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SOLUTION MINING Solution mining techniques present a means of extracting soluble ores, particularly such materials as salt and potash, from horizons which are not accessible by conventional mining. In the process of dissolving materials, it is evident that solution may be complete or partial. In general, the solution mining operations described in the following section relate to complete solution of the desired compound. Even though the solution of material is complete, there may be instances in which insoluble material is present to a large extent either as granular separated particles or as insoluble layers. The process required for obtaining the desired product involves access wells to reach the deposits, sufficient water supply to yield the production goals, and the development of an underground cavity. The process of solution mining, therefore, depends to a great extent on three factors: availability of a relatively pure strata or formation of salt or potash to be mined, access well or wells, and adequate control of the solutioning process so that enlargement of underground cavities can be fairly well delineated. Since halites represent the most general ores mined by this procedure, the considerations which follow are based primarily on the production of sodium or potassium chloride. The producing formations may be in the form of bedded evc~porites wherein the salt member may be some 30 to 500 ft thick or from salt domes in which great depths of salt occur. Solution mining has been carried out to depths of nearly 10,000 ft. The recovery of saturated brine from wells drilled to effect the solution-mining process leads to further processing. In many instances, the procedures are relatively simple and involve simple recrystallieation or fractional crystallieation, while in others more complex flow systems are required before a final product is obtained. The intent of this section is to provide information relative to the basic procedures for obtaining materials which are soluble in water and to acquaint the engineer with the various aspects of the overall problem which in many instances, may become quite complex and present numerous difficulties. The storage of fluids, particularly hydrocarbons, underground has proven to be a very important part of industry operations. Cavities formed in salt provide excellent storage facilities. The formation of well-defined controlled configurations of such cavities has been possible because of better understanding of the solution process, wide experience gained over nearly 30 yr, and improved technology in drilling and completing wells, surveying caverns, and the operation of numerous types of systems. Solution mining techniques will improve in the future. Many facets of the simple operation of pumping solvents and extracting valuable minerals require further study. Developments undoubtedly will occur to further the processes of mining by solution. In addition to those whose names appear in connection with the individual subjections which follow, a major role in assembling and processing the material in this section was played by Dr. D. A. Shock, Central Research, Continental Oil Co., Ponca City, Okla.

Jan 1, 1973

By E. C. Westman, W. R. Thomas, W. J. Conrad, A. J. R. Russell

"Understanding ground control problems continues to remain a focus of the mining engineering community. To aid mine operators and engineers in identifying and responding to ground control issues, the Ground Observation System (GOS) is being developed. The GOS is an integrated, web-based graphical user interface that displays ground response data collected wirelessly from an underground mine. It presents data in an intuitive manner to assist mine personnel, who are on- or off-site, in quickly identifying hazardous areas. Geotechnical instrumentation will be connected to wireless transmitters that will relay data in real-time to a surface computer that stores the information in a database. The GOS website will then display the geotechnical data in graphical and tabular forms, as well as in conditionally formatted mine maps. Data from each measurement device will be able to be viewed in its entirety or within a time interval, and can be downloaded for further analysis. The ability of the GOS to quickly interpret and communicate mine hazards to personnel of varying technical ability should prove to be a useful tool in understanding ground control and thus improving mine safety.INTRODUCTION Computer-based data information centers that convey operating parameters and conditions are prevalent in modern underground mines. Today’s systems are popular in showing ventilation controls and monitoring equipment performance (Jyothi & Meena 2013). In ground control monitoring, Conover, Ross, and Bigby, 2010 have installed a wired telltale roof monitoring system that sends roof displacement data every ten minutes to a computer on the surface. The computer receives, stores, and displays the data in real time. Data can also be viewed remotely through a password protected internet connection. Additionally, an internet connection allowed for remote updates to the system which streamlined software development and maintenance by eliminating travel (Conover et al., 2010). Currently, no such system beyond Conover et al.’s design has been accomplished. The Ground Observation System (GOS) is being developed to fill the void of real-time geotechnical monitoring in underground mines. A wide array of data will be transmitted wirelessly and broadcasted to on- and off-site mine personnel through the internet. The GOS will incorporate geotechnical data from roof deformation, borehole scratch testing, photogrammetry, and seismic monitoring into one interface, all while achieving permissibility for the use in gaseous mines. As a result, a comprehensive view of rock movement due to mining will be available. The overall purpose of the GOS is to deliver warnings; to ensure reliable data is relayed to personnel for the identification of potential ground failures, provide mine engineers information to design more stable mines, and assist with further geotechnical research."

Jan 1, 2015

By V. P. Petrov

There is a great number of asbestos deposits in the USSR. Some of them are quite large ones. The main deposits of chrysotile asbestos can be seen in the sketch map (fig. 1). Bazhenovo deposit situated in Sverdlovsk region is the largest of them. It is on mining operations since year 1889. Systematical studies of asbestos deposits were begun from the first years of Soviet Government and connected with the names of K.E. Tarasov, P. M. Tatarinov, B. J. Merenkov, N.D. Sobolev, F. V. Syromjatnikov, V. N. Lodochnikov, V.P. Petrov, V.P. Eremeev, L.A. Sokolova, V. R. Artemov, V.F. Dybkov and many others. This investigations served the USSR to be one of the most important producers of asbestos in the world. In the limits of the report a characteristic of the main asbestos deposits of the USSR may be done in general outline, from the point of view of their genesis, and in order to show their common features and differences that must be taken into account for forecasting, exploration, and mining of asbestos. All chrysotile asbestos deposits of the USSR were formed of magnesium rock as a result of comparatively lower-grade temperature hydrothermal alteration and free crystallization of fibrous chrysotile in open cavities that served as catalyst As a matter of fact an important mineral for industry is not chrysotile in general, a widely distributed rock-forming mineral, but a long fibrous and mainly vein variety of chrysotile. It must serve for geologists as an important prospecting criteria. A geologist should search for the mineral not only places of possible chrysotile generations, but places where asbestos may be crystallized in its long fibers that could be fiberized well. The Soviet geologists distinguish two groups of chrysotile-asbestos deposits: (1) related to ultrabasic rocks and (2) related to sedimentary dolomite terranes, taking into account what the maternal rock was affected by hydrothermal solutions. The largest deposits related to ultrabasite. The largest deposits in dolomite are small ones but their asbestos contains almost no iron. So much asbestos is a better filler into insulating plastics. There is a few types of asbestos deposits in the limits of the ultrabasic group. The largest of them is a Bazhenovo type which the deposits of Urals are attributed, and Bazhenovo deposits is the first instance. The Bazhenovo type is characterized by the most complete zonality in disposition of various kinds of asbestization. This type of deposits is practically the only one to be in working now in the USSR.

Jan 1, 1978

By Christopher J. Bise

INTRODUCTION Face haulage in underground mines and pit haulage in surface mines are the principal domains of rubber- tired haulage vehicles. In underground mines, cable- reeled or battery-operated shuttle cars and diesel-powered load-haul-dump vehicles are used; trucks are primarily used in surface mines. Although many concerns go into the selection of rubber-tired haulage vehicles, such as clearance and tire life, the most important factor from a mine-planning standpoint is the production capability of the vehicle in the mine environment. Therefore, this chapter will address this topic. UNDERGROUND FACE-HAULAGE VEHICLES The selection process for underground face-haulage vehicles is, in some respects, much simpler than that of the other haulage systems discussed to this point. It is simpler because these vehicles, which transfer the mined material from the face to the intermediate haul¬age system, are manufactured in various size ranges to cope with the confinement of underground opening widths and heights. However, since these vehicles oper¬ated in an intermittent fashion in conjunction with a constantly advancing face, the system's lack of perma¬nence and overall dynamic nature create a more diffi¬cult situation for predicting productivity. The emphasis in this section will be on prediction of productivity. There are three fundamental steps that must be taken to analyze the productivity potential of any face¬haulage system: l) Recognize the geologic (seam thickness, etc. ) and mining (opening widths, etc.) constraints that affect the velocity/clearance aspects of the haulage equipment, and select equipment from manufacturers' specifications with these con¬straints in mind. 2) Secure the elemental times of the face-haulage system. 3) Incorporate the elemental times into an accepta¬ble mine plan. By recognizing the geologic and mining constraints that affect the system layout, parameters, such as vehi¬cle payload, tonnage to be hauled per cut, and haulage distances, can easily be determined. Elemental times can be developed in two ways: 1) In an existing operation, a time study of the dynamic system can be conducted by placing three time-study engineers at the following static locations; (1) near the loading machine, (2) near the change-out point outby the face, and (3) near the dump. By synchronizing their watches and recording the actions of the haulage vehicles at these three locations, their time studies can be reduced to provide elemental times, such as vehicle tram rates (empty or loaded), vehicle discharge times, and loading rates. 2) In the absence of an existing operation, average values for the elemental times can be provided from other mines operating in similar condi¬tions, or by the manufacturers themselves.

Jan 1, 1986

By Nelson R. Shaffer

Glamorous, burgeoning biotechnology and mundane industrial minerals would at first glance seem to share little in common, but in truth, modern biotechnology depends on many minerals. Biotechnical processes also can be used in industrial mineral extraction and processing. Biotechnology is broadly defined as the application of biological organisms, systems, or processes to manufacturing and service industries. Genetic engineering has reinvigorated one of mankind's oldest sciences, biotechnology, into a booming business. Many modern processes depend on microorganisms cultivated under very stringent conditions in bioreactors. Minerals from carbonate, sulfate, chloride, nitrate, phosphate, and silicate families are used to provide essential nutrients and to regulate growth conditions (such as pH) in order to assure optimal growth of organisms. Certain cells or enzymes perform better when immobilized upon or within solids, and minerals are often used to immobilize cells, especially in continuous process. Minerals are also used extensively in separating and purifying products of biotechnology. Diatomite, zeolites, and silica are especially useful in purification processes. Industrial minerals also are commonly used to clean up large volumes of process water that must be treated. Biotechnology can be employed in exploration, extraction, and processing of geologic materials and in reducing mining or other environmental problems through bioremediation. Microbes have been shown to solubilize certain elements and so promote extraction of heavy metals, phosphate, aluminum, potassium, and even rare earth elements. In a related technique, unwanted materials such as pyrite impurities can be leached microbially to produce cleaner products in sand and clay industries. Microbial actions can modify surface characteristics and so enhance certain ceramic properties. Certain organisms can accumulate useful elements from dilute sources; others can transform unusable chemical species to more useful forms. Deterioration of stone, concrete, and even glass or brick, can be accelerated by microorganisms. Control of such biodeterioration could improve long-term performance of industrial mineral products. Microbial processes have shown promise in improving several mine-related problems. Certain bacteria help remove clays from phosphate slimes and other suspensions. Others are used to degrade cyanide or other organic chemicals such as floatation aids. Cells immobilized on clays have been especially efficacious in bioremediation. Biotechnology industries, like the industrial minerals industries, encompass huge ranges of materials and processes. Costs of products from these industries range from pennies to thousands of dollars per unit, and their products are vital for maintaining modern life styles. Many biotechnical processes depend upon industrial minerals and certain biological processes can be harnessed to do useful tasks in the minerals field. The interplay of industrial minerals and biotechnology is important today, and as biotechnology advances, its interaction with the industrial minerals industry can only increase.

Jan 1, 1995

By G. L. Boxer, R. A. Metz, C. B. Smith, W. J. Atkinson

Since the inception of the Ashton (formerly Kalumburu) Joint Venture in 1972 the parties have expended $24 million in exploration for diamonds in the Kimberley region. This has resulted in the discovery of the currently subeconomic Ellendale deposits in 1976/77 and the economic Argyle - Smoke Creek Deposits in 1979/80. In addition to Argyle and Ellendale, some 90 kimberlitic and lamproitic bodies have been discovered grouped broadly into three provinces, on the west, east and north margins of the Kimberley block. These bodies range in size from dyke-like features less than 1. m (3 ft) in width to pipes with a surface area of 128 ha (316 acres). The bodies with larger surface area are volcanic crater deposits, infilled with air-fall and water deposited tuffs and epiclastic sediments. Diamond content ranges from trace to economic concentrations. The exploration discoveries were facilitated by early recognition that the petrography, mineralogy and chemistry of the diatremes varied from the classical kimberlites of Kimberley, South Africa, to unusual more highly fractionated, alkaline, silicic varieties having affinities with leucitelamproite. Indirect methods of exploration were used, primary reconnaissance work being stream gravel sampling for kimberlitic indicator minerals. Evaluation showed Ellendale diamonds are 90% gem and near gem, but the low grades and tonnage render the deposits unpayable at today's diamond prices. After discovery in late 1979 and completion of a feasibility study by the end of 1982, evaluation studies proved Argyle to be economic. Alluvial diamond mining commenced in 1983 producing 6.2 million carats (Mct) that year, 60% being of industrial quality. Open-pit mining of the AK1 lamproite should start in 1985/1986 at a rate of 3 million t/a (33 million stpy) and produce 25 Mct/a, making this mine, and Australia, the world's largest producer of diamonds by weight. The revenue from diamond deposits is a function of the grade and the value of the diamonds. The grade is the product of the frequency of occurrence of the diamonds (stone density) and the mean stone size; the value of the stones is strongly related to their size distribution. During evaluation of the West Australian deposits, the diamond distribution was found to vary markedly in stone density and stone size. These variations corresponded with changes in the rock type hosting the mineralization. As a consequence, geological mapping of individual lamproites within the multiple vents and careful monitoring of the diamond distribution became an important part of the evaluation work. Similar variations in stone size and frequency were found to accord with separate alluvial terraces and fan gravels derived by erosion from the Argyle AM lamproite.

Jan 1, 1992

By Xiaoting Li, Richard Adasiak, Benjamin Mirabile

Pumpable J-Crib stopping walls and Jennmar high-strength (HS) stopping panel walls are widely used for resisting high-ventilation air pressures and roof support in underground mines due to their installation efficiency, convergence allowance, and better performance than traditional concrete block stopping walls. Based on the different entry dimensions and required maximum ventilation air pressures of up to 36-in. water gauge, 24-, 27-, 30-, and 36-in.-diameter pumpable J-Crib stopping walls, or 18- to 30-in. thick Jennmar HS stopping panel walls can be designed, and their support capacities and convergence allowances are evaluated for better roof control. Pumpable J-Crib stopping walls consist of 0.187-in.-diameter steel wire reinforced, JCrib material-filled bags, and non-wire-reinforced filler bags in between. Jennmar HS stopping panel walls consist of two, 20-gauge (0.04-in.-thick), galvanized, cold-formed steel panels with J-Seal materials pumped in between. Based on the fundamental structural design principles and specifications of ACI 318-19(22), the compression and flexural strength, and shear resistance of the walls can be checked to be compliant with the codes and specifications following the load and resistance factor design (LRFD) method. Specifically, the 0.187- in.-diameter steel wires in the pumpable J-Crib walls and 20-gauge steel panels in the HS stopping walls are integral parts of the walls and are considered to effectively confine the J-Crib or J-Seal materials. These steel elements play a significant role in reinforcing and improving the strength or support capacity of the stopping walls from a structural design perspective. Because of the high ductility of low-density J-Crib/J-Seal materials and steel elements, these walls are good at accommodating or absorbing the roof convergence (≥5% entry height), which cannot be matched by a traditional concrete block stopping wall (Figure 1). Based on the successful design and application of these stopping walls in different mines for improving roof stability and avoiding the air leakage, the authors have formulated the design methodology and verified independently by the finite element analysis (FEA) simulation technique. This design methodology combines the fundamental structural design principles with specific wall dimensions and material properties, facilitating mine engineers and government agencies to understand the in-depth working mechanism of these stopping walls.

Jul 1, 2023

By Samuel Rigert, Marco Bettelini

"INTRODUCTION AND OBJECTIVES Long rail tunnels require in most cases powerful mechanical ventilations. Besides requirements related to normal operation and maintenance, operational safety always requires a high level of smoke management. Identifying the optimum ventilation concept is essential for achieving proper performance and safety while keeping investment and operational cost at a reasonable level. For the purpose of the present paper, long tunnels have a length of typically 20 km or more. This is related to the European classification of trains (TSI 1303/2014), where the maximum distance from the portals to a firefighting point and between firefighting points is limited to 20 km (only category B passenger rolling stock allowed) or 5 km (general case). From TSI 1303/2014 it can be concluded, that tunnels over 20 km require in any case emergency stations with complex mechanical ventilations. Based on the experience arising from a number of recent projects in the European area, including in particular Gotthard (GBT), Lötschberg, Lyon-Tourin (LTF), Brenner (BBT) and Gibraltar, safety-relevant issues related to the ventilation of long railways tunnels are reviewed in this paper. Amberg Engineering is directly involved in these challenging design tasks and can provide first-hand experience and know-how. As a particular highlight, special attention is devoted to the longest tunnel worldwide, the 57 km long Gotthard Base Tunnel, which will be commissioned in 2016. THE GOTTHARD BASE TUNNEL Overview The Gotthard Base Tunnel will be commissioned in 2016 (official inauguration on the 1st of June and beginning of regular operation on the 11th of December) and will be the worldwide longest tunnel. Its complex and powerful ventilation system is very representative for many other long tunnels and is used as reference in this paper. Therefore, a few key characteristics of the Gotthard Base Tunnel and its ventilation system will be described in some detail in this initial chapter. The Gotthard Base Tunnel (GBT) consists of two single-track tunnel tubes with connecting galleries every 312 meters. Two so-called multi-functional stations (MFS), located at roughly 1/3 and 2/3 of the tunnel length, host the key equipment for normal and for emergency operation. At these locations, double crossovers allow trains to switch from one tunnel tube to the other. An emergency station is located in each multifunctional station, allowing trains to stop in case of emergency. The general layout of the GBT is presented in Figure 1."

Jan 1, 2016

By E. G. Joe

Introduction Uranium mining has been actively carried on in Canada for over twenty-five years mainly in Ontario at Elliot Lake in Bancroft, and in Northern Saskatchewan at the operations of Eldorado Nuclear Ltd. During this period, approximately one hundred million tons of mill tailings have been created and lie mainly on the surface close to the mining and milling installations. If all of the present reserves of uranium ores in Canada are mined, a further eight hundred million tons of mine tailings could be created in Ontario, Saskatchewan, the Northwest Territories, Labrador and British Columbia. The present control of effluents from existing tailings is managed by the operating mines under the regulations of both federal and provincial control agencies. It is the long-term effect of these tailings on the environment that has not been clearly defined or measured. Several years ago, the Canada Centre for Mineral and Energy Technology of the Department of Energy, Mines and Resources, embarked upon a program of research directed at the long-term effects of uranium mine tailings. Much of the research to date has been on tailings in the Elliot Lake, Ontario area where some tailings piles have existed for over twenty years. The program consists of two projects, one to address the problem of existing tailings and the other to examine alternatives in the management of current and future tailings. TAILINGS CHARACTERISTICS Uranium tailings are generally the result of sulphuric acid leaching in which the uranium and alkaline minerals such as carbonates and chlorites are leached out. If the ore contains sulphides, these minerals potentially present an additional hazard of acid generation over time and could increase the mobility of heavy metals and some radionuclides such as thorium-230. Except for the extracted uranium, most of the radionuclides from the ore remain in the tailings pile. Uranium ores in Canada span a wide variety of mineralization and associated gangue composition. Uranium minerals include pitchblende, uraninite, uranothorite, brannerite and the phosphate uranium minerals autunite and saleeite. Gangue minerals vary from acid consuming carbonates, and chlorites to acid producing sulphides and inert silicates. With such a wide variety in ore composition, the characteristics of the resultant tailings in Canada are in many cases site specific and the solutions to the long-term effects of these tailings may also be site specific.

Jan 1, 1980

By Pierre Mousset-Jones

I wish to submit this discussion item on an article published in the August issue of MINING ENGINEERING by Wala and Altman on the use of canonical diagrams for mine ventilation networks. The advent of computer graphics and plotting has enabled complex underground mine layouts to be displayed and plotted in a variety of three-dimensional formats that very closely represent the actual mine layout. This enables the ventilation engineer, who is familiar with the mine, to display the network pressures, quantities, resistances, and fan locations in a way that can be understood by everyone working at the mine. This is important if the ventilation engineer needs to discuss changes in ventilation with production personnel, or escapeway procedures with union personnel. While I can see some of the potential advantages in the canonical ventilation network diagram described by Dr. Wala, it appears to me that the fact that the diagram has no visual equivalence with the actual mine layout means that most mine personnel will find such a diagram almost incomprehensible. The authors have alluded to certain advantages with the canonical diagram. However, I find it difficult to see that these outweigh the fact that almost everything listed can be duplicated in isometric diagrams, and in a manner that is easily understandable to everyone in the mine from the miner to the mine manager. Perhaps the authors could show a clear example comparing an isometric with a canonical portrayal of a mine network showing the information that is immediately available from the canonical network that is not obvious in the isometric diagram. There is in this country a severe problem with the need for ventilation engineering and expertise to be used and accepted by mine management as a necessary part of mine planning. It seems to me that to introduce the requirement for further explanation so that management can understand a canonical network display will hinder more than help the recognition that ventilation engineering needs at so many mines in this country. However, I can see that the canonical approach does have its place in assisting the practicing mine ventilation engineer, wherever he or she exists in the organization chart for a typical mine. In this case, could the authors please indicate the availability of the computer program to compute and plot the canonical diagram for a mine ventilation network.

Jan 1, 1990

By Pierre Mousset-Jones

I wish to submit this discussion item on an article published in the August issue of MINING ENGINEERING by Wala and Altman on the use of canonical diagrams for mine ventilation networks. The advent of computer graphics and plotting has enabled complex underground mine layouts to be displayed and plotted in a variety of three-dimensional formats that very closely represent the actual mine layout. This enables the ventilation engineer, who is familiar with the mine, to display the network pressures, quantities, resistances, and fan locations in a way that can be understood by everyone working at the mine. This is important if the ventilation engineer needs to discuss changes in ventilation with production personnel, or escapeway procedures with union personnel. While I can see some of the potential advantages in the canonical ventilation network diagram described by Dr. Wala, it appears to me that the fact that the diagram has no visual equivalence with the actual mine layout means that most mine personnel will find such a diagram almost incomprehensible. The authors have alluded to certain advantages with the canonical diagram. However, I find it difficult to see that these outweigh the fact that almost everything listed can be duplicated in isometric diagrams, and in a manner that is easily understandable to everyone in the mine from the miner to the mine manager. Perhaps the authors could show a clear example comparing an isometric with a canonical portrayal of a mine network showing the information that is immediately available from the canonical network that is not obvious in the isometric diagram. There is in this country a severe problem with the need for ventilation engineering and expertise to be used and accepted by mine management as a necessary part of mine planning. It seems to me that to introduce the requirement for further explanation so that management can understand a canonical network display will hinder more than help the recognition that ventilation engineering needs at so many mines in this country. However, I can see that the canonical approach does have its place in assisting the practicing mine ventilation engineer, wherever he or she exists in the organization chart for a typical mine. In this case, could the authors please indicate the availability of the computer program to compute and plot the canonical diagram for a mine ventilation network.

Jan 1, 1989

By 000-000-604

HISTORIACAL INTRODUCTION Mineral processing has three principle branches, to quote Taggart, "Ore Dressing, which comprises the methods of separation of solids in inorganic crude by means which do not affect substantial chemical change; Extractive Metallurgy, which utilizes chemical reactions for separations of constituents from solids in inorganic crude; and, Fuel Technology, which employs both physical and chemical methods for separating and rearrangement of liquid gaseous and solid components in crude oil and natural gas, tar sands, shale oil, or coal." The scope of this handbook covers the first two classifications, that is, "ore dressing" and "extractive metallurgy," which have been combined in one term: "mineral processing." For a brief history of the development of mineral processing, one could well refer to the Introduction, Sec. I of the Handbook of Mineral Dressing by Taggart, Froth Flotation, Principles of Mineral Dressing by Gaudin, and the original Richard's Ore Dressing, volume No. 1, first published in 1903-1905. In these references and the references given in them a coverage of the history of "ore dressing" can be found and studied at the reader's leisure. For the history of extractive metallurgy as well as ore dressing, the bibliography in General References, taken from a History of Ex¬tractive Metallurgy by F. Habashi, will give a good background for those who are interested in more detail on the history of metallurgy in general. Mineral processing covers a very wide field as is illustrated by the topics discussed in Part II of this handbook and dates back to the early history of man which started with the production and use of native minerals such as gold, silver, copper, mercury, and meteoric iron which were washed or picked from deposits on the surface of the earth and worked because of their malleability. Later, melting was discovered and then it was possible to cast objects of these metals, excluding mercury. The discovery of a method for reducing the metal¬lic oxide probably was developed from melting fragments of oxides or roasted sulfides with charcoal, so that the native metal could be produced in simple blast furnaces such as are used today in rural parts of Spain, China, and elsewhere. Eventually, it was learned that iron could be readily worked when hot, which resulted in its replacing bronze for tools, weapons, and cutlery. Carbon dating and correlation with the Brittle Cone pine has

Jan 1, 1985

By Daniel Hodouin, Claude Bazin, Sami Makni

SCOTT COULTER: Thanks, Eric. Thank you all for coming. Our first speaker today is Claude Bazin. Claude received a degree in metallurgical engineering in 1980 from Laval University in Quebec. He worked for a short time in a mineral processing plant and then returned to Laval to complete graduate studies in the field of process modeling and control. He obtained his master's degree in 1983 and his Ph.D. in 1990. In 1987 he joined Brunswick Mining, New Brunswick, as research metallurgist and subsequently process control engineer. In 1990 he joined Helzfield Mines, New Brunswick, as senior metallurgist. In 1991 he accepted a position of professor at the department of mining and metallurgy at Laval University, a position he is still holding. He's a member of the CIM, TMS, and the Society for Mining, Metallurgy, and Exploration. Claude's topic today is "On-Line Material Balance for Flotation Plants." INTRODUCTION CLAUDE BAZIN: During the last two decades, the on-stream analyzer (OSA) has gained the stat& of key instrument for the control of flotation plants. The OSA is currently used in almost every sulphide flotation plant (Leroux and Franklin 1994), and its application to oxide mineral flotation plants is increasing. The OSA assays are sent to the flotation operators via an operator console or to control loops of various degrees of complexity (McKee 1991) implemented in a distributed control system (DCS). Operators and/or controllers take control actions based on these assays to ensure an adequate operation of the plant. Although this application pays off very rapidly for the purchase of the OSA, one could ask, "Could we get more from the OSA?" Some plants reported the use of OSA measurements for process optimization (McKee 1991). The optimization strategy is based upon economic indices calculated from metal recovery using the 2-product formula (Wills 1992, p. 124). The 2-product formula is sensitive to measurement errors in the assays and can lead to considerable scatter in the calculated indices (Hodouin et al. 1993). Least squares algorithms provide a robust alternative to filter out measurement errors (Spring 1992). This paper presents some applications of a recursive least squares algorithm that provides real-time estimates of the mass flow rates within a flotation plant using OSA and mass flow rate measurements.

Jan 1, 1998

By John L. Bolles

The mineral processing engineer must have some knowledge of mineral identification, and the greater his knowledge in this field, the greater will be his potential to do his own specialty well. Most metal-bearing ores and industrial minerals require processing of some kind to produce a salable product or a material suitable for further processing. The types of treatment are many, but each one is aimed at separating a mineral or family of minerals from others. Obviously, then, it is basic to all mineral processing to identify the minerals present in the raw material and in intermediate and final products resulting from processing. Very often the mineral processing engineer will enter planning while exploration of a mineral prospect is going on. He will examine hand specimens, drill cores and cuttings, bulk samples, and materials in place. He must identify the valuable minerals, their occurrence and associations with other minerals, and the identity of diluents or host rock. An exact and detailed knowledge of the raw material will usually suggest the treatment processes that should be investigated in the development of the most suitable scheme for that particular raw material in that particular location. Physical properties of a mineral often lead directly to a process for separating that mineral from others. Some well-known examples of these are: magnetic separations for such minerals as magnetite, rutile, ilmenite; gravity separations for gold, silver, galena. cassiterite; flotation separation for most sulfides; distillation of mercury from cinnabar; and selective dissolution in specific solvents such as halite or sylvite in water, gold and silver in cyanide solutions, copper oxides, carbonates, sulfates and silicates in dilute sulfuric acid. These processes and many others are described in detail elsewhere in the Hand¬book and so it is not appropriate to give details here, except to emphasize that processing is aided greatly by complete mineral identi¬fication. Developing a treatment scheme for a new mineral discovery is an exciting assignment fag the mineral processing engineer, but much more of the usual work relates to quality control in existing plants. Here too, mineral identification is important. Some processing is aimed toward producing an end product which will meet exacting specifica¬tions regarding purity or allowable diluents. In this situation it is vital that contaminants be identified so that the process can be adjusted

Jan 1, 1985

By David A. Gulley, William A. Vogely

INTRODUCTION The Scope of the Chapter This chapter discusses environmental regulation and closely-related public policies associated with mineral development in the United States. This chapter outlines the nature, extent, and amelioration of secondary effects of mineral development. It sketches the policy foundations of regulation; discusses the implementation of environmental law; describes land use conflicts and land management regimes; and surveys the costs and benefits of environmental regulation. Since regulations are subject to frequent change, the chapter emphasizes basic factual and conceptual material, rather than specific regulations. The goal is to familiarize the reader with the general nature of environmental impacts and mitigation which arise in the minerals industry, and with the issues surrounding the regulation debate. The chapter is organized as a series of sub- chapters. The first of these is a discussion of the conceptual foundations of regulatory policy. The second section summarizes the principal federal environmental statutes, and the implementation of such regulation. Following that, the third section summarizes the current state of knowledge regarding the types of environmental impacts associated with mineral development. This discussion, organized in a format similar to that used in environmental impact statements, can be thought of as a guide to reading and understanding such statements. Next, the fourth section surveys studies of the costs and benefits of environmental regulation. 'These empirical studies are evaluated in terms of the framework developed in the first section of the chapter. In the fifth section, the discussion turns to federal, state, and local approaches to land use control and siting, and the economic analysis of such conflicts. Included are discussions of the two principal forms of public lands mineral entry, the 1872 location patent system and the 1920 leasing approach. CONCEPTUAL FOUNDATIONS OF REGULATORY POLICY David A. Gulley The Role of Regulation in a Market Economy What is Regulation?: Regulation is the intervention of government in the activities of the private market. In a market society, the private sector is presumed to be the most appropriate economic agent. Given this presumption, regulation generally begins with a demonstration of persistent problems under laissez-faire in a given context. Environmental and related regulation occurs because the public believes the free market does not properly value environ- mental quality. In this section, concepts are advanced to aid the reader in understanding the government's role in this respect.

Jan 1, 1985

By Samuel S. Adams

The Grants uranium region of northwest New Mexico is the largest uranium district in the United States (approximately 50% of U.S. production plus reserves) and one of the largest In the world, with approximately 900 million pounds U308 production plus reserves. Deposits of the region are unusual among sandstone deposits for their high content of epigenetic carbonaceous material, generally interpreted but not proved to be of humic origin--that is, co-extensive with uranium in the primary deposits. Virtually all production in the region has been from the Jackpile Sandstone and Westwater Canyon Member of the Jurassic Morrison Formation. The tabular uranium deposits contain, in addition to humate and uranium, significant authigenic phyllosilicates, quartz overgrowths, humate-replaced detrital silicates, and a trace-metal assemblage typical of other sandstone uranium deposit types. Surrounding the deposits in the two sandstone units of the Morrison Formation is an alteration zone within which iron leaching has altered detrital ilmenite-magnetite to residual masses of titanium oxides. Feldspar alteration is locally present within this zone, below deposits in the Jackpile Sandstone, and above those in the Westwater Canyon Member. The feldspar alteration increases in inten¬sity toward the Brushy Basin Member which separates the two sandstone units, ranging from partial replacement to replacement and dissolution of plagioclase and sanidine. Spatial relations among the epigenetic humate, authigenic silicates, and the broad alteration zones that extend from the Brushy Basin Member to and including the uranium deposits suggest that (a) the organic material was involved in the unusual silicate alteration, transport, and authigenesis, and (b) that the humates originated in shales of the Brushy Basin Member. Stratigraphic relations among the Brushy Basin Member and the overlying Jackpile Sandstone and underlying Westwater Canyon Member suggest [in turn] that there was continuous, interfingering deposition controlled in part by contemporaneous basement subsidence along northwest- and northeast-trending zones. Following minor erosion of upper Jackpile Sandstone and deposition of basal organic-rich Cretaceous sediments, the silicates of the Jackpile Sandstone were once again altered by organic-bearing fluids, this time permeating down from Cretaceous sediments and partly obliterated ore-stage alteration.

Jan 1, 2013

By T. Stuczynski

In the past ten years about 3000 wastewater treatment plants have been built in Poland. The result of this development has been a massive increase in overall sludge production. According to data supplied by the Ministry of Environmental Protection, 400,000 dry tons of sludge are generated every year in Poland (Koblak-Kalinska 1996). Still it is difficult to estimate the amount of sludge, which is used in agriculture or for reclamation purposes. However, it can be assumed that this comes to no more than 10 percent of all sludge produced in Poland on a yearly basis. Thus it became obvious that an urgent solution to this problem was needed. Local authorities in Silesia realized in the early 90?s that a demonstration was necessary to encourage the proper utilization of sludge. This was the basis for establishing the Biosolids Subpart of the Silesia Project, which addressed the use of biosolids in the reclamation of mining and smelting dumps (Stuczynski et al. 1996). Metal waste sites themselves are known to contain more than 87 million tons of waste (Pistelok et al. 1995). Each year this amount increases by approximately 400,000 tons. We realized that a simple solution for stabilizing these sites would be to cover them with vegetation in order to reduce leaching of toxic elements, as well as to keep metallic fugitive dust from entering the environment. The reclamation of smelter waste sites, which was carried out within the framework of the Silesia Project was a joint effort of local government, industry and international research institutions/agencies, including the US Environmental Protection Agency (EPA), the Center for Research and Control of the Environment (OBIKS), Virginia Polytechnic Institute and IUNG. One of the goals was to evaluate the possibility of adapting the rules of sludge management currently used in the United States to conditions commonly found here in industrial regions of Poland. However, the main objective of the Silesia Project was the development of guidelines concerning all aspects of sludge use for the reclamation of degraded lands and waste sites. Biological aspects related to reclamation of metal waste with the use of biosolids will be discussed in this paper.

Jan 1, 2002

By Guillermo P. Salas

The Consejo de Recursos Naturales No Renovables of the Mexican government entered into an agreement with the United Nations in 1964 for the mineral exploration of a large area in Estado de Sonora, Mexico. The agreement called for a systematic exploration for copper in northern Sonora based on photogeologic mapping, aerial reconnaissance, and geochemical stream sediment sampling. The UN-CRNNR investigations resulted in the detection of anomalous copper values in sediment from the Arroyo Cruz de Cafiada. The anomaly was followed upstream to its source, which ultimately proved to be the La Caridad ore body (see Fig. 1). Soil copper and molybdenum values were found over a large area, and further detailed geologic and geophysical investigations were instituted of the anomalous area. David Coolbaugh was largely responsible for the follow-up work. An induced polarization (IP) survey found a roughly circular region of "highs" that coincided with a high soil copper anomaly. The circular anomalies ringed the topographic feature that ultimately was found to contain the Caridad ore body. Soil geochemical copper response over the ore body was subdued, because the soils were derived from a leached capping, whereas leaching in fringe areas that contained less veining was less intense. The ore body was also ringed by the typical high pyrite zone, and this was the anomaly detected by the IP survey. The UN began drilling in the fall of 1966. Eleven holes tested the IP-Cu geochemical high, but none were of commercial interest. The project was returned to the Consejo and was reviewed in the field by G.P. Salas and V.F. Hollister. It was found that the leached capping had not been tested by the past activities, and the Consejo elected to explore that area in 1967. The capping was evaluated by Salas and Hollister and drilling by the Consejo began in 1967. Commercial grade ore intercepts were found in the first hole. The Consejo drilled nine holes, of which eight were commercial. At least 90.7 Mt (100 million tons) of 0.8% copper were indicated by the Consejo in eight holes. The lesson learned in this discovery is that evaluation of leached capping is an important guide to exploration. The general-

Jan 1, 1991

By Omar A. Muhtadi, David A. Milligan

7.1 INTRODUCTION The circulating fluid (generally an aqueous cyanide solution) is the major active component of heap leaching. This solution extracts precious metal from the heap and is then processed to recover the precious metal. The solution continuously recycles through the heap to recover more precious metal. With each cycle through the heap, water and chemicals are lost. Make-up water and chemicals must be added to balance losses from evaporation, seepage, entrainment, and chemical reaction in the heap, as well as any other processing losses. Adding more water than needed can result in a build-up of water as inventory in the various ponds and can eventually require that water be discharged from the operation. This is an extremely undesirable condition, and can often be very expensive in both investment in water treating facilities and operating costs. Most heap leach facilities operate under a zero discharge permit; thus, a situation requiring water discharge can result in permit violation. Chemical solution control must be managed to maintain the optimum pH, dissolved oxygen content, and cyanide content, while preventing "scaling". Calcium-based precipitation is a common scaling problem in mill reclaim waters. A buildup of these deposits can result in severe reduction of water flow, loss of pump efficiency and eventual interruption in metal production. In addition, problems of plugged sprinkler heads, blinded leach pads and fouled carbon (in carbon recovery systems) can be and often are experienced when scale control is not maintained. The remainder of this chapter discusses chemical solution control and scaling prediction/prevention in the context of a "closed" system. Sizing of ponds to accommodate precipitation and runoff, collection systems, and other similar design considerations are not discussed here. These topics are deferred to later chapters, e.g. Chapter 10 considers design of collection systems while Chapter 12 discusses pond sizing. 7.2 CHEMICAL CONTROL Chemical composition of the circulating solution must be controlled by the operator if the heap leaching process is to be successful. The primary or essential chemical control parameters in any heap leaching operation are:

Jan 1, 1988

By Joseph Matoney, B. K. Parekh

INTRODUCTION The term "dewatering" refers to removal of water from coal. Water associated with coal can be categorized as "free or surface" and "inherent or chemically bound" moisture.' The free moisture is found on the surface of coal, in capillaries and small spaces between two or more particles. The inherent or chemically bound water is found in the interior of the coal and as part of coal structure. A significant amount of free moisture can be removed by mechanical dewatering techniques. However, inherent moisture can only be removed by applying energy intensive techniques, e.g., direct or indirect heating. Moisture in the coal offsets some of the benefits of coal cleaning. Extra water in clean coal adds to extra cost in transportation, heat lost during vaporization, and plugging of chutes. From a utility perspective, a 1 % increase in moisture can offset a 4.5% decrease in ash.2 Mechanical dewatering can be classified into two major process categories according to the principles involved, namely, 1. Sedimentation-liquid is constrained and particles move freely. 2. Filtration-particles are constrained by a medium and the liquid flows through. Each of the process categories is composed of various separation techniques shown in Fig. Equipment currently being used by the mechanical dewatering of coal of varying size ranges and final moisture content is illustrated in Fig. 8-2. This figure indicates that sizes larger than 13/, in. (37.5 mm) present no particular dewatering problem. Shaker screens of the very crudest types and designs are capable of producing these sizes at low surface moistures. High-speed vibrators are used for the intermediate sizes and can be used for smaller sizes down to 0.02 in. (0.5 mm) if high moistures (15% surface moisture or greater) can be tolerated in the product. Usually, however, the vibrator is not used below 3/, to 3/, in. (9.5 to 6.3 mm) because of the moisture associated with these fine sizes. At this level, centrifugal force is usually employed to aid dewatering. Centrifuges of various types and designs are used practically

Jan 1, 1991