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By F. D. Fox

Abandoned mill tailings deposits can be found scattered throughout the Northern Black Hills of South Dakota, indicative of past mining activities that originated during the great gold [ERRATA SHEET RESTORATION OF GOLD MILL TAILINGS, BLACK HILL, SOUTH DAKOTA 84-119 F. D. Fox Under subtitle Prospects Related to Present and Future Tailings Disposal Practices, include reference No. 12 in paragraph seven after "construction of the Grizzly Gulch tailings disposal project,"12 Reference 12 should read: Jeffries, Lawrence F. and Tczap, Andrew, "Homestake's Grizzly Gulch Tailings Disposal Project," paper presented at 1978 International Mining Show, October 11, 1978.]

Jan 1, 1984

By C. W. Owings

"PURPOSE OF REPORTMany bituminous coal-mine officials realize that coal dust presents an ever-present coal-mine explosion hazard, and that persons forced to breathe large quantities of it may be more subject to respiratory infection than persons working in less dusty atmospheres. As an outgrowth of the realization that coal dust should be allayed at its source, many mining companies have expressed the desire to install dust-allaying equipment, and in a number of mines, water or wetting solution is being applied on the cutter bars of mining machines, on mobile loaders, belts or conveyors underground, and tops of mine cars. Spraying equipment also has been installed on dumps to allay dust during dumping operations. Dust-allaying equipment has not been standardized, however, because manufacturers have found that many prospective purchasers of such equipment have different ideas. These manufacturers wish to standardize, so far as feasible, the types and placement of such equipment. Many mine officials, although interested, do not know the best or most effective methods for allaying dust.For a number of years the Bureau of Mines has advocated allaying dust by applying water or, more recently, water modified by a wetting agent on the cutter bar of mining machines and by applying water to loaded and empty mine cars in order to keep as much dust as possible from spilling onto the haulage roads. In recent years this Bureau has also advocated applying water with or without a wetting agent during mechanical loading of coal and during unloading of coal from trackless cars or buggies and from elevating conveyors. It has now become apparent that specific arrangement of pipes, hose, and nozzles should be standardized to at least some extent. It is the purpose of this report, therefore, to give in detail suggested arrangement of dust-allaying equipment in the hope that both manufacturers and mine officials will have available dust-allaying equipment with maximum efficiency to do the desired work."

Nov 1, 1945

By J. M. Stuve

Low-temperature heat capacities and the enthalpy of formation were deter-mined calorimetrically by the Bureau of Mines for CuO?CuS04. The derived standard entropy (S°298.15) was 40.36±0.04 cal/deg-mole, and the enthalpy of formation (?H°f) was -219.l±0.3 kcal/g-mole. A large thermal anomaly was observed in the heat capacity of CuO?CuS04 at 20±0.1 K. Gibbs energy of formation data are tabulated up to 1,200 K. Construction details of a precision low-temperature adiabatic calorimeter capable of determining heat capacities of solids in the temperature range 5 to 320 K are given. A calibrated miniature germanium resistance thermometer was incorporated into the calorimeter to extend the range of accurate measurements below 15 K. High-resistance dc heater windings were used throughout the cryostat to reduce heat conduction of inner connecting wires.

Jan 1, 1975

By Maureen M. Foss

Underground coal mining is hazardous due to changing geological conditions. One geophysical method showing promise for in-seam hazard detection is ground-penetrating radar (GPR). The Bureau of Mines recently completed preliminary studies to demonstrate the feasibility of using GPR for in-seam hazard detection. Investigations included air and coal tests for the purpose of checking equipment accuracy, coal penetration, and other factors such as the effects of receiver orientation. Further investigations involved using both a short pulse and a new prototype synthetic-pulse system to locate a clay vein in a coal seam using trans-illumination. Data were gathered on multiple travel paths, and a back projection processing technique was then used to create a tomographic image using the calculated velocities. A computer model of the same coal seam was subsequently processed using the same tomographic tech-nique, and the results were compared with those of the actual data. Analysis of the tomographic images shows the presence of the clay vein, although its boundaries are unclear due to the tomography method used. Results of these preliminary studies show that GPR is feasible for use in in-seam hazard detection and point the direction that future research should take. A need has been shown for research involving more sophisticated tomography techniques, transmission studies on thicker coal seams, and reflection studies using the synthetic-pulse system.

Jan 1, 1987

By S. Yaw Amponsah, E. Ben-Awuah, P. M. Takouda, P. Eme

Mining production scheduling is the process of determining the sequence of block extraction over a period of time that will yield the maximum net present value for a mining operation. The block extraction sequence needs to occur under certain resource constraints which presents an NP-hard problem that is computationally intractable and complex to solve for large scale problems using exact mathematical models such as Mixed Integer Linear Programming (MILP). In this paper, we used a metaheuristic optimisation model based on a Genetic Algorithm (GA) to solve the production scheduling problem. The problem definition and resource constraints are formulated using a mining specific GA that enforces block extraction precedence and mining capacity constraints through a normalisation method. A case study is implemented with the GA model, and the results and computational time are compared with that of a MILP model with CPLEX solver which is based on a branch-and-cut algorithm.

Sep 1, 2021

By Bernard Porter, E. A. Brown

Electrical conductivities and densities of the LiF- UF , LiF- ThF4 , NaF - C1F4 , and NaF - ThF systems were measured as functions of composition and temperature . The specific conductance and density varied linearly with temperature . Molar and equivalent volumes , as well as heats of activation for conductance , were calculated from the experimental data . At 1,000 ° C , the molar volumes ranged from 16 to 40 cubic centimeters per mole and the specific conductance ranged from 9.8 to 2.5 per ohm- centimeter as the actinide metal fluoride concentration changed from 0 to 60 mole - percent . Heats of activation for conductance were 3 to 7 kcal per mole . The data are interpreted on the basis of a semilattice model for the melts .

Jan 1, 1964

By Otto Ruhl

"INTRODUCTION With the conclusion of the war and the ensuing readjustment of industry to peacetime conditions, the Bureau of Mines recognized that definite and complete figures on the reserves of zinc and lead ores in the Tri-State District would be needed for an evaluation of the problem of reconversion. In October 1945 its engineers began examination of all the mines and pros¬pects in the Tri-State area and assembling of the basic data for a complete detailed estimate of the reserves of the field. Six to twelve months will be required to complete the report with the personnel available; therefore, it has been deemed advisable to provide as much data as possible for imme¬diate use. Accordingly, a confidential report prepared in January 1944 for the use of and in cooperation with the War Production Board has been brought up to date to form the basis of this preliminary estimate of reserves.The 1944 report has been revised by first subtracting from the reserves then set up for each mill group the amounts mined and milled by those properties for 1944 and 10 months of 1945, with November and December estimated. These production statistics were taken from the monthly reports of the Metal Economics Division of the Bureau of Mines. The remaining reserves were then adjusted by additions of tonnages of new reserves disclosed by developments during the years 1944 and 1945. Such additions were based upon the data furnished by various operators, upon estimates supplied by the Federal Geological Survey District Office at Miami, Okla., and upon estimates of the engineers of the Bureau of Mines Joplin field office.It is apparent from the work so far accomplished in the detailed exami¬nations now under way that the final estimate of reserves will probably be somewhat greater and will differ to a certain degree from these preliminary totals, not only as to the tonnages of ere but also as to grades and distribution by areas. This is due to the fact that all the factors of development, exploration, and geology are being considered in the present examination and report for each individual mine and prospect, whereas the previous reports covered only the immediate development factors surrounding each mill group then in active operation or projected for operation at some early date in accordance with the possible needs for war production."

Aug 1, 1946

By H. W. Kilau

The U.S. Bureau of Mines is evaluating water spray additives for the purpose of improving respirable dust control during coal mining operations, with particular emphasis on the longwall shearer. Recent field tests of surfactant-polymer reagents at two production longwall operations have shown favorable respirable dust reductions compared with water sprays containing no additive. Gravimetric dust samples obtained by a technician downwind of the shearer while following or preceding the machine showed dust reductions in the range of about 40% to 60% for some of the reagent formulations compared with using water alone. Three polymers were tested: two polyethylene oxide compounds of different molecular weight and hydroxypropyl methylcellulose (HPMC). All were effective for dust reduction, and two were cost effective when used in combination with sodium di(2-ethylhexyl) sulfosuccinate surfactant. How-ever, the use of these reagents requires the longwall operator to be more aware of headgate dust control. Experimental evidence indicates that dust captured by reagent-treated sprays at the shearer can be reemitted in the headgate area if stagcloader-crusher sprays and other dust controls are inadequate.

Jan 1, 2010

By X Zhang, B McFadzean, C T. O’Connor, S Pikinini

The Platreef in South Africa contains one of the world’s largest reserves of platinum group elements. One of the major platinum group minerals (PGM) components in this ore is sperrylite (PtAs₂), which has been found to be slow floating compared to the other PGMs. In a study aimed at determining the reasons for the poor floatability of sperrylite and to improve its recovery, tests were carried out to determine the interactions of the mineral with a range of standard and novel collectors. Microflotation tests were carried out to determine the hydrophobicity of the minerals before and after adsorption of collectors. In addition, experiments were carried out to determine the enthalpy and extent of collector adsorption on the minerals and to investigate electrochemical interactions between sperrylite and selected standard collectors. The results indicated that poor collector adsorption was the major cause for the poor floatability of sperrylite. Sperrylite had both poor natural (14.5 per cent) floatability and collector-induced flotation recoveries, the highest recovery of 26 per cent being observed using PNBX collector at pH 9. Moreover, the rest potential tests showed that the interaction of sperrylite with standard collectors such as xanthates was poor. The decrease in potential after the addition of the standard collectors ranged from 7.9 mV to 24.9 mV under alkaline conditions. Furthermore, sperrylite rest potentials remained unchanged with a change in pH from basic to acidic, indicating its resistance to surface alteration. Surface alteration of the minerals is key for the chemisorption of collectors to take place on the mineral surface. This was further emphasised by flotation recoveries at low pH, where only certain collectors responded positively to a decrease in pH and these were shown to have undergone a structural change. This work has highlighted the difficulties associated with sperrylite flotation and provides some direction for future research.

Aug 24, 2022

By Rajesh Kumar Mishra

About 500,000 troy ounces of Platinum Group Metals (PGM) will be available for recycling each year from spent automobile catalytic converters in North America alone. Platinum Group Metals? from spent catalyst can be extracted by Hydrometallurgical, Pyrometallurgical or Gas Phase volatilization processes. This paper is a review and comparative study of various processes investigated for PGM extraction. A number of processes described in this paper have already been commercialized. The technical and environmental aspects of the important processes are discussed.

Jan 1, 1989

By Joel N. Van Sant

The rapidly expanding economy of the West, with its growth of heavy industry, and increased steel production, is primarily responsible for the refractory clay industry's concern over the adequacy of the clay supply in States of the Great Plains and Rocky Mountains. Hence, the investigation by the Federal Bureau of Mines of the occurrence and use of refractory clays in North Dakota, South Dakota, Nebraska, Wyoming, Colorado, Utah, New Mexico, and Arizona has been encouraged by the major consumers and producers of this commodity. The Wyoming investigation is a part of the national program devised to close gaps in the domestic supply of specific types of clays to determine their characteristics and properties and to provide information that will assist the refractory-clay industry. Forty-two locations of clay-bearing rock in 17 areas in Wyoming were examined (fig. 1). Location 3 was not examined during this survey. Its description was taken from an earlier report. Locations 20, 21, and 22 were previously reported but were, also, examined by the Bureau. No samples were collected from these locations because field examination indicated that the shales were not refractory grade. The Hulett, Aladdin, and Newcastle areas are discussed in the section on the Black Hills district; the other 14 areas are described separately.

Jan 1, 1961

By H. I. Smith

THE recently developed potash industry in southeastern New Mexico, though based on a relatively new discovery, marks the latest and perhaps culminating phase of the effort to obtain a domestic source of potash that began with the leaching of wood ashes more than 300 years ago. In the search for mineral potash in America, the Geological Survey has played a conspicuous part and has paved the way for much of the private activity that now bids fair to free the nation of foreign domina¬tion in supplying the nation's potash requirements. HISTORICAL REVIEW A pamphlet published by Thomas Stephen in 1758 pictures the industry in its early struggling condition.1 Just before the Civil War, a deposit of mineral potash had been found in Germany and its value as a fertilizer had been discovered. On this account and because the supply of wood ashes had decreased, the Ameri-can potash industry gradually lost its importance. During the next 50 years, with European potash available with little effort and with satisfactory substitutes on the market for the manufacture of soap, the interest of the American people in American potash declined. In 1910 this interest was suddenly revived by the abrogation of American potash contracts in Europe. Congress passed an act, approved by President Taft March 4, 1911, providing for "researches with a view to determining geological conditions favorable to the presence of deposits of potash salts." Appropriations were made to the Geological Survey and the Bureau of Soils to carry out the provisions of this act. The work of the Survey was directed toward the finding of commercial bodies of natural soluble potash salts; the Bureau of Soils was more concerned with the processes of extracting potash from industrial wastes and organic sources. Private agencies also became interested in the program. The Geological Survey has continued its search throughout the ensuing period of more than 20 years and has studied many types of deposits in many parts of the country.

Jan 1, 1933

By J. B. Hadaway

The operation at Phu Kham commenced design and construction in early 2006 and was commissioned in May 2008. This paper will examine and discuss the project from the inception of flow sheet development and equipment selection, equipment design and manufacture, construction, commissioning and ramp up to full production. The paper will touch on the strategies employed to achieve a short schedule and the efficient use of capital, but with the main emphasis on the grinding circuit. Various challenges during the early years of operation will be discussed including the effect of ore characteristics, including competency, on the performance of the grinding circuit. Actions to overcome these challenges and to enhance performance will also be discussed. Finally, current and future plans to improve the performance of the grinding circuit and the overall plant will be summarised.

Jan 1, 2012

By E. D. Gardner

During the summer of 1935 a plan was proposed by which the Government should establish custom sampling plants for gold and silver ores in the mining districts of the West, where the construction of such plants would be justified as an unemployment relief measure. It was known that in many districts prospectors and small operators had small lots of smelting ore that could not be marketed for lack of sufficient capital to get out enough ore at a time to make carload shipments to distant smelters. Moreover, considerable ore of milling grade was available in many districts in which there were no custom milling facilities. It was felt that. accurate sampling and the classification and consolidation of small lots of ore produced from prospects and small mines, with quick cash returns to the shippers on a nonprofit basis, would stimulate the working of small gold and silver properties: Idle mines would be put to work, and there was a possibility that some of the prospects could be developed into regularly producing mines. Each sampling plant was to be centrally located so as to serve the greatest possible number of mines and prospects. Wherever possible, the plants were to be built on a railroad, is ore of smelting grade accumulated, it was to be shipped to a smelter in carload lots. Where a plant was not on a railroad, smelting ore was to be trucked to the railroad after being sampled.

Jan 1, 1936

By Robinson Newcomb

Gypsum is a form of hydrated calcium sulfate (CaS04.2H20) which is widely distributed over the earth's surface. The two varieties worked commercially are rock gypsum and incite. Rock gypsum, the variety commonly mined for commercial purposes, is a relatively soft mineral having a specific gravity of about 2.3 and weighing about 150 pounds per cubic foot. The chief producing States are New York, Michigan, and Iowa. Before being used the crude gypsum is ground and generally calcined. The predominant use of gypsum is for building purposes (the manufacture of plaster), for which calcined gypsum is required. Gypsum is also used as a retarder in Portland cement, as fertilizer, and for other purposes. GYPSUM MINING Crude gypsum is mined by two methods - underground and open-pit. Although the use of the former method predominates, open-pit mining increased in relative importance during the early twenties and contributed about two-fifths of the output during the period 1925-38.

Jan 1, 1940

By V Mutton, L Potts, D Joyce

This paper describes the method of extracting sill pillars within the underground operation from under unconsolidated mullock fill at the Cracow Gold Mine. This pillar recovery method was initially successfully used to recover sill pillars at Crusader Mine, Western Australia in 2001. Globally significant resources have been sterilised due to the placement of loose rock fill above crown pillars and within adjacent stopes. The method described here offers significant opportunities to increase recovery of sill pillar recoveries.The royal orebody sill pillars at Cracow Gold Mine form a significant resource. Extraction of these pillars needed to be undertaken with minimal ore dilution and maximum ore recovery. The application that was selected to consolidate the loose mullock fill above each pillar used an injection grouting process (Minova FB200).Cracow Gold Mine mining method is bottom up bench mining. The pillars were left within the orebody to allow for stoping to commence whilst the decline was being developed. Due to the remainder of the orebody being extracted the only access to consolidate the backfill was from the sill pillar extraction level. Numerous problems were encountered and overcome from product selection and trial, system of injection to extraction.This pillar recovery process achieved a 95 per cent recovery of the sill pillar compared with an estimated 60 per cent typical for other mining options.CITATION:Potts, L, Mutton, V and Joyce, D, 2012. Pillar recovery at Cracow gold mine using grouted consolidated mullock, in Proceedings Narrow Vein Mining 2012 , pp 179-184 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Mar 26, 2012

By Steve Karl

President Reagan may be "a nice guy," but he is "misinformed, misdirected, and misadvised," when the subject is the state of the US copper industry, according to Sen. Dennis DeConcini (D-AZ). DeConcini took the opportunity as keynote speaker at the Arizona Conference AIME in Tucson to fire a few salvos at the Reagan Administration's industrial policies. "American copper used to stand above the rest of the world," he said. Now 21,000 copper workers, about half of the total, are out of work due to less expensive foreign imports. "Those 21,000 are real people, not statistics," he said. US production has been cut to one-third of its capacity, he said. And the Administration shows no signs of changing its position to favor US copper protection. "Third world copper towns are booming," he continued, "while ours are dying." Regardless of profits and despite oversupply, Chile continues to produce, he said. And, while US mines continue to close, "the International Monetary Fund (IMF) is handing more than $1 billion to six copper producing countries." President Reagan wanted $8.6 billion from the IMF. "I'm damn mad about it," DeConcini said. "For the life of me, I can't understand how this Administration can stand by while this industry is brought to its knees." Last year, the International Trade Commission ruled that imports were injuring domestic copper and recommended relief. The President, DeConcini said, vetoed those recommendations. DeConcini softened his tough talk a bit saying the President's image makes it difficult for people to not like him or stand up to him. "How can anyone stand up to President Reagan?" he asked. "He's such a nice guy. But it's time someone did. He's just misinformed, misdirected, and misadvised. We must take real action and we must have a president who understands this." DeConcini said he has introduced legislation aimed at helping domestic copper. It would limit copper imports to 385 kt/a (425,000 stpy). Imports now stand at about 635 kt/a (700,000 stpy). The bill would also impose a $0.33/kg ($0.15-per lb) duty on foreign copper. DeConcini called the duty a sort of "environmental equalizer" because that is the amount domestic producers must spend on pollution control devices. Foreign competitors do not have such controls, he said. "I face people who are damn mad that this country is being pushed around," he concluded. "It's time we stand up and say we can be competitive. If they (foreign countries) put an import duty on our stuff, we will do the same. It's time this country stopped being the nice guy." As if to underscore domestic copper's desperate situation described by the Senator, Duval Corp. announced about the same time as the meeting that it has nearly closed its eastside office in Tucson. Staff has been reduced from 120 to four. Spokesman Dean Lynch said the four will consist of President A. Everett Smith, a secretary, a person in environmental affairs, and another in purchasing. Duval is also selling an office and a laboratory in Tucson. Pennzoil Co., Duval's parent, has been trying to sell the company for more than a year. It began dismantling Duval in November 1984. Pennzoil took over its subsidiary's profitable sulfur operation in Texas, sold the New Mexico potash facility, and spun off gold interests in Nevada, forming Battle Mountain Gold. Northwest Mining Association - Spokane Rock Jenkins, Associate Editor The true role of minerals needs to be realized by both the policy makers and the people of the US, according to Robert Dale Wilson, director of the Office of Strategic Resources, US Commerce Department. In addition, a re-thinking of the theory of free trade and competitive advantage is necessary. Wilson made his remarks in December at the opening luncheon of the 91st Annual Convention of the Northwest Mining, Association in Spokane, WA. At a later press conference, Wilson said one of the mining industry's main problems is that its presence in Washington has been reduced in the past few years. Part of this can be seen by events within the American Mining Congress (AMC), he said. "The problem with AMC," Wilson said, "is that in 1981, when Reagan came in, no problems were seen for mining and a lot of their (AMC's) lobbyists were let go." He

Jan 1, 1986

By G. Merle, David L. McKay, Elmar Randveer

"THE ENGINEERING AND TECHNICAL SERVICES department is responsible for supplying the following services:1. Administration and co-ordination of the work required for capital projects.2. Engineering, design and drafting services for inplant changes or improvements as requested by the operating• and maintenance departments.3. Rock mechanics.4. Preparation of plans and layouts required for efficient extraction of the ore as mutually agreed with the mine operating departments.5. Mine planning and long-term schedules in co-operation with the mine operating departments.6. Grade control (long term and short term) and the preparation of ore and waste removal schedules to maintain a uniform grade of mill feed. This also includes the calculation of metal reserves and metal production forecasts.7. Surveying, underground and surface.8. Operations research at the mine site.9. Industrial engineering.10. Chemical analyses and assays.11. Instrumentation.12. Environmental control.A staff of approximately 35 supervisors, engineers and scientists, and 80 technicians, supply the foregoing services. Consulting engineering and drafting firms are used to supply specialized services and technical personnel in-house at Timmins to handle overloads on capital projects under the direction of Ecstall engineers.The operating and maintenance departments depend on the engineering department to supply engineering, design and drafting services for any new facilities or for any planned alteration to existing facilities. To do this efficiently requires a high level of communication and co-operation with these departments. This has been a major factor in developing the present organization of the department shown in Figure 63.The organization is predicated on a strong central technical and engineering resource from which personnel can be assigned responsibilities for different projects, and in different areas, as the work load demands. Job satisfaction is very high because of the variety and challenge in the tasks. Additionally, participation in projects with production and maintenance personnel broadens each technical employee's knowledge of operating and maintenance problems."

Jan 1, 1974

By P. D. R. Maltby

This paper describes the background and markets for calcium carbonate and silica sand in Canada, as well as the results of recent test work carried out at the Ontario Research Foundation. Tests on sericite, tremolite, vermiculite, barite and graphite are also mentioned.

Jan 1, 1979

By J. C. Edwards

The Bureau of Mines developed a mathematical model for analysis of the impact of scrubber bed length, porosity, and gas flow rate on the absorption of C02 in a breathing apparatus. The model accounts for the decrease in available absorbent through chemical conversion. The pre-dicted efflux of C02 from a canister containing LiOR compared favorably with measured values reported elsewhere. It was determined from a com-putational study that the time for breakthrough of C02 at a prescribed level is nearly directly proportional to bed length and inversely pro-portional to gas flow and porosity.

Jan 1, 1987