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By J. H. Rose

This paper describing the milling practice at the Magma Copper Co., Superior, Ariz., is one of a series being prepared by the Bureau of Mines on milling methods and costs in the various mining districts throughout the United States. ACKNOWLEDGMENT The authors wish to acknowledge their indebtedness to William Koerner, general manager of the Magma Copper Co., for permission to prepare this article; to J. S. Garrott, former mill superintendent, for the historical facts; and to Walter Cooksley, general foreman, for his assistance in obtaining the data.

Jan 1, 1930

By G. W. MacLeod

The iron ore question in this country has been widely discussed for many years, but only recently has its real significance becoming generally understood. The exhaustion of the old Helen mine, in 1918, marked the last phase of hematite production in Ontario, and with the closing of the Magpie mine in 1921 , Canada ceased to be a producer of iron ore. For the past three years every ton of ore used in Canadian blast furnaces has been imported. In a recent issue of the Engineering and Mining Journal-Press, Arthur B. Pearsons, Assistant Editor, makes the following statement : Iron dominates the world. Some contend that coal is more vital. be-cause heat is needed to make iron and steel. But there are other sources of energy, more convenient and less costly and it is only a question of time when progress in hydro-electric development will have reached the point where coal will be but an incidental source of power and heat. Even more direct means than the generation of electricity by hydro-power eventu-ally will be developed by making available the latent energy of the sun. But iron; Science gives not the vaguest suggestion that anything will dis-place iron and steel as the most essential material tool of modem civiliza-tion. ? Hardness, tenacity, malleability-it possesses all these in unique de-gree. These are some of the qualities that make steel and iron indispensable in modern industry. The domestic consumption per inhabitant of the United States has climbed uniformly from 0.18 tons in 1900, to 0.36 tons in 1922. New kinds of machines and new types of structures are being devised every year; and steel or iron is the basis of most of them." It is unlikely that the Ontario Government were actuated by this motive when they appointed the Iron Ore Committee to investigate and report on the iron ore situation, nevertheless, these facts must have influenced them in some degree.

Jan 1, 1924

By D. F. Malan, U. Du Preez, P. S. Heyns

South Africa has two main platinum reef deposits, namely the Merensky reef and the UG2 reef. These reefs are currently mined using traditional drilling and blasting methods. Mechanized cutting could potentially enable continuous mining, which would offer significant advantages. This would require thorough understanding of the cutability of the rock. To explore this, a linear cutting machine was developed to conduct laboratory scale cutting tests. This work describes the development and commissioning of the cutting machine using sandstone, as well as subsequent characterization tests on UG2 reef samples. UG2 reef has large variability in strength on a millimeter scale. This introduces uncertainty in the test results due to added variance from one cut to the next for the same UG2 reef sample. Another problem is the variability in rock properties of the UG2 reef, when testing samples from different mines. The cutting tests led to fine fragmentation, which is known to be a significant problem for cleaning operations in underground stopes and warrants further research. A finite element method simulation of the rock cutting was conducted using ANSYS LS-DYNA and the continuous surface cap model to simulate rock cutting in the UG2 reef. It was found that it is possible to use LS-DYNA with the continuous surface cap model to model rock cutting of UG2 reef and get acceptable results, but the user must calibrate the model parameters using the experimental results. Therefore, the model is only fit for one set of cutting parameters and further work is required to generalize results.

Nov 27, 2024

By Arno C. Fieldner

Six years ago, I addressed the annual meeting of the American Society for Testing Materials on "Fuels of Today and Tomorrow."3/ Since then, our country has been drawn into another great war of veritably global extent, with unprecedented demands on fuels, foods, and materials in general. My purpose in this address is to review the changes in fuel supply and demand since 1937 and to give you my views on the outlook for the future. CONDITIONS IN. 1237 Daring 1936 the United States produced and consumed one-third of the world production of coal, two-thirds of the petroleum, and about 95 percent of the natural gas. Two-thirds of the oil produced in all countries since the discovery well was drilled in 1859 had come from American wells. With the exception of the three depression years 1931, 1932, and 1933, new oil reserves were being discovered since 1924 well in excess of our increasing rate of consumption. Discoveries of natural gas, likewise, were tremendous in volume, and this fuel was being transported to most parts of the country by pipe lines; some of them more than 1,000 miles long. We had all kinds of mineral fuels in abundance and at prices that did not stint anyone in the maximum utilization of the mechanical devices that were being developed on every hand. No one suspected that the time might come in a few years when, gasoline would be doled out to some of us at the rate of 1-1/2 gallons a week or that many of our fuel-oil furnaces would have to be converted to burn coal. Of course, these restrictions are due to unusual war conditions, such as lack of coastwise tanker transportation, unprecedented demand for aviation gasoline, and the shortage of rubber for automotive tires. However, these shortages do call our attention to the vital part of petroleum reserves in our country's future position among nations. Therefore, it is of special interest to review briefly the relations of recent supply and demand with respect to our various mineral fuels.

Jan 1, 1943

By Joan K. Kuenzi

This Information Circular brings together for consideration recommendations from U.S. Bureau of Mines research in the area of surface mine mobile equipment maintenance for the period 1982 through 1991. It updates the 1982 contract report by Baker and Alves that formed the basis for much of the work described in the present report. Recommendations for hazard abatement during work on mobile one equipment are presented and stem from the results and recommendations of the research in two areas: (1) equipment and workplace hazard reduction, and (2) management of maintenance information. Recommendations included in this report apply to both the operators and maintainers of mobile mining equipment as well as to the manufacturers of that equipment.

Jan 1, 1995

The borehole televiewer is a downhole geophysical logging device that produces continuous, oriented, 360¦ images of the drill hole wall. Two types of borehole images are currently being generated at the BHP Billiton Mount Whaleback deposit. The optical televiewer (OTV) tool captures a ærealÆ image of the borehole wall whereas an acoustic televiewer (ATV) generates an image through variations in physical borehole size, scattering the energy from an acoustic beam. Orientation of the resulting ævirtual coreÆ is derived through magnetometers and accelerometers, providing values within one degree for both inclination and azimuth. Downhole structures such as fractures, joints, foliations and bedding planes are selected directly off the borehole image, recorded and displayed in a 3D modelling package along side adjacent drill holes. Measurements are corrected from apparent to true dip and magnetic to true north. Strata-bound magnetic anomalies are identified and corresponding measurements excluded. The importance of borehole imaging increases substantially with its ability to integrate the OTV and/or ATV data with other forms of lithological and structural data. At Mount Whaleback, the borehole televiewer has been implemented to provide information for geotechnical exploration including structural analysis, lithological characterisation and rock-mass conditions. Within the large area in and around Mount Whaleback, drilling may intersect a number of different geological formations with various rock types and conditions. With the application of the borehole televiewer, reverse circulation drilling can provide information traditionally obtained by diamond drilling.

Jan 1, 2007

By E. Guerrini, M. Maccagni, J. Nielsen

"Lead is the most important material able to meet the current demand for energy storage. The lead acid battery is reliable, efficient and inexpensive. Continuous developments in battery construction are providing improvements in all aspects of the batteries’ performance. The lead acid battery is both the main lead product and the main raw material for lead production. More than half of the lead produced is from secondary smelters where batteries are the most important feed material. The environmental pressure on lead production has been increasing for many years, and continues to become stronger and stronger. The lead production processes and technologies themselves will require updating to meet the new regulations. Although they are very strict now, they will become even more so and current technologies may not be sufficient. Because recyclability is a strong point for the lead acid battery, the secondary smelters need to reduce the environmental impact as much as possible. In recent years, the secondary smelters underwent impressive changes in this direction, but some more improvements are possible. Electrochemistry can offer a step change improvement in making secondary lead production more environmentally friendly. Engitec has developed an electrochemical process base on a very high current density (high productivity) cell using an inexpensive electrolyte and at a relatively low cost. In this paper, the latest update on the technology is provided. INTRODUCTION The lead acid battery is considered the “walking dead” by some new technologies trying to replace it. It has played and will continue to play a very important role in our lives because it is inexpensive, fully recyclable and the existing lead and the mine reserves guaranty enough material for the extended future. According to the life cycle, the lead acid battery is the cheapest and the most effective system to store energy. Lead is practically a close loop where lead battery production consumes more than 80 % of the produced lead but contemporarily it is the most important raw material for the production of metallic lead. In fact, nowadays, the secondary production has overcome primary production and this trend is expected to continue. Primary lead is the make-up material for the existing battery production and the source of lead for the construction of the new ones."

Jan 1, 2018

By Harry E. Hughes

A section of the largest Superfund site in the country has become a success story for engineering innovation and for cooperative problem solving. “Superfund site” and “success story” are phrases that are not commonly found in the same sentence. Yet, their use seems justified. The project’s certification of construction completion from the US Environmental Protection Agency (EPA) includes a commendation. It reads, “for completing the project nearly a year ahead of schedule, at a cost substantially less than estimated originally and without com-promising the requirements for protection of human health and safety or the environment.” The EPA director who issued that certification also referred to the project as “a positive example of cooperation among all who have a stake in the outcome.”

Jan 1, 1996

By F. M. Jardine

I1944 the cry was for higher production more tons, more metal. New plants were built, capacity of old plants was increased and millmen all over the country were treating tonnages far above normal, sacrificing recoveries to vet that extra metal from extra tons. The list of "critical minerals," at first long, has been scratched until there remains, not a list, but only an item or two. Stocks of all metals and minerals, with possibly one or two exceptions, are now entirely adequate and numerous plants have curtailed or suspended operation.

Jan 1, 1945

By J. Qiu

By means of natural sedimentation, two different bentonite samples from Shandong province were purified, this paper studies the Hydro-properties of the two purified montmorillonite samples. Firstly, the layer charge of two purified montmorillonite samples were calculated by crystal structure formula reckon method and general hydro-properties were also measured. The research results showed that the layer charge of montmorillonite correlated well with its hydro-properties: mont-morillonite with lower layer charge had better hydro-properties, such as Mont-1, which had higher swelling volume and gelling value with lower CEC; while, montmorillonite with higher layer charge had worse hydro-properties, such as Mont-2, which had lower swell volume and gelling value with higher CEC; it proves that the hydro-properties of montmorillonite depends on its layer charge characteristics, layer charge characteristic is the inherent factors deciding the hydro-properties of montmorillonite, montmorillonite with lower layer charge has better hydro-properties than the one with higher layer charge. In this paper, the relation between the medium condition and colloid performance of Mont-1 are also studied. The results show that the hydro-properties of Mont-1 could be changed by changing slurry concentration (w/w) and shear rate or adding certain amounts of inorganic cation electrolytes, dispersants and surfactants. The viscosity of montmorillonite slurry could be enhanced by increasing slurry concentration,adding univalentcation electrolytes (less than 4% w/w) or proper amounts of dispersants and surfactants (less than critical micelle concentration); The slurry viscosity could be reduced by decreasing slurry concentration, increasing shear rate, adding proper bivalent (more than 4% w/w) cation electrolytes or proper quantities of dispersants and surfactants (more than critical micelle concentration).

Jan 1, 2014

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 G Neely

COPING WITH COMPLEXITY In every industry, and mining is no exception, plant and processes increase in complexity over time and managers and operators need correspondingly more knowledge. The mine manager has to delegate details to operators, engineers, metallurgists, accountants, safety specialists, personnel officers and the rest. Is it reasonable then, to expect the Mines Inspector to be competent to judge the conduct of all these operations against the criterion of the regulations? Obviously not, but what are the alternatives? One is a superficial inspection where the inspector goes on a hazard hunt for broken steps and missing handrails. Another is one in which an army of specialist inspectors marches on a mine, sometimes outnumbering the staff. Each is competent to assess some part of the operation and if he or she can find an opposite number among the mine staff, they can discuss details. But what good does it achieve? The system acts to remedy present defects and to make recommendations which, if only they were followed, would prevent the same things happening again. Given that this process has been going on since the first Factory Act of about 1840, how is it that there are any more defects left to put right? The answer of course is that defects keep appearing, and new defects arise as fast as the old ones are found and corrected. Further progress can only be made by preventing defects at their source.

Jan 1, 1994

By G. Montgomery

This is a summary of what has happened to the domestic production of two industrial minerals vital to a healthy US economy: fluorspar and barite. A few years ago we were self-sufficient in both minerals and good ore reserves still exist. FLUORSPAR Some 9% of the fluorspar presently being consumed in the US is imported, whereas the use of fluorspar has not declined proportionately. Several factors can be mentioned.

Jan 1, 1986

Recent developments in diamond drilling practice have been chiefly 'concerned with modifications in drill design and 'operating technique whereby an increase in daily footage rates and reduced footage costs have been achieved without any marked improvements in the recovery of core. This trend is perhaps due to the general acceptance by the mining and drilling engineer alike of the belief that diamond drilling has definite limitations in exploratory work on mineral deposits characterized by irregularities in continuity and grade, such a belief arising from the fact that drilling technique has not yet evolved coring devices to ensure the full recovery of the rock and mineral formations penetrated.Current diamond drilling operations at Moonta and Wallaroo Mines, carried out by the South Australian Department of Mines, have attained remarkable results in completely eliminating core-loss by the use of a special double-tube core barreI.It is considered that assays of borehole samples taken with this special barrel have a reliability comparable, if not superior to that of similarly situated mine samples and, provided they are spaced satisfactorily, can be used as, a basis for calculating tonnage and grade. Formerly, with only partial core-recoveries, positive borehole results on narrow irregular lodes, such as those in the Moonta and Wallaroo Mines, could be accepted mainly as indications of the presence of mineralization, and could have only a limited bearing on estimates of ore reserves.The value of this special double-tube core-barrel lies In the fact that it guarantees good core recovery and, therefore, good samples, and eliminates the need for sludge-sampling, which is prone to give unreliable assay results from several causes, such as gravity concentration in the bottom of the hole and return water losses which cannot be overcome.In view of the increasing demand for minerals and the probability that the search for them will be carried on largely by boring, it is felt that it would be of interest and value to direct the attention of mining engineers to core-recovery results obtained by diamond drilling plants in South Australia and the features of the special core-barrel, designed by the writer, which has made this possible. Also, the writer is desirous of placing on record two other core-recovery devices designed to extract accurate samples in relatively soft or unconsolidated formations. The latter are used with percussion and calyx plants, respectively and their value has been proven on phosphate rock and coal deposits in South Australia.

Jan 1, 1943

By E. Lutz, M. Momayez, K. W. Brown Requist

As real-time air quality monitoring becomes more prevalent in US underground mines, it is important to provide the highest data reliability with the fewest possible sensors. Real-time sensors remain costly, and these costs are not exclusively financial; the time required to install, calibrate, and maintain real-time sensors poses a large barrier to widespread implementation. Current atmospheric monitoring systems typically rely on displaying point-specific values. This requires operators to infer real-time airborne contamination distributions. Monitoring and control software utilizing mine ventilation network (MVN) solvers has been implemented in limited cases because of their ability to simulate ventilation systems quickly, but these solvers use a one-dimensional representation of the mine, limiting spatial resolution of estimated distributions. Computational fluid dynamics (CFD) has likewise been considered as a means to improve spatial resolution, but processing times prevent its use as a basis for monitoring and control. For the real-time monitoring of airborne contamination distributions, we propose a spatial interpolation method that can estimate the distribution of airborne contaminants in near-real time. This method provides a middle ground between fast processing times and increased spatial resolution. With the use of a pathfinding algorithm and optimization through absolute percentage error minimization, this method outperforms spatial interpolation with a Euclidean distance. By providing contamination distribution information to operators, this method and its derivatives stand to outperform current atmospheric monitoring systems.

Apr 16, 2024

By Bruce Gellar

In March, the Prospectors and Developers Association of Canada (PDAC) held its annual conference in Toronto, Ontario. This is the third PDAC meeting the author has attended. The following are some impressions of the meeting. And the author looks forward to the joint meeting of the PDAC and the Canadian Institute of Mining, Metallurgy and Petroleum to be held March 5-10, 2000, entitled Mining Millennium 2000. One of the features of next year’s gathering is a proposed forum of world mining ministers, the first ever to be held anywhere.

Jan 1, 1999

By Egil Aukrust

"An American Iron and Steel Institute Task Force evaluated developing direct steelmaking technology worldwide to seek a replacement for the coke-oven, blast-furnace, basic-oxygen process technology now in use. To remain internationally competitive it is essential to move away from the traditional series of batch processes towards continuous processing and the associated energy savings which are possible with high technology process control systems. The group identified in-bath smelting of iron ore pellets or fines with coal as the process most sui table for domestic raw materials (including abundant scrap) and called for research to study operation with varying degrees of preheat and prereduction of the ore by the gases generated from the coal and various degrees of combustion of these gases above the melt.A coordinated, 3-year, $27 million, direct steelmaking research program is proposed. Concurrent projects include design, construction, and experimental operation of an in-bath smelting pilot plant; modeling, simulations, and laboratory-scale experiments at universities on slag-phase and metallicphase reactions and interactions; and large-scale heat transfer and reaction rate trials. Also included are modeling studies and pilot plant trials of on-stream decarbonization and desulfurization; application of circulating fluid bed technology to fine ore reduction and hot gas cleanup; and specific heat transfer and fluid flow research projects.IntroductionThe American Iron and Steel Institute (AISI), based on the Task Force studying direct steelmaking, believes strongly that a coordinated program of research on the reduction of domestic raw materials to liquid steel should be undertaken as part of the Steel Initiative program. To specify the steelmaking process for development best suited to the American steel industry and domestic raw materials, it was important to determine the state-of-the-art of direct steelmaking worldwide, both as practiced and under development, and then, by expert analysis of the processes and their potentials, to choose the process most likely to provide a domestic competitive edge."

Jan 1, 1988

The principal activities of the Bureau of Mines Explosives Research Center (now Safety Research Center) during fiscal year 1968 (July 1, 1967, to June 30, 1968) are reviewed in part 1. Part 2 presents short abstracts of the publications issued during this period in the Bureau series and in other media. Part 3 describes a short study on the thermal decomposition of RDX and HMX not destined for publication elsewhere. ACKNOWLEDGMENTS The Bureau gratefully acknowledges the support received through cooperative agreement in fiscal year 1968 from The Manufacturing Chemists Association.

Jan 1, 1970

By Andreas Jungbauer

The Chinese steel producer Rizhao Steel is now focusing on the highly attractive local and export markets for high-quality, thin-gauge strip products. The first line of five Arvedi ESP plants began operations in the spring of 2015. The new casting-rolling complex is designed for a total annual production capacity of 11 million tons of highquality, ultra-thin, hot-rolled strip products with widths of up to 1,600 mm and thicknesses down to 0.8 mm. The energy consumption and related costs are reduced by up to 45% compared with conventional casting and rolling processes. This also means a major reduction in CO2 emissions. During the project phase, the plant personnel from China received extensive training at the licensor’s plant – Acciaieria Arvedi S.p.A. in Italy – to prepare them to deliver the best operational performance with the new state-of-the-art endless casting-rolling facility. The plant setup, the training and support program, as well as the latest results from the start-up are presented in this paper.

Aug 16, 2017

By P. E. Churchward

Rhenium sources and recovery methods were investigated by the Bureau of Mines to delineate potential resources of the metal. The only significant rhenium resource appears to be about 28,000 lb of rhenium contained in the domestic annual output of approximately 20,000 tons of byproduct molybdenite concentrates from porphyry copper operations. An estimated 70 to 80 pct of this rhenium is potentially recoverable by processing the rhenium-bearing fumes and dusts obtained during conventional roasting of molybdenite concentrate. At 70 pct recovery this would amount to 19,600 lb of rhenium. A more conservative estimate by the Committee on Refractory Metals of the National Research Council (1513 is that 12,000 lb of rhenium metal could be produced annually from current production of molybdenite from porphyry copper operations in the United States. A procedure was developed in the laboratory for recovering rhenium in the form of electrolytic flake by electrowinning the metal from a solvent extraction strip solution. The procedure included (1) water leaching of molybdenite roaster flue dust, (2) selective extraction of rhenium from the leach liquor by contacting it with a kerosine solution of a quaternary amine, (3) stripping of rhenium from the loaded organic solution by a perchloric acid solution, and (4) electrodeposition of rhenium from the loaded strip liquor. Raw material for the studies was flue dust containing 0.48 pct Re, 35 pct Mo, and 23 pct S in sulfide and sulfate form, and small amounts of numerous metallic impurities. Water leaching dissolved 85 pct of the Re and yielded a solution that was 13 in sulfuric acid and contained, 1 g/l Re and 16 g/l Mo. The solvent extraction strip solution that was electrolyzed for rhenium deposition was 1 molar in perchloric acid and 1 molar in ammonium sulfate and contained 13 g/l Re and 0.01 g/l Mo.

Jan 1, 1963