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By J. W. C. Wong, T. A. Songberg, S. D. Miller, J. J. Jeffery

Natural degradation of cyanide has been widely used by the gold mining industry for removal of CN from cyanidation processing wastes. However, little documented study has addressed the decay and fate of cyanide within residue storage ponds. 'fhis paper describes a study on the cyanide behaviour in a residue storage pond at the Boddington Gold Mine in Western Australia. Depth profile samples were collected from the active residue storage to determine the distribution of CN forms and complexing metals throughout the settled residue.

Jan 1, 1991

By Richard D. Christie, K. Jay Pillai

In the past, it was not unusual for coal preparation plants to discard fine run-of-mine coal. This practice has changed due to increasing quantities of fine material, improvements in beneficiation methods, and the need to recover revenue from these fines. It is in this context that the coal industry has increasingly been turning to froth flotation for fine coal beneficiation. Reagent schemes have been developed to promote coal flotation and to treat the resulting refuse material. While reagent technology has improved, however, most plants rely on manual control of reagent dosing and circuit operation. This often results in misuse of reagents, loss of coal recovery, and consequent loss of revenue. Fine coal circuit operations can be dramatically improved through automation. Intelligent process control systems are now in use which are capable of optimizing reagent usage, maximizing coal recovery, and minimizing chemical costs associated with refuse handling. This paper describes a type of control system currently used in preparation plants, and provides data and information on the significant improvements such systems can produce.

Jan 1, 1994

By J. Derwin King, Harrison R. Cooper

Applications of nuclear magnetic resonance (NMR) offer possibilities for on-line sensing of the concentrations of several elements in flowing sample streams. In addition to hydrogen, these elements, generally of low-order atomic number, include aluminum, phosphorus, fluorine, sodium, boron, and lithium contained in minerals having commercial importance. Many such elements have been difficult or impossible to successfully measure on-line using the more familiar X-ray fluorescence and neutron activation analysis techniques. The availability of practical on-stream analysis methods is essential to applying advanced controls to processes incorporating these elements. On-stream NMR instrumentation has been demonstrated in the past for several process applications including, as an example, coal flow and analysis; and the technology has recently been extended to the measurement of phosphorous BPL in Florida beneficiation plants. The technique involves simultaneous sensing of proton (hydrogen) and 31P intensities to provide data for continuous calculation of BPL in the phosphate through calibration to volume fractions of water and solids. Initial operating results are described using the PhospholyzerTM on-stream phosphorous analyzer designed for plant application.

Jan 1, 1990

By Sean Harvey

One of the manifestations of the dynamically induced failures in deep coal mines is the violent ejection of coal from the ribs. A possible protection against such failures is the use of a specifically designed dynamic support system with reinforcement units having the sufficient capacity to absorb the kinetic energy of the dynamic failure and a skin support that can adequately contain the disintegrated coal. With this method of mitigation in mind, a recently introduced yielding rock bolt, trade name Roofex, has been identified (Harvey and Ozbay, 2009) as a possible energy absorbing component of a dynamic support system. According to the manufacturer?s specification, the Roofex bolts can yield 300 mm (or more) displacement while holding 80 kN pull load. In order to assess the performance of this support unit in coal ribs, a series of in situ pull tests performed in two coal mines in Colorado. The results show that, under conventional pull test loading conditions, Roofex yielding bolts perform very close to their claimed specifications, thus showing a potential for their use as the main energy absorbing component of a dynamic support system. Further studies are required to confirm the in situ performance of these bolts under dynamic loading conditions and also to develop a containment component for a dynamic support system for the mitigation of dynamic coal rib failures.

Jan 1, 2009

By K. Hansson, A. Jedborn

Background In the mining industry, conversion of fine particles into a slurry is often part of the normal processing of the ore. Therefore, from a system's point of view, slurry transporta¬tion would be considered as a natural alternative, all the way from the working face to the final processing. In underground mines, there is sometimes a considerable inflow of ground water that has to be pumped out. When the mine dewatering installations are integrated with a hydraulic hoisting system, the cost of power needed to pump out the ground water can be excluded from the cost of hoisting, compared with other modes of transporting the solids to the surface. The chief advantage of hydraulic hoisting is that the hoisting capacity can be increased at comparatively low total cost without necessitating the sinking of new shafts. Alterna¬tive examples include deepening of the existing mechanical hoisting system, truck, or conveyor belts transport in ramps to the present level. These often become very expensive. The economic effectiveness of hydraulic hoisting and hydraulic design considerations have been discussed by Kostuik (1965) and Sellgren (1985, 1986) for both small shallow mines and large deep underground mines. Objective and scope The objective of this study was to demonstrate the feasi¬biliy of hydraulic hoisting in hypothetical examples of mine deepening. Underground grinding to a maximum particle size of about 700 um (about 25 mesh) is considered. The pumping of ground ore products with positive displacement plunger or membrane type of pumps at working pressures of up to 15 MPa (2200 psi) is a thoroughly tested technique (Venton, 1986). Hydraulic hoisting system A hydraulic hoisting system is described schematically in Fig. l . The ore is mined, handled, and crushed conventionally. It is then ground wet underground. The slurry is then tempo¬rarily stored in an agitated tank and pumped to an agitated receiving tank on the surface. The ore is then further processed in the concentrator. The capacity of a pipeline is very high. For example, an annual production of 500 Kt (550,000 st) of ore can be handled in a 100-mm-diam (4-in.-diam) pipeline. Systems layout - economic effectiveness Schematic mine layouts are presented that represent situ¬ations where hydraulic hoisting often is the most economical alternative. A situation where the ore is trucked to the level of the existing hoisting system is shown in Fig. 2 (following page). With hydraulic hoisting, only a shaft for ventilation, pipe¬line, and personnel are needed. In a first phase (Fig. 2), a hydraulic hoisting installation with crushing and grinding units, storage facilities, and pumps has been located at a level of about 400 to 600 m (1310 to 1970 ft) below the surface. With further development of the mine, the hydraulic hoisting

Jan 1, 1989

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 D. R. Nagaraj

The chemistry and structure-activity relationships for four new classes of sulfide mineral and precious metals collectors developed recently are discussed in this paper. These collector classes are alkoxycarbonyl alkyl thionocarbamates and thioureas, dialkyl (or diaryl) monothiophosphates and dialkyl monothiophosphinates. The main emphasis will be to highlight the differences between collectors and their affinities for various minerals on the basis of data on kinetics of adsorption on pure minerals, natural ore flotation and microscopy of flotation concentrates. The mechanism of interaction of these collectors with sulfide minerals is also discussed with the available data on the FTIR and solution chemistry studies.

Jan 1, 1989

By S. E. Restrepo

To innovate and make the operation sustainable it is necessary to identify the externalities and impacts completely. This paper presents the results of a proposed methodology to make circular economy initiatives viable in mining operations using these aspects: • Economic, safety, and environmental (HSE) risk analysis • Technology observation • Mineralogical characterization • Identification of potential waste uses • Use of government economic benefits The results of the project can be summarized as follows: • Implementation of new technologies in the aggregates process, • efficient use of water, • the valorization of waste to convert it into a by-product, • and access to tax benefits for investment savings.

Mar 2, 2022

By Kevin Sharman, Peri Mehling

A detailed assessment of acid rock drainage (ARD) potential was conducted at the Quintette Coal Mine site in northeastern British Columbia The site is unusual in that the coal seams contain low sulphur levels as compared to eastern coals (typically less than 0.5%), and the non-coal wastes generally do not to have the potential to generate acid on the basis of static ABA tests. The presence of small iron-stained seeps on the pit walls indicate localized sulphide oxidation, while the overall mine site drainage has remained of excellent quality with extremely low levels of metals after approximately 15 years of mining. Thus the site provides an excellent comparison to more problematic coal mine sites. For the Quintette assessment, static acid-base accounting (ABA) analyses of individual samples were compared to criteria for potentially acid generating materials developed for the U.S. Appalachian coal, as well as criteria developed in British Columbia for hard rock mines. Geologic units were characterized by the percentage of samples, or weighted thickness, that was deemed potentially acid generating (PAG). Links were then made to actual seepage and water quality emanating from geologic units around the site. Seeps at the site demonstrate a large range in pH (2.32 to 8.18). The few acidic seeps (pH < 4.0) were found to contain elevated levels of sulphates, dissolved iron, manganese and aluminum, consistent with the metals typically of concern in Appalachian coal mines. Other heavy metals that were detected in acidic seeps at Quintette included copper, zinc, nickel and cadmium. The use of simple ABA tests, and comparison of individual sample results with the Appalachian and British Columbia criteria, was found to be useful in predicting the probable sources of the small localized acidic seeps.

Jan 1, 2000

A bearing isolator is a noncontact, nonwearing, permanent bearing protection device. It has a rotor and a stator, and the two are unitized, so that they do not separate from one another while in use. The rotor turns with a rotating shaft, while the stator is pressed into a bearing housing. The two components interact to keep contamination out of the bearing enclosure and the lubricant in. Bearing isolators do not require lubrication or any particular shaft finish or condition. The best bearing isolators are made of metal, usually bronze. They use a vapor-blocking feature that inhibits the free transfer of vapor contamination when the rotating equipment is cycled on and off.

Jan 1, 2004

By Robert S. Neil, O&apos

The basic transportation planning process consists of: 1. Inventories and analyses of existing conditions. 2. Estimates of future growth. 3. Determination of future travel demand. 4. Testing alternative systems to satisfy future travel demand. The many modeling techniques used in the transportation planning process are well known, commonly accepted, and thoroughly described in readily available literature. This paper will concentrate on the fourth step of the planning process, specifically the development of alternative systems for testing, and will discuss some of the factors which should be considered during the development of alternative systems. There are many factors which require consideration and which have a bearing on the configuration of alternative test systems. These comments will be limited to the influence of geographic, demographic, geologic, and economic factors. Although addressed separately, the four are to a great extent related and have a significant effect on each other. The objective of examining these factors during the early phases of system planning is to assure that more detailed corridor studies will not be stymied by considerations which could have been anticipated and accommodated at an earlier time. It is particularly important that feasibility of construction be assured before test systems lead to corridor decisions and accompanying commitments to

Jan 1, 1974

By D. A. Stanley, B. J. Scheiner

The U.S. Bureau of Mines has thoroughly investigated the flocculation of phosphatic clay waste with polyethylene oxide (PEO). The studies included both theoretical and applied aspects of the flocculation sequence. The screen dewatering technique developed by the Bureau was field tested at four different Florida phosphate mines. The results of these field studies are presented. Also, to determine the mechanisms of the interaction of PEO with montmorillonite clays common to the phosphatic clay waste, a number of theoretical studies were conducted. An empirical equation was developed to describe the amount of PEO needed for flocculation. Infrared, ion exchange, and rheology techniques were used to study the interaction of PEO with Florida clays. The results of these studies are also presented.

Jan 1, 1993

By Harleigh V. S. Tingley

Investment in the mining industry has increased substantially throughout the world in recent years. So have acquisitions, divestitures, and financial restructurings. The return of outside investors to the industry is welcomed. The trend toward stockholder litigation is not so welcomed. Both have provided the impetus for commissioning outside professional due diligence studies of potential minerals transactions. For a number of reasons, some unique to the industry, evaluation of mining investments is a challenging task for the investor. Investments in exploration prospects and undeveloped properties have a high speculative content. Buyers pay for uncertain future prospects. Alternatively, most developed mining investments are large and long-lived and cannot easily be modified during that life. Even so, to be successful, they must compete in an environment in which their reserves - the source of their profits - are often imperfectly known. And markets, competition, technology, and politics are among the many continually changing factors that affect investment performance. Minerals investment evaluation is further complicated because each minerals investment has its own singular combination of risks and opportunities. Each ore type and each ore body presents different problems in reserve evaluation, mining, and extraction. Each minesite has its own often unique combination of mine, infrastructure, political, environmental, and other risks. And the key requirements for commercial success differ substantially among various minerals.

Jan 1, 1990

By J. R. Stoltz, E. Thompson, S. Pattee

On May 15 and 16, 1999, a mine ventilation survey was performed in the 705-m- (2,312-ft-) deep Cayuga Mine, Cargill Salt Division, Lansing, NY. The purpose of the survey was to develop a numerical model of the existing ventilation system and to perform a computer simulation study for long-term environmental and ventilation planning. Because the natural ventilation pressure (NVP) has significant effects on the ventilation system at the Cayuga Mine, there was a need to assess the NVP acting in the mine. Due to the ventilation arrangements in the Cayuga Mine, the authors decided to use the direct-measuring method to determine the NVP by measuring differential pressure across the automatic fan door. This difference in pressure was measured immediately after the fan was stopped and the automatic door was closed to stop the flow throughout the entire mine. To show seasonal changes in NVP, two additional measurement for NVP were performed, one on Aug. 22, 1999, during the hot (summer) season, and another on Feb. 6, 2000, during the cold (winter) season. The mutual interaction between the natural ventilation pressure and the main fan at the Cayuga Mine is also discussed

Jan 1, 2003

By Peter Bourke

It was in 1982 that the first SK-80 flash flotation machine was introduced at Hammaslahti concentrator in Finland to produce a final grade copper/gold concentrate. Since then the size and number of flash flotation units has steadily developed with the SK-240 being introduced in 1984 and the SK-500 unit in 1990. To date over 130 units have been installed worldwide many of which have been used to maximise the recovery of precious metals such as gold and platinum by preventing overgrinding in the grinding circuit prior to flotation. This paper briefly describes results achieved at several major gold mines in Australia and overseas that operate large flash flotation cells.

Jan 1, 1995

By K. S. E. Forssberg, M. I. Hallin

In many cases, the reuse of process water in flotation plants is desirable both for plant operating reasons and for environmental protection. The main advantages are better housekeeping of fresh water and process chemicals together with the reduction of polluting species to the environment. There are however a number of problems involved in the use of recycled process water. The main problem is that recycling sometimes has a deterious effect on the process and can occur months after the start of water recycling. The Division of Mineral Processing of Luleå University of Technology has been conducting experiments on recycling of process water at various sulphide plants in Sweden for over ten years. The experiments have been carried out in pilot- and full industial scale, in collaboration with the mining companies operating the plants. Until 1988 investigations were carried out in four different sulphide plants. The objectives of the experiments were: first to document differences in the composition of the process water during recycling; secondly to investigate any changes in the pulp chemistry of the flotation circuits wich may be due to the influence of recycled water; and lastly to establish critical levels, if any. of the parameters measured. While conducting experiments of this kind several things have to be kept in mind. Normally, recycling is done by using tailings pond water as process water. This means that time effects are important, because of the time lag between water input in the tailings pond and the reclaim of that water back to the plant. As will be shown, the

Jan 1, 1989

By R. M. Carland, F. F. Aplan

The ion-exchange capabilities of natural zeolites from the western United States, representing the species chabazite, clinoptilolite, erionite and mordenite, have been studied because of their potential use in environmental remediation and in hydrometallurgical processes. These raw zeolite samples were found to contain Na+, K+, Ca+2 and Mg+2 as exchangeable cations, and all of these, with the exception of Na+, were found to seriously interfere with the exchange of Cu+2 from solution. Placing these zeolites in the Na+ form was found to increase their cation-exchange capacity, often massively. In addition, the elution of Cu+2 from the Na+ pre-exchanged zeolite is greatly facilitated when the deleterious K+, Ca+2 and Mg+2 have been largely expelled. The relative influence of these deleterious ions on the uptake and elution of Cu+2 was determined.

Jan 1, 1996

By A. G. Fabbri

This paper aims at the application of quantitative criteria for evaluating the mineral potential of square cells representing areas in terrains being explored at a reconnaissance level. The assumption is made here that the evaluation methods used by an expert economic geologist can be organized into geological models for establishing associations within imaged areas, that correspond to pixels with similar characteristics. UTM-registered multiple data sets have been constructed which include seasonal LANDSAT 2 and 4 images, SEASAT scenes, selected airborne radar images, digitized aeromagnetic, gravity, bedrock geology and topographic elevation maps. The area of interest is located in the Bathurst Inlet, District of MacKenzie, N.W.T., where a preliminary mineral potential evaluation was performed by the Geological Survey of Canada to assess its suitability for a national park. The multiple data sets described in this paper can be used for many studies at different resolutions, for comparing processing methods in remote sensing and, most importantly, for evaluating the physical and spatial relationships between the different images in registered data sets.

Jan 1, 1989

By Steven J. Kirk

In the past decade, many hardrock surface miners have revegetated dumps and tailings ponds to allow those waste disposal areas to blend more easily with the surrounding landscapes. Efforts have also been made to more creatively use the flat land resulting from the disposal of overburden and tailings. However, the mines which serve the best post-mining land uses are those that have been preplanned to incorporate such end uses. To more fully explore such a philosophy, interdisciplinary team from The University of Arizona conducted a study during 1974 and 1975 of six open pit copper mines in the Santa Cruz River Basin south of Tucson, Arizona for the purpose of investigating both interim and end-use possibilities for mine waste disposal areas. Among other reasons for the study, it was felt that alternatives for such waste areas would be more socially acceptable than barren dumps or tailings ponds. The team, known as the Mines Project Group, consisted of architects, engineers, and hydrologists. As it would have been economically infeasible to move the existing waste rock dumps or tailings ponds, preplanning was limited to the disposal of waste generated after the inception of the project. To better present their concepts, architecture professors Kenneth Clark and Fred Matter constructed a large-scale cardboard relief model of the mines and the surrounding Santa Cruz River Valley (1). The model was built at a scale of 1:12 000 (1 in = 1000 ft) with 30.48 m (100 ft) contour intervals and covered an area of 40.23 km by 32.18 km (25 miles by 20 miles) in scaled area. The mines being studied were cut into the model, but the proposed waste dumps and tailings ponds were built separately so different disposal configurations could be evaluated.

Jan 1, 1980

By Qing-Wang Hao

In this paper, the authors attempt to develop engineering based approaches for estimating safety factors against pillar and floor failures and predicting likelihood of subsidence events over abandoned coal mines in Illinois. There are two critical problems involved in the analysis: determination of geotechnical properties, and consideration of time effect. The authors attempt to solve the problems by generating hypotheses, which are used to modify existing engineering models for estimating pillar and floor safety factors. The modified models are validated using data from two well established databases of subsidence events over active and abandoned mines in Illinois. The data analysis suggests that most of the trough type subsidence events in Illinois were caused by floor failures rather than pillar failures. The subsidence incubation period seems to be directly related to initial floor safety factors at the time of mining. This correlation can be used to predict the likelihood of subsidence and to assess subsidence risks within both spatial and temporal contexts where detailed mine maps are available.

Jan 1, 1986