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By Fumitaka Tsukihashi

Increasing amounts of steel scrap are being used as resources for steelmaking. Therefore, there has been a growing interest in the removal of harmful tramp elements such as antimony, zinc, tin, arsenic, bismuth, lead and copper from the molten steel. The problem that should be solved is the economic removal treatment of residual tramp elements in the steelmaking processes and the production of high quality steel by reducing the effect of the contaminated tramp elements and satisfying the environmental regulations. In this paper, the available thermodynamic data of the residual tramp elements in the molten steel arc summarized and the possibility of the removal of residual tramp elements from the molten steel is thermodynamically estimated.

Jan 1, 2003

By J. N. Van der Merwe

The current state of the South African mining industry is briefly reviewed from the point of view of an engineer not schooled in the finer details of predictive economics. Based on the assumption that current world exploration targets are indicative of which commodities the world will want in the future, it is concluded that the South African mining industry will continue to be viable and growing well into the future. South Africa holds the minerals the world wants and needs, and as long as the world has people, the demand for those, including gold, will continue to grow. There still is a growing demand for vanity commodities' and even the demand for platinum as a jewellery material displays significant growth. Mine safety still needs to improve, but significant improvement has already been made although the industry is not always acknowledged for the effort in this field. The safety target set for 2013 is within reach but will require sustained effort. The physical mining conditions for the main revenue earners, coal, platinum, and gold, will change substantially in the near future. Research in mining has declined alarmingly and it is urgently necessary for that to be revitalized to generate the knowledge that will be required. In order to streamline the transfer of knowledge to the mining engineers of the future, research needs to be conducted with the full involvement of the universities. It will also be necessary for the universities to continually review curricula to incorporate the latest knowledge and to embark on a campaign of knowledge transfer to the older generation of mining engineers. The mining industry is well supported by the universities, who have done their duty with regard to societal transformation, and the universities are in turn supported by the industry through vehicles like the METE Industry is also strongly supported by a number of professional and vocational societies. The SAIMM will continue to play its vital role as the meeting point of the mining technical sciences, and will continue to disseminate knowledge via the journal, schools, and conferences. In the future, it will review its modus operandi to support the needs of growing membership in the remote branches. It will enter the research arena in an appropriate manner and give effect to the developing integration of mining and society. The most important threat to the future of the mining industry is the recurrent mention of nationalization. While interaction between the mining industry and political and economic development of South Africa has always been characteristic, the current debate is emotional more than rational, and engineers are not well equipped to participate. This matter needs to be finalized before it becomes a popular force that politicians cannot control.

Jan 1, 2011

Reduce costs of recontouring surface mined land by improving bulldozer blades. Approach A specialized 48-foot-wide bulldozer blade set at an angle, a 13-foot bulldozer blade with swept-forward end sections, and a 24-foot grading bar are used in conjunction with conventional bulldozers to reduce the cost of recontouring surface mined land. How They Work The angle blade is used to do the initial and intermediate leveling of long spoil banks. It is mounted at an angle on two 410-horsepower crawler tractors in a side-by-side offset configuration, but requires only one operator since both tractors are controlled by a single set of controls. The angle blade usually begins its cycle at one end of the spoil bank where the operator fills the blade and moves forward, continuously cutting and casting the material to the repose slope. At the opposite end of the spall bank, the angle blade turns around and begins cut-ting and casting material to the opposite repose slope. This action continues until adjacent banks meet or the lateral distance from the center line of the spoil bank to the repose slope exceeds approximately 40 to 50 feet. At this distance, the sidecasting angle blade is no longer effective, and conventional bulldozers are used to do the final land shaping.

Jan 1, 1981

When the Mining Bill came before the Victorian Legislature not so many months ago, the question arose whether mining managers required education, and to what extent. Some members of the House expressed themselves in a way which appeared to leave the impression that mining managers would be all the better if they were not brought up in a scientific school.To try and prove what we owe to science I will give a short history of colonial mining from the earlier period to the present time and compare results.I believe I am right in saying that South Australia is the pioneer colony in mining and to her belongs the credit of not dnly being the first mining colony, but also that her beginning turned out so successful, as the history of the Burra Burra copper mine will testify. At about the same time a little galena mining was carried on nearer to Adelaide, but as this did not prove a success and was only worked by tributing parties, little notice was taken of it.

By J. P. McGee

As part of a joint U.S. Atomic Energy Commission-Federal Bureau of Mines program for using nuclear energy to supply process heat, a simulated nuclear loop has been constructed to test components. This loop has been operated for more than 1,800 hours at 100 p.s.i.g. Of this period, 23 hours were at 2,500° F. and higher; 540 at 2,000° to 2,500° F.; 840 at 1,500° to 2,000° F.; 200 at 1,000° to 1,500° F.; and 260 below 1,000° F. Leakage at flanges and welds was not a serious problem. A helium-recycle system with gas temperatures of 2,300° to 2,500° F. and a static pressure of 250 p.s.i.g. appears feasible. Difficulties were encountered with the recycle compressor due to thermal distortion of the impeller and shaft. The use of sealed bearings limits compressor operation to the life of the bearings.

Jan 1, 1960

By John C. Calhoun, Raymond G. Loper

Theoretical calculations for the decline of pressure and the variation of instantaneous producing gas-oil ratio with increased cumulative production have been made for reservoir systems under various producing drawdown values and for various spacings. These variables have been included by a modification of previously Published techniques. This consists essentially of utilizing a radial system flowing gas and oil in a succession of steady state calculations. The results of the calculations do not show any variation in the predicted behavior of the internal gas drive reservoir when either the drawdown or the spacing are changed. The prediction of performance on an internal gas drive reservoir has been presented by various authors. ',"' These predictions are in the form of a pressure decline and an instantaneous producing gas-oil ratio as a function of cumulative oil withdrawal. In making these predictions a basic assumption has been that the saturation of the reservoir is uniform throughout at any time, or that the pressure differential imposed on the reservoir system is zero. Because of these assumptions the validity of such predictions has been questioned. Their application to actual systems, where saturations are not uniform and where producing differentials exist, has been a hazardous procedure. The authors cited have used different methods of approach to the derivation of equations for making their predictions and for arriving at a solution of both equations, but basically the same relationships are utilized in each case. In all instances the instantaneous producing gas-oil ratio is calculated from the equation: In utilizing this equation an average reservoir pressure and an average reservoir saturation must be known, the former to define ß, v, s, and uo/ug and the latter to define kg/ko. Predictions can be made, therefore, only for the conditions of a uniform reservoir saturation and a uniform reservoir pressure. This restriction of requiring a uniform oil saturation can be resolved by applying two-phase steady state flow for the radial system to the reservoir's history. Radial steady state flow is defined when the ratio of phases flowing,

Jan 1, 1949

J. E. JOHNSON, JR., New York.-It seems to me that it ought to be somebody's job to tie these notch tests with the reversed-stress tests, because the thing that causes failures in structures, in a great majority of cases, is where the material is stressed repeatedly up somewhere near the elastic limit, and the repetition of that stress seems to bring about what I suppose you may call a growth of crystals and that eventually develops into a break. It seems to me that it would be of the greatest value if there could be a coordination of the results of a shock test of some kind with the reversed-stress test, so that we could be sure that a material that had shock-test resistance would have reversed-stress resistance. H. F. MOORE,* Urbana, Ill.-The question raised by the speaker concerning the correlation of results from impact tests of notched bars with the results of repeated-stress tests is a very complicated one. Impact on a specimen sends energy into the specimen, and if the specimen absorbs this energy without fracturing there must be developed both stress and elongation. A notch in the specimen allows but little elongation to take place before rupture, and develops the ductility of the

Jan 5, 1919

By Trevits MA

The United States Steel Corp. in cooperation with the United States Government is conducting a large-scale methane drainage field demonstration using stimulated vertical boreholes drilled in advance of mining. A grid pattern of 23 boreholes, isolating approximately 1.5 km2 of coalbed area, has been drilled to the lower bench of the Mary Lee coalbed, Jefferson County, Alabama. Upon completion of drilling operations, various hydraulic stimulation treatments utilizing nitrogen-generated foam, water, and gelled fluid were performed to enhance the rate of methane gas removal. Production from the grid pattern began in September 1977 and continued as the last borehole was placed on production during October 1980. To date, in excess of 33,800,000 m3 of methane gas has been drained as a result of this effort. Underground mining operations were approximately 3.2 km from the grid pattern when production began and have currently progressed to within 1.6 km. Underground interception of the grid is expected in 1986.

Jan 1, 1982

"Depletion of known ore reserves and increased demand for precious metals have caused a revolution in biohydrometallurgical processing technology for gold recovery. Known ore deposits and future discoveries are most likely to be lower grade sulfide ores that can be difficult to recover with current leaching technology. Future metal recovery operations will increasingly use bio-oxidation techniques.Bacteria are an integral part of mineral cycling and mineral transformation in nature. Although biological processes are recognized as part of the mineralization and oxidation reactions in some ore deposits, they have only recently been applied to enhancing metal recovery in hydrometallurgical procedures. This paper explores the traditional metallurgical application of biological leaching and oxidation reactions and reviews the complete range of bacteria available for metal recovery systems. Pre-treatment of ores with bacteria improves metal recoveries in tank leaching systems and shows promise for heap leaching methods.IntroductionThere is no longer any question that bacteria playa natural role in the on-going transformation of some ore deposits (1,2). As applied to sulfide ores, a few strains have been specifically identified that exhibit a natural leaching potential (3). These bacteria can be isolated from waters and soils in old mining districts where they contribute to continuing leaching and pollution problems in acid drainage and heavy metal solubilization. Sulfur and iron bacteria as well as many heterotrophic strains have also been found in ore deposits and sedimentary rocks at depths up to 2000 meters (4). Their presence in both ore deposits and processed ores shows the microbial association with natural leaching and the potential role that bacteria can play in the development of new leaching technology."

Jan 1, 1988

By A. R. Miller, M. C. Bétournay, D. L. Barnes

"A number of successful proof-of-concept projects have been carried out to replace conventional power application, such as diesel and rechargeable batteries, in underground mine vehicles. This has led to the development and testing of the world’s first fuel cell production vehicle, a mine locomotive. A fuel cell loader is being built and tested.This paper provides an insight into other projects that are being carried out. Some are related to further underground applications, and some to further research, such as refueling options, power plant durability, and vehicle automation.Also outlined is an evaluation of the overall mining applications and advantages this technology can bring to underground mining, including the facilitation of automation and tele-remote operation."

Jan 1, 2003

By Paul B. Crawford, Bobby L. Landrum

Electrical model studies have been made of the effect of drainhole drilling on production capacity. Drain holes are those lateral holes which are sometimes drilled to assist in increasing the oil drainage into the main wellbore. The studies indicate that if the drainhole length i.r near 0.2 of the drainage radius, the increase in production capacity may be approximately 1.8, 2.08, trnd 2.33 for the case of one, two and four drain holes, respectively. If multiple drain holes are drilled, shorter holes are required to achieve a specific increase in production capacity than if one or two holes are drilled. To achieve increases in production capacities by factors near three it is shown that the drainhole lengths divided by the drainage radii must be approximately 0.64, 0.48, cnd 0.37 for the case of one, two and four drain holes, respectively. IN T RO DUCTION Kecent developments in drilling techniques have permitted the drilling of lateral or horizontal holes to increase the rate of production. The number of these drain holes may vary from 1 to 10, and they have been drilled laterally as much as 100 ft. Drainhole drilling at substantial depths is of recent origin but has been used in the Spraberry field of West Texas, the La Pas field in Western Venezuela, and certain fields in California. The diameter of the drain holes has been approximately 6 in. In drilling drain holes it is desired to know how much increase in production capacity may be expected, what additional benefit may be gained by drilling more than one drain hole, and what increase in production capacity may be brought about by lengthening the existing drain holes. In realization of the importance of lateral drilling, electrical model studies were made to provide quantitative estimates on the effect of drain holes on production capacity. ANALYSIS An electrical model was used in studying this problem. A wooden circular reservoir approximately 30 in. in diameter and 2 in. deep was filled with a dilute salt solution to a depth of 1 in. A copper band formed the periphery of the tank, and a copper wire was inserted in the center of the tank to represent the well. The drainage radius divided by the well radius was equal to 500. A diagram of this type model is shown in the inset of Fig. 1. An electrical potential was applied to the wire well and copper band at the periphery to determine the flow of current. Following this measurement copper wires of various length were soldered to the vertical wire well in such a manner as to simulate lateral wells drilled into the reservoir. Multiple lateral holes of various lengths were studied by varying the number and length of copper wires soldered to the vertical wire well. All multiple lateral wells were located symmetrically about the vertical well. The effect on production capacity by drilling an infinite number of lateral holes was studied by replacing the lateral hole with a copper disk. For each condition the flow of current was measured and compared with the flow of the vertical well only. The model which is thus described provides the steady state increases in production capacity which may be expected in some cases. The data conform to those which would be observed for a uniform homogeneous reservoir. The data may have primary application to those reservoirs producing above the bubble point. It is realized that few lateral holes are drilled in reservoirs of this type, but the data may be of some value in guiding future work or aiding to explain observed phenomena.

Jan 1, 1956

Downtime cannot be tolerated on electric shovels whose cost may approach or exceed $400,000 each. The same may be said for larger-variety off-highway trucks which require an operational expenditure upwards of $50 per hour. One company, for instance, in order to ensure a more continuous operation, has specified centralized lubrication for all of its new equipment. In wet or dry weather, the mining of asbestos can place undue strains on machinery and other equipment. When the mineral is dry, its dusty, loose fibers work their way into crevices, and when wet, the glutinous asbestos may adhere to axles, gears and other wear components. Such conditions are multiplied during the extreme cold winters of eastern Canada. It is more difficult to lubricate and maintain equipment, and erosiveness becomes more punishing to wear parts. Resultant breakdowns rapidly drain off profits.

Jan 1, 1971

By K. B. Shedd

Questions regarding possible adverse health effects from exposure to zeolites arose when the inhabitants of two villages in Turkey were found to have high incidences of mesothelioma, a disease generally identified with exposure to asbestos. No asbestos deposits are known in the area, but some fibrous zeolites have been found. Further investigations have resulted in conflicting opinions as to whether fibrous zeolites are related to the high incidence of mesothelioma in Turkey. The U.S. Department of the Interior, Bureau of Mines examined the habits of domestic zeolites by scanning and transmission electron microscopy. Only erionite and mordenite particles possessed acicular to fibrous habits. With the exception of a rarely occurring woolly erionite sample, the fibrous zeolites were not dimensionally equivalent to asbestos.

Jan 1, 1982

By A. F. Usov

A potential of electric pulse disintegration in benification used for primary deposits ores containing precious metals is shown. Of special significance is that PGM and gold grains, being highly plastic, are easily liberated and are not smeared on the disintegrated rock fragments surface. It al-lows gravity separation, which is less expensive and more efficient, to be used instead of chemical processing, which is expensive and environmentally faulty.

Jan 1, 2014

By Louis M. Perlman

CAN PRESENT TRENDS CONTINUE? Can population growth in the world keep going at the average rates of the last few decades, till, say, the year 2000? And beyond? At the same time, can we expect steady increases in mineral consumption per head, all over the world, as the living standards of many nations converge toward the living standards of North America? If they do converge? Does the total fund of world resources extend, with foreseeable techniques, to supplying the consequent demands for metals, non-metallic minerals and energy? Do we have the requisite economic and scientific techniques available to answer these questions? Certainly, we cannot forecast over decades with any certainty. There are many, of course, who seem to believe that by the simple fitting of trends, they can tell us something about the world and resource constraints in the year 2000, twenty-three years from now. It is significant that many studies of this sort have added sustenance to the 'doom-watching' fraternity of commentators. The reason is simple. The extrapolation of exponential trends into the distant future frequently leads to the most astounding and impossible scenarios. Another feature of exponential growth is the suddenness with which certain fixed limits are approached. It took world population two hundreds years to increase by 1/2 a billion, from 1650 to 1850. Yet some U.N. estimates suggest that the net addition to human population will be over 2 billion between now and the end of the century. Thus, the present world population would increase from a little under four thousand million today to rather over six thousand million in the year 2000.

Jan 1, 1977

By Duluth Engineers' Club, Engineers' Club of Northern Minnesota

"During the last ten years great strides have been made, on the Mesabi Range, in the practice of beneficiating low grade iron ore material. By .beneficiation is meant all methods of removing impurities, and raising the iron content to a point where it can be sold in open market, the principal impurities being silica and moisture. The • general processes to which low grade iron ores are amenable are as follows:1. Thermal(a) Drying ; removes hydroscopic or atmospheric moisture. .(b) Calcining; removes carbon dioxide from iron carbonate, molecular water from hydrated hematites, and atmospheric moisture.Roasting; removes sulphur, carbon dioxide, molecular water and atmospheric moisture.Agglomeration; primarily for the purpose of preparing finely divided material for blast furnace; briquetting and sintering.2. MechanicalScreen sizing; removes rock and sand.Classification; removes sand by means of currents of water of varying velocities.Log washing; removes fine sand.Jigging; removes larger particles of impurities than is possible by log washing. Certain types of jigs remove fine sand.Reciprocating tables; recover fine iron particles from sand discarded by above processes.Magnetic separation; applicable to the commercial separation of the magnetic oxide of iron from gangue material. From a scientific standpoint it is possible to separate certain hematites and limonites from their gangue:(g) Miscellaneous processes; comprise dry concentration, electro-static separation and other processes."

Jan 1, 1920

By D J. Williams

The approach to the disposal and storage of mine tailings is slowly evolving. Tailings disposal has been based on minimising short-term capital and operating costs, with rehabilitation costs discounted by the application of a high discount factor in a net present value approach to accounting. This has led to the widespread adoption of surface tailings storage facilities (TSFs) to store slurried tailings delivered by robust and cheap centrifugal pumps and pipelines. Depending on the site climate, rate of rise of the tailings, nature of the tailings and the extent to which supernatant water is removed from the surface TSF, the tailings may or may not dewater, densify and gain strength. High rates of rise of dilute tailings to a facility used to store both tailings and supernatant water results in a wet, low-density, soft tailings deposit that not only occupies a large storage volume but also presents rehabilitation difficulties. A low tailings density results in high containment wall costs, very high rehabilitation costs and a low potential for future land use or ecological function. Overall, the cost of slurried tailings disposal, thought to be low, is actually high. However, low rates of rise, even of dilute tailings, in a dry climate with efficient supernatant water removal can produce a dewatered, high-density, stiff tailings deposit that may occupy a large footprint but to shallow depth that is relatively easy to rehabilitate. There are advantages in dewatering tailings in the processing plant to recover process water and chemicals, facilitate tailings disposal in a more solid form and facilitate rehabilitation. However, the cost of dewatering in-plant can be high, and the process water may not lend itself to reuse. There are also advantages in removing supernatant water to facilitate solar and wind drying of exposed tailings, although water is lost to evaporation and the dried tailings may best be harvested prior to inundation by fresh tailings or rainfall run-off. This paper discusses the background and trends towards the elimination of conventional surface slurried TSFs, with examples presented of the management of black coal and other tailings, including those that are clay mineral-rich.CITATION:Williams, D J, 2015. Towards the elimination of conventional surface slurried tailings storage facilities, in Proceedings Tailings and Mine Waste Management for the 21st Century , pp 11–24 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Jul 27, 2015

By Robert Lepsoe

IT is generally realized that in cyaniding the precipitation efficiency of zinc dust is due to the fine division or extended surface of its metallic particles; but frequently it is thought that the presence of other, metals, say 2-3 per cent. lead, is advantageous,. causing more complete precipitation. The results of testing about fifty brands of commercial zinc .dust have led to the conclusion that there is a distinct relation of precipitation efficiency to fineness and that the effect generally can be estimated by examining the size of metallic particles. The presence of lead was not found to be of any importance. SPECIFICATIONS Generally the term "97 percent. to pass a 350-mesh screen, 95-97 per cent. uncombined metallic zinc" is used by the leading European exporters. Among the many methods of determination of metallic zinc, I have found the iodine test (iodine in potassium iodide) very satisfactory and rapid. It has been controlled by the other methods, samples of the same product having been sent to three different analysts: Iodine method 98. 11 per cent. metallic zinc, Volumetric method 97.63 per cent. metallic zinc, Ledoux Co., New York Bichromate method 98.16 per cent. metallic zinc, Watson Gray, Liverpool, England Bichromate method 98.20 per cent. metallic zinc, Norway Inst. of Tech., Trondhjem

Jan 2, 1925

By S. N. Titkov

Flotation of halite?new, recently begun to be developed method of processing water-soluble minerals. In the paper the results of studies of the new directions of the application of halite flotation are represented. Studies on the flotation separation of halite and sylvite in the salt solutions of different composition, showed the possibility of the halite flotation realization not only in the carnallite brine (content of salts: MgCl2 25.5% ~ 26.0 %, chlorides of potassium and sodium 5.5% ~ 6.0%), but in the sylvinite brine, which contains 10.5% ~ 10.8% KCl and 20.5% ~ 21% NaCl. On the basis obtained results are carried out experiences on the halite flotation from samples of the converted products of sylvinite ores by flotation method and by the method of the electrostatic separation. It is shown that in all cases it is possible to accomplish effective and selective recovery of halite. The halite recovery into the foam product of flotation makes 80% ~ 90% with an increase in the content of KCl in the cell product of flotation in comparison with a composition of flotation feed: - from the product after the electrostatic separation of ore ? from 76% KCl to 95% ~ 97% KCl; - from the small fraction of ore (- 0.25 + 0 mm) ? from 30% KCl to 60% ~ 64% KCl; - from middlings (intermediate products) of sylvite flotation from 16% ~ 31% KCl to 45% ~ 80% KCl. An increase in the molecular weight of alkylmorpholines increases the selectivity of the flotation separation of halite and sylvite. Halite recovery from small size fraction of ore or/and middling of sylvite flotation with the sub-sequent joint filtration halite product and tails of sylvite flotation allows to reduce considerably expenses for manufacture potash chloride from Pilot-industrial tests for the first time confirmed the possibility of the effective halite flotation in the saturated solutions of chlorides of potassium and sodium (sylvinite brine).

Jan 1, 2014

By A. Meek

This report compares the compressed air driven rocker shovel to the newly developed Warthog Non-throw development end loader. The two machines were compared on aspects such as safety, loading potential, energy efficiency and costs. The objectives of the comparison were to determine whether or not the replacement of the rocker shovel with the Warthog will be operationally and financially justifiable. The results from this study were obtained from underground observations and time studies on the machines, as well as consultations and data collection at the shaft and suppliers. This paper compares only the Warthog loader to the Trident 215 rocker shovel used at Anglo Platinum?s Brakspruit shaft and does not compare the other models of rocker shovels, which are fundamentally the same but will have different loading potentials and specifications. Cleaning times for the rocker shovel are based on underground observations at Brakspruit shaft. These times can be influenced by factors such as blasting practices, compressed air pressure and operator experience and skill. For this reason the times will most likely vary at different shafts. The Warthog cleaning times are based on manufacturer specifications and results from trial stages and therefore further work is required to confirm cleaning times achieved.

Jan 1, 2009