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By James A. Deane

Strip mine reclamation Fs the process of restoring the land affected by the mining process to its most productive use. This can be timber production, pasture, crop land, wildlife and/or recreational use. The mining companies must determine, through the advice of their technicians, what the most advantageous use of the land will be. If the Company does not own the surface, the owner or owners must be contacted to determine their desires as to how the land should be reclaimed. Many times, in making the plans to restore an area with vegetative cover, the watershed and the quality of the water in the area is overlooked. The water itself must be an integral part of the reclamation plan. Many lakes and/or pits can be created with proper planning. In areas in the Midwest, where lakes are a scarcity, these strip mine lakes can become storage reservoirs for large amounts of water, They can help control runoff and low flow augmentation. The strip mining operation will affect the watershed regardless of whether a reclamation plan in made or not. It is up to the reclamation technician to see that the plan benefits the watershed instead of affecting it adversely. This can be done during the operation by intercepting the water before Pt enters the active pit. Diversion ditches above the highwall will handle the runoff water from the watershed. Water that does gain entry into the pit should be removed as quickly as possible. If the rules and regulations adopted by the Ohio River Valley Sanitation Commission in Resolution 5-60 are followed, water encountered during the operation can be handled with little or no adverse effect to the receiving watershed.

Jan 1, 1965

By William A. Vogely, Lawrence J. MacDonnell

This section begins with an introduction to several key environmental laws. This is followed by a discussion of some of the issues raised by such environmental regulation. Finally the subject of regulatory reform is addressed. Overview of Selected Major Environmental Laws The number, type and complexity of environmental laws and regulations affecting mineral resources development have grown at an astonishing rate since the 1960s. The most significant laws and regulations are those addressing the use of the public lands; those concerned with air quality, water quality, and surface reclamation; and those defining government responsibility for its actions having important environmental consequences. The laws and regulations governing activities on the public lands will be taken up in the section 5.15C, "Minerals and Land Management." In this section we will concentrate on five primary laws: the Clean Air Act, the Clean Water Act, the Surface Mining Control and Reclamation Act, the Endangered Species Act, and the National Environmental Policy Act. The Clean Air Act: The legislative and regulatory framework for controlling air pollution has developed in a series of steps. Most important for present purposes are the Clean Air Act of 1970 (P.L. 9 1-604) and the 1977 Amendments (P.L. 95-95). The rather complex air quality control scheme includes four key elements-national ambient air quality standards, state implementation plans, the prevention of significant deterioration program, and the non- attainment program. National Air Quality Standards. The 1970 Clean Air Act is a landmark law because it contains the first explicit recognition that pollution is a nationwide problem requiring a national control program. The federal government through the Environmental Protection Agency (EPA) was to establish national air quality standards for at least the six pollutants named in the Act (sulfur dioxide, carbon monoxide, total suspended particulates, photochemical oxidants, hydrocarbons, and nitrogen dioxide). These standards were to be established so as to protect public health, "allowing an adequate margin of safety." The cost of achieving these standards is not to be considered. The 1970 Act unrealistically required that these standards be achieved in all areas of the country by 1975. As the program has developed, the air quality control regions are now to be designated as "attainment" or "nonattainment" with respect to each of the national standards. State Implementation Plans. Under the Act the states are given the primary role in achieving the ambient standards. States are to develop and implement control plans governing emissions from all existing and new sources. These plans can include emission limitations for existing stationary sources, transportation control plans to reduce emissions from mobile sources, and pre- construction review of new stationary sources to assure compliance with new source performance standards. The EPA must approve all state implementation plans. Sanctions are given to the EPA to be applied if states fail to submit acceptable

Jan 1, 1985

By Ronald L. Wiegel

The United States produces approximately 40 mil- lion tons of phosphate rock per year. Most of this rock is converted to diammonium phosphate and used as a fertilizer component for the domestic and international agricultural market. Much of this phosphate rock production is concentrated in the southeastern United States, with about half coming from washing and screening operations and half from flotation separation from sand and clay. This paper summarizes current operating practice in the industry and touches on some of the emerging technologies required to solve the problems associated with a diminishing high- grade reserve and the need to implement dolomite/francolite separations on a commercial scale.

Jan 1, 1999

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 Norman F. Schulz

The technical excellence of separation achieved in a mineral concentration process, or any other process where two constituents of any kind are physically separated from each other, is expressed uniquely and quantitatively by the Separation Efficiency: ES = (R ? Rg) where R is the percentage of the valuable constituent and Rg the percentage of the waste appearing in the concentrate. The Separation Efficiency meets all the usual requirements of a true efficiency and is independent of the nature of the process used. It can be visualized as the percentage of the feed material that, in effect, actually undergoes complete separation while the rest of the feed is distributed randomly and unchanged into the two separation products.

Jan 1, 1969

By Jeff W. Butwell

Mill flotation tailings impounded at the Gooseberry Mine site between 1976 and 1984 were determined to be an economic source of gold and silver recoverable by standard heap leach technology in conjunction with feed agglomeration. Metal recovery at 85 percent Au, 75 percent Ag is attained on properly agglomerated (pelletized) tailings which average 85 percent -75 micron. Because the impounded tailings averaged over 18 percent moisture (32 percent moisture maximum at depth) in place behind the storage dam, the mining method, mixing and agglomeration technique, and materials handling practice were major considerations in making this operation a financial success.

Jan 1, 1990

By J. M. W. Mackenzie

Three major developments have dominated the recovery of gold from ores, viz; 1846 Elsner's studies of gold solubility in aerated alkaline cyanide solutions 1887 MacArthur and Forrest's process based on zinc precipitation 1980+ Large scale development of the CIP process The brevity of this list for a metal whose extractive metallurgy has been as widely studied as any metal reflects the fact that the chemistry of the gold recovery process, as opposed to the engineering has seen few significant breakthroughs in over a century of application. to The purpose of this paper is introduce a new chemistry for gold recovery which may, in the future, add significantly to the technology of gold recovery. This new chemistry is based guanidine functionality - (R2R2N) 2 C = N R2 on the In developing the use of the guanidine functionality for the recovery of gold as the aurocyanide anion from leach solutions and pulps, Henkel has, as its objective, the development of an effective gold selective ion exchange resin. As will be seen, the initial investigation of the properties of the guanidine functionality in the solvent form for gold recovery lead to some significant metallurgical developments of their own but, the foremost objective was, and remains, the development of a resin for gold recovery. As a part of this development project, Henkel has entered into association with Mintek, South Africa, and this ongoing association has the potential to develop RIP/RIS technology for the gold industry. More details on Henkel's gold recovery technology and Mintek's role in this programme are given in (1). an The application of ion exchange resins to gold recovery is not new and many reviews have been published on the advantages of this process, and on the current state of the art of gold recovery by ion exchange resins. (2)(3)(4) Widespread application of ion exchange resin based processes for gold recovery has, however, not occurred to date. Fleming and Cromberge (5), described some significant pilot plant RIP trials in South Africa and the partial success of these pilot plant trials held out the tantalising possibility of a breakthrough in gold recovery based on RIP technology. Despite this pioneering work, only two really significant applications of RIP technology for gold recovery exist today. These are the Golden Jubilee Plant in the Eastern Transvaal South Africa and the widespread, although in some respects technically backward, use of ion exchange for gold recovery in the former USSR. There are two main reasons for the current scarcity of RIP and RIS plants used for gold recovery. These are: 1. 2. The perceived problems of engineering RIP plants The lack of a resin having suitable chemistry for both gold loading and gold elution The problems of engineering RIP plants have been largely overcome in the last 25 years. Much of the development in RIP plant design took place in the uranium industry during the rapid expansion of that industry in the mid 1970's. In addition, the development of CIP engineering systems has lead to the development of in-pulp solid extractant based metallurgical plant designs which can, with limited modification, be adopted to RIP. The lack of a resin having suitable chemical properties has almost certainly been the main reason for RIP/RIS not being introduced into the gold industry over the past decade. Attempts to use RIP/RIS have focussed on either conventional we ak base or conventional strong base resins. The weak. base resins have the disadvantage that they

Jan 1, 1993

By Antti J. Niemi

Radioisotope tracers have so far been used for extraction of residence time distributions of flotation devices. They have also been proven applicable to evaluation of rate coefficients k of industrial flotation. It is now shown how values of k are scaled up on the basis of laboratory data on flotation and chemical conditioning, and of laboratory testing of samples from output of industrial conditioning vessel. Subsequently a model of conditioning and flotation is obtained which may be used for simulation and control of the steady state of the combined process. Discussion extends to modelling, simulation, CAD and opti- mization of flotation plants with re- circulation, and of ore dressing systems which consist of grinding and flotation plants.

Jan 1, 1990

By S. Dixon

The use of warm (40-50°C) solution for the selective elution (pre-strip) of copper cyanide from gold and silver cyanides adsorbed on activated carbon was found to elute +90% of the adsorbed copper compared to the use of ambient (20°C) solution eluting 50-70% of the adsorbed copper. The warm solution pre-strip elution did have higher co-elution of gold (1-4%) and silver (10-18%) with the copper. The use of ambient solution pre-strip elution co-eluted less gold (0.2%) and silver (2%).

Mar 2, 2022

By J. W. Wilson

In the ultrafine coal cleaning process, small coal particles (-400 mesh) are produced during the pulverizing operation. After the coal cleaning process, these ultrafine particles are very difficult to dewater, and create problems in coal transportation, storage and handling at utility plants. Research work on ultrafine coal dewatering and briquetting has resulted in the development of a single stage operation that is potentially more effective and economic than conventional thermal drying and briquetting processes. The final coal product have a moisture content of less than 15% and possess high strength and water resistance that satisfies coal transportation, storage and handling requirements.

Jan 1, 1995

By Lawrence E. Mannion

In southwest Wyoming lies buried the world's largest source of natural sodium carbonate, or soda ash. Perhaps a hundred billion tons of trona (sodium sesquicarbonate) are contained in ancient lake beds in the Green River basin'). There the Green River Formation encloses more than 40 extensive beds of trona. At least 25 of these exceed 3 feet (1 meter) in thickness and most of them are more than 300 square miles in extent. Five have been exposed in mines and lie between 800 and 1500 feet below the surface. Others lie at depths of from 400 to 3500 feet. Three companies have underground mines that supply trona to adjacent soda ash plants. These are the FMC Corporation, Allied Chemical Corporation, and Stauffer Chemical Company. A fourth, Texasgulf Corporation, has a mine under development. In 1974, annual soda ash capacity in the Green River area was approximately 4,300,000 tons, which requires the mining of about 7,500,000 tons of trona.

Jan 1, 1975

By Don Macfarlane, Brian Heer, Tom Martin

The Manapouri Power Station, commisioned in 1969, is located in Fiordland National Park in the South Island of New Zealand. It is the country’s largest hydro power scheme and can generate 700MW of electricity. The power station utilizes the hydraulic head of Lake Manapouri, using an underground power station and a 10 km-long tailrace tunnel was constructed by drill-and-blast to allow discharge to Doubtful Sound. Power generation fell short of expectations due to higher than expected friction in the tailrace system. To remedy this a second tailrace tunnel was constructed between June 1998and May 2002. It consisted of a 10 m diameter, 10 km long tunnel in predominately gneissic rock and was excavated using an Atlas Copco Robbins TBM. High water inflows, Owner/Contractor production incentives and a major claim settlement were handled during the 5 1/4 year project. This paper discusses TBM advance rates, utilization factors that increased in the second half of the project plus an innovative method for sealing Tunnel 1 to construct the bifurcation.

Jan 1, 2003

By M. E. Buzon, M. E. Gunter

Talc has been the focus of recent civil litigation based on claims that asbestos minerals exist in talc deposits and therefore have caused asbestos-related diseases in those who have regularly used talc products. Such litigation, and ensuing confusion over the petrology and asbestos content of these deposits, challenges the talc mining industry in Montana and elsewhere in the world. The talc deposits in southwest Montana were formed by hydrothermal alteration of dolomitic marbles and are still actively mined. In general, talc formed by hydrothermal alteration of preexisting carbonate rocks is known to be nearly monomineralic and lacking in amphiboles. This paper includes data from analyses of representative ore samples from this mining region in southwest Montana. The results conclude that the presence of asbestos minerals — both amphiboles and chrysotile — is unlikely and that the ores are nearly monomineralic, as expected. Samples were characterized using a suite of analytical methods, namely, powder X-ray diffraction, X-ray fluorescence spectroscopy and electron microprobe analyses, which allowed us to determine the minerals present and the formation process. Our data and interpretations suggest that previous identification of asbestos minerals in these deposits is not accurate.

Jan 1, 2018

By M. E. Buzon, M. E. Gunter

Talc has been the focus of recent civil litigation based on claims that asbestos minerals exist in talc deposits and therefore have caused asbestos-related diseases in those who have regularly used talc products. Such litigation, and ensuing confusion over the petrology and asbestos content of these deposits, challenges the talc mining industry in Montana and elsewhere in the world. The talc deposits in southwest Montana were formed by hydrothermal alteration of dolomitic marbles and are still actively mined. In general, talc formed by hydrothermal alteration of preexisting carbonate rocks is known to be nearly monomineralic and lacking in amphiboles. This paper includes data from analyses of representative ore samples from this mining region in southwest Montana. The results conclude that the presence of asbestos minerals — both amphiboles and chrysotile — is unlikely and that the ores are nearly monomineralic, as expected. Samples were characterized using a suite of analytical methods, namely, powder X-ray diffraction, X-ray fluorescence spectroscopy and electron microprobe analyses, which allowed us to determine the minerals present and the formation process. Our data and interpretations suggest that previous identification of asbestos minerals in these deposits is not accurate.

Jan 1, 2017

By C. J. Bise, M. F. Sindelar

Regulations, such as the MINER Act of 2006, require the installation of redundant and secondary communication systems to assure that contact can be established with coal miners who may become trapped underground as a result of an event such as a fire, explosion or inundation. For half a century, the orientation towards underground communications has been that more complex systems better serve the coal miner. However, if a goal is to provide for an alternative means of establishing communication between the surface and trapped miners underground, then some of the technology employed should be simple, reliable and cost-effective. Coal mines spend hundreds of thousands of dollars on exploratory drillholes to characterize reserves, sometimes decades ahead of mine development. During the pre-mine planning phases, certain exploratory drillholes could be located and then outfitted with a simple communication link that would remain compatible with the continuing evolution of communication systems. Inexpensive links, whose locations would be accurately recorded, would be exposed by continuous miners during mine entry development, thereby allowing an underground phone to be connected to a surface station in the event of an emergency. A latent network of these communication links could be installed for less than $500 each, minimally affecting drilling and grouting operations, and could be designed to be compatible with many communication devices. This research examines methods and materials for incorporating an embedded communication link during pre-mine exploration drilling, addresses significant factors affecting its implementation, and presents a recommended design. Since mine plans are known to change, the objective is to minimize cost so that, if not used, the investment is minimal for a potential secondary means of communication between the surface and underground workings.

Jan 1, 2014

By S. Makni, R. E. McIvor

Grate discharges historically outnumbered the overflow type of industrial wet ball mills. However, overflow discharge mills now strongly dominate. In order to understand their comparative advantages and disadvantages, Corem carried out a broad review of this topic. Where the data made it possible, the Functional Performance Equation was used to separate circuit classification from mill grinding effects. Batch tests were conducted in a torque-metered mill at different slurry levels. This paper presents the outcome of these investigations, which is a very strong case for the industry to once again consider grate discharges.

Feb 1, 2023

By H. B. Trinh, R. R. Srivastava

"Spent auto-catalyst is a potential secondary resource because of the higher concentration of valuable platinum group metals (PGMs) as compared to the primary ores. Despite the well-developed commercially tenable technologies, further researches are being carried out to extract the PGMs with high efficiency. It is however, critical in this context to reuse not only the PGMs but also other metals contained in the spent auto-catalyst particularly that of the cordierite substrate such as aluminum, magnesium and cerium oxide (CeO2). This is important in view of the fact that no recycling process has ever stressed upon the recovery of cordierite substrate and CeO2 since the main target metals are mostly the PGMs. In this study, a new hydrometallurgical approach has been proposed in order to recover the PGMs as well as cerium oxide and materials from the cordierite substrate by using sodium hydroxide roasting followed by sulfuric acid dissolution. Under the optimal conditions for roasting at above 600°C, and weight ratio of sample to NaOH of 1:1 for 60 min, the cordierite was converted to the soluble phases. Dissolution of the roasting products using H2SO4 solution (1M) at 25°C for 60 min enriched the PGMs and Cerium oxide contents in the residue. Subsequently, PGMs in solution after dissolution can be cemented using Al and Cerium oxide in residue can be recovered by hot digestion using concentrated H2SO4.. INTRODUCTION Auto-catalyst can significantly control the gaseous emission of automobiles, and has been considered as a potential secondary source of Platinum group metals (PGMs) after being decommissioned from the vehicles. The PGMs demand is continuously increasing to comply with the growing vehicle population and the tightening of emission standards all over the world; meanwhile the natural resources of these metals is facing the threat of depletion. Therefore, it is crucial to progressively substitute with an alternate resource to supply PGMs other than that of the primary ores. Nowadays, vehicular transportations worldwide are totally installed with the auto-catalysts. However, they should be replaced after reaching their service life. If there is no recycling of such resources, huge amount of valuable metals will be wasted. The quantity of PGMs that can be recovered from the spent auto-catalyst depends on the size of car, which averages to 1-2 grams for small cars and 12-15 grams for the big truck; this is significantly higher than that of the primary ores containing 2-10 grams PGMs per ton. Consequently, the recovery of PGMs from spent auto-catalyst becomes extremely favorable as compared to the primary resources due to higher concentration of PGMs, with much lower and simpler processing steps, and lesser pollution."

Jan 1, 2018

By Thos. B. Douglas

In 1907, the Oklahoma Portland. Cement Company built a small dry process plant at Ada, Oklahoma, then Indian Territory. This plant was later acquired by the Ideal Cement Company of Denver, Colorado, who in 1918 built a new wet process plant along side the old dry plant. The older plant was later shut down .and eventually razed. In 1955, the Ideal Cement Company decided to increase the production at its Ada, Oklahoma operations. After many studies it was decided to build a complete new plant along side the old, near the site of the original 1907 plant. .The new plant was to have a. production of three million barrels annually while the plant then in. operation had an annual production of two and one quarter million barrels

Jan 1, 1961

By John D. Price

In the constant search for ways and means of improving the quality of coke and thus making its use at the blast-fornace more satisfactory and economical, it has become increasingly evident that the present laboratory tests do not show the full picture of a coke's value as a blast-furnace fuel. This fact was recognized by Dr. A. C. Pieldner thirty-five years ago: (Ref. 1) here is perhaps no phase of fuel technicology which has aroused more discussion or regarding which there is more difference of opinion than the properties of coke which make it most suitable for blast-furnaces and other uses." Dr. Fieldner followed this assertion with a statement to the effect that men who write on this subject today (1923) have, because of conflicting experimental evidence brought forth in recent years, far less positive opinions on the matter than did writers of some years past. One is led to wonder if these statements are not just as true now as they were when first made.

Jan 1, 1959

By B. Weaver

Every year Pit & Quarry Magazine surveys the industry to produce their annual review. Here's a sampling of some of the statistics the survey produced from the end of the year 1994 survey.

Jan 1, 1995