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By W. Bakiewicz

The Lower Indus Basin deposits form a substantial unconfined alluvial aquifer of excellent quality. This aquifer contains basically highly saline groundwater, overlain in places by considerable amounts of freshwater whose origin can be traced to the present and historical courses of the River Indus. In the past the main source of groundwater recharge has been direct river seepage and water tables were generally deep. Since the establishment of a perennial irrigation regime however, deep percolation from the increased irrigation supplies has predominated and the water-table has risen to within a few feet of the surface. The river system itself is being progressively developed for irrigation and very shortly a situation will arise where the entire low winter flow will be utilised. Fresh groundwater will then be exploited to supplement the surface supplies, and at the same time a drainage system, mainly based on wells will be used to stabilise the water-table at safe depths. This paper discusses some of the methods used to ensure optimum-economic development of the fresh groundwater and describes the general design philosophy evolved by the authors firms for both irrigation and drainage wells, with respect to both well configuation and operation. Water quality standards are discussed in as much as they affect subsequent use of the groundwater. A few particular aspects are considered, including that of the values of the relevant aquifer constants, the construction of wells and the determination of screen losses. A major problem solved during the Lower Indus Project investigations has been the design of wells to-produce fresh water from layers overlying saline water. This solution is also discussed.

Jan 1, 1967

By Kefton H. Teague

An article entitled "The Rule of the Geologist in the Industrial Mineral Field" by G. R. Gullet, was published in the August, 1967, issue of the Canadian Mining Journal. Mr. Gullet defined industrial minerals as follows: "Industrial minerals are largely non-metallic minerals and rocks that find value because of their physical or chemical properties." This definition is brief, but all-inclusive. Mr. Gullet continues, "They include all useful minerals and mineral commodities except those used as fuels and those from which metals are extracted. Factors in the evaluation of an industrial mineral deposit are generally as different from those used in the evaluation of a metal deposit as is the assessment of a potential oil field. The key to the successful development of an industrial mineral, deposit is more often a balance of accessibility, transport, and proximity to markets than to any natural quality advantage of the deposit itself."

Jan 1, 1972

By Naomi H. Harley, Daryl E. Bohning, Isabel M. Fisenne

INTRODUCTION Underground mines in many parts of the world have elevated levels of short-lived 222Rn daughters. Lung cancer implicating exposure to short-lived daughters is documented in the U.S., Czechoslovakia, Canada, Sweden, the U.K., France and Newfoundland. An elevated lung cancer mortality (in excess of that expected) has been observed when cumulative exposure to alpha emitting short-lived 222Rn daughters (218Po, 214pb 214Bi 214Po) is greater than about 60 working level months (WLM) [1]/ (Hewett, D. 1979). This is equal to an absorbed alpha dose of about 30 rads to shallow basal cells in bronchial epithelium. Long-lived alpha emitters are also present in underground mines, and especially uranium mines because of airborne particulates containing uranium. The 238U parent of this primordial series supports other long-lived emitters 234U 230Th, 226Ra, Pb(210Po) which are in some degree of radioactive equilibrium with the parent 238U. Airborne particulates can be present due to drilling on the face of the ore body as well as in all parts of the mine through resuspension from the mine floor. Particles from 1 µm to about 5 µm penetrate the nose with reasonable efficiency and deposit primarily in the tracheobronchial tree. They are removed by ciliary motion (the bronchial escalator) but deliver an alpha dose to basal cells in bronchial epithelium during clearance in the same manner as short-lived 222Rn daughters. It is the purpose of this work to indicate the alpha dose to basal cells in bronchial epithelium delivered by the long-lived emitters 234, 238U. The dose calculations reported here based upon a few measured values of these isotopes in air in uranium mines in New Mexico and Colorado. MEASURED 234, 238U IN URANIUM MINE ATMOSPHERES In 1979, the U.S. Bureau of Mines undertook a study to evaluate personal monitors to be worn by miners to measure short-lived 222Rn daughters. One of these devices sampled air at 100 cm3/min through a 13 mm glass fiber filter, with a small pump worn on the belt. Alpha particles emitted by 222Rn daughters on the filter were measured continuously by a thermoluminescent dosimeter (TLD) chip. Each monitor was worn by a miner for a 170 hour working month and approximately one cubic meter of air was sampled during this period. Six different mines were selected for the test in New Mexico and Colorado. The mines used either wet or dry drilling methods. Miners in each location were equipped with the personal monitors. Subsequent to their use in evaluating the shortlived daughters, Dr. Robert Droullard of the Bureau generously gave us these filter samples along with a few blank glass fiber filters from the same box of filters used in the study so that long-lived emitters present in these mine atmospheres could be determined radiochemically. Four of the samples have been run for 234, 238U. The radiochemical procedure for uranium is adapted from USDOE, Environmental Measurements Laboratory Manual (Harley, J.H., 1976). Briefly, the samples were placed in platinum crucibles, spiked with 232U tracer and pretreated with nitric and hydrofluoric acid. The residue was fused with potassium fluoride to transpose to pyrosulfate. The fused cake was dissolved in 7 [N] hydrochloric acid and the solution passed through an anion exchange column to isolate uranium. Iron was removed using mercury cathode electrolysis. Uranium was electrodeposited onto platinum dies and counted using solid-state alpha spectrometry. The samples from each type of mine (wet and dry) were analyzed. The samples in the "wet" mine in New Mexico were selected on the basis of the original TLD measurement because they were near the maximum occupational standard for radon daughters. These samples should also represent upper limits to longlived activity encountered, since they were obtained at drilling operations on the face of the ore body. Samples collected in the "dry" mine in Colorado were pot associated with a particular location in the mine and should be representative of a month long overall exposure in many locations and operations. The values are shown in Table 1. The two uranium isotopes are in equilibrium and their alpha activity

Jan 1, 1981

By J. M. Duke

Significant resources grading less than about 1 % nickel occur in magmatic sulfide deposits of two types. In the Mt. Keith type, extensive zones of disseminated nickel sulfides occur in the central portions of certain synvolcanic dunite-peridotite sills of komatiitic affinity in Archean greens tone terranes. In the Duluth type, disseminated copper-nickel sulfides occur near the basal margins of intrusions of flood basaltic affinity associated with intracontinental rifting. In both types, the parent magmas became saturated with sulfide following the onset of fractional crystallization and the separation of the immiscible sulfide melt was accompanied by the precipitation of a relatively large proportion of silicates. The abundant silicate crystals impeded the coalescense and accumulation of the sulfide droplets with the resulting formation of large but low grade deposits.

Jan 1, 1982

By C. Zhou, B. Whisner, J. Carr

Proximity Detection Systems (PDSs) are used in the mining industry for protecting mine workers from striking, pinning, and crushing injuries when they work in close proximity to heavy machines such as continuous mining machines (CMMs). Currently all Mine Safety and Health Administration (MSHA) approved PDSs are magnetic field based systems which can be influenced by the presence of wire mesh that is commonly used for supporting roof and ribs in underground coal m ines. In this paper, researchers at the National Institute for Occupational Safety and Health (NIOSH) characterize the influence of the mesh on the performance of magnetic PDSs by measuring the magnetic field difference around a CMM caused by the presence of the mesh. The results show that the magnetic fields are generally enhanced by the mesh which causes the PDS detection zones to be increased correspondingly. It was discovered that the fields around the joints of two mesh sections have the greatest enhancement and thus deserve more attention. In addition, it is found that the presence of mesh can also cause a variation in the generator current. The influence of mesh is characterized by the change in the generator current with respect to the distance between the generator and the mesh. It was found that the generator current change caused by the mesh can be significant (on the order of ten) when the mesh is extremely close to the generator (e.g, less than 1 cm) and is negligible when mesh is relatively far (greater than 0.15 m). The findings in this paper can be used to develop guidelines and best practices to mitigate the influence of mesh on PDSs. INTRODUCTION The Mine Safety and Health Administration (MSHA) requires operators of underground coal mines to equip place-changing continuous mining machines (CMMs) with proximity detection systems (PDSs) to protect mine workers from striking, pinning and crushing injuries when they work around these heavy machines. Although a variety of technologies can be implemented for proximity detection, the magnetic-field-based PDS that was originally developed at the National Institute for Occupational Safety and Health (NIOSH) has shown great effectiveness in challenging mining environments and currently all MSHA-approved PDSs are magnetic-field-based systems. As shown in Figure 1, a magnetic PDS typically includes two major components----the magnetic field generator and the Miner Wearable Component (MWC). Magnetic fields are generated by injecting a high electric current into a ferrite-rod antenna sealed in the generator. The magnetic field strength detected by an MWC varies with the distance between the MWC and the generator. In a typical PDS, multiple generators are mounted on different locations of the machine. The relative location/zone of an MWC is determined based on the field strengths from different generators picked by the MWC. Ideally, for a PDS to work properly in the underground, the magnetic fields generated by the different generators should be stable and not vary with the environment, as the system would interpret any variation of the magnetic field as a result of the distance change between the machine and the miner wearing the MWC. In reality, however, this is not always the case since magnetic fields can be altered by a number of environmental factors such as the presence of steel wire mesh that has been widely used in underground coal mines for supporting roof and ribs In this paper, the influence of mesh on the PDS performance is investigated and the magnetic field change caused by the mesh is measured.

Jan 1, 2019

By Charles S. Robinson

The Henderson ore body is east of the Continental Divide in the Front Range of the Colorado Rocky Mountains about 50 miles west of Denver. The ore body is being developed for mining by workings that extend more than 3500 feet below the topographic surface. During construction of the mine workings, ground water in fractures in crystalline rocks has been encountered. From 1969 to 1973, Charles S. Robinson & Associates, Inc., in cooperation with the engineering and geologic staffs of the Climax Molybdenum Company, a division of Amax Inc., studied the ground water geology of the Henderson mine development area. Detailed geologic records of the Henderson mine were available as a result of the exploration, evaluation and development of the mine. Records of the flow, chemical composition and temperature of the ground water at and near the surface, from the entire mine, from portions of the mine, and from exploration holes drilled in the mine, were kept as the mine was developed. Where possible, ground water pressures in drill holes and changes in pressure with time, were recorded. The geologic, hydrologic and chemical data were correlated. The following conclusions were drawn from the correlations: The ground water in the Henderson mine occurs in fractures in Precambrian igneous and metasedimentary rocks and in a series of Tertiary intrusive rocks. Two zones of ground water were recognized; an active zone, in which the fracture systems are recharged and discharged annually into the surface water system, and a passive zone, in which the fractures were filled with water in the geologic past. Discharge from the passive zone is through mine workings that intersect the fracture systems. Discharge from a fracture or fracture system is initially high but decreased with tire!. The rate of decrease in flow (or pressure) is exponential. By measuring the change in flow with time, it is possible to calculate the amount of flow at some given period of time in the future. Based on changes in rate of flow and pressure, and the geology, and assuming rates of mining of the ore, it will be possible to predict the volumes of water that will have to be handled during the life of the mine and the area around the mine that will be drained by the mining operation.

Jan 1, 1976

By G. Reed Marchant

The control systems engineer is often faced with the problem of designing tests or experiments where the cost of obtaining information is expensive. This is true in aerospace as well as in process industries. In these situations the details of test design should be carefully evaluated before any test is executed so that the maximum amount of information is obtained for the effort expended. In recent years there has been a steady trend towards increased automation, In the process industries this has resulted in extensive review of process variables and, instrumentation techniques, development of more accurate system mathematical models, and extensive investments in complex control system as well as completely automated plants. When planning and developing these systems, where each measure of a process variable is usually expensive, it behooves the design engineer to give considerable thought to the details of test design before instrumentation is procured and installed so that the maximum amount of information can be obtained for the expense incurred.

Jan 1, 1968

By W. G. Miller

A series of computer programs for the analysis and mapping of coal-related data has been developed at the Illinois State Geological Survey; these programs, known collectively as the Coal Data System, represent the latest achievements in computer processing of geologic data at the Survey. Building upon programs previously developed in the Survey's Computer Services Unit, they expand the scope of the computerized data base that the Survey has been using for analyzing coal-related data. The System was partially developed during a joint study by the Illinois State Water Survey and the Geological Survey entitled, ?Coal and Water Resources for Coal Conversion in Illinois.? 2 In that study the available coal reserves more than 42 inches thick in the two principal coal seams throughout the state were mapped. The System was used to calculate the coal reserves and to report the average number of tons of coal in place per square mile in each township (Figures 1 and 2). It also produced maps of the coal features of sufficient quality to be printed on material that was scribed as master copy for the printing of full-color 1:500,000 scale maps (see Figures 3 and 4).

Jan 1, 1975

Geostatistics is well known as a tool for ore reserves calculations at the exploration stage. The goal of this paper is to show geoscatistics can also contribute to productivity gains, allow better selection of the mining methods and better control of the grades during production. The first two examples show how geostatistics can provide sophisticated models, using conditional simulations and the use of them for simulations or optimizations of mining processes. A third example will show how to use geostatistics for short term planning in a large polymetallic vein type mine.

Jan 1, 1983

By Constance F. Acton

This paper presents an overview of -- the carbon-in-pulp process for gold and silver recovery as seen in the early 1980's. Traced back to its origins in the mid-nineteenth century the process development through the present state-of-the art is described. The process technology and equipment design are described in detail for the carbon-in-pulp process. A typical process flowsheet is given with a description of appropriate design criteria. Technical advantages and disadvantages as compared to the traditional countercurrent decantation process are discussed including some illustrative comparisons of capital and operating costs. A summary of currently operating carbon-in- pulp plants throughout the world is given with an insight into future developments in this industry.

Jan 1, 1982

By L. H. E. Weyher

In a previous paper presented at the 1966 Annual Meeting of AIME we reported our work, conducted at the Pennsylvania State University, on the hydrocyclone washing of fine coal.' The initial evaluation based on that work demonstrated the feasibility of hydrocyclones as fine-coal cleaning devices, and in that previous paper we presented selected test data that showed in principle how product yield and assay respond to variations of the major cyclone operating variables. The present paper reports in greater detail on the findings and presents a comprehensive evaluation of our data as follows: ? Hydrocyclone throughput rates were related to feed pressure and other variables by regression equations. These equations are compared with other capacity- versus-pressure drop expressions taken from the literature on classification cyclones.

Jan 1, 1968

By Hugh W. Evans

Many reports and papers have been delivered on projects under construction or already in operation, but we believe there are few that have been written about projects yet to be built specifically dealing with advanced mine and environmental planning. This paper describes such planning for Atlantic Richfield Company's Black Thunder mine. Project planning is a cyclic phenomenom involving four broadly overlapping planning steps (Figure 1). The demands of the public include needs that can be satisfied through planned resource development. Using a base of information that partly exists and must in part be gathered and updated, the preplanned development can be, evaluated. The evaluation process, with built-in environmental constraints leads to an implementation procedure. Implementation results in the development, including the release of the affected area to other public demands that follow.

Jan 1, 1975

By Arthur J. Borst, Joseph P. Gildner

In a recent National survey, Seattle topped the list for having the worst daily traffic congestion. To address this problem, Sound Transit is planning to build 40km (24 miles) of light rail, including ten kilometers (six miles) of twin tunnels with four subway stations 40 m (130 ft.) to 65 m (210 ft.) deep. The overall schedule is very aggressive and Sound Transit is preparing four separate heavy civil construction contracts for simultaneous underground construction. Three of these contracts are being considered for design-build. Final design will start in March2000 and all underground construction must be completed by the end of 2005.

Jan 1, 1999

By Horst Huettenhain

The Rowland Coal Preparation Plant is located on Workman's Creek in Raleigh County, West Virginia, approximately 20 miles Northwest of Beckley and 10 miles Southeast of Ameagle. It is owned and operated by the Rowland Division of Consolidation Coal Company. This paper describes the plant flowsheet, process considerations that were evaluated in its development, and observations made during and since the plant was constructed. The final flowsheet was developed specifically to wash the coal from the Rowland Mine and contains several equipment combinations and applications heretofore never placed in a single, commercial operation. The major process equipment is presented in a functional description of the flowsheet. The coal reserves are leased from the Rowland Land Company and consist primarily of #2 Gas and Middle Eagle coals and various major splits of the Middle Eagle seam. The Rowland Coal Preparation Plant was designed to process 560 TPH of raw coal consisting of 50 percent #2 Gas coal intimately mixed with 50 percent Middle Eagle coal and containing lumps no larger than a 12-inch cube.

Jan 1, 1970

By Roger G. Rowe

The Crandon deposit, located in northern Wisconsin, is a 65.8 million ton Precambrian volcanogenic massive sulfide deposit which averages 1.4% copper and 5.8% zinc. The deposit is classic in origin, mineralogy and shape. Comprehensive understanding of the geology of both the deposit and the project site has been fundamental to the credibility and success of Project feasibility studies and regulatory permit preparation. Mine development in the current investment and regulatory climate requires thorough and timely application of geologic tools. From 1977-1980 geologic activities were focused on the typical objectives of orebody delineation, reserve estimation, depositional geology, and general site investigation. Results from these programs formed the basis for the Project's preliminary feasibility studies. Since 1981 further geologic investigations have provided criteria for project design, site management, and operational permitting. Activities have included mine entry position definition drilling, developing geostatistical reserve modeling, large diameter (150 mm) core drilling for mill pilot samples, rock mecha¬nics testing, and evaluation of the glacial overburden/deposit geohydrology for computer simulation.

Jan 1, 1983

By M. Karmis

According to international projections and future energy scenarios, coal will continue to be a prominent fuel for the next 25 years. In fact, in many regions around the world, coal is expected to dominate the electricity sector until the year 2030. At the same time, with instability and volatility of oil prices, coal is also positioned as an alternative feed stock for conversion into liquid fuels. Energy economists maintain that coal liquefaction is viable at crude oil prices of $35 or more per barrel. Depending on technology and coal composition, 1 ton of coal can produce 1 to 4 barrels of oil. Increased coal production and the expanded utilization of coal also raise environmental concerns regarding greenhouse gases and the problem of handling CO2. Carbon sequestration research, currently conducted in many parts of the world, has demonstrated considerable potential for C-storage in unminable coal seams. Such geologic storage, when possible, can also be integrated into an enhanced coal bed methane recovery process Can coal fuel power plants and industrial facilities, provide diesel and other liquids and, at the same, also be used as a medium for permanently storing CO2? This presentation will provide a global perspective on these questions and stress on the need to reconsider, or even redefine, coal as the fuel for the future.

Jan 1, 2006

By R. E. Thill

An ultrasonic, pulse-immersion apparatus and method are described for determining the effects of moisture on the dynamic elastic properties of rock. The method provides an alternative approach for assessing the moisture sensitivity of rocks. Ultrasonic wave velocities are continuously monitored in immersed rock samples as a function of water absorption and time up to saturation. Moisture effects on compressional wave velocity vary as a function of the type of rock and the time and amount of water absorption. Regression analyses are used to curve-fit plots of the data and to derive empirical expressions for compressional wave velocity as a function of water content for different categories of rock. Results indicate that compressional wave velocity can be used to predict both the moisture content and its effect on strength and deformational properties of rock. These results have potential for detecting or monitoring bad roof conditions in situations where the mine rock exhibits strength degradation with moisture absorption.

Jan 1, 1986

By Randolph E. Scheffel

Mill design and project execution are very demanding and interactive processes requiring the dedication and cooperation of many parties. The development philosophy which lead to the successful completion of Ranchers Exploration and Development Corporation's Escalante silver mill is reviewed. The project spanned 25 months from initial feasibility studies to start-up with the major construction effort requiring only 4 months. Mill performance for the second and third months after start-up, as well as fiscal 1983, is compared against the design parameters. Capital and operating costs are also discussed.

Jan 1, 1983

By G. S. Dobby

High-intensity wet magnetic separators have been successfully introduced into the mineral processing field over the past ten to fifteen years, due largely to rapid advancements in magnet design. Wet magnetic separation, until recent years, was applied solely to the concentration of minerals of high magnetic susceptibility, such as magnetite, at relatively coarse sizes. Now, however, high-intensity separators are capable of treating weakly paramagnetic minerals and have extended the range of treatable particle size down to about one micrometre(1,2). . One of the more recent-high-intensity separators developed is the Kolm¬Marston Marston type high-gradient magnetic separator (HGMS) (3,4) It consists basically of an iron-clad solenoid surrounding a matrix material - a fine, ferromagnetic steel wool or expanded metal lath. A schematic diagram of the device is shown in Figure 1. Large, highly localized, pertebations of the magnetic field are created by the ferromagnetic matrix. It is these field gradients that are instrumental in developing large magnetic forces which act on the mineral particles. Operation of the separator is simple. Slurried sample is fed through the matrix and, depending upon the mineral parameters of particle size and magnetic susceptibility and. the operating parameters of flow rate, field strength and feed weight, some particles will be attracted to and adhere to the magnetized matrix, while the others will flow through the matrix. The separation is completed by later removing the background magnetic field and flushing the captured mineral particles into a separate container. The process can also be applied on a continuous basis (S).

Jan 1, 1977

By d&apos, I. J. Agati

The stockpiling and reclaiming of bulk materials can be a challenging task for engineers seeking the optimum solution for plant needs, reliability, and at lowest unit cost. The objective of this paper will be to expose advantages, disadvantages and limitations of many storage and reclaiming systems to the responsible engineer and management. The paper will emphasize the practical aspect of stockpiling and reclaiming methods. Many valuable and interesting papers are available dealing with the theoretical viewpoint and application of a particular manufacturer's machine. Several of these are mentioned in the bibliography. As many practical parameters as possible will be given. After twenty years in the field of designing and selling bulk materials handling systems, the needs of the user and the plant are recognized and reasonably understood. This paper cannot give solutions to all problems In this vast field but will stress practical applications and examples of various installations. The evolution of advancements in materials handling is based upon not only technological innovations, but learning from many experiences of others and utilizing them as stepping stones to improved installations.

Jan 1, 1969