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By Frank J. Wiebelt

Work on the Abbott-quicksilver property was part of the general program of th~ Bureau of Mines in its investigation of domestic mineral resources, which are essential to national defense or industry and of which our present or probable future supplies are inadequate. The mine was discovered in 1862, and the intermittent production up to 1947 has totaled around 37,500 flasks of quicksilver. Output has come from ore shoots formed in the vicinity of fault intersections in a narrow zone composed of lenses of silicified serpentine breccia interbedded with shale. Work by the Bureau included the drilling of six diamond-drill holes aggregating 2,845 feet. Several possible ore zones were intersected by the drill holes. Field work was begun in April 1948 and concluded in October of the same year. This report gives detailed results of the diamond drilling and a brief account of the history and description of the ore deposits.

Jan 1, 1949

By Edward D. Thimons

As U.S. mines go to greater depths, the high temperatures and humidities characteristic of such depths make it difficult to maintain a comfortable environment in working areas. Better techniques for cooling these deep working areas are needed. At the Homestake gold mine in South Dakota the Bureau of Mines has tested a water spray cooler inserted into the fresh air vent tube entering a warm stope. The cooler supplied more than 6 tons of refrigeration to the stope air, which dropped from an inlet temperature of 83° F dry bulb and 75° F wet bulb to 73.5° F dry bulb and 71.5° F wet bulb. These preliminary results show the water spray cooler to be a feasible concept. However, there is a need for substantial refinement and further testing, and work on the concept will be continued under contract to the Bureau.

Jan 1, 1979

By Fred C. Turin, Lisa J. Steiner, Kim M. Cornelius

Like many experienced workers, remote control continuous miner operators perform their everyday jobs making choices and decisions that they may not consciously think about. While performing tasks, they are continuously processing feedback and cues which guide them for the next move. Initial training teaches the operators the tasks necessary to operate the equipment and perform the job. However, with experience they are better able to deal with hazardous conditions and non routine situations. To better understand what potential cues and feedback help to guide the operators, a questionnaire was developed to learn what factors affect decisions. Operator responses address issues related to specific tasks, equipment operation, visibility, lighting, and communication issues. The information collected is useful to understand what cues experienced operators use to make task performance decisions. Results will be used to develop interventions and training for safe and effective operator performance.

By John Paul Gries

During World War II, when the curtailment of imports led to an unprecedented demand for domestically produced mica, beryl, and other pegmatitic minerals, the Bureau of Mines and the Geological Survey entered upon a program designed to expedite the production of these minerals from the Black Hills area of South Dakota. The program involved mapping, sampling and drilling many pegmatite dikes found in the southern portion of the area and beneficiation tests in the field and in the Bureau of Mines laboratories at Rapid. City, S. Dak., Rolla, Mo., Salt Lake City, Utah, and College Park, Md. This paper describes the mode of occurrence and the sampling and beneficiation tests on one dike, the Helen Beryl pegmatite, which was investigated as part of the general pegmatite study in South Dakota. Investigation of the Helen Beryl Pegmatite by the Bureau began in August 1943 and was terminated in April 1944. During this period the Bureau took a series of bulk samples from pits for beneficiation tests, drove an adit through the center of the dike to obtain feed for a bulk-sampling plant operation, and finally drilled a series of long holes to sample the deposit further. Geologists of the Federal Geological Survey mapped the deposit and the faces of all excavations and logged drill holes from sludge samples recovered from long-hole drilling.

Jan 1, 1949

By R. W. Stahl

One of the broad purposes of the Bureau of' Mines since its establishment has been conservation of mineral resources. As some of the coal beds approach depletion, especially those coals suitable for making metallurgical coke, more and more attention is being given to means of recovering a larger percentage of coal in place. The customary system of mining in the United States is by room and pillar, or some variation thereof, which leaves pillars of coal to support, the roof. In many operations, where the pillars are not systematically recovered, the loss of coal often amounts to 50 percent or more of the original deposit. In many instances in developing new mines, It is planned to recover chain and barrier pillars on retreat when the mine has reached established boundaries. Too often, however, mines are abandoned for some unforeseen reason before completion of mining without recovering any pillars. Usually, these pillars are lost forever. With this in mind, the Mining Division, Region VIII, of the Bureau; of Mines is encouraging mining by longwall methods. It is a generally known fact that almost all of the European coal is mined by longwall methods, which are conducive to a high percentage recovery of coal. A comparison between mining systems usually is on the basis of tons per man per shift. Unless all operating conditions are similar, such a comparison could be misleading. Generally, the output per man shift in European longwall mines is less than that obtained in room-and-pillar mining in the United States. In European mining, maximum recovery of coal is not only mandatory but it must be accomplished without major damage to surface by subsidence. These restrictions necessitate packing or stowing with consequential increases In manpower and decreases in output per man shift.

Jan 1, 1954

By Robert W. Freedman

The Bureau of Mines investigated methods of analysis of free silica in respirable dust, including both work done at the Bureau of Mines and work done elsewhere. The review covers both coal dust and noncoal dust, taking into account both existing and proposed chemical and spectroscopic procedures.

Jan 1, 1971

By Joan T. May

The Federal Bureau of Mines investigated the potential for recovering aluminum from copper-dump leach liquors by use of single-contact ion-exchange technology. A strongly acidic ion-exchange resin was used to extract aluminum from a typical dump leach liquor and from synthetic leach liquors. Aluminum was stripped from resin with a HS04 or NaCl solution. Bench-scale experiments indicate that a single-contact ion exchange is technically feasible, but that the process is limited by the relatively low loading capacity of the resin and the excessive amount of stripping agent required. A further limitation is that significant amounts of magnesium and iron are loaded and stripped along with the aluminum.

Jan 1, 1976

By D. W. Richardson

This Bureau of Mines publication provides the enthalpy of formation of malachite [Cua(COs)(OH)2] as determined by hydrochloric acid solution calorimetry. At 298.15 K the enthalpy of formation from the component oxides is -15.l0±0.30 kcal/mole and from the elements, -251.9±0.5 kcal/mole.

Jan 1, 1974

By S. R. Borrowman

Mill tailings from conventional uranium extraction processes contain nearly all of the radium originally in the ore. Such tailings require controlled storage in perpetuity to safeguard the surrounding environment from radioactive contamination. Alternatives to controlled storage of the tailings are (1) removal of the radium from the tailings for separate storage or use or (2) removal of the radium when processing the uranium ore. In laboratory tests conducted by the Federal Bureau of Mines, radium was leached from tailings using either hydrochloric acid or ethylenediamine tetraacetic acid. A hydrochloric acid leaching method was used to extract both radium and uranium from the ore to yield tailings containing less radium than those produced by either conventional sulfuric acid or alkaline leaching processes. From 77 to 94 percent of the radium in mill tailings was concentrated by sedimentation in slime fractions representing nearly 25 weight-percent of the original sample.

Jan 1, 1975

By R. V. Ramani

"In Part 1 of this two-part paper the characteristics of mine disasters and their effects are presented with case studies from coal, metal and non-metal mines leading to an amplification of their causes and opportunities for control. The disasters discussed encompass those which threaten the health and the safety of miners and those which affect the general population. In Part 2 of the paper, which will be published in the November 1995 issue of Natural Resources Forum, the approaches to hazard and disaster control are reviewed with particular attention to laws and regulations to promote health and safety at the workplace, and general welfare in mining communities. Further, a systems approach to disaster control is outlined.The mining industry is one of the three basic industries the other two being agriculture, and wildlife and fisheries. It is the process of mining which makes available the riches of the earth - the energy and mineral resources - to benefit humanity. In fact the progress of the human race through the ages is indelibly attached to prowess in exploiting these riches. The stone, iron and bronze ages are markers not just of a time in history but achievements of monumental proportions in the mining and beneficiation of natural resources. Even in agriculture, the remarkable success stories are associated with the prudent use of mined products to enhance production and productivity. The significance of a thriving mining industry to the wealth and security of a nation is therefore unquestioned.Unfortunately, the public's image of the mining industry is often associated with the mining disasters which receive wide coverage in the local and national media. Mine disasters command tremendous attention because of their infrequent occurrence and the extent of human suffering involved. Whether it is an explosion or a fire, or the opening or closing of a mine, the lives of people are touched by the personal and societal impacts of these events.Courts of inquiry of mining disasters have often concluded that the disaster situation was ever present and could have been detected with diligent search. In addition human error has been identified as one of the most frequent immediate causes for the precipitation of the disaster. For the most part, then, mining disasters are caused by man."

Dec 1, 1996

By Len Blackman

The Absaroka-Beartooth Study Area is a tract of approximately 1.4 million acres of National forest land in southern Montana, part of the Greater Yellowstone Area. This study evaluated the mineral potential of four mineral terranes containing undiscovered resources in the area. The geological data is probabilistic, with estimates of the possible number: of deposits and their grades and tonnages. Possible future development scenarios range from no development to many mines, including some very large. As two thirds of the study area is within the Absaroka-Beartooth Wilderness, the future development scenarios reflect the area's mineral potential, not what we expect to see in the foreseeable future. Based on the analysis performed on these four terranes, the most likely future scenario for the study area would include the potential for two medium sized, (predominately) gold, mines, each employing a few hundred workers. There is a small chance, less than 5%, that a large Porphyry Copper or Superior Iron deposit would be discovered and be economically feasible to develop.

Jan 1, 1994

By H. D. Pallister

A review of? reports and literature on the pyrite deposits at Pyriton, Ala., indicated that a large tonnage of pyrite, some of which contained a small amount of copper, had been mined and shipped to fertilizer plants throughout the South. The information contained in this literature tended to demonstrate that the ore occurred in separate lenses of greater or less extent and of varying thickness and richness in pyrite as well as in copper. The outcrop being parallel with the Atlantic Coastline Railroad and just south of it makes the deposits readily accessible for shipment. Slopes could be sunk as they were in the past in the ore body if it were of sufficient grade and thickness, and the ore could be hoisted up the slope and milled close to the slope mouth with an ample supply of water from Talladega Creek, which follows the outcrop closely.

Jan 1, 1949

By S. E. Khalafalla

The Bureau of Mines investigated variations in the activation energy for the carbon monoxide reduction of magnetite and ferrous oxide with respect to the state of aggregation of the oxide material. Reduction phenomena can only be satisfactorily explained by including an adsorption step in the reduction process. Summation of the values of the exothermic heat of chemisorption and the variable apparent activation energy for reduction yields a nearly constant value of about 50 kcal for either ferrous oxide or magnetite regardless of whether they are aggregated in pelletized form or coarsely crystalline particles.

Jan 1, 1965

By E. P. Youngman

Except possibly by individual natives and Liberians (small specters), is now being carried on in Liberia, according to a late report. definite information is obtainable with respect to the mineral resources of e country, except that iron ores are said to be abundant. Tin, copper, zinc, site, corundum, lead, bitumen or li nite, and diamonds have all been re- parte, but no commercial Geposits are known to have, been found. Gold has been duce, but not in significant amounts, as may be inferred from the customs - rt for Liberia recording the exportation of gold to the value of $4.80 Germany from the port of Cape Mount in 1925. It is not uncommon for atives to come into towns with African gold and valuable minerals, but they e reluctant to sive information concerning then. Some years ago the Liberian Government was seeing a loan in return for oil concessions, but apparently no drilling bea boon don

Jun 1, 1932

By Benjamin W. Haynes

As part of the first-order assessment of potential manganese nodule processing reject waste materials, the Bureau of Mines estimated the physical and chemical characteristics of reject waste materials that would be generated from each of five potential process flowsheets. These processes were chosen because of their economic and technical feasibility for first-generation nodule processing. A brief description of the five processes is given to show process inputs and outputs, The physical characteristics are predicted based on land-based laterite processing where applicable, and where no land-based analog exists, on the basis of process chemistry. The probable chemical characteristics such as element content and compound form are tabulated for each process for 16 elements: As, Ba, Be, Cd, Go, Cr, Cu, Fe, Mn, Mo, Ni, Pb, Sb, Se, TI, and Zn. These elements were chosen based on their presence on the toxic substance list of priority pollutants, EP toxicity criteria, and major and minor elements of economic importance (Co, Fe, Mn, and Mo). Physical and chemical analyses as well as results of the EP toxicity test of one industrially supplied pilot plant reject waste material are presented.

Jan 1, 1982

By W. P. Yant

A previous report of the Bureau of Mines dealt with the toxicity of dichlorodifluoromethane, a new refrigerant that has a remarkably low toxicity. Continued research by the Frigidaire Corporation and toxicological experiments performed in the Laboratory of Applied Physiology of the University of Cincinnati revealed another organic fluoride, dichlorotetrafluoroethane, whose toxicity also appeared to be of a very low order and whose physical and chemical properties make it suitable for refrigeration purposes. In addition to low toxicity, safety in its use is further enhanced by its physical properties, which permit the design of equipment that operates at comparatively low pressures and hence mitigates the dangers and problems of leakage. The investigation described in this report was performed by the Bureau of Mines at the request and with the cooperation of the Frigidaire Corporation.

Jan 1, 1932

By C. J. Walker

The Bureau of Mines undertook a theoretical and laboratory study to determine the feasibility of using ethylene as a tracer for natural gas in underground gas-storage reservoirs. The study indicated that ethylene was a useful gas tracer in underground gas storages. Tracer losses were not excessive. Laboratory tests were conducted at pressures as high as 500 psia in both wet and dry consolidated-sandstone cores, evaluating tracer loss with gas blends containing natural gas with different concentrations of ethylene tracer. Under certain conditions losses were less than 17 percent.

Jan 1, 1966

By W. V. Kuster

The investigation described in this report is part of a survey by the Federal Bureau of Mines of the titanium resources of the United States. The purpose of this project was to study a typical coastal deposit of beach sands in the Middle Atlantic States, particularly in the area surrounding the Delmarva Peninsula. The field investigation consisted of a reconnaissance survey of the Eastern Shore of Maryland, followed by surface sampling and drilling of the sands on Assateague Island, off the Atlantic coast of Maryland. The study covered the period January-December 1957. Detailed analyses were made of 5-foot sections of eight drill holes along the Maryland section of the island. The heavy-mineral fraction of these samples was separated by sink-float tests, using acetylene bromide as the heavy liquid. The minerals comprising the heavy fraction were examined microscopically, and mineral counts were made on selected samples.

Jan 1, 1959

Develop a user-friendly computer program that permits those interested in mine health and safety to access and analyze on a personal computer (PC) employment, production, and accident data for U.S. coal and metal-nonmetal mines. This software is being designed with a major focus on flexibility and case of use. The Mine Accident Decision Support System (MADSS) will be available for distribution in mid-1994. Currently, the U.S. Bureau of Mines (USBM) is seeking volunteers willing to pilot test a preliminary version of the software and to provide suggestions for its improvement. Background Since 1975, the Mine Safety and Health Administration (MSHA) has compiled large data bases of information about U.S. mines and the reportable accidents, injuries, and illnesses that have occurred in those mines. Employment and production data arc collected on a quarterly basis from each mine and accident information is collected on an incident -by-incident basis. The USBM has compiled estimated costs for each of these accidents using computer models. All of this information is potentially useful to mine health and safety researchers. However, it has been underutilized because it is stored in large mainframe data bases that arc inaccessible to many users and/or are cumbersome and difficult to use.

Jan 1, 1993

By R. V. Ramani, A. S. C. Owili-eger

A mass balance equation can be written for the unit block of Figure 7 for changes within the volume during time At as: [ ] where x and y are the coordinates; q is the flow across any surface; p is the density of the fluid flowing through the medium; qvol is the volumetric flowrate; @ is the medium porosity; and Ax and Ay are the dimensions of the block. The subscripts t and (t+At) denote time levels and At is the change in time. Writing this equation in nota- tional form and on rearranging, the following expression is obtained:

Jan 1, 1974