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By Yeonuk Choi, Patrick R. Taylor, Lyle Cunningham

Laboratory experiments have been performed to evaluate the potential for metal removal and recovery from river bed tailings by ferric chloride leaching. The lead, zinc, silver and other metals in the river bed occur due to the old method of dumping mill tailings into rivers. This was practiced prior to the introduction of tailings impoundments. The effects of the leaching method, leaching time, pulp density, ferric chloride concentration, and leaching temperature on the rates and recoveries of lead, zinc and silver were studied. The effects of pulp density and leaching temperature were significant on the extraction rates of lead, zinc and silver. The lead content in the leached tailing was reduced to 0.023 percent, when using an 353O K leaching temperature and 0.384 g of FeC13/1 g of sample.

Jan 1, 1992

By E. J. Peuraniemi, J. T. Yli-Penttilä, A. Jokilaakso, K. M. Riihilahti

Dust formation and the reaction mechanisms of copper matte particles were investigated in simulated flash-oxidation conditions. The granulated and ground matte consisted of 72% Cu, 4% Fe and 21 % S (by weight). Experiments were conducted by using a laminar flow furnace with a reaction-gas composition ranging from 20% to 75% O2 (by volume) in nitrogen. The particle feeding was carried out by a single-particle method, and samples were quenched after a specified reaction time ([~] 0.05 to 0.4 s) in a cold water film. Experimental temperatures ranged from 800o to 1,300o C. Chemical analysis was used to determine the degree of oxidation, and optical and scanning electron microscopes, combined with energy dispersive analysis, were used for characterization of the reacted particles.

Jan 1, 1999

By Changwoo Lee

Under drastically deteriorated situations, diesel equipment was introduced to some of local coal mines, aiming at higher productivity and better safety. To accommodate various diesel equipment in conventionally developed mines, mining system itself had to be modified; much larger trackless haulage ways were excavated. Possible health hazards of diesel not taken into account at the beginning become a serious concern and effective control measures are being searched for. The purpose of this paper is to study the diffusion characteristics of diesel exhaust in local coal mines. One of the parameters affecting dispersion of diesel contaminants is the coefficient of turbulent diffusion. Since CO2 is known to be closely correlated with other contaminants such as CO, NO, NQ, SO2 and RCD, it was chosen as a tracer gas in a series of dispersion experiments. A large diesel passage as well as a conventional track haulage way were the sites for the experiments. Rectangular dispersion pulses were generated for 30 ~60 seconds and CO2 concentrations were recorded at several locations 50~190 m downwind. The diffusion coefficients calculated graphically vary between 0.10~0.48 m2/s at both haulage ways. The results are analyzed to find any correlation with the air velocity and the distance from the disperser. Skobunov's empirical formula is applied to the experimental data for comparison and the relationship between Reynolds number and Ex/Dp/sci0.4 Sc1…

Jan 1, 1995

By Kim A. Lapakko, William W. III White

The ASTM standard method D 5744-96 was developed to provide a well-defined kinetic test protocol, conducted under controlled reaction conditions, with the intent of generating reproducible results. The US Bureau of Land Management, American Assay Laboratories, and the Minnesota Department of Natural Resources cooperated in a intralaboratory and interlaboratory testing of the protocol. Intralaboratory testing was conducted on duplicate samples of gabbro (8) and siltite-argillite (5) rocks for periods of 20 to 125 weeks. The difference between replica& intralaboratory pH readings on drainage from the gabbro for the drip-trickle leach alternative typically did not exceed 0.1 units, although differences as high as 0.4 units were observed. The difference from the mean for rates of sulfate, calcium and magnesium release was typically within 10%. Intralaboratory results for the siltite-argillite samples were generally similar, although a one unit pH difference was observed for one sample. Three different laboratories tested a gabbro sample for 125 weeks, with a maximum difference from the mean pH of 0.5 units. The percent difference from the mean for sulfate and calcium release rates was typically within lo%, although values as high as 30% were observed. Data on intralaboratory and interlaboratory agreement on the flood rinse alternative of the method were limited. Replication on the sample tested was comparable to of better than that observed for the drip-trickle method testing of the same sample.

Jan 1, 2000

By Richard G. Almes

Since the failure of a major coal refuse disposal embankment and impoundment in the Buffalo Creek watershed near Man, West Virginia in early 1972, there have been extensive changes in the design and construction requirements for coal refuse disposal facilities located throughout the United States. The primary emphasis has been on improving the safety of these facilities, particularly for impoundments which are capable of storing millions of gallons of process water and storm runoff. The Mine Safety and Health Administration (MSHA) of the U.S. Department of Labor (formerly the Mining Enforcement and Safety Administration, U.S. Department of interior) has been the lead federal agency in promulgating regulations pertaining to coal waste disposal. In 1974 and 1975, studies were undertaken by our firm under contract to the Mining Enforcement and Safety Administration to prepare a comprehensive engineering and design manual to be used by operators and engineers in the planning and design of coal refuse disposal facilities with the intent ion of avoiding any more Buffalo Creek failures. The resultant 800-page document addresses major subjects such as safety, environmental controls, and cost. Specific topics include characterization of coal refuse, classification of disposal facilities, project planning, geotechnical investigations, testing and design requirements, hydraulic and hydrologic design, environmental factors, operations, and monitoring, instrumentation, and maintenance.

Jan 1, 1980

By H. Huang, R. N. Gow

"In Part I, Gibbs’ phase rule was applied to mass-balanced EH-pH diagrams for the Cu-As-S-H2O system. The diagrams were generated using the stoichiometry of enargite as a basis. In this study, the calculations were expanded to cover the stoichiometries of three other Cu-As-S minerals – tennantite, sinnerite and lautite – and compared with enargite. Stability regions within the resulting EH-pH diagrams were found to change with stoichiometry such that a particular mineral would predominate if its stoichiometry was used in the calculation. Solution speciation was also found to vary, with thioarsenate being the best example. This stoichiometric effect helps to explain results reported in the literature and would be difficult to realize if it were not for mass-balanced calculations. IntroductionA comprehensive thermodynamic review has been conducted on the aqueous copper-arsenic-sulfur (Cu- As-S) system (Gow et al., 2014, 2015a, 2016b; Gow, Huang and Young, 2016c). Data on the free energies of more than 100 species were collected from various authors, and thermodynamic databases collated to produce mass-balanced EH-pH diagrams using the thermodynamic equilibrium calculation software STABCAL (Huang, 2014). The full database is listed and discussed in Gow et al. (2015a). Diagrams were generated for enargite and confirmed with Raman spectroscopy using bulk mineral electrodes in order to identify reactions spectroelectrochemically. Theoretical calculations agreed well with the experimental results under alkaline conditions (Gow et al., 2015a), acid conditions (Gow et al., 2014) and alkaline sulfide leaching conditions (Gow et al., 2015b).In the present study, additional mass-balanced EH-pH diagrams were generated by changing the Cu-As-S stoichiometry from enargite (Cu3AsS4) to tennantite (Cu12As4S13), sinnerite (Cu6As4S9) and lautite (CuAsS). Regions for the thermodynamically stable species were shown to change with the four different mineral compositions. Potential leach conditions, both for co-dissolution and selective dissolution techniques, were examined for differences in predominant species according to changing copper-to-arsenic ratios, sulfur compositions and sulfur oxidation states."

Jan 1, 2016

By Richard M. Tinlin

Some of the practices of the mining industry that may place an undesirable stress on the groundwater environment are coming under increasing scrutiny from legislators and regulatory agencies. Among these practices are mine dewatering, the use of tailings ponds, land rehabilitation, and technological innovations such as in situ leaching of waste clumps and ore deposits. Pernichele, noting that 24 states have enacted legislation controlling to varying degrees the environmental effects of mining, has emphasized the importance of assessing the potential for damage to groundwater when evaluating, planning, and designing mining projects. 1 Illinois has enacted legislation requiring anyone opening, operating or abandoning a mine site to obtain a permit from the Illinois EPA. The law is one of the first to require regular monitoring and reporting to a control agency. Legislation has also been recently enacted at the national level that will have a significant impact on the mining industry; e. g., the Federal Water Pollution Control Act Amendments of 1972 (Public Law 92-500). The stated objective of this Act is to restore and maintain the chemical, physical and biological integrity of the nation's waters. Specifically, according to Sec. 102(a), the Administrator of the U.S. Environmental Protection Agency (EPA) is required to prepare or develop comprehensive programs for preventing, reducing or eliminating the pollution of the navigable waters and groundwaters and improving the sanitary condition of surface and underground waters. The definition of the terms "pollution" and "pollutant" is of particular significance to those who must comply with PL 92-500. The definitions are quite broad and include most of the adverse water quality effects of man's activities. As defined in Sec. 502(19), "pollution means the man-made or man-induced alteration of the chemical, physical, biological and radiological integrity of water." Within the Act, the list of pollutants includes dredged spoil, solid waste, incineration residue, chemical wastes, radioaetive materials, heat, wrecked or discarded equipment, rock, sand, cellar dirt, and industrial waste discharged into water.

Jan 1, 1973

By R. L. Grayson

For the years 1990 and 1991, West Virginia's underground coal small-mine fatality rate « 20 employees) was approximately ten times higher than the national coal industry rate. Although the total number of fatalities decreased to 17 in 1992 (from 22 in 1991), West Virginia still led ,the nation in coal mining fatals. A team of mining and safety professionals from West Virginia University studied the problem over the past year, interfacing with the Mine Safety and Health Administration and the West Virginia Office of Miners' Health, Safety and Training. A clear path for 'formal intervention was determined and is presented here.

Jan 1, 1994

By William C. Paschen

Damen Avenue to Roosevelt Road, the Tunnel and Reservoir Plan (TARP), a Deep Tunnel Project for the Metropolitan Sanitary District of Greater Chicago consists of 25,189 lin. ft. of 32 ft. tunnel with 1 ft. 0 in. concrete liner throughout. The 17,100 ft. main tunnel connects at both ends with two other Deep Tunnel contracts. A branch tunnel connecting to the mainstream tunnel, commences approximately 4,140 ft. from the construction shaft and runs 8,089 ft. south and terminates at the Racine Avenue Pumping Station. Shaft work consists of one 28 ft. 6 in. diameter construction shaft, one 3 ft. 6 in. diameter access shaft and 25 drop shafts-four of which have vent shafts. The drop shafts vary in diameter from 4 ft. 0 in. to 17 ft. 0 in. All shafts vary in depth to invert from 225 ft. to 235 ft. Work has been underway for 16 months and as of this writing the construction shaft and access shaft are complete. Seven shafts have been excavated and concreting operations have started in four of them. The starter tunnel is complete, the mining machine has mined 250 lin. ft. and the muck removal system is in full operation. The contractor for the project is a joint venture of Paschen/Morrison-Knudsen/Kenny. Paschen Contractors, Inc., Chicago, Illinois is the sponsor. The total contract amount is $107,837,300.00.

Jan 1, 1979

By J. Payton

Public Service Company of Oklahoma began burning sub-bituminous coal in December, 1979. Initially PSO had a single source coal supply from Jacobs Ranch Mine, and in 1982 added deliveries from Clovis Point mine. Both are Powder River Basin (Wyoming) coal mines. In 1986 PSO began burning Oklahoma coal to meet Oklahoma's 10% native use law. PSO experienced random s lagging during certain blends of these coals. PSO installed a boiler performance system to help control the slagging problems from the various coal blends, to improve boiler efficiency, and increase total coal consumption.

Jan 1, 1990

By R. Miller

Lowering our globe’s emissions is a major effort as we move toward a future net-zero carbon environment requiring significant investment in a new, low-carbon infrastructure, along with key market incentives to change. Industry will play a key part in this transformation, requiring expertise in both energy and emissions. Key elements of the de-carbonization strategy are: energy data, emissions reporting method, governance, de-carbonization project generation and drivers, the MACC, electrification, and the de-carbonization checklist. For a zero carbon future, it will be key for business leaders to understand decarbonization, anticipate technological changes, and implement new business me

Mar 2, 2022

By F. Ysla, M. Mendoza

This proposal, based on the CIEMAN Cajamarca - Hualgayoc initiative, focuses on “Transforming Abandoned Mine Lands’’ We aim to study and assess the feasibility of an innovative rehabilitation method. Contaminated soils will be moved from the upper to the lower site, encapsulated with geosynthetic barriers, and covered with topsoil. The decontaminated upper area will be used for planting trees and large-stemmed plants for hiking and tourism, while the lower encapsulated area will support livestock and short- stemmed crops. This study will evaluate the economic viability and multi-use potential of this technique, promoting sustainable land recovery in Cajamarca, Peru.

Feb 1, 2025

By J. D. Miller

Fluid flow phenomena and therefore the flotation efficiency of air-sparged hydrocyclone (ASH) flotation are strongly dependent on the operating and design variables such as air flow rate, slurry flow rate, underflow and overflow opening areas, percent solids in the feed, reagent levels, particle size, ASH length, etc. Time-averaged multiphase flow characteristics, as deter-mined by x-ray CT and described in a previous publication, are used to understand and explain the steady-state ASH flotation of quartz. A detailed parametric study of quartz flotation by a nominal 2-inch diameter air-sparged hydrocyclone (ASH-2C) revealed the influence of these variables on the flotation response which is discussed in terms of the multiphase flow characteristics. Thus, a phenomenological description of quartz flotation has been established to assist in the further development and utilization of the ASH technology.

Jan 1, 1995

By L. L. Oriard

There are certain site-specific geological and physical features of a rock mass which control its behavior under the dynamic stresses induced by the action of explosives. It is essential that blasting technology be adapted specifically to those features. There does not exist a single, simple "right" way for each type of blasting operation, but rather each operation must be custom-designed for each site. When this is done, it is often possible to produce unusual but highly desirable end resglts, such as undisturbed narrow rock walls, monoliths and square benches. Although the techniques illustrated here were developed specifically for "sculpture blasting", the geomechanics principles would apply to other types of blasting control, both large-scale and small-scale. Because the techniques are designed more for the purpose of modifying the site responses which would ordinarily be expected than they are to developing new "blasting formulae?, the name "Modified Site Response Blasting" will be used.

Jan 1, 1984

By T. K. McMahon

Formally, a mathematical model could be defined as: A set of equations whose solution will approximate the response of a physical process or system to a set of stimuli which appear as parameters in the equations. The purpose of a mathematical model is to permit the rationalization of experience to proceed by simulation rather than by physical experimentation. In the application of digital computer control to an industrial process, the mathematical model of the process (subsequently called the process model) is needed to calculate the present process performance from the measured variables and to predict the response of the process to a control change. Functionally, the cardinal element in process model development is a concise set of control objectives. These, besides implicitly defining the boundaries of the system to be modeled, will determine the accuracy demanded of the model its nature: dynamic or steady-state, and so forth, The objectives should explicitly define what process efficiencies, production rates, qualities are to lie within the scope of the computer control project, thereby providing a basis for simplifying assumptions in the development of the model. This requirement, a limited set of control objectives, is so often disregarded in formulating industrial control problems that its repetition can scarcely be avoided.

Jan 1, 1965

By Biswajit Samanta, Rahul Kumar, Pranjal Pathak

The Open Pit Mine Production Scheduling Problem (OPMPSP) is a complex optimization problem that seeks to determine the best sequence for extracting mineralized material from the ground in order to maximize the Net Present Value (NPV). This process must take into account various capacity constraints, such as mining rates, processing limits, stockpiling capacities, blending requirements, and precedence constraints, which dictate the order in which blocks can be extracted. Traditionally, the OPMPSP has been formulated as a mixed integer programming problem, employing binary and continuous variables to represent the extraction of each block. However, this approach has limitations, particularly when it comes to addressing the stockpiling issue. In response, some researchers have proposed mathematical models, which offer a more accurate representation of the problem but come with their own set of challenges. In this study, an alternative approach to tackle the OPMPSP with stockpiling by employing constraint programming (CP) is explored. The method was carefully tested on the Newman1 dataset from the well-known Minelib library. The results show that the CP-based model obtained a production schedule having about 2.69 % higher NPV than the NPV of the solution, which is recorded in the Minelib Library.

Jun 25, 2023

By Robert M. Dreyer

The first time that a geologist is confronted with the necessity of evaluating a lateritic ore deposit, he may feel that nothing could be easier. Why should there be any problems in making an economic evaluation of a relatively flat-lying, surficial ore body? After several hundred thousand dollars worth of frustrating work often culminating in a series of non-reproducible data - the evaluator may be a sadder and wiser man. This paper will try to illustrate why the evaluation of lateritic bauxite and nickel deposits is among the most difficult problems confronting an economic geologist - and, more especially, how this problem can be solved. Volumes have been published on descriptive and genetic studies of lateritic ores. Obviously, there is time today only for the briefest description of such an ore body. The laterite is a soil formed under tropical conditions and resulting in the concentration, within the soil zone, of certain tri-valent metals.- especially, aluminum and nickel. The soil zone is divided into two parts: (a) the true soil or lateritic zone and (b) the zone of, partially altered bed rock or saprolite. It is important to remember that, whereas bauxite generally is confined to the laterite zone, nickel deposits occur in both the laterite and

Jan 1, 1977

By L. Xinguang

Shandong MinMetals Corporation, a state-owned import and export organization located in the city of Qingdao, Shandong Province, China, was opened in 1954, with the mission of marketing metal products and industrial raw material in oversea areas for hard currency to support the modernization project of the country as well as the province. The management officers are appointed by the provincial government, and report to the Foreign Trade Department of Shandong Province. Meanwhile, the company also receives guidance from MinMetals head office in Beijing, the capital city of China. The head office does not own and control any provincial MinMetals organizations, but merely coordinate business among provinces.

Jan 1, 1990

By S. J. Cohen

Changes in our energy, national security, and commerce needs have necessitated identification of new sources of minerals, such as rare earths, lithium, copper, silver, aluminum, titanium, and the minerals on the U.S. Geological Survey’s (USGS) list of critical minerals (USGS, 2022). With the need to domestically produce these minerals, more mining will be required within the U.S. Some of these critical minerals deposit with naturally occurring radioactive materials (NORM), therefore, mining these minerals may concentrate NORM to the point that some states may require licensing and radiation protection programs. NORM is not regulated by the Federal government; it is regulated by the individual states. Consequently, overall national state of NORM regulation is chaotic with each individual state either choosing to regulate or not regulate NORM, and, if a state chooses to regulate NORM, then that state develops its own unique regulations. Further complicating the regulatory environment, states utilize a wide variety of strategies for regulating NORM, which sometimes results in inappropriate regulations, inconsistencies with specific radionuclides that are regulated, and inconsistencies with specific NORM types that are regulated. This paper will review the nature of NORM regulations, identify regulatory traps, and provide general guidance for identifying NORM and potentially avoiding regulatory jeopardy. Because of the chaotic nature of NORM regulations nationally, seeking guidance from qualified professionals with relevant expertise is recommended. Also, contacting the appropriate regulatory agency to gain a complete understanding of the NORM regulatory environment is useful for maintaining compliance.

Feb 1, 2023

By Corey Vaughan

Unplanned shutdowns from abrasive wear part failure in crushers, chutes, and slurry pipe assets can cost millions in lost production and reactive maintenance. 2Censor patented sensor technology enables real time abrasive wear monitoring of mineral processing equipment, turning passive assets into smart, data driven components. Wireless sensors embedded in liners and pipework transmit wear data live to operators, allowing for predictive maintenance, safer scheduling, and optimized asset life. This paper will present global case studies showing reductions in downtime, increased throughput, and improved maintenance accuracy. The system is ready to retrofit, neutral to original equipment manufacturers, and proven across more than twelve countries in abrasive wear liners and slurry pipe applications.

Feb 22, 2026