate sump capacity is recovered many times over through reduced pump maintenance. The importance of removing abrasive solids from the mine water increases as the head against which the pump operates increases. Mine-Pump Motors: Modern mine-pump motors are predominantly a-c induction motors. The type of motor enclosure is dictated by the conditions prevailing at the pump location. High-voltage current for major pump installations is transmitted by cables down the shaft or through boreholes and is transformed adjacent to the pump station to meet the requirements of the pump motor. The pump-motor voltage is selected according to economic considerations, including the cost of the transforming equipment, the motor-control equipment, and the motors. Small utility pumps of approximately 7.6 L / s (120 gpm) and 45.7 m (150 ft) total head may operate on 689 kPa (100 psi) of compressed air, consuming approximately 0.019 m3/s per kW (30 cfm per hp). Ventilation: Ventilation is an important consideration for any underground pump installation. Some mine waters release noxious gases that must be diluted and exhausted from the mine by means of adequate ventilation. More frequently, ventilation must be provided to remove the heat emitted by the pump motors and transformers. The total electrical energy supplied to the pump motors less the energy required to lift the water against the head is converted to heat; this may be calculated from the equation: E = (56.92 X P ) -(0.011 X F X L,) where E is the heat in British thermal units per minute, P is the power in kilowatts, F is the water flow rate in gallons .per minute, and L, is the static lift in feet.

UNDERGROUND MINING METHODS HANDBOOK

Fig. 8. Diagram of a horizontal sump showing details of the settler section (courtesy of H.L. Monroe).

The heat must be dissipated by either ventilation air or transferring the heat to the mine water pumped to the surface. One method of transferring the motor heat to the mine water is to enclose the pump motor so that the air circulated over the rotor and stator is in a closed system. This air then es over a water-cooled heat exchanger before being recirculated through the motor, and the warmed water from the heat exchanger is dumped into the pump suction and transported to the surface. Materials of Construction: The materials of construction are critical to the success of a pumping installation. The "wetted parts" in with the pumped liquid must be constructed of materials that resist corrosion and abrasion. For mine water with a neutral pH, a regular fitted pump with a cast-iron casing and a bronze impeller, wearing rings, and shaft sleeve is satisfactory. For slightly acid mine water, an all-bronze pump, sometimes called "iralty metal," is the best construction. As the corrosive nature of the pumped water increases, it may become necessary to use chromenickel alloy. The pump manufacturer should be consulted for recommendations; the information that should be supplied to the pump manufacturer for proper selection of the pump materials includes: (1 ) the liquid to be pumped; (2) the principal corrosives; (3) the pH and specific gravity of the mine water; (4) the undissolved impurities and other constituents, including the specific gravity of the solids, the percentage of solids in the liquid by weight, and the particle size and distribution; (5) details of the expected pump service; (6) the materials

used for pipelines; and (7) any previous experience with materials of construction. T o accurately assess the performance of various materials, the pump manufacturer may request a sample of the mine water. When the mine water is corrosive and circumstances permit, the most accurate method of evaluating alloys is to place weighed "tabs" of likely alloys in a moving stream of mine water. At intervals, the weight loss is determined for each sample alloy. When the mine water presents a serious operating problem, the most practical solution may be to treat the water in the sump before it is pumped. Such treatment could involve neutralizing the liquid with lime or some other additive or increasing the acidity with sulfuric acid to discourage the deposition of ocher in the pump columns. The economics of such treatment procedures must be analyzed for each individual installation. It has been observed that pump maintenance caused by abrasive particles in the mine water has increased markedly when a mine has been converted from rail haulage to rubber-tire haulage. This is attributed to the rubber-tired vehicles constantly agitating the drainage water in the haulageways. If rubber-tired haulage is used, extra capacity for settling the solids should be provided in the sumps and a higher pump-maintenance cost anticipated. Bid Form: The use of a bid form is suggested when requesting quotations from various pump manufacturers. Table 1 lists the items that should be included on such a form. The portion of the form listing the design conditions should be completed by the mine engineer and

ANCILLARY EQUIPMENT Table 1. Suggested Items for a Bid Form Project: Purchaser: Address: Dealgn Condltlona Quantity Service Liquid Temperature, "C ("F) Capacity, Us (gpm) Max Discharge Pressure, kPa (psi) Max Suction Pressure, kPa (psi) Differential Pressure, kPa (psi) Specific Gravity Total Head, m (ft) Viscosity or Slurry Density pH Value Performance Pump Selection Speed, radls (rpm) Efficiency at Design Power, DesignIMax, kW (bhp) NPSH, AvailableIRequired, m (ft) Performance Curve Construction Packing or Seal Gland Type Piping Seal Flange Rating, SuctionIDischarge BearingdLubrication Trico Oilers Coupling Coupling Guard Bedplate Gage TapdVentslDrains Rotation (Viewed from Coupling End) Materlala Casing Impeller Shaft Shaft Sleeve Wearing Rings, ImpellerICasing Drlver TypeIFramelManufacturer Power, kW Iradls (hplrpm) Rotation (Viewed from Opposite Coupling) Furnished ByIManufactured By Conditions Prlclng Shipping Weight, PumpIDriver, kg (Ib) Pump Shipment, weeks Net Pump Price, Each

Date: Ref. No.:

-1

-1 CW

-

CCW

-1-1-

-1-1CCW

CW

CW -CCW

-CW

CW

-CCW

-1-1-

I -CW -CCW

the balance of the form should be completed by the vendor. The use of such a form facilitates comparing bids received from various manufacturers, and it assists the purchaser in making sure that the comparison is between equipment of comparable construction and performance. Overall, the use of such a form helps eliminate misunderstandings. Pump Pefiormance Curves: Pump performance curves are the most convenient method of indicating the operating characteristics of a centrifugal pump. Fig. 9 illustrates the pump performance curve for a typical two-stage single-suction centrifugal pump. If the system curve of the mine-pump installation is plotted with the same ordinate and abscissa scales as used for the pump performance curve, the two curves

I

I CCW

--I

may be superimposed as shown in Fig. 10. The system curve consists of the static head plus the friction head. The point at which the system curve crosses the headcapacity curve is the operating point for the installation. As an example, assume that a two-stage singlesuction pump is driven by a 56-kW (75-hp) electric motor at 372 rad/s (3550 rpm). The pump is fitted with a 241-mm (9.5-in.) diam first-stage impeller and a 216-mm (8.5-in.) second-stage impeller. The static head on the pump is 168 m (550 ft), and pumping is into a 102-mm (4.0-in.) standard-weight steel pipe. The pipe length is a total of 274 m (900 ft), including equivalent lengths for fittings. Fig. 10 shows that the operating point is at 15.8 L/s (250 gpm), with 183 m (600 ft) of head [I68 m (550 f t ) of static head plus 15

UNDERGROUND MINING METHODS HANDBOOK

1342

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Fig. 9. Pump-performance curve for a typical two-stage single-suction centrifugal pump. Metric equivalents: ft X 0.3048= m; in. X 25.4= mm; gpm X 0.063 090 2 = L/s; bhp X 0.745699 9 = kW.

Fig. 10.

Pump-performance curve with a super-imposed system curve. Metric equivalents: ft X 0.3048= m; in. X 25.4= mm; gpm x 0.063 090 2 = L/s; bhp x 0.745699 9 = kW.

m (50 ft) of friction head]. The pump efficiency is 63% and the power is 45.5 kW (61 bhp). The pump requires a minimum of 4.0 m (13 ft) net positive suction head (NPSH) . For mine drainage or dewatering, a pump should have a head vs. capacity curve that rises constantly to shutoff. If this curve has a "hump," the pump may surge under certain operating conditions. Since the total dynamic head of a mine-drainage system is fairly constant, a reasonably flat curve is desirable. As water accumulates in the pump-section sump, the capacity handled by the pump increases because the suction head increases. That reduces the total dynamic head. For a mine-dewatering pump, where the total dynamic head increases as the water in the mine recedes, a steep head vs. capacity curve is desirable. As the head increases, the capacity does not decrease significantly. In selecting a pump, it is important to pick one with a characteristic curve that permits the anticipated operating-condition point to be close to the maximum pump efficiency. That is for reasons of both mechanical performance and power economy. Continuously operating a pump at an extreme above or below the point of maximum efficiency may cause unbalanced dynamic forces that can result in excessive flexing of the pump shaft, an overload on the pump bearings, and separation cavitation damage in the impellers. The performance of a centrifugal pump with a given impeller design may be altered by changing the peripheral or tip speed of the impeller: (1) the capacity varies in direct relationship to the peripheral speed, (2) the head varies in direct relationship to the square of the peripheral speed, (3) the power varies in direct relationship to the cube of the peripheral speed, and (4) the efficiency remains constant for small changes in the peripheral speed. The peripheral speed may be changed by altering the diameter of the impeller or the rpm of the pump. However, there are some limitations. Only a radialflow centrifugal pump impeller can be altered, and too great a change alters the characteristics so that the performance does not conform to the relations stated. The impeller should not be cut so small that the vanes do not overlap. Otherwise, the performance may become

unstable. Too large an impeller in a casing interferes with the flow at the cutwater and reduces the overall efficiency of the pump. Net Positive Suction Head (NPSH): The NPSH is the absolute pressure in meters (feet) above the vapor pressure of the liquid being pumped. The NPSH is measured at the pump suction flange on a gage mounted at the centerline of the pump. The available NPSH is the sum of the suction gage reading and the atmospheric pressure minus the vapor pressure. In equation form, this is expressed as: NPSH = 2.3 1 (Pa

+ P, - vp - fs)

where NPSH is the net positive suction head in feet, Pa is the atmospheric (barometric) pressure in pounds per square inch, P, is the suction pressure in pounds per square inch at the pump suction nozzle corrected to the pump's horizontal centerline (if this is a suction lift, this is a negative value), vp is the vapor pressure in pounds per square inch, and fs is the friction loss in the suction piping in pounds per square inch. The 2.31 value is a constant to convert pounds per square inch to feet of water. The same relationship may be applied to values using metric units. At sea level, the theoretical maximum suction lift of a pump is 10.4 m (34 ft) and indicates the distance from the surface of the water to the centerline of the pump. In practice, a suction lift of 6.1 m (20 ft) should not be exceeded. At altitudes above sea level, the suction lift should be reduced to correspond to the reduction in atmospheric (barometric) pressure. Most pump performance curves indicate the NPSH required by the pump. The available NPSH calculated from the equation always must be equal to or greater than the required NPSH. Mine-Pump Cost

After reliability, the cost of the mine pump is the most important consideration in the selection process. The cost considered should be the total cost for the entire life of the pump. This total cost includes the purchase price, freight, installation costs, power costs, and maintenance costs. Over the life of the pump, the purchase price is only a small increment of the total

ANCILLARY EQUIPMENT cost, and the costs for power and maintenance should be evaluated carefully. As already indicated, the reliability of the pump installation probably is the most important consideration. If the mine is flooded, loss of production plus all of the costs related to reopening the mine far exceed the cost of the pumping equipment. In critical locations, standby equipment must be considered. For cost calculations, a ten-year life for the pump and accessories is an acceptable estimation. That "life" frequently is used when calculating equipment depreciation. First Cost: The first cost is the purchase price of the equipment. This cost may be obtained from the equipment supplier. In recent years, prices have been fluctuating so widely that it is hazardous to place any faith in cost curves for equipment. Installation Cost: Because of many variables, the installation cost cannot be estimated here with any degree of accuracy. Underground, there normally is rock in place to provide a base on which to pour a thin slab of concrete where the pump bedplate is anchored. The cost of such a foundation is nominal. The principal costs of installing an underground pump involve excavating the pump room, building the pump sump, installing the power lines and shaft column, and conveying power to the pump motors. Power Cost: The cost of power is becoming increasingly important and the emphasis on pump and motor efficiency is growing. The cost of power may be calculated from the horsepower of the pump, the unit cost of power, and the number of hours the pump actually operates. The formulae are:

where C, is the power cost in dollars, Ckw,, is the cost per kilowatt-hour in dollars, P,, is the power consumption in kilowatts, T , is the pump-operation time in hours, Pbh, is the brake horsepower of the pump motor, and Em is the efficiency of the pump motor. The utility company selling power to the mine should be ed to obtain the charge per kilowatt-hour and an estimate of the increase in power rates over the next ten years. Maintenance Cost: Assuming the pump is handling clean cold water, the maintenance cost may be estimated at $4/kW ($3 per hp) per year. Abrasive or corrosive materials in the mine water can increase this estimate considerably. Installation When properly selected, installed, and maintained, centrifugal pumps operate satisfactorily for a long period of time. Location: The pump should be located so that the suction pipe can be short and direct with a minimum of fittings. If possible, the pump suction should have a positive head; Fig. 11 illustrates a piping arrangement with a positive head on the suction. Adequate space must be provided to inspect, remove, and repair units, and provisions should be made for lifting devices needed to handle heavy pieces such as the complete pump or the complete motor. Frequently, it is desirable to allow adequate space in the pump room for the installation of additional pumps at some future date.

GATE VALVE-,

PET COCK \

/GATE

VALVE

Fig. 11. Typical piping arrangement with a positive head on the suction. Foundation: The foundation should form a rigid for the pump's bedplate and should absorb mechanical vibration. A foundation must not be located on a fault or rock fracture that might move or shift and disturb the pump alignment. The most satisfactory foundations are constructed of reinforced concrete. Elevation drawings obtained from the pump manufacturer identify the locations for the anchor bolts, the size of the bolts, and the dimensions for required grouting. In installing the foundation bolts, the threaded bolt length above the rough surface of the concrete should be somewhat longer than specified; any unused excess can be cut off later. When applying grout, a rough finish on the top of the concrete foundation is desirable. Fig. 12 illustrates a typical template for hanging foundation bolts while pouring the foundation. Fig. 13 illustrates the typical arrangement of the foundation bolt within the foundation. Bedplate Leveling: The procedure to level the bedplate should include: 1 ) Disconnect the flexible coupling between the pump and the motor. 2 ) Prepare iron wedges or shims 102 to 152 mm ( 4 to 6 in.) long and 51 to 76 mm (2 to 3 in.) wide to go on each side of all foundation bolts. The wedges or shims should be thick enough to allow 19 to 38 mm (0.75 to 1.5 in.) of grout to be placed under the edge of the bedplate. Fig. 14 illustrates the method of placing the wedges or shims with a pinch bar. 3 ) Level the bedplate using a 229-mm (9-in.) machinist's level on the machined surface and snug down the foundation bolts. When the bolts have been tightened, recheck the level. Alignment: It is extremely important that the pump and motor be aligned properly. A flexible coupling is not a universal t. There will be some vertical expansion when the pump is running under normal condiallow bolts to project for grouting under bed plate

make this distance equal to lug on bed plate

Fig. 12. Typical template for hanging foundation bolts while pouring a foundation for a pump.

UNDERGROUND MINING METHODS HANDBOOK

1344

allow ample threaded bolt length above rough concrete

rough finish

stuff wastearound bolt while pouring

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pipe sleeve to be three times diameter of anchor bolt

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and pipe sleeve to

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.

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.

.

Fig. 13. Cross section of a concrete foundation showing

the arrangement of a foundation bolt. tions; the vertical difference between the pump and motor should be measured when the equipment is cold, and this difference should be recorded on a tag attached to the coupling. Generally, pumping a cold or cool liquid allows the motor to "grow" more than the pump; when the pump and motor both are cold, the motor coupling should be 0.13 to 0.20 mm (0.005 to 0.008 in.) lower than the pump-half coupling. Fig. 15 illustrates the steps necessary to align the coupling, and the alignment must be within 0.08 mm (0.003 in.) when the equipment is operating at normal temperature. The procedural steps shown in Fig. 15 are: 1 ) Measure the vertical angular misalignment; the coupling faces must be parallel to within 0.08 mm (0.003 in.). 2 ) Measure the horizontal angular misalignment; the coupling faces must be parallel to within 0.08 mm (0.003 in.). 3 ) Measure the vertical alignment; the coupling faces must be parallel to within 0.08 mm (0.003 in.). 4 ) Measure the horizontal alignment.

Fig. 15. Method of aligning the motor-to-pump coupling.

,. .

Fig. 14. Method of leveling a bedplate using wedges or shims and a pinch bar.

Grouting: Grouting is used to distribute the pump load uniformly over the foundation. Fig. 16 illustrates the method of placing the grout, and the procedure is: 1 ) Build a wood dam around the foundation as shown in Fig. 16. Since the leveling wedges may be removed after grouting, the locations of the wedges should be marked before pouring the grout. 2) Prepare the grout mixture. A good mixture consists of one part cement to two pads clean sharp sand. Enough water should be added so that the mixture

ANCl LLARY EQU l PMENT GATE ULM

CHECh VALVE CENTRCl REEKER

ffi RADIUS ELBOW

STRAINER ECCENTRC

SUCTION PPC SLOPES NWARD f ROM PU*P RADIUS ELBOW

CORRECT Fig. 16. Cross section of foundation grouting, showing the

position of the wood dam used when pouring grout. flows evenly and is approximately the consistency of heavy cream; too much water allows the cement to separate out of the mixture. 3) Pour the grout to fill the area under the bedplate completely. Holes in the bedplate allow air to escape and serve as inspection ports. 4) After the grout has hardened completely, remove the wood dam and the leveling wedges. Use additional grout to fill the holes left by removing the wedges. 5) Pull down the foundation bolts, recheck the pump level, and recheck the pump and motor alignment. Many grouting materials are available, but only some of them are usable in this application. The proposed use of any new material always should be checked with someone who has used it and whose opinions are reliable. Do not connect any piping until the grout has hardened thoroughly and the foundation bolts have been pulled down. Pump Column: The pump column should be of a diameter sufficient for the water velocity to approximate 4.6 m/s (15 fps). Too small a diameter increases the power consumption, while too large a diameter can result in "water hammer" problems. A check valve and a gate valve should be installed in the discharge pipe; the check valve should be between the gate valve and the pump discharge flange. The check valve protects the pump and packing from excessive pressure surges and it prevents the pump from running backward. The gate valve allows the check valve to be inspected, and it may be used for priming and starting the pump. Suction Pipe: The suction pipe should be short and direct. The horizontal section of the pipe should have a gradual rise so that no section of the horizontal line is above the pump's suction nozzle. If possible, a flooded suction should be provided. If a gate valve must be installed in the suction line, the valve should be mounted to position the valve stem in a horizontal or bottom direction, thus reducing the possibility of encountering air pockets or air leakage. The suction line should be large enough so that the water velocity does not exceed 2.4 m/s (8 fps). Fig. 17 illustrates correct and incorrect methods of installing suction and discharge pipes.

Fig. 17. Correct and incorrect methods of installing

suction and discharge pipes for a mine pump. Priming: Before starting a centrifugal pump, it is necessary to prime the system. If the pump has a flooded suction, there is no problem; a vent on the top of the pump casing should be opened to bleed all air out of the system. However, if the pump has a suction lift, one of two possible priming methods must be used: 1 ) The pump suction line may be equipped with a foot valve that is installed below the water level. The pump and suction line can be filled with water from some source such as a fresh-water line from the surface or water from the discharge of another pump. The proper location of the foot valve is shown in Fig. 17. 2) The pump may be provided with an aspirator (ejector) or a vacuum system to remove the air from

1346

UNDERGROUND MINING METHODS HANDBOOK

the pump casing and to "suck" water into the casing and suction pipe. When this method is used, a foot valve should not be used. This is the preferred method of priming a pump and a simple aspirator, operating on compressed air, can be assembled from standard pipe fittings. Or, a commercial ejector can be purchased. Fig. 18 illustrates the arrangement for priming with an ejector. Startup Procedure If properly performed, the startup procedure can prevent time-consuming and costly problems. Frequently, the personnel starting the new pump installation are not the same as those who installed the equipment. Therefore, the following steps should be taken: 1 ) The entire unit and surrounding area should be cleaned. 2 ) All main and auxiliary piping should be checked to make certain that the piping has been connected properly and is free of foreign objects such as rags, gloves, pieces of wood, welding slag, rocks, and lunch pails. It is prudent to install a conical strainer at the pump's suction flange before startup. 3) The pump and motor bearings should be cleaned and lubricated. 4 ) The level and alignment should be rechecked. 5) The motor's direction of rotation should be checked before connecting the coupling. After being checked, the coupling should be assembled. 6 ) The discharge valve should be closed. 7 ) The pump should be primed, making certain that all air is bled out of the casing and suction pipe. A pump that is run dry may "seize." 8) The water to the stuffing boxes should be turned on, and the pump unit started. 9 ) As soon as the pump reaches operating speed, the discharge valve should be opened slowly. 10) With the pump operating, the stuffing-box packing should be checked. When the pump is packed, the glands should not be drawn up very tightly, and there should be a considerable amount of leakage when the pump is started so that the packing stays cool and does not glaze. As the pump runs, the stuffing-box gland nuts may be tightened to reduce the leakage, but there always should be some leakage to lubricate the packing and cool the stuffing box.

CCCNTRIC REDUCER ONG RADIUS ELBOW

Fig. 18. Typical arrangement for pump-system priming by means of an ejector.

11) After a few hours of operation, the pump and motor alignment should be rechecked. 12) After several hours of operation, the bearing temperature should be checked; this temperature should not exceed 71 "C (160°F). 13) The suction and discharge pressure gages should be checked. If the readings are not at or near the anticipated pressures, the unit should be shut down and the problem located and corrected. 14) After running for several days and completing a final check of the alignment, the unit should be doweled. Tapered dowel pins between 6.4 and 25.4 mm (0.25 and 1.0 in.) should be installed in diagonally opposite feet of the pump and motor. It is not necessary to dowel small- or medium-size single-stage pumps. 15) When the pump is subject to freezing temperatures while not in operation, the casing should be drained by removing the pipe plugs in the bottom of the casing. Automatic Pump Control Automatic pump control frequently is installed and pumps are checked only once a shift. The basic automatic control is a sensing device that starts and stops the pump as the level of the mine water in the suction sump fluctuates. That can be a simple float switch, or it can be an array of electronic probes. If the pump operates with a suction lift, it is important that a device be provided to make certain that the pump is primed properly before it starts. If clean water is scarce or expensive, automatic water valves can be installed on the stuffing box. Highly sophisticated sensing devices of various types also are available to further safeguard the pump and motor. In all cases, an alarm system should be provided to indicate when the water level in the sump rises above a predetermined limit. Maintenance If the pump has been installed properly and if the suction sump is adequate to allow abrasive solids to settle, the maintenance of a mine pump usually is quite simple. Rotating Elements: For pumps that are vital to mine operations, at least one spare rotating element should be kept on hand, complete with all elements necessary for immediate installation. This includes a pump-half flexible coupling so that a damaged or worn rotating element can be removed and a new rotating element can be installed quickly. Some mines have a heavy welded steel box in which the spare element is placed, lowered into the mine, and stored in the pump room; the element is not removed from this box until it is installed directly into the pump. The rotating element must be handled with extreme care since the aligment of the element is critical to proper operation. To assess the wear on internal pump parts, it is good practice to install an ammeter that s the motor amperage. When the motor amperage falls below a predetermined lower limit, the pump rotor should be replaced-such a decrease in amperage indicates that the internal clearances have increased to a point where excessive internal water recirculation is occurring. This is particularly important on multistage pumps. The use of the ammeter eliminates the need for frequently opening the pump casing to inspect the internal parts; as long as a pump is functioning properly, it is advisable to avoid opening the casing.

ANCILLARY EQUIPMENT Lubrication: The ideal lubricant for ball bearings is a straight well-refined neutral mineral oil, preferably of a turbine type. For the majority of applications, SAE 10 motor oil meets the requirements. Table 2 summarizes some suggested oil specifications. It is good practice to change the oil in the bearing housings once every 600 hr of operation. Record Card: For each pump, a record card or log book should be maintained conscientiously. Table 3 lists the contents of a suggested record card; this information greatly assists in diagnosing any problem that might develop. Operating Difficulties: Some 85% of the troubles encountered with centrifugal pumps occur on the suction side. The possible problems may be classified into four groups: no water or insufficient water delivered, insufficient pressure, intermittent operation, and excessive power consumption. No Water o r Insufficient Water Delivered-Problems indicated by no water or insufficient water delivered may be caused by: improper priming with the pump casing not full of water, too low an operating speed, too high a discharge head, too high a suction lift, a plugged impeller age, an incorrect direction of rotation, air leakage into the suction pipe or stuffing boxes, an insufficiently submerged suction-pipe entrance, mechanical defects or worn internal clearances, or too small an impeller diameter. Insufficient Pressure-Problems indicated by insufficient pressure may be caused by: too low an operating speed, mine water containing excessive entrained air or gas, too small an impeller diameter, or a total head higher than that calculated. Intermittent Operation-Problems indicated by intermittent operation, with the pump operating for a while and then stopping, may be caused by: air leakage into the suction line or stuffing boxes with a subsequent loss of priming, an improperly functioning water seal, mine water containing excessive entrained air or gas, or too high a suction lift. Excessive Power Consumption-Problems indicated by excessive power consumption may be caused by: a total head lower than that calculated; too high an operating speed; mechanical defects such as a binding rotor, a misaligned pump, or an excessively tight stuffing box; or electrical defects such as low voltage or frequency that cause motor overheating. MINE-DEWATERING PUMPS Most mine-dewatering pumps are of a vertical design. They may be hung in a shaft to follow the water level down, or they may be installed as submerged pumps in a shafts or boreholes that intersect the mine workings. When dewatering a mine, the pumped water is usually free of solids because the water has been standing (and settling) for an appreciable period of

1347

time. If a standard vertical pump is installed in the shaft of a flooded mine, it can be mounted on a crosshead on the old shaft guides and lowered as the water recedes. The discharge is connected to the pump column by rubber hose or, in some instances, a telescopic pipe arrangement that allows the lower length of pipe to slide out the lower end of the pump column through a packed stuffing box. Another method of mounting the pump is to secure it to a float or raft that follows the level of the water as the pumping progresses. Selection of Pumping Equipment The selection of the proper size pump for dewatering a mine requires a calculation of the volume of the flooded mine workings plus estimated water inflow, and the total head against which water must be pumped. Since the total head varies as the water rece s, selection of the pump frequently depends upon the q t e n t of the head variation. In some cases, it is desirable to select a multi-stage pump capable of pumping against the maximum head which will be encountered; when the pump is operating against a lesser head, at the start, remove several stages of impellers, replacing them with spacers. In another approach, the dewatering pumps are staged. An initial pump Lowers the water to a predetermined level, a permanent pump is installed on that level, and the initial pump then lowers the water to the next predetermined level. This method allows a permanent pump to be installed on each level as it is reached. Frequently, these pumps are horizontal splitcase designs which may be more economical than the vertical dewatering pumps. It is not practical to propose a specific pump arrangement; the best arrangement usually depends upon many different factors that vary from mine to mine. Some of these factors include: the quantity of water to be pumped, the time available for the dewatering operation, the depth of the shaft to be dewatered, the depth at which the major water volume is located, the available power supplies, the physical conditions of the mine and shaft, and the purpose of the dewatering operation. When dewatering a mine, a formal provision must be made for disposition of the pumped water. The lack of proper arrangements has delayed a number of mine dewatering projects and has resulted in legal problems. In arid country, allowing even clean mine water to flow onto a rancher's property can result in troubleparticularly if the rancher sees an opportunity to profit from litigation. On occasion, it may be possible to make a deal with such an individual prior to commencing the dewatering operation, allowing that individual to buy the water for some nominal amount, but making him feel that he outsmarted the mining company.

4e

Table 2. Recommended Speclflcations for Bearing Lubricants Item

Napthene Base

Paraffin Base

-

Flash Point Saybolt Viscosity, 38°C (100°F) Pour Point

166°C (330°F) min 150 sec min 200 sec rnax - 15°C (5°F) max

182°C (360°F) rnin 140 sec min 185 sec max 2°C 135°F) rnax

UNDERGROUND MINING METHODS HANDBOOK Table 3. Typical Record Card Contents tor Pump Maintenance Serial No. 01 43 783

Size & Type 3GF

Pump Mfr. Ingersoll-Rand

Rated Condltlons: Gpm . . .360 . . . . . . . . . . Total head, feet . .320.. Suction ++or- feet. -5. Rpm . . . ,2900 . . . . . . . . Liquid . . . . water . . . . . . Temp. O F . . . .72". . . . . . . Viscosity . . . .97 cent . . . Sp. gr. . . .l.O . . . . . . . . . . Impeller Pattern 3GT3H-R Dia 8-114 In.

Mfr. Order No. 01-54 Item No. 2A Cust. Order No. 431

Stuff. Box Dlmonslons: O.D. 2-7/8 . . I.D. 1-9116 Packing Size 318 In. Sq. No. of Rings 1-6, 2-6.

.

Packing Mfr.. 5-R-N.. . Packing No. 505.

.....

.....

1

7-7/16 . . . . . . Driver - Motor Manufacturer - GE

Date Shipped 1-29-43

Pump Materlrls: Casing . . .CI . . . . . . . . Casing Rings. . Br . . . . Impeller.. Br . . . . . . . . Imp. Rings. . Br . . . . . . Shafi . . .st . . . . . . . . . . Shafi Sleeves.. Ph-Br Radial Brg. Type-Ball . . Size 1307 Thrust Brg. Type-Ball Size 74-05-0 Casing Gasket . . . . . . . Thickness 1/32" Normal Wearing.. . . . . Ring Clearance 004"

Serial No.-123870 Type -OPEN -

H.P. - 40

RPM - 2900

Volts - 440

Phase - 3

Inlet Steam, psi. ga. -

Enclosure - Tri-Clad

Frame - 404 Cycles - 50

Exhaust, psi. ga. -

Total Temp. "F -

Control: Type - CR-7051

Manufacturer - GE INSPECTION 8 REPAIRS

Date:

Condition:

Due to:

Repaired by:

Cost:

Remarks:

6/29/43

Good

Reg-Inspect

G WM

-

-

Costs of Dewatering The costs of a dewatering operation are dependent upon many local factors, making it impractical to attempt a definition of dollar costs. Instead, it is helpful to describe the various items that affect the costs. Fist Cost: The first cost can be calculated only after the contributing factors previously listed have been determined. An important consideration in evaluating the first cost is to establish the source of power necessary to operate the pumps. If the mine has been shut down for an appreciable length of time, the power lines and electrical distribution system often have deteriorated to a point where a major expense is involved in reestablishing power supplies.

Power Cost: The cost for the power needed to dewater a flooded mine is a function of the water volume, the pumping height, and the volume of ground water that continues to flow into the mine as the residual water is removed. For most purposes, the water inflow may be assumed to equal the inflow experienced prior to the mine being flooded. Cost Determinations: T o estimate the cost of pumping the residual water from the flooded mine, a map of the mine workings may be used to calculate the volume and the average head. T o facilitate the calculation, arbitrarily divide the workings into logical units, calculating the volume of water and an estimated average lift for each unit. Then integrate the individual

ANCILLARY EQUIPMENT Table 5. Typical Submergences for Alr-Llft Pumps Customary Allowable Submergence, %

Lift, m (ft)

and a high-capacity, low-lift jet. In either case, water forced under pressure down the age at the right enters the Venturi throat at high velocity and draws water from below. The two streams merge in the gradually widening Venturi and they are propelled upward into a discharge pipe. Fig. 26 illustrates the use of a jet pump for draining a sump. In this case, a motor pump (centrifugal) used for dewatering the sump may provide the high-pressure water to operate a jet pump at a lower level.

Best Submergence, %

Fig. 27 illustrates the use of a jet pump for draining a ageway. The jet is stationed in a low spot and is equipped with a float-operated valve. The operating water is obtained from a pressure line or from a centrifugal pump. HYDRALlLlC MINING

Modern underground hydraulic mining in the United States began in 1948 with the mining of gilsonite by the American Gilsonite Co. near Salt Lake City, UT.

Table 6. Dimensions and Rated Capacltles for VA System Alr-Lift Pumps Pipe Smallest Connections Diam. Size of Well Discharge, Air, No. mm (in.) mm (in.) mm (in.)

0.8-1.3 (13-20) 1.5-2.3 (23-37) 2.3-3.8 (37-60) 4.1-6.3 (65-1 00) 6.6-8.5 (105-1 35) 8.5-1 1 (135-1 70) 11-14 (170-220) 14-20 (220-320) 22-32 (350-51 0)

0.8-1.1 0.6-1.0 89 (3.5) (12-1 8) (10-1 6) 1.3-2.2 1.l-1.9 108 (4.25) (20-35) (17-30) 1.9-3.5 1.7-3.2 130 (5.125) (30-55) (27-50) 3.8-6.3 3.5-6.0 140 (5.5) (60-1 00) (55-95) 6.3-8.2 6.0-7.6 149 (5.875) (100-1 30) (95-1 20) 8.2-10 7.6-9.5 187 (7.375) (130-1 60) (120-1 50) 9.5-12 200 (7.875) 10-13 (160-200) (150-1 90) 12-1 7 222 (8.75) 13-1 8 (200-290) (190-275) 20-29 19-28 248 (9.75) (320-460) (300-440)

1.2-2.Q (19-32) 19 (0.75) 2.1-3.6 (34-57) 25 (1.O) 3.3-5.6 (53-88) 25 (1.0) 6.1-9.7 (97-1 54) 25 (1.O) 8.4-14 (133-222) 32 (1.25) 12-1 9 (190-305) 38 (1.5) 15-25 (240-400) 38 (1.5) 20-33 (310-520) 38 (1.5) 32-53 (505-840)

1.1-1.8 (18-29) 1.9-3.2 (30-50) 3.1-4.9 (49-77) 5.4-8.5 (85-1 35) 7.7-12 (122-1 95) 10-17 (165-270) 14-22 (220-350) 18-29 (285-455) 29-46 (460-735)

1.O-1.6 0.9-1.3 (16-26) (14-20) 1.8-2.7 1.6-2.5 (28-43) (26-39) 2.8-4.2 2.5-3.8 (44-66) (40-61 ) 4.9-7.3 4.4-6.4 (77-1 15) (69-1 02) 6.9-1 1 6.3-9.7 (110-1 67) (100-1 53) 9.5-15 8.5-13 (150-230) (135-21 0) 13-1 9 11-1 7 (200-300) (180-275) 16-25 15-22 (260-390) (235-355) 26-40 24-37 (420-630) (380-580)

51 (2.0)

19 (0.75)

3

152 (6)

64 (2.5)

25 (1.O)

4

152 (6)

76 (3.0)

25 (1.O)

5

152 (6)

89 (3.5)

25 (1.O)

6

203 (8)

102 (4.0)

32 (1.25)

7

203 (8)

114 (4.5)

38 (1.5)

8

254 (10)

127 (5.0)

38 (1.5)

9

254 (10)

152 (6.0)

38 (1.5)

Wlth Tapered Dlwharge Plpes 1 102 (4) 38 (1.5) 13 (0.5)

3

152 (6)

64 (2.5)

4

152 (6)

76 (3.0)

5

152 (6)

89 (3.5)

6

203 (8)

102 (4.0)

7

203 (8)

114 (4.5)

8

254 (10)

127 (5.0)

9

254 (10)

152 (6.0)

50

40

0 D, mm (in.)

0.9-1.5 (15-24) 1.5-2.5 (25-40) 2.5-4.1 (40-65) 4.4-6.6 (70-1 05) 7.3-9.5 (115-1 50) 9.5-12 (150-1 90) 12-14 (190-240) 15-22 (240-350) 24-35 (380-560)

127 (5)

51 (2.0)

Submergence, % 60

2

127 (5)

Dimensions

70

Wlth Stralght Dlscharge Plpe 1 102 (4) 38 (1.5) 13 (1.5)

2

Rated Capacity. Us (gpm)

Overall Length, m (ft)

Weight, kg (Ib)

1.96 (6.44)

24 (54)

1.99 (6.52)

31 (69)

2.01 (6.58)

40 (88)

2.04 (6.69)

48 (106)

2.05 (6.74)

50 (110)

2.07 (6.79)

66 (146)

2.09 (6.85)

77 (169)

2.1 1 (6.91)

97 (213)

2.1 1 (6.94)

115 (254)

89 (3.5)

1.96 (6.44)

24 (54)

108 (4.25)

1.98 (6.5)

31 (69)

130 (5.125)

2.01 (6.58)

40 (88)

140 (5.5)

2.04 (6.69)

48 (106)

149 (5.875)

2.05 (6.74)

50 (110)

187 (7.375)

20.7 (6.79)

66 (146)

200 (7.875)

2.09 (6.85)

77 (169)

222 (8.75)

2.1 1 (6.91 )

97 (213)

248 (9.75)

2.1 1 (6.94)

115 (254)

UNDERGROUND MlNl'NG METHODS HANDBOOK Table 7. Dimensions and Rated Capacities for VC System Airlift Pumps

Size

No.

Smallest Diam of Well mrn (in.)

Pipe Connections

Rated Capacity, U s (gpm) Submergence, %

Discharge, mrn (ih.)

Air*, mm (in.)

Weight, 70

60

50

40

kg (Ib)

1.3-2.1 (21-34) 2.1-3.3 (33-53) 3.6-5.4 (57-86) 6.3-8.2 (100-1 30) 7.8-10 (124-1 58) 9.8-13 (156-200) 13-19 (206-300) 21-30 (330-480) 30-44 (470-690) 40-59 (640-930) 73-106 (1150-1 680)

1.2-1 .O (19-31) 1.9-3.1 (30-49) 3.3-5.0 (53-80) 5.7-7.4 (91-117) 7.1-8.9 (112-141) 8.8-1 1 (140-1 81) 12-1 7 (190-275) 19-28 (300-440) 27-40 (435-630) 37-54 (590-850) 67-97 (1060-1 530)

1.1-1.8 (17-29) 1.6-2.8 (25-45) 3.1-4.1 (49-65) 5.4-7.1 (86-1 12) 6.8-8.4 (108-133) 8.3-1 0 (131-1 65) 11-15 (172-230) 17-25 (275-400) 25-36 (390-575) 33-49 (530-775) 61-88 (960-1 400)

0.9-1.6 (14-25) 1.4-2.6 (22-41 ) 2.8-4.1 (45-65) 5.2-6.3 (83-1 00) 6.3-7.9 (100-1 25) 7.8-9.8 (123-1 56) 10-1 5 (164-235) 17-24 (265-380) 24-34 (375-540) 32-47 (510-740) 58-82 (920-1 300)

26 (58)

1.4-2.4 (22-38) 2.1 -3.6 (33-57) 3.6-6.1 (57-97) 5.0-8.8 (80-1 40) 8.8-15 (140-240) 13-21 (200-340) 20-34 (320-540) 29-49 (460-780) 39-66 (620-1 050) 53-88 (840-1 400) 88-148 (1400-2350)

1.O-2.0 (16-31 ) 1.5-3.2 (23-51 ) 2.5-5.6 (40-88) 3.7-7.9 (58-1 25) 6.3-13 (100-210) 8.8-18 (140-280) 14-28 (225-450) 20-40 (320-640) 27-55 (430-865) 37-74 (585-1 175) 62-1 24 (975-1 960)

0.8-2.3 (13-36) 1.3-3.0 (20-48) 2.1-5.4 (34-85) 3.2-6.6 (50-1 05) 5.4-1 1 (86-1 72) 7.6-1 5 (120-240) 12-24 (190-380) 17-34 (275-540) 23-47 (370-740) 32-63 (500-1 000) 53-1 06 (840-1 675)

0.7-2.1 (11-33) 1.O-2.6 (16-42) 1.8-4.4 (28-70) 2.5-6.6 (40-1 05) 4.4-8.8 (70-1 40) 6.3-13 (100-200) 10-20 (160-320) 15-29 (230-460) 20-39 (310-620) 26-53 (420-840) 44-88 (700-1 400)

W#h Straight Discharge Pipe 1

102 (4.0)

51 (2.0)

13 (0.5)

2

114 (4.5)

64 (2.5)

19 (0.75)

3

127 (5.0)

76 (3.0)

25 (1.0)

4

140 (5.5)

89 (3.5)

25 (1.O)

5

152 (6.0)

102 (4.0)

32 (1.25)

6

178 (7.0)

114 (4.5)

38 (1.5)

7

203 (8.0)

127 (5.0)

38 (1.5)

8

229 (9.0)

152 (6.0)

38 (1.5)

9

254 (10.0)

178 (7.0)

51 (2.0)

10

279 (11.O)

203 (8.0)

51 (2.0)

11

330 (13.0)

254 (10.0)

64 (2.5)

34 (76)

43 (94) 49 (108) 57 (125) 67 (148) 85 (187) 102 (225) 111 (245) 151 (334) 212 (467)

Wlth Tapered Discharge Plpes 1

102 (4.0)

51 (2.0)

13 (0.5)

2

114 (4.5)

64 (2.5)

19 (0.75)

3

127 (5.0)

76 (3.0)

25 (1.O)

4

140 (5.5)

89 (3.5)

25 (1.0)

5

152 (6.0)

102 (4.0)

32 (1.25)

6

178 (7.0)

114 (7.5)

38 (1.5)

7

203 (8.0)

127 (5.0)

38 (1.5)

8

229 (9.0)

152 (6.0)

38 (1.5)

9

254 (10.0)

178 (7.0)

51 (2.0)

10

279 (11.0)

203 (8.0)

51 (2.0)

11

330 (13.0)

254 (10.0)

64 (2.5)

26 (58) 34 (76) 43 (94) 49 (108) 57 (125) 67 (148) 85 (187) 102 (225) 111 (245) 151 (334) 212 (467)

* In the well, use the smallest diameter air line possible without producing excessive friction.

In mining gilsonite, a 6.4-mm (0.25-in.) water jet having a pressure drop of 15 860 kPa (2300 psi) across the nozzle will cut 23 to 27 t / h r (25 to 30 stph). The 6.4-mm (0.25-in.) nozzle will approximately 6 L / s (100 gpm) of water. Approximately 22 L/s (350 gpm) of low-pressure water is used to flume the ore to a receiving pocket where it is sized and crushed to 19 mm (0.75 in.) and then pumped 244 m (800 ft) vertically to the slurry preparation plant on the surface. On the surface, a 40% slurry is pumped through 116 km (72 miles) of pipe to the refinery. Interest in the use of hydraulic techniques for coal mining began in the United States in 1958. However,

the Soviet Union had reported success in hydraulically mining and transporting coal as early as 1936. A greater emphasis was placed on developing coal-mining techniques in the Soviet Union, Japan, and European countries because those countries relied heavily upon coal, while the United States relied heavily on cheap oil and gas. Since 1971, Kaiser Resources, Ltd., Sparwood, BC, has been operating a successful hydraulic coal mining and transport system, using Soviet and Japanese methods and equipment. The "hydraulic monitor" used in that operation breaks coal at a rate of 4 to 9 t/min (5 to 10 st per min).

ANCILLARY EQUIPMENT

Fig. 23. Typical twostage combination jet pump with a first-stage jet and a second-stage centrifugal.

In the Kaiser Resources' operation, the main highpressure pump is located on the surface. This is a seven-stage pump that is driven by a 1860-kW (2500hp) motor and delivers 95 L/s (1500 gpm) at 13 790 kPa (2000 psi). The high-pressure water is carried underground through a 203-mm (8-in.) pipeline to the sublevels, and the water is delivered to the monitor through a 152-mm (6-in.) pipeline. The monitor is fitted with either a 23.0-mm (0.91-in.) diam nozzle or a 28.3-mm (1.1 1-in.) diam nozzle. The nozzle selection depends upon the hardness of the coal in the area being mined. The pressure drop across the nozzle is approximately 11 030 kPa (1600 psi). The monitor is controlled from a remote-control console positioned 11 m (35 ft) downslope from the monitor. The monitor is positioned by two hydraulic cylinders, with one for the swing and the other for the dump. The hydraulic cylinders are actuated by 2760 kPa (400 psi) of water

pressure obtained through a reducing valve from the monitor's 1 1 030-kPa ( 1600-psi) supply line. This monitor can break coal at a distance of up to 21 m (70 ft) from the nozzle. Assisted by a small remote-controlled auxiliary monitor with a 12.0-mm (0.47-in.) nozzle, the broken coal is sluiced to a breaker that reduces the coal to approximately -152 mm (-6 in.). The breaker is located downslope from the monitor, but upslope from the control console. Behind the breaker, the coal and water enter a steel flume that carries the coal down the sublevel and into the mainline roadway flume that leads to the treatment plant on the surface. This has proven to be an efficient method of mining thick coal seams with a steep dip. Hydraulic mining systems also are being developed for use in some of the uranium mines in the western United States. Where deposits of uranium ore are con-

LlNDERGROLlND MINING METHODS HANDBOOK LOW-LIFT JET

26W

HIGH- LIFT JET

240-

220-

Fig. 24. Comparative operating characteristics of typical low- and high-lift jet pumps. Metric equivalents: f t X 0.3048=m; gpm X 0.063 090 2 = L/ s.

P

20

PUMPED CAPACITY IN GALLONS PER MINUTE

LOW CAPACITY HGH LIFT

HIGH CAPACITY LOW LIFT

Fig. 25. Comparative jet constructions of a low-capacity high-lift jet (left) and a high-capacity low-lift jet (right). Metric equivalent: gal = 3.785412 L.

Fig. 26. Method of using a jet pump for draining a sump.

ANCILLARY EQUl PMENT

P i s c h a r g e Line

-

Jet

-

Fig. 27. Method of using a jet pump for draining a mine ageway.

tained in loosely consolidated sandstone, some mining has been done through a borehole with a high-pressure water jet that knocks down and sluices the uraniumbearing sandstone to a vertical submersible pump. The slurry then is pumped to the surface. This technique still is undergoing development-mechanical maintenance problems have been quite persistent as a result of the abrasive nature of the sandstone. HYDRAULIC HOISTING

Under certain conditions, hydraulic hoisting of ore has proven to be practical. This method is particularly applicable when a large quantity of water must be pumped to keep a mine dry, or when a hoisting shaft is operating at full capacity while additional ore must be hauled without sufficient justification for the installation of a new mechanical hoisting system. Several important hydraulic hoisting installations are working satisfactorily. At the Devillaine coal mine near St. Etienne, , a demonstration hydraulic hoist was installed in 1960. It hoisted 45 to 54 t / h (50 to 60 stph) of -82.6 mm (-3.25 in.) coal up a 180-m (590-ft) shaft and through a 76-m (250-ft) horizontal pipeline t o the treatment plant. That lift required a total of 48.5 kW (65 hp), of which 12.7 kW (17 hp) was used for the horizontal transport. In Czechoslovakia's Kutna Hra district, lead-zinc ore is lifted 460 m (1500 ft) with an hydraulic system. At the Lengede Broistedt iron-ore mine in West , the conventional mechanical hoisting system has been replaced by an hydraulic system that handles up to 4540 t/d (5000 stpd) from a depth of 120 m (395 ft). One of the most interesting hydraulic hoist installations is at Anglo-American Corp.'s Vaal Reefs gold mine near Klerksdorp, South Africa. This system is pumping gold-bearing quartzite from the 2190-m (7200-ft) level to the surface. Using MarsT" reciprocating pumps, 22 700 t [(25,000 st) dry tonnage] are pumped per month through four lifts. The installation of an hydraulic hoisting system was prompted by the fact that the shaft already was operating at its maximum capacity of 136 000 t (150,000 st) per month, and it was necessary to hoist additional ore.

In the South African operation, the run-of-mine ore is screened. The -6.4 mm (-0.25 in.) material is ed through a ball mill in which it is reduced t o a sludge consisting of -65 to +200 mesh material (80% ) and -200 mesh material (20%). The oversize ore goes from the screening operation to the conventional hoist. In the past, the fines in the ore caused delay problems in conventional hoisting as a result of the sticky nature of the ore; removing the fines from the conventional hoisting system has increased its hoisting capacity. PUMP INFORMATION SUMMARY Table 8 summarizes the pump-system parameters and features for various mines operating in the United States. The table includes references to numbered notes that are as follows: Note 1 Information concerning the AMAX operations at Climax, CO, was obtained from Al Smith, chief engineer. Information on the Henderson mine was obtained from D. E. Julin, chief engineer. Information on AMAX Lead Co.'s Buick mine in Missouri was obtained from AMAX Lead Co. of Missouri and Homestake Lead Co. For the Buick mine, the pumping cost, including power and maintenance, is $0.62 per 100 L / s ($0.39 per 1000 gpm). The approximate cost of the pumps at the time of purchase in 1968 was $20,800 each, including the pump, motor, and starter. Note 2 At Anaconda Co.'s Butte mines, underground water from the surrounding mines is collected in the Kelley mine. The collected water is pumped to the surface from pump stations located on the 4000 level [elevation = 664 m (2177 ft)] and the 3900 level [elevation = 710 m (2328 ft)] of the Kelley mine. The elevation at the collar of the Kelley mine shaft is 1820 m (5970 ft) above sea level, and the elevation at the bottom of the shaft is 353 m (1 159 ft) above sea level. At present (19781, the Butte mines are flooded to the 4000 level. Approximately 290 L/s (4600 gpm) of mine water is produced underground at the Butte mines, and this amount must be pumped to the surface. As of 1978,

UNDERGROUND MlNllVG METHODS HANDBOOK

1356

Table 8. Pump Information Summary

Item Depth of Shaft, In (ft) Total water pumped, Us (gpm) Pump level interval, In (ft) No. pumps on each level Capacity, each pump, Us (gpm) Total head, each Pump, m (ft) Motor power, each pump, kW (hp) Motor current, 60 Hz, 3-phase Pump control Year installed Pump manufacturer Motor manufacturer Suction lift or flooded Pump type Sump retention time Pump column, diam [mm (in.)]and material Casing material

AMAX Lead Co., Buick Mine, Boss, MO

Anaconda, Kellog Mine, Butte, MT

Anaconda, Kelley Mine, Butte, MT

192 (629) 3

946 (3103) 158-1 70 (2500-2700) 183 and 707 (600 and 2350) 4

396 (1300) 215 (3400) 10

1466 (4811) 145 (2300) 55 (180) 4

1466 (4811) 290 (4600) 1170 (3840) 8

189 (3000) 199 (654) 447 (600) 440 v

126 (2000) 762 (2500) 1305 (1750) 4160 v

69 (I loo) 396 (1300) 373 (373) 4160 v, 61 amp

158 (2500) 84 (275) 224 (224) 2300 v, 67.5 amp

63 (1000) 1250 (4100) 1119 (1119) 41 60 v. 176 amp

Automatic

Automatic

Automatic, B 8. W probes

Automatic, probes

Manual, Remote

Wx

6-J Reliance Flooded

Peerless Westinghouse'

6-H Reliance Flooded

Ingersoll-Rand Westinghouse Flooded

AMAX Mining Co., Climax, CO

AMAX Mining Co., Henderson, CO

192 (629) 378

1971

Flooded

Single Level

1968

1978

1967

Vertical

Horizontal

Vertical

Horizontal

Horizontal

75 min

2 hr 305 (12) [two]

2 hr 254 (10) [three] schedule 80 steel

21 h r 254 (10) [two] 316 stainless

26 h r 254 (10) [four] 316 stainless

Iron

Carbon steel

Carbon steel

316 stainless

Impeller material

Bronze

Hardened steel

Bronze

316 stainless

Wear-ring material

Bronze

Bronze

Stainless steel

316 stainless

steel

steel 105 stainless steel 105 stainless steel 385H stainless steel

Notest

1

1

1

2

2

steel

-

-

-

-

steel

steel

--

Informationeither not provided or not applicable. t See text for meaning of notes. 'Barrett Haentjens and Co. *

145 L/s (2300 gpm) are pumped from the 4000-level pumping station and the remaining 145 L/s (2300 gpm) flow by gravity through a drain tunnel to the 3900-level pumping station. The 145 L / s (2300 gpm) pumped from the 4000 level goes to a drain tunnel above, where it s the mine water at that level. The total mine water [290 L/s (4600 gprn)] flows through two vertical settlers that remove silt and into two pump sumps located at the 3900-level pumping station. From those sumps, the water is pumped to the surface through four 250-mm ( 10-in.) ID 3 16 stainless-steel pipe columns. At the surface level of the shaft, each pipe column connects to a 305-mm (12-in.) mild-steel pipe that is lined with polyvinyl chloride (ParalineT" RD coating applied by Barber Webb Co.). These four lines extend for an additional 930 m (3050 ft) to a final elevation of 1880 m (6168 ft) above sea level before discharging into a wooden flume. From the flume, the mine water flows by gravity through two 406-mm (16-in.) ParalineT'-lined steel pipes to a rubber-lined steel tank that measures 4.9 m (16 ft) high and 12 rn (40 ft) diam. This tank serves as a sump and a control tank for the surface pumping station. From the tank, the water is pumped to a mixing tank at the tailings pond [eleva-

tion = 1890 m (6200 ft)] where the mine water is mixed with concentrator tailings and additional milk of lime. The tailings, salts, and other solids settle out in the pond, and the water is reused in the copper concentrator. The estimated cost of pumping mine water for all three pumping stations is $1220 per 100 L/s per day ($770 per 1000 gprn per day). Both underground pumping stations have been provided with additional pumping capacity to accommodate underground sloughs, which can occur and trap mine water. When the water finally breaks through, additional pumping capacity is required to prevent the pumping stations from being flooded. The temperature of the underground mine water averages 29.4"C (89°F) and the water is extremely corrosive. The water carries cupric and ferric sulfates and basic iron sulfate in solution, and it has a pH of approximately 4. Sulfuric acid is added to bring the acidity close to a pH of 2, thus holding the materials in solution and preventing deposition on the pipe walls. All pumps, pipelines, and other components that comc into with the mine water must be constructed of materials capable of withstanding the corrosive action. According to Anaconda, the pumps working against

ANCILLARY EQUIPMENT

1357

Table 8. Pump Information Summary+continued) Anaconda, Kelley Mine, Butte, MT Depth of Shaft, m (ft) Total water pumped, Us (gpm) Pump level interval, m (ft) No. pumps on each level Capacity, each Pump, Us (gpm) Total head, each pump, m (ft) Motor power, each Pump, kW (hp) Motor current, 60 Hz, 3-phase Pump control Year installed Pump manufacturer Motor manufacturer Suction lift or flooded pump type Sump retention time Pump column, diam [mm (in.)]and material Casing material Impeller material Wear-ring material

Gulf Resources and Chemical Co., Bunker Hill, ID

Homestake Mining Co., Winze No. 6, Lead, SD

Homestake Mining Go.. Winze No. 4, Lead. SD

1036 (3400) 35 (550) 549 and 336 (1800 and 1200) 2

610 (2000) 32 (500) 366 and 183 (1200 and 600) 2-3

44 and 32 (700 and 500) 556 and 390 (1825 and 1280) 336 and 186 (450 and 250) 2300 v

32 (500) 390 and 198 (1280 and 650) 186 and 93 (250 and 125) 2300 v

Automatic

Automatic

Automatic

1975-1 978 Ingersoll-Rand General Electric Flooded and suction lift Horizontal 3-90 hr 305 (12) [one] schedule 40A53 steel Cast iron

1973and 1976 Ingersoll-Rand General Electric Flooded

1961 and 1966 Ingersoll-Rand General Electric Flooded

Horizontal 6 and 1 hr 305 (12) [one] schedule 40A53 steel Cast iron

Horizontal 6 and 24 hr 305 (12) [one] Cast iron

Bronze

Bronze

Bronze

Stellite on 410

Cast iron

Cast iron

3

3

3

Homestake Mining Co., Ross Shaft, Lead. SD

Surface 290 (4600) 12 (40) 3 158 (2500) 76 (250) 224 (300) 2300 v, 67.5 amp Automatic, probes 1973 B-H Reliance Flooded Horizontal 20 min 406 (16) [one] pipeline 316 stainless steel 316 stainless steel 316 stainless steel 2

Automatic, probes Ingersoll-Rand General Electric Flooded Horizontal 10 hr schedule 40 + 80 steel Cast iron and stainless steel Stainless steel Stainless steel

' Information either not provided or not applicable.

t See text for meaning of notes.

an 84-m (275-ft) head cost (in 1971) approximately $8000 each, the motor cost $3530, and the motor control center for all of the pumps cost $37,500. The pumps working against a 1250-m (4100-ft) head cost (in 1961) approximately $52,000 each, the motors cost $18,000 each, and the motor control center for all of the pumps cost $101,000. The pumps mounted on the surface and working against a total head of 76 m (250 ft) cost (in 1971) approximately $8000 each, the motors cost $3530 each, and the motor-starting equipment was available from another project and was supplied at no cost. Note 3 Homestake Mining Co. estimates that the cost of pumping water at Homestake is $0.42 per 1000 L ($1.60 per 1000 gal). This includes power, labor, and mechanical maintenance, but it excludes equipment depreciation. At the time of purchase, pumping equipment for the Ross shaft cost approximately $56,000 for each unit, including the pump motor and the starting gear. The total cost of the pump installation at the Ross shaft is estimated to be $210,000, including equipment, installa-

tion cost, pump-room excavation, electric cables and transformers, and the pump column. For winze No. 6, the original purchase cost of the pumps, motors, and starters was $1800 for the 335-kW (450-hp) units purchased in 1973 and $24,000 each for the 186-kW (250-hp) units purchased in 1976. The total cost of the pump installation, including the equipment, installation costs, pump-room excavation, electric cables and transformers, and pump column was $140,000 for the 335-kW (450-hp) units and $70,000 for the 186-kW (250-hp) units. For winze No. 4, the pumps, motors, and starters had purchase costs of $1 1,000 for the 186-kW (250hp) unit and $8000 for the 93-kW (125-hp) unit. The total costs of pump installation, including equipment, installation cost, pump-room excavation, electric cable and transformers, and pump column, were $60,000 for the 186-kW (250-hp) installation and $90,000 for the 93-kW ( 125-hp) installation. The 186-kW (250-hp) system was installed in 1961, and the 93-kW (125-hp) system was installed in 1966. Information on Homestake Mining Co.'s pump in-

UNDERGROUND MINING METHODS HANDBOOK Table 8. Pump lntormatlon Summary+contlnued) Homestake Mining Co., Bulldog Mine, Creede. CO

Item Depth of Shaft, m (ft) Total water pumped, Us (gpm) Pump level interval, m (ft) No. pumps on each level Capacity, each pump, Us (gpm) Total head, each pump, m (ft) Motor power, each Pump, kW (hp)

140 (460) 63 (1000) 122 (400) 6

Pathfinder Mines Corp. Lucky Mc Mine, Riverton, WY

37 and 45 (50 and 60)

Motor current, 60 Hz, 3-phase Pump control

480 v

440 v

Automatic

Manual

Year installed Pump manufacturer

1971 and 1977 Ingersoll-Rand

Motor manufacturer Suction lift or flooded Pump type Sump retention time Pump column, diam [mm (in.)]and material Casing material Impeller material

'

1976 and 1977 Flygt and Warren Rupp Flygt Flooded

Horizontal 72 h r 305 (12) [one]

Submersible

Cast iron Bronze

Wear-ring material Notest

Steel Alloy, 60 Rockwell C

Bronze 3

4

(4oo)

St. Joe Minerals Corp., Virburnum No. 28, Bonne Terre. MO

St. Joe Minerals Corp., Virburnum No. 29, Bonne Terre. MO

3 or less (50 or less) 3 electric 1 air 6 and 3 (100 and 50) 23 (75) 19 and 7 (25 and 10)

17-20 (275-31 5) 122

Pilot Knob Pellet Co., Ironton. MO

25 and 69 (400 and 1100) 91, 152, 366 (300, 500, 1200) 75 and 298 (100 and 400)

50 and 32 (800 and 500) 293 (960) 186 [7] and 93 [21 (250 and 125) 440 v

Automatic, probe 1975 and 1967 Ingersoll-Rand, B-H, Peerless General Electric 0.6-m (2.04) lift Horizontal 48 hr 254 (10) [one] schedule 60 steel Carbon steel Stainless steel

Automatic [21 and manual 171 1959-1 965 Peerless

Manual

US Motors Flooded

US Motors Flooded

Vertical 100 h r 254 (1 0) [one] steel

Vertical 50 h r 254 (10) [one] steel

Cast iron Cast iron

Cast iron Cast iron

Stainless steel 5

Bronze 6

Bronze 7

1964 Peerless

' Information either not provided or not applicable.

t See text for meaning of notes.

stallation was prepared by Robert Magers, chief mechanical engineer, and Jerry Pontius, assistance chief mechanical engineer. Information supplied on the Bulldog mine at Creede, CO, was prepared by T. R. Robertson, resident manager. Note 4 The information on the Lucky Mc mine in Wyoming was prepared by J. F. Crouch, chief mine engineer. Note 5 The Pilot Nob Pellet Co. of Missouri has advised that the power cost at their operation is $0.042 per 1000 L ($0.159per 1000 gal), and the labor cost is $0.0016per 1000 L ($0.006per 1000 gal). This totals to $0.068per 1000 L ($0.256per 1000 gal). The estimated cost of the pumps, motors, and starters purchased in 1967 was $82,140. Other estimated costs were $10,800for the pump column, $3400 for the horizontal mine line, $90,000 for mining costs, $15,000for miscellaneous costs, making the total installation cost $201,340. This information was provided by R. J. Zgonc, general superintendent.

Note 6 The estimated pumping costs at St. Joe Mineral Corp.'~Vibernum No. 28 mine are $0.034per 1000 L ($0.13 per 1000 gal), including power, labor, and mechanical maintenance. The estimated purchase cost of the pumps, motors, and starters was $106,500,and the estimated total cost of the pump installation, including equipment, installation cost, pump-room excavation, electric cables and transformers, and pump column, was $1,120,000.This information was supplied by the Mining Research Dept. of St. Joe Minerals Corp. Note 7 The estimated pumping costs at St. Joe Mineral Corp.'s Vibernum No. 29 mine are $0.024per 1000 L ($0.09per 1000 gal), including power, labor, and mechanical maintenance. The estimated purchase cost of the pumps, motors, and starters was $18,500,and the estimated cost of the pump installation, including equipment, installation cost, pump-room excavation, electric cables and transformers, and pump column was $195,000. This information was supplied by the Mining Research Dept. of St. Joe Minerals Corp.

ANCILLARY EQUlPMENT Table 8. Pump lnformatlon Summary+contlnued)

Item Depth of Shaft. (ft)

Total water pumped, Us (gpm) Pump level interval, m (ft) No. pumps on each level Capacity, each pump, Us (gpm) Total head, each pump, m (ft) Motor power, each pump, kW (hp) Motor current, 60 Hz, 3-phase Pump control Year installed Pump manufacturer Motor manufacturer Suction lift or flooded Pump type Sump retention time Pump column diam [mm (in.)] and material Casing material Impeller material Wear-ring material Notest

St. Joe Minerals Corp.. Fletcher, MO

St. Joe Minerals Corp., Indian Creek No. 32, Bonne Terre. MO

St. Joe Minerals Corp., Brushy Creek, MO

Sunshine Mining Co., Sunshine Mine, Kellogg, ID

UV Industries,

Continental Mine, Hanover, NM

41 1 (1348) 252 (4Ow None

63 (1 317 (1040) 298

(a)

Automatic 1967 and 1969 Peerless US Motors Flooded

Automatic 1967 Peerless US Motors Flooded

Automatic 1973 Peerless US Motors Flooded

2300 v, 96 amp Automatic 1975 Ingersoll-Rand AC 69-11 (20-ft) lift

Vertical 8 hr 305 (12) [one] steel

Vertical 8 hr 254 (10) [one] steel

Vertical 8 hr 305 (12) [one] steel

Horizontal 7.4 hr 203 (8) [one] steel

Vertical 45 min 203 (8')[one] steel

Cast iron Cast iron Bronze 8

Cast iron Cast iron Bronze 9

Cast iron Cast iron Bronze 10

Cast iron Bronze Stainless steel 11

Cast iron Bronze Bronze 12

Automatic 1978 BJ US Motors Flooded

' Information either not provided or not applicable.

t S e e text for meaning of notes.

Note 8 The estimated pumping costs at St. Joe Mineral Corp.'s Fletcher mine are $0.040 per 1000 L ($0.15 per 1000 gal), including power, labor, and mechanical maintenance. The estimated purchase cost of the pumps, motors, and starters was $112,900,and the estimated cost of the pump installation, including equipment, installation cost, pump-room excavation, electric cables and transformers, and pump column was $1,190,000. This information was supplied by the Mining Research Dept. of St. Joe Minerals Corp. Note 9 The estimated pumping costs at St. Joe Mineral Corp.'s Indian Creek No. 52 mine are $0.040per 1000 L ($0.11 per 1000 gal), including power, labor, and mechanical maintenance. The estimated purchase cost of the pumps, motors, and starters was $56,033,and the estimated cost of the pump installation, including equipment, installation cost, pump-room excavation, electric cables and transformers, and pump column was $555,000. This information was supplied by the Mining Research Dept. of St. Joe Minerals Corp. Note 10 The estimated pumping costs at St. Joe Mineral Corp.'s Brushy Creek mine are $0.029 per 1000 L

($0.11per 1000 gal), including power, labor, and mechanical maintenance. The estimated purchase cost of the pumps, motors, and starters was $102,000,and the estimated cost of the pump installation, including equipment, installation cost, pump-room excavation, electric cables and transformers, and pump column was $1,075,000. This information was supplied by the Mining Research Dept. of St. Joe Minerals Corp. Note 11 The estimated pumping costs at Sunshine Mining Co.'s mine are $0.333 per 1000 L ($1.26per 1000 gal), including power, labor, and mechanical maintenance. The 1976 purchase cost of the pumps was $6782 each. The cost of the 298-kW (400-hp)motors was $8479 each, and the cost of the starters was $4893 each. The total cost of the pump installation, including equipment, installation cost, pump-room excavation, electric cables and transformers, and pump column, was $82,500.This information was supplied by the Engineering Dept. of Sunshine Mining Co. -

-

Note 12 The estimated cost of the pumps, motors, and starters at UV Industries operation in New Mexico was $18,000. This information was supplied by R. C. Weagle, vice president in charge of operations.

LINDERGROLIND MINING METHODS HANDBOOK

Table 8. Pump lnformatlon Summary-+continued)

Item

UV Industries. Continental Mine, Hanover, NM

Hecla Mining Co., Star-Morning Mine, Shaft No. 4, Wallace, ID

Hecla Mining Co., Star-Morning Mine, Shaft No. 4, Wallace, ID

Magma Copper Co., San Manuel Shaft 5, 2075 Level, San Manuel, AZ

Magma Copper Co., San Manuel Shaft 5. 2675 Level, San Manuel, AZ

Depth of Shaft, In (ft) Total water pumped, Us (gpm) Pump level interval, m (ft) No. pumps on each level Capacity, each pump, Us (gpm) Total head, each Pump, In (ft) Motor power, each Pump, kW (hp)

452 (1483) 11 (175) 253 (830) 2

1615-762 (5300-2500) 47 (740) 853 (2800) 3

2225-1 615 (7300-5300) 41 (650) 610 (2000) 2

1257 (4123) 240 (3800) 311 (1020) 7

1257 (4123) 256 (4050) 183 (600) 10

63 (1000) 305 (1 298 (400)

44 (700) 853 (2800) 522 (700)

50 (800) 625 (2050) 522 (700)

38 (600) 189 (620) 149 (200)

Motor current, 60 Hz, 3-phase Pump control Year installed Pump manufacturer

2300 v

2400 v

2400 v

50 [51 and 57 [21 (800 and 900) 319 (1045) 224 [51 and 261 121 (300 and 350) 2300 v

Automatic 1976 Ingersoll-Rand

Automatic 1975 Ingersoll-Rand

Automatic 1975 Ingersoll-Rand

Motor manufacturer

Westinghouse

Westinghouse

Westinghouse

Automatic 1970 B 8 J [51 and Ingersoll-Rand [2] General Electric

Suction lift or flooded Pump type Sump retention time Pump column, diam [mm (in.)] and material Casing material Impeller material

Flooded

Flooded

Flooded

Flooded

Horizontal 1 hr 203 (8) [one] steel

Horizontal 1.3 hr 254 (10) [one] schedule80840 steel Cast steel Chromium-nickel steel Stainless steel 13

Horizontal 3.7 hr 254 (10) [one] schedule80840 steel Cast steel Bronze

Horizontal 10 min 305 (12) [two]

Horizontal 3 min 305 (12) [two]

Steel Bronze

Steel Bronze

Stainless steel 13

Stainless steel 14

Bronze 14

Wear-ring material Notest

Cast iron Bronze Bronze

' Information either not provided or not applicable.

t See text for meaning of notes.

2300 v Automatic 1971 Pacific Pump General Electric 8 US Motors

ANCILLARY EQUlPMElVT

Table 8. Pump Information Summary--(continued)

Item Depth of Shaft, f7-I (ft) Total water pumped, Us (gpm) Pump level interval, f7-I (ft) No. pumps on each level Capacity, each Pump, Us (gpm) Total head, each pump, m (ft) Motor power, each Pump, kW (hp) Motor current, 60 Hz, 3-phase Pump control Year installed Pump manufacturer Motor manufacturer Suction lift or flooded Pump type Sump retention time Pump column, diam [mm (in.)] and material Casing material Impeller material Wear-ring material Notest

Magma Copper Co.. San Manuel Shaft 5, 4123 Level, San Manuel, AZ

Magma Copper Co., San Manuel Shaft 1, 820 Level, San Manuel, AZ

Magma Copper Co., San Manuel Shaft 1, 1475 Level, San Manuel, AZ

Automatic 1974 B & J and Ingersoll-Rand General Electric

Automatic 1974 B&J

Automatic 1953 Pacific Pump

Automatic 1955 Pacific Pump

B&J

Flooded

Flooded

General Electric & US Motors Flooded

General Electric & US Motors Flooded

Horizontal 5 min 203 (8) [onel

Horizontal 5 min 305 (12) [two]

Submersible 60 min 203 (8) [two] 305 (12) [one]

Horizontal Booster pumps 305 (12) [two] 203 (8) [one]

Horizontal 25 min 305 (12) [two] 203 (8) [one]

Carbon steel Stainless steel Stainless steel 14

Iron Bronze Stainless steel 14

Iron Bronze Bronze 14

Steel Bronze Bronze 14

Steel Bronze Bronze 14

Magma Copper Co., San Manuel Shaft 5, 2950 Level, San Manuel, AZ

Automatic 1973 Pacific Pump General Electric & US Motors Flooded

Magma Copper Co., San Manuel Shaft 5, 3530 Level, San Manuel, AZ

Information either not provided or not applicable

t See text tor meaning of notes.

UNDERGROUND MINING METHODS HANDBOOK

1362

Table 8. Pump Information Summary+contlnued)

Item Depth of Shaft, In (ft) Total water pumped, Us (9Pm) Pump level interval, (ft) No. pumps on each

level Capacity, each Pump, Us ( 9 ~ m ) Total head, each Pump, In (ft) Motor power, each Pump. kW (hp) Motor current, 60 Hz, 3-phase Pump control Year installed Pump manufacturer Motor manufacturer Suction lift or flooded Pump type Sump retention time Pump column, diam [mm (in.)]and material Casing material Impeller material Wear-ring material Notest

Magma Copper Co., San Manuel Shaft 1, 2075 Level, San Manuel, AZ

Magma Copper Co., San Manuel Shaft 1, 2375 Level, San Manuel, AZ 863 (2830) 50

Magma Copper Co., San Manuel Shaft 1, 2675 Level, San Manuel, AZ

Magma Copper Co., San Manuel Shaft 1, Bottom Sump, San Manuel, AZ

Magma Copper Co., San Manuel Shaft 5, 1055 Level, San Manuel, AZ

863 (2830) 3 (50) 47 (155) 2

1257 (4123) 240 (3800) 322 (1055) 7 50 [5] 8. 57 [21 (800 8. 900) 322 (1055) 224

863 (2830) 189 (3000) 200 (600) 12

91 (300) 3

w"3

863 (2830) 91 (1450) 91 (300) 6

38 (600) 191 (625) 149 (200) 2300 v

38 (600) 94 (310) 75 (100) 2300 v

38 (600) 191 (625) 149 (200) 2300 v

95 (1500) 61 (200) 56 and 67 (75 and 90) 2300 v

2300 v

Automatic

Automatic

Automatic

Automatic

Automatic

1958

1968

1968

1973

1970

Pacific Pump

Pacific Pump

Pacific Pump

Fly@

General Electric & US Motors Flooded

General Electric & US Motors Flooded

General Electric

Flygt

B 8. J and Ingersoll-Rand General Electric

& US Motors

Flooded

Flooded Horizontal Booster pump 305 (12) [two]

Flooded

(300)

Horizontal

Horizontal

Horizontal

Submersible

10 min 305 (12) [two] 203 (8) [one]

5 min 305 (12) [one]

5 min 305 (12) [one]

2.25 hr 102 (4) [one] 152 (6) [one]

Steel Bronze Bronze

Steel Stainless steel Stainless steel

Steel Bronze Bronze

Aluminum Steel

Steel Bronze Stainless steel

14

14

14

14

14

Information either not provided or not applicable.

t See text for meaning of notes.

Note 13 Hecla Mining Co.'s Star-Morning mine is illustrated in Fig. 28. The main components of the No. 4 shaft pumping system are the Ingersoll-Rand 4HMTA-9 and 6RTL-6 pumps, and the information herein pertains only to those pumps. Since the Star-Morning mine has been operating for many years and since the pumping system has undergone and continues to undergo almost continual change, it is impossible to define the cost of the entire system. The ~HMTA-9pumps, motors, and switchgear cost approximately $106,000, and the entire 7300-5300-2500 level installation cost approximately $600,000 (including the 7500-level vertical settler). The vertical settler was a "first" at Hecla Mining Co.'s mines in this district, and it has been the key to

providing clear water to the 6RTL-6 pumps. The vertical settler removes the considerable amounts of suspended solids caused by the hydraulic sandfill system used to backfill the stopes. Water jets near the bottom of the settler are used, together with frequent pumping, to remove accumulated slimes. The total operating cost of the Star-Morning pumping system is approximately $0.25 per 1000 L ($0.93 per 1000 gal). This information was supplied by W. E. Crandall, chief engineer. Note 14 Details of Magma Copper Mining Co.'s operations at the San Manuel mine were provided by J. R. Tinnen, manager of Engineering and technical services, P. M. Castro, mine engineer, and V. S. Konur, chief design engineer.

ANCILLARY EQUlPMENT

Sloping Area 1450 LEVEL

*

8800 11l o Burke (Hala) 2WO LEVEL ADIT(E1ev. 375011) ------ -- -

-- ------

Z.~.RZMRV.~H.P..*~V. 2300LEVEL

- .. .. . -

--

, . ',I

%---'I-O-'.+-l 4

2aX)LEVEL

I

t 1

1 0 . m 11to Mullan 2500LEVEL ADIT(Y0RNINQ NO. 6)

r..l - - - - - :. 2-1.R.ZMRV.SOH.P.,440V.

-

2lWLEVEL l-l.R.ZRVH.20H.P..440V. WLEVEL

I

i

+

---- --

-*

ZWLEVEL (Elev. 3250 11)

,

-0-..--J

I t

+l u a f t

*

t

---

L--+

I I I

4000 LEVEL

I

+

!

I I I

I

t

Sloplng ~ i e a

w

r z - i . k . z v r ~ v n , m ~ . ~ . , * o v, .

2

3-1.R. 4HMTA-@

I I

.

~

I

'&

53673 LEVEL (Elev. 450 11)

\

50.000 GAL SUMPS

Sloping Area Water to

I

1

'2-1.RBRTL6,7Ol H.P.. 2400 V.

I

iI

I

7300 LEVEL 7MLEVEL 2-1.R. ZRVH,J)H.P. 77W LEVEL 7W7 LEVEL

(THICKENER)

8fW LEVEL (Elev. 2350 It) DUPLDC YUDPUWP

~CLYGT81804; 7% H.P.

Fig. 28. Pumping system at the Star-Morning mine of Helca Mining Co. at Wallace, ID. Metric equivalents: ft X 0.3048 = hp X 0.7456 699 9 = kW.

1364

UNDERGROUND MINING METHODS HANDBOOK REFERENCES AND BIBLIOGRAPHY

Bogeat, J.R., 1963, "Naica Battles Water and Costs as LeadZinc-Silver Mining Goes Deeper," Mining World, Aug . Brookes and Murdock, 1977, "Application of High Capacity, High Head Pumps for Mine Drainage Using a Flood Protected Pump Station," Fifth Technical Conference o f British Pump Manufacturers' Association. Clarke, C.D., and Reinberg, G., 1956, "Corrosion Problems in Pumping Acid Mine Water," Trans. AZME, Vol. 205, pp. 821-825. Corbett, R.P., and Ralph, F.E., 1968, "Dewatering with a 4,100-Ft Head Pumping Plant," Mining Congress Journal, Sept., pp. 33-43. Ferguson, C., and Morris, M., 1970, "Mine-Water Treatment, Inco Sudbury Operations," Ontario Water Resources commission. Hall, J.G., 1949, "History of Pumping at the Chief Con-

solidated Mine, Eureka, Utah," Trans. AZME, Vol. 184, pp. 229-234. Hydraulic Institute, 1975, Hydraulic Institute Standards. Loofbourow, R.L., and Lehmann, E.K., 1968, "A Mine Flood, Vancouver Island," Preprint 68AG346, SME Fall Meeting, Minneapolis, MN. Miller, H.W., and Jolley, D.H., 1964, "Flooding and Recovery of the Jefferson City Mine," Mining Congress Journal, Jan. Monroe, H.L., 1965, "Design of a Water Settler at Pea Ridge," Mining Engineering, Dec., pp. 81-84. Saul, H., 1978, "Current Mine Drainage Problems," Transactions, Institution of Mining Engineers, Sec. A, pp. le-9e. Westaway, C.R., and Loomins, A.W., 1977, "Cameron Hydraulic Data," Ingersoll-Rand Co. Wiles, G.M., 1943, "Development and Dewatering Practices at Park City Consolidated Mines," Trans. AZME, Vol. 153, pp. 115-120.