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By W. J. C. Venter

The use of activated carbon to improve the selectivity in the separation of base metal minerals from bulk concentrates played an important role in the development of separation techniques employed at Tsumeb Corporation's Tsumeb and Kombat mines. In this paper the Kornbat mill flowsheet and metallurgical data are given with particular reference made to the separation techniques using activated carbon. The mine's historical background, geology and mining methods are described briefly.

Jan 1, 1973

Steady increases in longwall production have required operators to apply greater quantities of ventilating air in an effort to control and dilute respirable dust. Significant increases in shearer speeds necessitate that longwall supports also be advanced at a faster rate. Both of these factors may contribute to overall respirable dust levels on the longwall face because as supports are lowered and advanced, broken material falling from the top of the canopy is entrained directly into the air stream. To address this issue, the Pittsburgh Research Laboratory collected respirable dust samples from four longwall faces to characterize shield-generated dust. This paper investigates the influence of air velocity and shield advance rates on respirable dust levels. Also discussed are engineering controls currently used to reduce shield dust and alternative controls being investigated by the National Institute for Occupational Safety and Health (NIOSH).

Jan 1, 2009

In this presentation, CiDRA?s patented technology platform and its applications will be described. CiDRA's non-invasive, passive sonar array-based flow meter technology provides the volumetric flow rate of single or multiphase fluids by measuring the speed at which naturally occurring structures such as turbulent eddies or density variations convect with the flow past an axial array of sensors. These sensors are incorporated in a band that is wrapped around the outside of the pipe, resulting in no process downtimes for installation and unprecedented reliability. This technology has resulted in a unique ability to measure the flow rate of most fluids ? clean liquids, high solids content slurries, pastes, and liquids and slurries with entrained air. Unique and difficult minerals processing flow measurement problems and their solutions will be described. Examples of these problems include flow measurements in froth lines and flotation feed lines with entrained air, slurry lines with magnetite and other magnetic ore, slurry lines with abrasive or corrosive materials, high pressure lines, and lines exhibiting scale buildup. Recent technology developments will be covered.

Jan 1, 2008

By T. B. Acton

There are two types of ore transportation systems in use at Newmont's Magma Copper Co. San Manuel mine in Arizona-rail-mounted, box-type rotary cars and the newer rail-mounted, bottom-dumping ASEA cars. Though the cost per car for the ASEA units greatly exceeds the cost per rotary car, the advantages of the ASEA units, including much faster dump times, have made the ASEA system a successful alternative at the San Manuel mine. The rotary system of ore transportation has been in use at San Manuel since production began in 1956. The system employs 7.9-m3 box-type cars to transport ore by rail to shaft pocket areas. A rotating dumping mechanism turns three cars at a time upside down to empty them, and returns them to an upright position. Trains of 15 cars each are dumped in about six minutes. Each 15-car train is pulled by an 18-t rated trolley locomotive. There are about 400 rotary cars in service at San Manuel and the system is used for the majority of ore haulage. This well-proven rotary method was instrumental in achieving the December 1977 world record of 272 Mt hoisted from an underground copper mine. Magma Copper Co. began using ASEA cars in late 1977. Designed by ASEA of Sweden, the cars are built for San Manuel by Kasper-Hall Manufacturing Co. in Tucson. The cars basic design feature is a hinged floor that opens at the side as the car is pulled through the dump. As it passes over the dump, a fifth wheel attached to the hinged floor (opposite the hinges) travels along a rail in the dump. This rail dips down into the pocket and then returns to track level. As the fifth wheel travels along the rail, the car floor opens, the car dumps, and the floor is then returned to track level. As the car is dumping, the body remains suspended over the pocket by wheel rollers attached to each side of the dump. Trains of 10 cars each are emptied in about 45-50 seconds. Each ASEA train is pulled by an 18-t rated trolley locomotive, adapted at San Manuel to allow it to pass through the ASEA dump. At minimal cost, "wings" are welded to each side of the locomotive. These wings suspend the locomotive over the pocket as the train passes through the dump. Advantages of the ASEA System Major design characteristics of the ASEA and rotary systems are shown in the accompanying table. The comparison points out some of the following advantages demonstrated by the ASEA system. • Faster dumping-An ASEA train dumps in 50 seconds, while a rotary train takes at least six minutes. There is no stopping or starting when dumping an ASEA train. The train enters the dump area, dumps, and leaves in one continuous motion-in contrast to rotary trains which must stop and start five times to dump. With the rotary system, three cars are spotted in the dump mechanism by remote control. When the cars are in place, the train operator activates the dump, the cars are turned over, and then returned to an upright position. This process is repeated until all 15 cars in the train are emptied.

Jan 4, 1980

By S. Vogely, J. Trescot, D. Connor, F. Beloy

In 2001, the Minntac Division of US-Steel retrofitted one of their Grate-Kiln Iron Ore Pelletizng lines with a Ported-Kiln Air Injection System (PKAIS) the first of it’s kind in the world for oxide pellets. The Ported Kiln System injects air under the bed of pellets in the rotary kiln, causing rapid oxidation of the magnetite pellets. This rapid oxidation allows for lower kiln temperatures, reducing fuel demand; less heat load on the annular cooler; and higher pellet quality. Both the process and the equipment are patented developments by Metso Minerals. This paper discusses the process, the key equipment, and the benefits to the pellet plant and the downstream blast furnace operations.

Jan 1, 2004

By Lorraine Brandt Yde

This paper describes development of a cost report that is descriptive, logically oriented, and concise. Since the costs involved relate to mining, this reporting technique could help bridge any possible communications gap between "mining men" and computer personnel, at the same time giving the computer-oriented mining individual information to assist him in his job performance. As computers become entrenched in the mining world, meaningful report assimilation becomes a major task. No one should be more capable of defining required results than the man requesting a report. If he is able to clearly state his needs and has researched his problem, it will be reflected in the computer output. During 1970, The Anaconda Company's Berkeley Pit Operation, at Butte, Montana, received many different computer-generated equipment cost reports. Up to thirty-six different components for each type (class) of pit equipment contributed cost data to the Berkeley Pit cost system files for both operating and repairs during current month, year-to-date and accumulation-to-date time periods. This reporting approach was taken to facilitate analyzing this voluminous data. SUMMARY A Major Component Cost Analysis (Exhibits 6-A thru 6-C) developed by arranging the top ten operating and repair percentages (component cost divided by total cost) in descending order, and then accumulating these percentages to a possible one-hundred percent. While tabulating the operating and repair cost percentages by equipment unit number in the current month, year-to-date and accumulation-to-date time periods, a frequency chart is constructed for each equipment

Jan 1, 1971

By C. R. Montgomery

Coal companies in order to supply their customers En the metallurgical market, both home and abroad, must be able to control their production in order to meet carbonization specifications over and above those of the proximate analyses which has been the prime consideration of purchases in the past. It is the purpose of this paper to review in brief some of the tests used and give data to show the application of such as it applies to the customers needs. It is now recognized that coal is not homogeneous in any of its properties and an amazing fact is that it has been used for so long a time as the principal raw material for the manufacturing of coke without more emphasis having been placed on the variation between coals; yes, even from coals in the same seam at different geographical locations, Recently Kuchta and Clendenin pointed this fact out In a study of the(1) carbonizing behavior as related to chemical and plastic properties of Alabama medium volatile coal.

Jan 1, 1962

By Paul T. Allsman

The guiding principle in developing this plan resulted from evaluating potential future markets for oil, the quantity of mineable oil shale and the optimum rate of production comensurate with market demand on the available oil from shale. In addition, the rate of production may depend upon a solution to the problems of scarcity of resources other than oil shale. The rate of production finally will tend to establish the choice of technologies with these limits. The principle components discussed will be: 1) The place of oil shale among the various energy sources and its relative adaptability for use in the area of major consumptive demand. 2) A recalculation of the reserves and their classification on the basis of quantity, grade - gallons per ton, - and physical characteristics principally thickness, overburden and depth.

Jan 1, 1982

By Sandip K. Mukherjee

In underground mining operations, ventilation and water sprays are the common methods of controlling dust. In recent years there has been a proliferation of technical literature dealing with water sprays for dust control. However, guidelines for the design of an effective water spray system have not been presented to the mining industry. This paper reviews developments in water spray dust control technology and recommends guidelines for water spray systems to control dust in under- ground coal and non-coal mining operations. These guidelines suggest type, number, location and orientation of nozzles, desirable operating water pressure, and associated filtration system.

Jan 1, 1983

By Oluwasegun Samuel Odebiyi, Shaona Wang, Feng Gao, Biao Liu, Hao Du

Recovering vanadium from vanadium titanium-magnetite (VTM) ore using ( NH4)2C2O4 is a clean hydrometallurgical process, but the drawback is the low recovery and slow kinetics due to the formation of inhibitor. A novel energy-efficient mathematical model was derived for green leaching of VTM in which the mechanical activation (MA) removed the inhibitor “δ” (formation of impermeable product layer of CaC2O4) covering the reacting core of the CaV2O6 leaching process in ( NH4)2C2O4 solution. Before the MA processing, the formation of the CaC2O4 layer affects the kinetics (slow) and NH4VO3 leachability (low recovery). The dissolution rate enhancement and economic importance (in terms of leaching kinetic/recovery) of mechanical activation (MA) pretreatment in hydrometallurgical processing cannot be overemphasized. It is shown from the experimental and developed mathematical model results that the rotating speed of the ball mill (ωb) has a significant effect on the NH4VO3 recovery. At 360 rpm, the experimental result gave an 82% optimum recovery rate and a reaction rate constant of 0.01889s−1 with close correlation with the present models at 82.8% and 81% for liquid-to-solid layer diffusion and chemical reaction controls, respectively, with a reaction rate constant of 0.018883s−1. The close correlation between the experimental recovery rate results and the diffusion recovery rate model result justifies that the leaching process is diffusion control shrinking core kinetic with experimentally measured activation energy (Ea) value of 19.502 kJ/mol . This present model proved that MA enhances the dissolution rate regardless of the formation of a passivation layer on the material and best describes the kinetics of the MA hydrometallurgical processes compared to the shrinking core model.

Nov 3, 2023

By C. Okrusch, C. Roos, M. Akers, S. Rosenthal

Modern mining consistently faces controversy. Public sentiment impacts the permitting and development of mines, so a quality public relations (PR) program for mining companies may improve society’s impression of the mining industry. Developing mines face more permitting challenges than operating mines, which stems from a lack of societal trust given the history of mining and its impact on the environment. Two case studies were selected based on the type of public controversy they face to demonstrate how pervasive permitting issues are in industry. Both Pebble Mine, owned by Northern Dynasty Minerals (NDM), and Black Butte, owned by Sandfire Resources America Inc (SRA), experienced difficulties with their water permitting due to potential risks their mine developments posed to local fish populations. Pebble has, to date, failed in all of their attempts to become permitted due to concern for the water and the fish. Black Butte dealt with the same problems, on a smaller scale, but was able to become permitted. These two mines will be discussed in detail including local history, mine setting, mining history in America, prevalent culture groups, technology development, and intercultural communication competence (ICC). The mining industry needs to evaluate its ICC skills since ICC directly determines the effectiveness of PR. Based on Barna’s Stumbling Blocks for intercultural communication, methods for improving the mining industry’s PR will be suggested in the hope of easing the permitting process for future mines by developing ICC.

Mar 2, 2022

By John S. Anderson

The need for fuels and minerals in this country is estimated to double, triple, or even quadruple by the end of the present century. Even assuming more recycling of scrap metals and some priority allocation of energy, as has been done, for instance in war time, the projected increase in the nation's population and ever-increasing wants of that population will require vastly more minerals than are now being produced. Since mineral ores are being mined at lower grades, and since all minerals, including fuels, are having to be mined from deeper deposits, the amount of surface land to be disturbed will, inevitably, be increased. We cannot depend on foreign sources to supply all the extra requirements, since the non-U.S. population is increasing, in most cases, faster than our own. Furthermore, starting from a lower base, their mineral needs may accelerate more rapidly than ours. Restrictions on exports may be applied in foreign countries, if it appears that remaining reserves are not sufficient to fill the national needs. In vice; of the opposition which the mineral industry is receiving, as has been well described at these sessions and elsewhere, what can we, as mineral producers, anticipate as regards our ability to continue to operate, to sway nothing of expanding production? Although not minimizing the problems involved, it seems obvious that, except under emergency conditions, the country cannot tolerate a reduction in the available

Jan 1, 1971

Steady increases in longwall production have required operators to apply greater quantities of ventilating air in an effort to control and dilute respirable dust. Significant increases in shearer speeds necessitate that longwall supports also be advanced at a faster rate. Both of these factors may contribute to overall respirable dust levels on the longwall face because as supports are lowered and advanced, broken material falling from the top of the canopy is entrained directly into the air stream. To address this issue, the Pittsburgh Research Laboratory collected respirable dust samples from four longwall faces to characterize shield-generated dust. This paper investigates the influence of air velocity and shield advance rates on respirable dust levels. Also discussed are engineering controls currently used to reduce shield dust and alternative controls being investigated by the National Institute for Occupational Safety and Health (NIOSH).

Jan 4, 2010

By A. L. Crandell

The Cortez Mining District has had a long history of mining activity dating back to 1862 as previously reported (1) (2). More recently Cortez Gold Mines (i) has operated a cyanide leach, counter current decantation (CCD) recovery gold mill from January 1969 to February 1976. This type of plant has been standard in the U.S. for treating higher grade finely disseminated gold in Carlin type ores. The mill was initially operated from 1969 to 1973 at 1520 tonnes per day on oxidized ore from the Cortez ore body. Starting in 1973, the mill was operated at 2050 tonnes per day on softer, less oxidized, high clay ore from Gold Acres which is located 13 kilometers to the west of the Cortez installation. In February of 1976 the oxidized portion of the ore body at Gold Acres was depleted and the mill ceased operation. Successful heap leaching of the lower grade portion of the ores was practiced at both Cortez and Gold Acres to supplement the milling operations. Much valuable experience was gained in the operation of these two heap leaching programs and is well described in an earlier publication (3). Releaching of the ore heaps at Gold Acres and Cortez was continued with a limited crew from 1976 to 1979.

Jan 1, 1986

By Muhammad Kamran, NIAZ MUHAMMAD SHAHANI

This study elucidates a new idea to predict mine fire levels by employing several machine learning techniques. A total of 120 patterns of various mine fire influencing parameters, such as oxygen, nitrogen, carbon monoxide, and temperature, were compiled from the Adularya coal mine in Turkey. Techniques like t-distributed stochastic neighbor embedding (t-SNE) and k-means clustering were used to process the data, and support vector classification (SVC) was executed to predict various levels of the mine fire. The results revealed that the proposed model has higher credibility to predict the various levels of underground mine fires.

Feb 14, 2022

By J. S. Whatley

The properties, origin and industrial uses of kaolin clay are briefly reviewed. The general waterwashed beneficiation process is described. Yost aspects of filtration and solids-liquid separation as practiced in the kaolin industry are mentioned along with devices that are currently in the developmental stage. The paper focuses heavily on the well known art of rotary vacuum filtration, including general construction and operating details. Devices under investigation that might be used to mechanically or electrically dewater clay slurries to higher cake solids levels than can be achieved with rotary vacuum filters are described briefly.

Jan 1, 1986

By T. P. Meloy

Riffles on a shaking table have a major effect on particle separation. This effect is modeled in a spreadsheet.

Jan 1, 1993

By R. J. Thompson

Well-designed and maintained haul roads are the key to minimizing truck haulage onroad hazards and costs, as well as increasing productivity. In practice, however, designing and managing a haul road for optimal performance is often difficult to achieve, especially when resources assigned to design and construction are constrained. By understanding how a road design is developed from geometric, structural, functional and maintenance considerations and, critically, the interplay between these components in design and operation, optimal performance can be achieved. This paper briefly summarizes the evolution of mine haul road design, from the seminal USBM work of Kaufman and Ault in 1977, through to current geometric, structural, functional and maintenance management design components. These augmented design and management guidelines have been developed over the past decade, both in response to the requirements of mine operators for safer and more efficient haulage systems, the truck manufacturers’ requirements for a more predictable and controlled operating environment and the recognition of human factors as a significant contributor to haulage accidents. While the human factor is the most problematic to address in a road design, the paper shows that the more that is known about human error, the better a road can be designed to accommodate those actions or non-standard practices that would, on a poorly designed road, invariably escalate an error into an accident.

Jan 1, 2010

By Konrad J. Banaszak

At least for the time being, these seems to be general but not universal agreement that Mississippi Valley type ore deposits formed entirely or in major proportion from heated connate brines (e.g. 1) Even with that agreement, major questions remain. I will present a coherent geochemical model and look at alternative views in the context of that model. The pattern of the following discussion is 1) the general geochemistry of the ore fluid, 2) the density-temperature relations and possible mechanisms of flow of those fluids, 3) the mechanisms of transportation and deposition of the ore minerals, and 4) a summary of a coherent model of genesis. The data equivocally define much about the deposits. The answer is still elusive.

Jan 1, 1979

By J. Hupka

The limited effectiveness of the original hot water process for recovery of bitumen from certain Utah tar sands containing bitumen of higher viscosity (e.g. Sunnyside, Tar Sand Triangle)1,2 indicated that bitumen viscosity strongly' influences the separation efficiency. In this regard, there should exist a critical value of bitumen viscosity above which the effectiveness of the hot water process decreases significantly. Apparently certain tar sands contain bitumen of such high viscosity that even a digestion temperature of nearly 100°C is insufficient to lower the viscosity below the critical value. In addition it seems that differences in physico-chemical forces which act between sand and bitumen are negligible in comparison to the difference in visco-mechanical forces. Predominantly mechanical forces hold viscous bitumen on the rough surface and in the pores of sand particles, resulting in strong adhesion. This phenomenon is a critical feature in the phase disengagment of oil-wetted domestic tar sands with viscosity control by temperature. Besides increasing the temperature for viscosity control the effectiveness of the original hot water process could be enhanced by control of bitumen viscosity with diluent additions. Strictly speaking this appraoch is the only possibility for heavy bitumen for which the high temperature of digestion does not lower the viscosity sufficiently. As a result of viscosity control by diluent addition the digestion temperature can be lowered which is important from an industrial standpoint. Another important consideration is that effective phase disengagement occurs only when the entire bitumen phase has the same viscosity. This means that some time (penetration time) is necessary for complete and uniform dilution of the bitumen. If the viscosity of bitumen, which is a function of temperature, diluent addition and penetration time, controls the separation efficiency, hot water processing of many different kinds of tar sands should be possible, assuming that the sand phase consists primarily of quartz-type minerals.

Jan 1, 1982