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By D. Harrington

Hatch (260) made the following pertinent statement regarding the present status of engineering design of dust-control equipment: Textbooks on ventilation and engineering handbooks devote little or no space to methods of control of industrial dust, and in the technical journals papers on fundamental engineering design of equipment are conspicuous by their absence. In a recent bibliography of the literature on pneumoconiosis less than 1 percent of the articles dealt with the engineering control of the disease. The science of dust control has not developed beyond the stage of trial and error, and the design of structures for the suppression of dust is based almost entirely upon empirical data together with one or two elementary formulas. The latter were derived from the generalized experience in a limited number of Industries such as woodworking, where conditions and requirements are not at all like those, for example, in a sand-pulverizing plant. Wide experience and good judgment are essential to the proper use of the scanty information that has been collected and systematized. Without attempting to minimize the importance of experience in engineering design, it is necessary to point out that most of the past experience obtained in the empirical design of dust-control equipment was not evaluated by means of quantitative studies of the actual reduction in dust , fence, past experience does not necessarily furnish the proper guide for future design. In fact, recent surveys in certain industries, employing modern methods of investigation, have shown that existing equipment is in many cases inadequate.

Jan 1, 1935

By R. I. Cavanagh, A J. Last

THE USE of higher grade charges in blast furnaces in the form of sintered or pelletized concentrates has been increasing rapidly. The question of beneficiation of iron ores for this purpose is therefore receiving much attention as more deposits are developed. Many iron ores may respond well to magnetic roasting procedures followed by magnetic concentration, however, in most cases other more standard ore dressing methods are competitive and cheaper. For magnetic roasting as applied to iron ore beneficiation, the present question is "Can it be economically justified in situations where it appears to produce good results?" The following collection of information on the general status and operations of magnetic roasting methods may be helpful in considering this question. Magnetic Roasting Magnetic roasting involves the transformation of non-magnetic iron oxides, hydrated oxides and carbonates by means of heat and suitable

Jan 1, 1961

By J. A. Singmaster

IT will perhaps be wise to define my terms in begin-ning to talk about my subject, especially so where the popular and commercial terminology are as con-fused as they are in the case of zinc. While our French friends know zinc by its true name, and we find Balzac, Daudet, and other literary celebrities using it correctly in their novels, it is quite the contrary in English, particularly here in America. The quotation of a definition for zinc recently appearing in one of our leading technical magazines, "zinc is the place where they wash the dishes," will emphasize the difference. Zinc suffered in the first place by becoming an article of commerce long after its alloys with copper were in common use under the name of brass. Then again, when the art of zinc coating iron and steel objects was commercialized, we called it galvanizing, which is really a meaningless term. The French and Germans use the obvious terms-zinguerie and verzinken-for the opera-tion. Since these two uses of zinc, brass making and galvanizing, have been by far the largest consumers of zinc, is it any wonder that the popular knowledge of zinc is as vague as it is? In fact, since the disappear-ance of the sheet of zinc along with the parlor stove, the zinc-lined bath tub and refrigerator, there has been little popular contact in this country with the undis-guised metal zinc. On the Continent, where zinc has been used for over a hundred years under its real name, particularly for roofing and building purposes, the situ-ation is quite different. It is quite refreshing to turn for a moment to the contrast offered by my friend, Dr. Merica's specialty, nickel. They put 2 or 3 per cent of it into steel, and we have nickel-steel, or a larger amount into an alloy, and we have nickel-silver. To be sure there is no silver there, but what need that matter, nickel is used in the alloy and is first in the name. They plate with nickel and call it nickel-plating, no galvanizing about that. And, finally, they take that noble coin which admits us daily to underground New York, composed of three parts of copper and one part nickel, and get away with nickel as its popular name.

Jan 6, 1927

By F. Q. Dong

According to the principle that should be originated from nature, compatible with nature, used in nature and back to nature and based on conception of designing of eco-material, the author combined the ideas of material, environment, zoology and healthy. Properties of natural mineral materials were used to produce micro-aggregate elements by bionic method, so its components and function could accord with living environment. Eco-mineral functional materials which can adjust, purify and optimize the microclimate were reviewed. The authors pointed out the multifunction, com-pounding, the compound characteristics and integration regularities of micro-aggregates. It was the first time in the world to put forward the ?gene? technique or ?material chip? technique of manufacturing function micro-aggregates and eco-function elementary materials. The results of this re-search supported by the national ?863? Hi-tech Project, mainly including the high-efficient air purifying mineral compound material indoor, the clay elementary antibacterial materials, the masonry cement/coating/putty/compound with preventing radon radiation, environmental friendly composite functional coatings, mosquito repellent and healthcare material and zeolite-based energy-saving composite materials, were introduced. Finally, the foreground of mineral materials in the field of future advanced eco-friendly materials was also discussed.

Jan 1, 2014

Although not immune from the problems affecting the U.S. economy generally, the mineral industry in 1991 contributed nearly $300 billion in the value of processed materials of mineral origin. Supporting this contribution, the Bureau of Mines continued the research and analytical programs highlighted in this annual review. Featured in 1991 were such relatively new programs as minewide monitoring applications in ground control and advances in processing of ceramics and composites, along with more traditional research into health, safety, and mining technology, minerals and materials science, and environmental technology. Under Bureau sponsorship, a National Minerals Policy Forum brought together some 200 executives from industry and Government concerned with minerals policy to begin a dialogue on developipng a policy statement on current minerals issues. A major feature of the forum was the keynote address by Secretary of the Interior Manuel Lujan, Jr.

Jan 1, 1992

By F M. Weir, M Fowler

A discrete fracture network (DFN) approach involves numerical modelling that explicitly represents how defects may be spatially distributed through a rock mass. A DFN is a 3D realisation of the ‘smaller scale’, non-deterministic defects; it is not an attempt to model larger, deterministic structures that should be identified as part of an engineering geology model. The approach utilises structural data in stochastic analyses to give a range of possible models that provides a tool for visualisation and analysis of a rock mass and indicates the potential large-scale slope or tunnel performance and stability.Stochastic fracture modelling for rock mass characterisation has significantly advanced over the past 25 years. With recent improvements to field data collection and computational power, it has become recognised internationally as a valuable tool for modelling some geomechanical problems encountered when designing excavations in fractured rock masses.This paper provides an introduction to the DFN approach, particularly the necessary input parameters and derivation of these from typical structural data sources, such as boreholes or scan line mapping. Of particular importance for engineering applications is validation of the simulated fracture network and techniques for doing so are discussed here.CITATION:Weir, F M and Fowler, M, 2014. An introduction to discrete fracture network modelling and its geotechnical applications, in Proceedings AusRock 2014: Third Australasian Ground Control in Mining Conference , pp 435–444 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Nov 5, 2014

By John S. Alexander

By W. T. Abel

The difficulties associated with wet-processing fine size coal led the Bureau of Mines to investigate a dry process for removing pyrite from coal pulverized to powerplant fineness. The dry process that was investigated consists of two cleaning steps: First, centrifugal separation is used to remove a fine, pyrite-depleted portion as a product; second, the remaining coarser, pyrite-enriched portion is taken to electrostatic separation in which pyrite is concentrated and rejected. Ball milling and Hardgrove milling were used to pulverize the coal. Three coals from the Pittsburgh seam were treated by the dry-removal process. Over 55 pct of the pyrite, which amounted to 70 pct of the available pyrite, was removed in a reject of 10 to 20 pct from one of the coals. Similar treatment of the other two coals removed about 35 to 50 pct of the pyritic sulfur, which amounted to about 70 pct of the available pyritie, sulfur from these coals. Both centrifugal and electrostatic separations were more efficient when pyrite particles were as large as possible. Separation efficiency was improved by confining the particle size of the feed to a relatively narrow range and by avoiding excessive amounts (more than 10 pct) of dust in the electrostatic range. The removal efficiency was increased with the use of stage grinding.

Jan 1, 1973

By Kyle W. Charlton

The Bureau of Mines utilizes special testing methods for the analysis of underground mine atmospheres for use during or after mine disasters and fires. These methods depend upon drawing sample gas to the surface through multiple tube bundles with the subsequent analysis of grab samples or the automatic analysis by often remotely located instruments on a continuous, 24-hour basis. During cold weather, low ambient temperature causes condensation and freezing of condensable vapors in the sample which can result in delayed response times or complete blockage of the sample line. This report covers research and resulting development conducted by the Bureau of Mines to produce a reliable method to selectively remove condensable vapors and particulate in the sample gas stream under worst-case field conditions. The effort resulted in two prototype systems which have greater field utility than originally anticipated. The innovative project resulted in two patent applications submitted through the Bureau of Mines.

Jan 1, 1981

By James T. McCartney, Joseph D. Davis

For more than 10 years coke-oven technologists have been investigating the expanding properties of coal on a scale larger than that afforded by laboratory test tubes. Koppers 4/ was among the first to realize that coals can not be differentiated satisfactorily with respect to expansion in coke ovens by the simpler test-tube methods; in his first method 80 grains of fine coal were coked in a cylinder heated from the bottom, so that the zone of fusion (plastic layer) advanced from the bottom to the top. The scale of test was too small; it has been modified by other investigators, but without significant improvement in practical application of the results. Somewhat later Koppers and Jendne 5/ experimented with a small-scale coke even, one wall of which was movable, in which the layer-coking in a coke oven could be simulated closely. This oven was heated from both sides. Their results with this oven showed a peak in the time-pressure curves near the end of the coking, period when the two plastic layers, advancing from opposite walls, meet. They also found that although the smaller oven was heated from one side only and did not show the Pressure peak characteristic of two-sided heating, it still gave results entirely too high. Russell built an oven similar to the movable-wall oven of Koppers and Jenkner and compared results obtained in it on Beckley expanding coal with these obtained on the some coal in the Altieri 7/ small-scale apparatus. Both tests were conducted at the same constant pressure, but heating was from two sides in Russell's oven and from one side in the Altieri tester. Russell found that the two types of test gave comparable results under constant pressure conditions even though the heating procedures were quite different. He showed later, however, that a "borderline" coal 8/ that contracted in the Altieri tester at constant pressure developed a peak pressure of 4 pounds per square inch in the movable-wall oven heated from both sides at constant volume. He concluded from this that testing at constant volume gave results more accurately indicative of dangerous expansion tendencies than those at constant pressure. He also found that heating from both sides in this oven gave higher pressure than heating from one side only.

May 1, 1942

By S. H. Lorain

This paper briefly describes the principal commercial and near-commercial deposits of gold-bearing gravel and the important placer-mining operations in Lemhi County, Idaho. It is on of a series on western mining districts being published by the Bureau of Mines. This paper is based on a field survey of the placer-mining districts of Lemhi County in the summer of 1938. Available information concerning gold-bearing gravels was obtained from prospectors and claim owners; operators supplied the data on mining operations. No attempt was made actually to test the gravels. The principal object of the examination was to indicate placer areas worthy of further investigation by prospective operators.

Jan 1, 1939

By Oliver C. Ralston, Dorsey A. Lyon

Volatilization in retorts has been, until recently, the only commercial process of producing spelter, hence the zinc mine operators have had to meet the terms of the zinc smelters in regard to the following requirements: (1) Minimum percentage of zinc the ore must contain; (2) the chemical combination of the zinc in the ore; (3) the proportion present of those elements that interfere with the suceessful recovery of the zinc when the ore is retorted. In consequence of these requirements, only a comparatively small proportion of the zinc ores mined can be shipped directly to the smelters.

Jan 1, 1919

By NORA Mining Sector Council

The National Occupational Research Agenda (NORA) is a partnership program to stimulate innovative research and workplace interventions. In combination with other initiatives, the products of this program are expected to reduce the occurrence of injuries and illnesses at work. Unveiled in 1996, NORA has become a research framework for the National Institute for Occupational Safety and Health (NIOSH) and the United States. Diverse parties collaborate to identify the most critical issues in workplace safety and health and develop research objectives for addressing those issues. NORA entered its third decade in 2016 with an enhanced structure. The 10 sectors formed for the second decade will continue to prioritize occupational safety and health research by major areas of the U.S. economy. In addition, NORA’s seven cross-sectors will continue to focus on the major health and safety issues affecting the U.S. working population. While NIOSH serves as the steward to move this effort forward, it is truly a national effort. NORA is carried out through councils comprised of members with many diverse interests that are developing and implementing research agendas for the occupational safety and health community over the third decade (2016-2026) of NORA. Councils address objectives through information exchange, partnership building, and enhanced dissemination and implementation of evidenced-based solutions. NORA groups industries into 10 sectors using North American Industry Classification System (NAICS) codes. The Mining Sector encompasses NAICS code grouping 21xxxx where “xxxx” represents the different subcodes of the mining “21” classification. Mining encompasses the extraction of solid mineral and mineral-like substances from their place in the Earth’s crust and supplies them to processing industries that produce economically valuable materials. It does not include oil and gas extraction. The Mine Safety and Health Administration, MSHA separates mining into coal, underground and surface, and metal and nonmetal, underground and surface.

Feb 1, 2024

By R. W. Smith

Living and killed organisms, particularly microorganisms, and extracellular products derived from the organisms are increasingly finding use in minerals engineering. Goals include both enhancement of mineral processing/11.ydrometallurgica,l operations and remediation of mineral industry wastes. Some of the applications, such as biologically assisted leaching of ?sulfide ores and bioxidation of refractory gold ores, are well established commercial ?processes used around the world. Others, such as the use. of organisms for the removal of heavy metal ions from dilute aqueous streams, are nearing commercial application. Many other uses of microorganisms and. their derivatives are potentially possible. These include use of microorganisms in flocculation or flotation of minerals., remediation of organics potentially discharged from mineral engineering operations, degradation of cyanide, the recovery of bitumen from heavy oil reservoirs and tar sands and the solubilisation of lignites and low rank coals. In order to fully exploit these many possible uses of organisms and their derivatives, extensive fundamental .and .applied research work exploring the fundamentals, potential and practicality of the various possible uses of microorganisms in mineral engineering should be vigorously pursued. ?

Jan 1, 1991

By M. B. Mesina

Mechanical separation systems are widely used nowadays for scrap metal processing, but they have natural limitations in product quality. The quality of the final product is considerably improved when sensors are used in the separation process. This paper describes new methods using sensors for scrap metal sorting and quality control. An example is the electromagnetic sensor, which uses the electrical and magnetic properties of materials to distinguish between different non-ferrous metals. The measurement results of two prototypes are reported. The benefits and the possibility to integrate such systems into practical applications regarding the processing of secondary raw materials are also described.

Jan 1, 2003

By Robert T. Davis

An award is a form of recognition given for superior performance in a special field of endeavor. Each year awards are given by the Joseph A. Holmes Safety Association and the National Safety Council to the coal-mining industry's underground and open-pit mines that have worked a specific number of man-hours without a lost-time injury. These awards have a dual significance in that they prove efficiency can be attained without injury to persons. Safety awards do not result from luck or good fortune but do result from sincere desire coupled with sufficient effort and cooperation to achieve a desired goal.

Jan 1, 1964

By Michael J. Klishis

West Virginia University researchers examined risk and exposure in the roof bolter operator's job and developed approaches for preventing accidents and for evaluating system and human performances that may be appropriate as a general application to improve safety and efficiency in the industry. Using a microanalysis of accident data and underground observations, the researchers classified bolting injuries within one of four work routines: 1) drilling bolt holes; 2) bolt installation; 3) machine tramming, (re)positioning and setting the ATRS; and 4) general face preparation. Time and motion studies were then combined with injury data analysis to develop risk and severity indices, as well as a severity-weighted index that served to determine the degree of risk and exposure by work routine. More than two dozen bolting-related problems were identified as potential situations that could lead to injuries or expose workers during their job. Approaches to avoid these situations were suggested and then applied at six mining operations to evaluate specific problems in roof bolting operations. These suggestions encompassed the three E's of Safety (Engineering, Education, and Enforcement) and emphasized the analysis of worker behaviors that lead to human error accidents.

Jan 1, 1993

By L. T. Matthews, C. E. Loo, R. P. Williams

The behaviour of iron ores and fluxes in the high temperature zone of a sintering bed is extremely complex. Following a review of current knowledge, an attempt is made to define relevant terminology to describe the processes that occur in this part of the bed. A deformation temperature is used to quantify the initial formation of melt, which is produced predominantly by reactions between fine particles in the sinter mix. The subsequent assimilation of larger particles is considered to depend on the reactivity of the melt and the assimilation resistance of these particles. Novel laboratory experimental techniques are used to quantify these parameters. Results demonstrate that the properties of the raw materials used have an extremely important influence on the initial processes of melt formation and assimilation and also on the nature of the sintering reactions and sinter-bonding phases.

Jan 4, 1992

By T. H. Janes

"IntroductionSULPHUR is a constituent of many industrial products. It is part •of almost anything we eat, wear, or use. In fact, sulphur is so important that there has been an increasing tendency in recent years to measure industrial growth in terms of sulphur consumption.The uncertainty of obtaining adequate supplies •of elemental sulphur from the Frasch-mined domes. of Texas and Louisiana in the United States led all countries in 1950 to seek alternative sources of supply of this necessary element.Canadian industry has been supplied, for many years, with most of its sulphur requirements by United States Frasch-mined sulphur. World demand for this sulphur has necessitated the imposition of controls on its distribution, as production has not kept pace with demand. Until the third quarter of 1950, Canadian manufacturers of pulp and paper, heavy chemicals, explosives, and textiles •experienced little difficulty in obtaining their needs of elemental sulphur from the United States. However, at that time, low producers' stocks and declining reserves threatened to reduce shipments from producers, with the prospect of a continuing shortage for some time. These conditions, together with higher prices, stimulated the search for alternative sources of supply in Canada."

Jan 1, 1952

By Bruce Bryant

Silver ore was discovered at Aspen in 1879, but the district did not reach full production until 1888 after lawsuits were settled and railroads furnished less expensive transportation to the outside world. The boom years were 1888-92; production declined thereafter. From the middle 1920's until 1950, the Midnight mine in the Richmond Hill district furnished most of the output in the Aspen quadrangle. Since 1950, little mining has been done at Aspen. The metals produced were silver, lead and zinc. Native silver dissolved from the sulfide ores was redeposited by waters circulating as deep as 300 m below the land surface, resulting in great secondary enrichment of many of the deposits. Over 100 million ounces of silver were produced in the Aspen quadrangle. Low-grade lead-zinc deposits remain between the old workings locally, and data available suggest that primary ore below levels mined is also of low grade. The ore occurs in the Mississippian Leadville Limestone and the lower part of the Pennsylvanian Belden Formation in sites that were made favorable for deposition by a number of stratigraphic and structural factors.

Jan 1, 1982