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By L Bertoss, D Carvalho

In the last decade, the use of advanced implicit modelling software/algorithms in mineral resource workflows has become a best practice in the mining industry. In most cases, these workflows can easily replicate the level of detail of explicitly modelled geometries, even for very complex deposits. These techniques are flexible and can produce fast results since software is responsible for generating 3D surfaces and solids based on geological and interpretation data. Nevertheless, depending on how unique and complex some deposits are, intense manual editing and input are required to honour the geological context and produce the desired outcome. The current geological modelling workflow at George Fisher Mine (GFM) is based on the semi-automatic built-in tool that generates stratigraphic sequences (stacked lithology layers) based on logging and mapping data. This tool (stratigraphic sequence from Leapfrog Geo™) works for the majority of areas in the mine but fails to capture observed mineralisation pinch-outs in operational areas and at extrapolated boundaries of the deposit. These pinch-outs have the potential to negatively impact grade forecasts if not resolved manually. Using built-in software tools only, the alternative for a more accurate model is to generate each individual layer and adding tens of thousands of manual interpretation points to honour pinch-outs (based on the amount of existing drilling in the mine and number of layers). This approach would require an estimated minimum of two to four years of a full-time employee (FTE) to be exhaustively completed. This study presents an automated approach to generate pinch-out points using a set of Python scripts that only take a few minutes to run. The newly generated points are then combined into the commercial software workflow as interpretation points, honouring observed pinch-outs. The remarkable time difference between approaches removes chance of manual errors and allows mine geologists to spend valuable time in validation and testing of scenarios, ensuring they are more representative of the deposit’s geology.

May 24, 2023

By M. Mpofu, G. Stenzel, F. Magweregwede, B. Maphalala, T. Kgarume

Surface coal operations in which mining activities are conducted above old underground workings experience hot holes after drilling. In a coal mine, hot holes are defined as shot holes, which after being drilled have an in-hole ambient temperature of 40°C or above or show a temperature increase of 3°C or more during monitoring. Hot holes and other cavities, such as cracks, pose health and safety risks to workers, such as exposure to hot air and high concentrations of noxious gases released from these holes. In addition, workers may be exposed to premature detonation of explosives caused by in-hole temperature increases and chemical reactions. To this end, Coaltech Research Association commissioned a project to develop a Best Practice Guideline for the management of hot holes. This paper is a compilation of the activities conducted in the development of the Best Practice Guideline between 2021 and 2022. The activities included a review of standard operating procedures and hot-hole temperature-measuring and -monitoring devices, and the assessment of current hot-hole procedures at selected mines. The results indicated that management of hot holes requires a focus on pre-emptive risk assessment of mining blocks, identification of hot holes using the correct temperature-measuring devices, and continuous monitoring of hot holes from the time of drilling until just before blasting. Hot-hole management accessories, such as polyvinyl chloride sleeves, were found to be effective in insulating the hot-hole emulsion from the rock mass temperature, thus preventing the potential for premature detonation.

Sep 9, 2024

By E. G. Davis, H. P. LeVan, L. S. Smith

Leaching of a Georgia umber ore when using both ferrous sulfate and pickle liquor was studied in the laboratory . The ferrous sulfate content of the leach solution was the major factor affecting the extraction of manganese from the ore . Time , temperature , and the sulfuric acid content of the leach solutions had relatively little effect on leaching of manganese from the ore ; however , these factors did affect the amount of iron extracted from the umber and/or precipitated from solution . Simulated countercurrent leaching of the ore with pickle liquor containing 130 gpl (grams per liter ) ferrous sulfate ( 48 gpl ferrous iron ) produced a pregnant solution having 16 gpl manganese and 41 gpl iron . Filtration tests of the leach slurries indicated that separating the leach solution and solids by vacuum filtration was impractical , whereas pressure filtration was feasible when the cake thickness was limited to about three- fourths of an inch . Fired pellets of the filter cake yielded a firm , hard product analyzing 56 percent iron and less than 0.1 percent sulfur .

Jan 1, 1964

By Richard J. Wardle, Ambrose F. Howse

The industrial minerals industry in Newfoundland and Labrador is a significant contributor to the provincial economy. The variety ofcommodities produced reflects the diverse geological environment from which they come. A highlight of the past decade has been the continuing development of dimension stone quarries, with producers now active in anorthosite, gabbro, granite and sandstone. Other dimension stone prospects have been identified and are in various stages of assessment and development. Western Newfoundland hosts a large resource of limestone, dolomite and marble. It provides raw material for industries that produce Portland cement, agricultural limestone and aggregate, as well as chemical-grade limestone and dolomite products. In western Labrador, dolomitic marble is quarried for use in the production of self-fluxing iron ore pellets. The recent opening of a new gypsum quarry at Fischells Brook signalled the beginning of a new era in the commercial production ofgypsum, a commodity which the province has produced since the 1950s. Hopefully it will emulate the nearby Flat Bay Quarry (now closed) which was a long-time exporter to markets along the U.S. eastern seaboard, in addition to supplying local demands. Oil production and continuing exploration in the Newfoundland offshore has renewed interest in local barite deposits for potential use in drilling fluids. Already there has been some production from the Collier Point deposit, and at Buchans, an existing plant is being refurbished to recover barite from a large tailings pond. Emerging new industries include the development of an antimony mine in central Newfoundland, the development of silica deposits near Labrador City for silicon metal production, and reactivation of the St. Lawrence fluorspar mine. The province has many deposits with development potential such as rare metals at Strange Lake, white marble at Roddickton and salt deposits near St. George's Bay region.

Jan 1, 2001

By Frank E. Williams

This Bureau of Mines report describes 147 known fluorspar deposits in New Mexico and briefly mentions 54 miscellaneous occurrences for which little or no information was obtained. Most miscellaneous occurrences are minor and too poorly exposed to be considered more than prospects. History and production of fluorspar in New Mexico, type of deposition, mineralogy, uses, and grade specifications are discussed. Total mine production of fluorspar in New Mexico is nearly 641,000 tons of various grades of crude ore and hand-sorted material. Fluorspar deposits occur in 13 of the State's 32 counties. Grant, Valencia, and Luna Counties account for 86.4 percent of the total production. During the investigation, 141 deposits were visited. A total of 72 character samples was collected for assay, and 3 larger samples were collected for bench-scale metallurgical tests. Results of these metallurgical tests indicate that an acid-grade product can be obtained with 95 percent recovery of the CaF2 content of the crude ore.

Jan 1, 1966

By Frank E. Williams

This Bureau of Mines report describes 147 known fluorspar deposits in New Mexico and briefly mentions 54 miscellaneous occurrences for which little or no information was obtained. Most miscellaneous occurrences are minor and too poorly exposed to be considered more than prospects. History and production of fluorspar in New Mexico, type of deposition, mineralogy, uses, and grade specifications are discussed. Total mine production of fluorspar in New Mexico is nearly 641,000 tons of various grades of crude ore and hand-sorted material. Fluorspar deposits occur in 13 of the state's 32 counties. Grant, Valencia, and Luna Counties account for 86.4 percent of the total production. During the investigation, 141 deposits were visited. A total of 72 character samples was collected for assay, and 3 larger samples were collected for bench-scale metallurgical tests. Results of these metallurgical tests indicate that an acid-grade product can be obtained with 95 percent recovery of the CaF2 content of the crude ore.

Jan 1, 1966

By C. W. Davis

During the fiscal year 1935-36, the Ore-Testing Section has been active in carrying out a program designed to attain the objectives that have been set up for it. For the Purpose of standardizing important testing methods, an attempt has been made to develop a rationalized scheme for ore testing, starting with preliminary investigations to determine the physical and chemical properties of the ore, following this with a logical selection and trial of processing tests to find out how the ore may be most effectively treated, and concluding with a discussion of what interpretation may be placed on the results in terms of plant design and operation. A selection of Procedures that appear well-suited to the ore-dressing problems under investigation is included in the following paper of this report so that other experimenters may be enabled to verify our findings and to offer criticisms and suggestions for improving our practice. A tentative scheme for the evaluation of flotation reagents is being investigated, and some progress has been made in a study to determine the significance of small-scale testing. These projects have required 899 analyses. Papers on these and others on ore testing, such as testing for amalgamation and for cyanidation, will be included in future annual reports.

Jan 1, 1937

By C. W. Davis

During the fiscal year 1935-36, the Ore-Testing Section has been active in carrying out a program designed to attain the objectives that have been set up for it. For the purpose of standardizing important testing methods, an attempt has been made to develop a rationalized scheme for ore testing, starting with preliminary investigations to determine the physical and chemical properties of the ore, following this with a logical selection and trial of processing tests to find out how the ore may be most effectively treated, and concluding with a discussion of what interpretation may be placed on the results in terms of plant design and operation. A selection of procedures that appear well-suited to the ore-dressing problems under investigation is included in the following paper of this report so that other experimenters may be enabled to verify our findings and to offer criticisms and suggestions for improving our practice. A tentative scheme for the evaluation of flotation reagents is being investigated, and some progress has been made in a study to determine the significance of small-scale testing. These projects have required 899 analyses. Papers on these and others on ore testing, such as testing for amalgamation and for cyanidation, will be included in future annual reports.

Jan 1, 1937

By C. E. Dobbin

The coal fields of Montana are widely distributed through the plains region in the eastern and northern parts of the State, and the mountain regions in the central, southern, and southwestern parts of the State. (See fig. 1.) SURFACE FEATURES The Fort Union region in eastern Montana is a broad plain of almost horizontal rocks, characterized by extensive "bad lands" along the larger streams and by red hills, benches, ridges, and buttes which represent shale and sandstone that have been fused by the burning of an underlying coal bed.

Jan 1, 1932

By Edward L. McHugh

The appraisal of mineral resources of the Challis National Forest, Idaho, by the U.S. Bureau of Mines, was made so that the mineral resources of the forest could be appropriately considered in land use planning. Information from this study is intended to help the U.S. Forest Service to incorporate mineral resource data into forest plans. The study was done in conjunction with the U.S. Geological Survey, which released a companion report on the geology and mineral potential of the Challis National Forest in 1989. Mineral development activity in and under the Challis National Forest has been of great economic significance to Idaho and the United States. Since the 1960's, mines within the forest have produced mineral commodities worth more than $590 million A current (1989) commodity prices. Identified mineral resources have a gross value of about $2 billion at current prices, including 8 strategic or critical minerals. The U.S. Bureau of Mines study identified and described 723 active and inactive mineral properties within the forest. Mineral properties with identified resources were evaluated to determine their economic significance, and an assessment was made of the feasibility of mineral development. Of the 2,516,191 acres in the Challis National Forest, about 390,000 acres were classified as having mining development interest commercially important mineral production, mainly of molybdenum, gold, and silver from the Challis National Forest is likely for the foreseeable future.

Jan 1, 1991

By William Campbell

(Cleveland Meeting, October, 1912.) [SECRETARY'S NOTE.-To avoid repetitions of foot-notes, references to authorities are made in the paper by means of figures, referring to a numbered list in the appendix.-J. S.] I. INTRODUCTION. IN the olden days the making of alloys was au art, and the secrets of the craft were jealously guarded. To-day it has become a science, though the old ideas in regard to the secrets and formula are dying hard. Modern progress may be attributed to scientific research and testing of materials, and the substitution of chemical analytical control for " cook-book " methods. We know to-day a great deal about the constitution of alloys, the reasons of the change in structure and physical properties by heat and mechanical treatment; and this new knowledge is due for the most part to the physical chemist and metallographist, who have shown us that alloys are simply solutions, and as such obey definite laws. The application of the theories of solutions and of the phase rule tells us what ought to happen when our alloys are in a state of equilibrium. The working-out of the temperature-composition diagram (thermal diagram) for numerous alloys has thrown a light on the structure and constitution which has dispelled most of the darkness in which we labored before the advent of metallography. The work began with the determination of the freezing-point curves, and here the research of Le Chatelier,1 Gautier,2 Roberts-Austen,3 and the other pioneers broke the ground. Next the physical chemists, Tammann,4 Rooseboom,5 Bancroft,6 and their colleagues, showed us the complete thermal diagram and its meaning. Then the researches of Heycock and Neville 7 on the Cu-Sn series and of Shepherd 8 on the * Associate Professor of Metallurgy, Columbia University in the City of New York.

Dec 1, 1912

By E. W. Dean

This report on the physical and chemical properties of typical crude oils of Oklahoma is the sixth in a series of preliminary chapters of a bulletin covering the producing districts of the United. States. Preceding reports* may be obtained on request. The details of the methods used in this survey in collecting samples, making laboratory tests, and interpreting results are discussed in the first three papers. If any errors or omissions are noted by readers, it is hoped they will be brought to the attention of the Bureau of Mines for correction before the appearance of the permanent report. Samples of Oklahoma crudes analyzed in this report were taken from those fields representing the major production of the State. The Oklahoma Geological Survey designates 172 different oil and gas fields in the State, S1 being in Osage County, 14 in Tulsa County, 14 in Okmulgee County, 9 in Washington County. The list of samples collected by the Bureau of Mines represents only 5 fields in Osage County - Bigheart, Burbank, Hominy, Osage Junction, and Pershing - yet these samples, together with those from adjoining fields, are representative of nearly all crude produced in the county. The sample 'from the Pershing field, for example, is representative of the crude produced in several fields in that part of the county - such as Nelagoney, Pawhuska, Wyomona - and the sample from the Skiatook,

Jan 1, 1922

By R. E. Head

[Recent investigations at the Intermountain Experiment Station of the Bureau of Mines at Salt Lake City indicate that metallurgists have given little attention to the occurrence of jarosite minerals in the oxidized ores of lead and silver. These investigations have also emphasized the importance of lowing when these minerals occur in the oxidized ores, especially those containing lead, silver, and gold, as their presence is a material factor in selecting a suitable kind of treatment. Since the question of the occurrence of jarosites in oxidized ores has come to the attention of the Bureau of Mines, investigation has indicated that plumbojarosite and argentojarosite are quite common. These two minerals appear to be widely distributed and probably escaped recognition by persons who had attempted to treat certain oxidized lead ores in which the jarosite minerals represented a material portion of the metal content. Consideration of the physical characteristics of the jarosites also indicates that in many cases failure to treat some of the oxidized lead ores with success has been directly due to the fact that the greater portion of their lead and silver content was present as plumbojarosite and argentojarosite. The data and the description of these minerals given in the body of this paper indicate that attempts to recover lead and silver from ores in which appreciable amounts of too metals occur is plumbojarosite and. argentojarosite would be unsuccessful if confined to gravity methods of concentration. There are undoubtedly considerable tonnage of oxidize lead ores in the various mining regions of this and other countries, and it is quite probable tat in some of these ores the metal content of lead and silver may be largely anglesite (lead sulphate) and cerussite (lead carbonate) but that they will also contain cerargyrite (silver chloride), argentojarosite, and plumbojarosite. The treatment of such ores therefore presents an important problem, since a product is discarded from]

Jan 1, 1928

This paper aims to increase our understanding about existing capacity-building approaches and their implications for obtaining a social license to operate in the mining industry. The notion of ?capacity building? is gaining increasing currency in the mining sector in developing countries due to a rapid rise in the globalisation of mining operations. Capacity-building is conceived here as a process that lasts after the mine-cycle, intended to provide local mining communities with tangible skills and knowledge to gain meaningful employment in mining or other industries relevant for the local economy. Building community capacity to understand and effectively respond to these transformations is vital for obtaining a social license to operate, as it promotes sustainable and locally relevant development. Accountability mechanisms such as global norms and international standards increasingly highlight the need to build capacity among stakeholders, particularly among local communities adjacent to mining operations. International frameworks and mining companies have embraced the notion of capacity-building as a driver to assist corporate social and operational performance. However, this narrow understanding of capacity-building through the prism of corporate social responsibility and ?best practice? is preventing the industry from meaningfully impacting communities and maintaining a social license to operate. This latter notion is being widely embedded across multiple industry sectors, as a social and economic reward from mining companies to compensate communities for natural resource extraction and gain social acceptance. Although both concepts are widely recognised in the minerals industry, insufficient attention has been paid to the implications of applying a top-down (mining-orientated) or a bottom-up (community-orientated) capacity-building approach for obtaining a social license to operate, or indeed how these two concepts are linked and applied in practice. At times, communities lack the necessary capacities in the form of education and skills to deal with mining-led livelihood transformations. This is preventing both mining companies and communities from forging sustainable livelihoods and responding to mining-led livelihood transformations, a situation that is creating discontent among communities and reducing the possibility of obtaining and renewing a social license to operate for the industry. Based on a review of current scholarly debates, accountability mechanisms in the mining industry and fieldwork findings in Colombia, this paper will contribute to an understanding of the implications of existing capacity-building approaches that support a social license to operate.

Aug 1, 2013

By Rollien R. Wells

The Bureau of Mines was created in 1910 by an act of Congress and subsequently directed to: "...conduct inquiries and scientific and technologic investigations concerning mining, and the preparation, treatment, and utilization of mineral substances with a view to improving health conditions, and increasing safety, efficiency, economic development, and conserving resources through the prevention of waste ..." Under this broad charter, the Bureau's responsibilities have changed and grown from an almost exclusive concern with coal and coal mine safety to the present emphasis on a full spectrum of mineral producing and consuming problems. In the past 30 years, the domestic consumption of coal, oil, gas, metals, and industrial minerals has more than quadrupled, in parallel with the rapid and enormous growth in industrial production. Of the scores of metals and nonmetals essential to the Nation's progress and security, many are scarce and difficult to wrest from domestic sources. Reserves of some ores are dwindling. Available ore resources are becoming leaner and more difficult to treat. In recognition of this many faceted problem, the Bureau has engaged in a continuing quest for new and improved technology to enable economic exploitation of marginal minerals and fuels, to find substitutes for minerals in short supply, and to create better materials to meet the expanding and diverse requirements of the growing economy. The current central concern of the Bureau is focused on meeting projected fuel, metal, and mineral demands at the lowest real cost by recovery from available resources by new and improved technology that minimizes waste, hazards, and social and environmental problems.

Jan 1, 1970

By Robert Alfred

This paper is one of a aeries being published by the Federal Bureau of Mines on methods and practices used in mining and preparing crushed stone for market. Performance, in terms of units of work or tons produced per machine and per operator man-hour, is given whenever that information can be obtained. Direct operating costs are useful for comparing different methods and are included if available. In addition to descriptions of equipment and methods used the Bureau considered it desirable to discuss the engineering reasons for the choices that have been made, This paper is particularly concerned with the operation of the Liberty quarry and plant of the Campbell Limestone Co, The plant is in Pickens County, adjacent to the main line of the Southern Railway, and is about 18 miles west of Greenville, S, C. Access also is available by United States Highway No, 123, The company's main offices are at Knoxville, Tenn.

Jan 1, 1958

By F. L. Thompson

MAN has been using lubricants of one type or another for at least four thousand years, and probably for a much longer period. We have learned from the inner wall of the tomb of Tehuti-Hetep, on which is a decoration illustrating the method of moving a great stone statue, that as early as 1650 B.C. lubricants were used to facilitate the movement of heavy loads. The Egyptians had available nearly every animal oil and fat, as well as at least thirteen vegetable oils, of our time, all used for food products and in the arts. Examination of the deposit on the axle of a chariot from an Egyptian tomb of 1400 B.C. showed it to consist of animal fat, quartz, sand, iron, and compounds of aluminium and lime-indicating a manufactured lime-soap grease made with lime-soap and possibly tallow. This would not be a bad lubricant for the axles of chariots which had to travel over sandy soil in hot weather. As to the method of grease application, it is remarkable that, from the time wheels were first used in the far distant past up to the present day, no one has ever thought it necessary to design a seal to keep the lubricant in and the dirt out. While time certainly marches on, we have today, in waggons throughout the world, exactly the same form of lubrication as was used in the earliest chariots. From the early days of the chariot until shortly before 1800 A.D. (when the steam engine was introduced), the main heavy equipment required for mining purposes, for machines of war, etc., was made of wood. The bearings were rough, but usually they had metal in the lower half. Light machinery was made of bronze, brass, or iron. Large clearances and poor alignment, plus the fact that speeds were much below present-day demands, combined to provide conditions that were quite satisfactorily met by the lubricants available. These were often produced locally by the machine operator. In northern countries, lard oil, prepared from the fat of hogs, was the universal lubricant employed in machine shop, as a belt and leather dressing, and for cutting operations. Sperm oils were used for light machinery, whereas beef and mutton tallow were more generally employed for the largest bearings. For the early steam cylinders, a slug of heated beef tallow was injected wherever the cylinders gruntingly complained of a lack of lubricant. Southern countries, however, resorted to the use of vegetable oils-olive, cocoanut, etc.

Jan 1, 1940

By D. Tao

Froth flotation is widely used in the coal industry to clean -28 mesh or -100 mesh fine coal. A successful recovery of particles by flotation depends on efficient particle-bubble collision and attachment with minimal subsequent particle detachment from bubble. Flotation is effective in a narrow size range outside which the flotation efficiency drops sharply. A fundamental analysis has shown that use of picobubbles can significantly improve the flotation recovery of particles by increasing the probability of collision and attachment and reducing the probability of detachment. A specially designed column with a picobubble generator has been developed for enhanced recovery of fine coal particles. Picobubbles were produced based on the hydrodynamic cavitation principle. Experimental results with one metallurgical coal and one steam coal have shown that the use of picobubbles in a 2" column flotation increased fine coal recovery by 10-30%, depending on the feed rate, collector dosage, and other flotation conditions. Picobubbles also acted as a secondary collector and reduced the collector dosage by one third to one half.

Jan 1, 2006

By R. S. Dean

"INTRODUCTION The metallurgical research program of the Bureau of Mines has been somewhat disorganized, but generally advanced by the increased activities of the war period. The present report is for the purpose of summarizing the work of the Bureau in this field for the past 15 years and indicating its future plan.Fifteen years ago the Bureau turned from its pioneer work on the physical chemistry of steelmaking to an emphasis on raking a pure steel synthetically, rather than by refining, that is, :producing each of the steel 'constituents in the pure state and combining them by simple melting. Such a procedure permits the use of less high-grade ores, not only of iron, but of the ferroalloy metals, such as manganese and chromium,This program has led to extensive work on iron-ore concentration, agglomeration, reducibility of ores and agglomerates, direct reduction of iron ores and concentrates by a wide variety of processes; special refining processes for iron, the production of pure mangenese, chromium, and cobalt from low-grade ores by electrolytic processes, the production of ferrochromium, ferronickel, and ferronickel-cobalt from low-grade domestic ores, and the development of many special alloys to effectively use the new products.The status of the work in each of these fields and the future program of work, together with a bibliography of papers and patents by the Bureau staff on each of these subjects, are given."

Jul 1, 1946

By P. D. Rao

Chemical and physical properties of typical low-rank coal (LRC) ash are significantly different than bituminous coal ash. With the exception of extraneous ash, which is incorporated during mining or is due to ash partings within or between coal seams, LRC ash consists primarily of inherent ash that is bonded into the coal's organic matrix or finely disseminated mineral matter. This paper reviews the nature of LRC ash, both inherent and extraneous, and how this impacts the prospects of washing and utilizing LRCs. A literature review, as well as washability data, proximate and ultimate analyses and ash analysis of 25 Alaskan LRC seams are used as a basis for this discussion. The authors' recent research into the nature and distribution of phosphorous in an Alaskan LRC is also discussed

Jan 1, 1997