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By Sydney H. Ball

AMERICAN consumption of industrial diamonds has increased five fold in the past 25 years and today accounts for 15 to 20 percent of the world's sale of rough diamonds. In another decade the value of industrial diamonds sold may well equal or exceed that of gemstones. It is generally understood that industrial diamonds are one of the strategic minerals being stocked by the Government in the present crisis to ensure rapid and efficient armament production. Diamond die making is a trade largely confined to artisans in Switzerland and in certain parts of France. Today, in addition to turning out pilots, we should train expert artisans in diamond die making, for thousands of miles of tremendously small-gauge wire will be needed to make the instruments by which the efficiency and safety of these pilots is assisted.

Jan 1, 1941

Optimisation of the Advanced Automation System at Inmet Mining's PyhSsalmi Mine, Finland

Sep 13, 2010

By Ruddle R. W.

An outline account is given of the smelting of copper and the chemistry of the process. A table provides compositions of the more important minerals from which copper is won by smelting. Roasting is discussed as is smelting using reverberatory furnaces, blast furnaces and flash smelting. A brief discussion of converting covers the upright (Great Falls) converter and the horizontal (Peirce-Smith) converter.

Jan 1, 1953

By D. E. Hirsch, J. W. Davis, Norman G. Foster, F. G. Schwartz

This investigation was undertaken to identify nitrogen , oxygen , and sulfur compounds (polar components ) found in catalytically cracked distillate fuel . It is significant that these compounds concentrate in the sediments and gum that form when the fuel is stored . The polar components were divided in three portions by elution from a chromatographic column filled with alumina . After the hydrocarbons were washed through the column with pentane , a benzene eluted extract was removed followed by an ether eluted extract and then an alcohol desorbed fraction . These extracts were individually distilled in a molecular still and the fractions were analyzed by gas chromatography , mass spectrometry , infrared spectrometry , and elemental and functional analyses . Naphthalene and its homologs , phenanthrene and its homologs , and other compounds such as methyl indene , C₂ quinolines , phenyl indan , and the benzothiophenes , appear in the benzene extracts . Quinolines are the major components of the lower boiling fraction of the ether extract , although carbazoles , acridans , and indoles are present in some concentration . Elemental and functional group analyses of the alcohol fraction indicated 10 percent of the distillate portion was nonhydrocarbon , and in this portion the average molecule contained more than one nonhydrocarbon element . Compounds of such complexity are not well known , and standards for positive identification are limited .

Jan 1, 1963

By D. Scott Barr

The Zarafshan/Newmont Joint Venture operates the Muruntau heap leach project, located in the Kyzylkum desert of central Uzbekistan. The mine produces more than 12.4 t/a (400,000 oz/year) of gold from low-grade oxide ore stockpiles adjacent to the Muruntau open pit. It is op¬erated by the Navoi Mining and Metallurgical Combine and is one of the largest gold resources known (Fig. 1). Since commissioning in 1995, total heap leach production has exceeded 21 t (675,000 oz). The joint venture uses four-stage crushing and screening to produce a final product for heap leaching, Merrill-Crowe processing and local refining.

Jan 1, 1998

By Yasushi Ishikawa

The fact that the degree of granulation and the state of granulated particles of sinter raw mixtures are the influential factors in ensuring coke combustibility and permeability during sintering has been clarified. Based on this knowledge, Nippon Steel developed the divided coke-addition process and the technology to utilize binder, and applied them on a commercial scale. Productivity and sinter quality are thereby greatly improved with a significant reduction in fuel consumption.

Jan 1, 1977

By J Harris, M Shi, S Vink, P A. Kirsch

Across the life-of-mine, water is both an essential commodity to mining, and one of the most significant hazards. In Australia, a land of drought and floods, availability of water is a critical strategic risk for mine sites and neighbouring stakeholders, with both insufficient water leading to curtailed operations and contested space, and extreme water closing operations through flooding of mine sites, transportation infrastructure and unplanned regulatory restrictions. In addition to these major strategic risks, water must be addressed in operational risk management activities in many different ways.This paper develops a set of categories for classification of water risks based on academic papers from the water in mining literature. These categories are applied to media content analysis of articles in International Longwall News (ILN) (an online coal industry news site) obtained with the search terms ‘water’, ‘rain’ and ‘flood’. Identified risks are discussed within the context of the life-of-mine. The paper uses these same categories to analyse the treatment of water risks in a new coal industry risk management body of knowledge called RISKGATE (http://www.riskgate.org, Minerals Industry Safety and Health Centre, The University of Queensland). The discussion of water risks in both INL and RISKGATE is compared and contrasted to pinpoint opportunities (and a roadmap) for further development of a specific RISKGATE water module for site-based operations. The media review also identifies areas for development of RISKGATE expansion topic(s) that would address other strategic water risks, eg severe weather events.CITATION:Shi, M, Kirsch, P A, Vink, S and Harris, J, ?2014. Water as risk in mining – media analysis and the RISKGATE body of knowledge, in Proceedings Life-of-Mine 2014 , pp 205–218 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Jul 16, 2014

By F. R. Cattoir, R. E. Cumings

Columbium metal was electrorefined in a fused - salt electrolyte . Excellent results were obtained in lowering the impurity content in a 94 - percent columbium anode feed material to produce a 99.8- percent - pure metal . The reductions of the major impurities follow : Oxygen from 19,800 to 500 ppm , carbon from 9,700 to 25 ppm , iron from 9,200 to 630 ppm , nitrogen from 2,100 to 90 ppm , and silicon from 750 ppm to not detected . Columbium with a purity of 99.9 percent was produced from 99.5- and 99.8 - percent grades of columbium. The investigation was devoted to the evaluation of a fused - fluoride - salt electrolyte ( KF - NaF- K₂ CbF, ) for electrorefining columbium. The effects of the columbium concentration and the voltage upon the product's purity were investigated . The effect on the cathode current efficiency of ampere - hours of deposition and the formation of a dual valence state of the columbium was also investigated .

Jan 1, 1964

By José Hugo de Carvalho Souza

Buscando melhorar a detecção das causas de falhas em equipamentos pela equipe no setor de trefilados e ampliados, o tempo de reparo de manutenção, diagnóstico de desempenho dos processos e melhoria na segurança operacional, foi criado um sistema de informação integrado de engenharia de manutenção e processos, com plataforma de carta de controle online e off-line integrada, monitorando aproximadamente quatro mil e trezentas variáveis de processos analógicas e digitais, adicionadas câmeras IP nos processos e desenvolvido um sistema de rastreabilidade de volumes produzidos que garante o correto apontamento de produção da área, minimizando dessa forma as divergências de inventário. A criação da rede integrada, permite unificar as comunicações de automação, possibilitando monitoramento e modificações das lógicas nos PLCs na central da automação, agilizando os diagnósticos e padronizando backups. A partir das implementações e projetos, foi possível aumentar no período de 12 meses em 5,5% a produtividade e otimizar em 2,9% o resultado de interrupção de manutenção dos equipamentos.

Aug 16, 2017

By Jr. Herty

As the problem of inclusions in steel has become increasingly important, more and more attention has been paid to the source of the oxide inclusions in steel. In killed steels the oxide inclusions are traceable to the reaction of deoxidizers with the iron oxide dissolved in the steel during the refining period of the open-hearth heat. In a large class of steel known as "rimming steel" the action of the steel during solidification depends entirely on the gas evolved, and this evolution in turn is controlled by the amount of iron oxide in the liquid steel in the mold. It is therefore of great importance to be able to determine the amount of iron oxide dissolved in steel and to devise methods for the control of iron oxide in any class of steel. The object of the present investigation was to obtain a true value of the oxygen con-tent of liquid steel. If the steel has not been deoxidized, the greater percentage of the oxygen is present as iron oxide in solution.

Jan 1, 1932

By C. F. Wingquist

As part of an ongoing study to determine how the wear of mining tools affects dust generation, the Bureau of Mines has measured bit tempera-ture rise during cutting of abrasive rock. Radial bit wear-flat tem-peratures generated by linear cutting in Berea Sandstone were measured as a function of cutting depth and speed. Depths of cut (DOC) were 1/8, 1/4, and 1/2 in, and cutting speeds were 10, 40, and 80 in/s, respectively. Temperature sensing was accomplished by emplacement of a miniature thermocouple into the center of the wear flat. Temperatures observed ranged from 2000 to 5000 C. Correlation between depth and temperature was weak. Temperature increased linearly with speed at 1/2-in DOC, but data taken at 1/8-and 1/4-in DOC produced inconclusive results. The results indicated that at least for deeper cuts (1/2 in), bit temperature, and therefore wear, can be reduced by lowering the cutting speed.

Jan 1, 1987

By P .. H. Grimley, N. Champigny

"Fourteen companies (Appendix) representing senior mining organizations in Canada were canvassed in order to assess: (1) the current usage and trends, and (2) the usefulness of computer applications in ore reserve estimation and grade control. The results of the questionnaire suggest that:• computers are unsurprisingly, predominant in the mining industry for calculating reserves and performing grade control;• time and cost savings are realized;• computer-based approaches are applicable to underground situations;• geological information is incorporated to the computerization process; and• computer usage does not hinder the collaboration of geologist and mining engineer.A clear need is identified for case histories comparing computer-calculated ore reserves and actual production data.IntroductionAmong the management and technical staff of some mining companies there is a perception that the application of computer based technology for the estimation of ore reserves and grade control, has as many drawbacks as benefits. Some of the objections raised against the utilization of computers for ore reserve estimation are that:• computer-based reserve models work for large open pit mines but not for underground situations;• computer-generated reserves ignore the geologist's knowledge base; they are strictly a number crunching exercise; and• the use of computers for ore reserves hinders collaboration between the geologist and mining engineer.In order to determine (I) the extent of current computer usage and future trends and (2) whether the objections noted above are borne out by experience, a number of senior Canadian mining companies were canvassed.The respondents were asked to provide:• an assessment of the importance of the computer in the ore reserve estimation and grade control process;• the level of involvement of individuals and staff groups with computer-based ore reserve estimation;• the advantages perceived and realized from the utilization of computer-based ore reserve approaches;• the current and future human resources requirements for the evaluation, implementation, maintenance and development of computer-based ore reserve systems;• the hardware and software resources presently used and planned; and• the developments needed to increase the use and acceptance of computer-based ore reserves."

Jan 1, 1990

By J. F. Boux

"The study of the total utilization of fly ash has involved all of the known technology in the processing of this waste material into useful products. In addition, a complete knowledge of all the possible uses of fly ash and its products in the market area was probably the most important factor in evaluating the theory and practical feasibility of the total utilization of fly ash from a single large supplyLaboratory tests carried out on the separation of fly ash into different fractions were shown to improve its value and utilization. Four main fractions were studied: a fine pozzolanic low-carbon fraction; a coarse fraction for light-weight aggregate production by pelletizing and sintering; a high-iron fraction; and a carbon-rich fraction. The term ""beneficiation"" here refers to a process of separating fly ash into more useful components.Laboratory and pilot sinter strand tests were employed to optimize the sintering capability and the quality of the heat-hardened pellets through a study of the agglomeration cycle in four principal heat zones, under controlled conditions of air flow, temperature and atmosphere, and including the controlled sizing of pellets.The suitability of the heat-hardened pellets as light-weight aggregate was evaluated in test batches of concrete, which were compared with concrete containing commercial lightweight aggregate of established quality.A study of beneficiated fly ash pozzolan as a partial cementitious binder component in normal and high-temperature cured concrete was reported in a paper at the re-cent Second International Fly Ash Symposium.Samples of raw and beneficiated Lakeview ash were compared with samples of other established high-quality fly ash pozzolans. The evaluation indicated the usefulness of beneficiated Lakeview ash as a pozzolan. Economic studies indicated that to accomplish the primary objective of total utilization of any single source of fly ash (in this case. fly ash from the Lakeview Generating Station, producing approximately 400,000 tons per year), a broad knowledge of the technology of various mineral processes was essential.The design of the fly ash processing plant had to be based on the disposal of all the raw fly ash produced by the generating station. This is contrary to the normal design of a processing plant in which raw materials are supplied and produced according to product demand. The design, therefore, had to be of such flexibility as to pro-duce as wide a variety of products as possible, and the ability to market them had to be well researched and understood."

Jan 1, 1970

By J. F. Myers

AT the Regional meeting in Columbus, Ohio, in September 1949, the authors presented a progress report of the first year's operation with a Hardinge tricone mill in closed circuit with a Dorr hydroscillator. The present report covers our findings on this grinding circuit to January, 1950. In order to clarify our position, the authors wish to state that no invention or discovery is claimed. The Tennessee grinding circuit is simply an engineered arrangement of known equipment arranged to incorporate all of the recognized efficiency factors of comminution as they are known today. As we concluded our first report, it was not clear how effective the Tennessee mode of operation would be on harder ores. The only information we had at that time was that the Bond grindability test at 48-mesh gave 6.04 g of undersize per revolution. A later test on the same sample at 100-mesh reduced this to 2.04 g, which is definitely in the harder ore class, and which makes the reported 8.80 kw-hr per ton of -200-mesh produced a very creditable figure.

Jan 1, 1950

By Robert D. Schmidt

The Cyprus Casa Grande Corporation has provided Bureau of Mines researchers with an opportunity to investigate the hydrology of leaching an in place copper ore deposit. Hydrologic investigations of underground in situ copper leaching are being jointly conducted under a cooperative agreement. The hydrologic concerns of leaching operations at the Casa Grande mine focus on maintaining adequate solution injection and recovery rates, and on distributing the injected leach solution effectively within the ore deposit. Hydrologic considerations underlying these concerns relate to the permeability of the oxide ore zone during leaching, the unsaturated condition of the deposit prior to leaching, and the constraints imposed on in situ hydrologic design by the underground mine setting. The investigation involves monitoring of flow and pressure conditions in 58 injection and recovery wells, estimating permeability conditions using a hydrologic model, and on-site testing of hydrodilation and airlift pumping. Transient, fracture-controlled permeability is determined to be the dominant hydrologic consideration. A statistical modeling procedure has been developed for estimating changes in permeability during leaching. Flexibility in well design and operation is essential for accommodating the changes in fracture permeability that occur during leaching.

Jan 1, 1990

By Sina Z. Yekta, Zhangwei Ning, Pierre Frappin

This paper describes a DC (direct current) electrical resistivity method, which uses the contrasts in resistivity measurements to estimate the diameter of jet grouted columns as soon as they have been completed, with varying depth and water table, and without excavation. The measurement procedure is illustrated by several examples of application sites, including the Grand Paris tunneling works during the last 3 years where the method was systematically recommended in quality control for jet grouting works.

Sep 8, 2021

By Jason Baird, Joshua Hoffman, Phillip Mulligan

The purpose of this report is to address the method of reducing the overall explosive weight of Explosively Formed Projectiles (EFPs) while still achieving satisfactory performance. This reduction is crucial in order to comply with outdoor explosives testing standards for Missouri University of Science and Technology’s (Missouri S&T’s) Experimental Mine. Initial EFP design testing exceeded given limitations, making reliable data difficult to ascertain. EFPs must be tested outdoors to allow for specific information recordings which aid in defending against them.

Jan 1, 2010

By H. H. Hausner, H. S. Kalish

M. Hansen—This paper certainly is an interesting study. Although I have not had too much experience in the powder metallurgical methods of studying phase equilibria, I would like to say the following concerning the interpretations of the results obtained: 1. The existence of a zirconium-rich eutectic having a melting point close to 950°C and containing approximately 5 pct beryllium is well established. 2. Undoubtedly sintering of the original compacts (i.e., without repressing and resintering at 1350°C) resulted in a condition being far from equilibrium, even in the low-melting point zircon-rich region where undissolved zirconium particles have been observed. This means that only partial reaction between the component powders has taken place. 3. In preparing and handling powder mixtures for pressing and sintering, we have found that with powders differing considerably in density, and also in particle size, separation in layers of different composition may occur. This means that a concentration gradient would exist within such samples. This phenomenon may, at least to some extent, account for the difference in microstructure of the top and bottom regions of some of the sintered samples. If this is the case, density figures for some of the nominal compositions would not represent actual densities of those mixtures. 4. Fig. 1 shows that the low densities of mixtures with 40 and 60 pct beryllium sintered at 1350°C are changed to much higher densities if the products sintered at 1100°C are repressed and resintered at 1350°C, whereby an approach toward equilibrium takes place. This would mean that the low density and growth in volume is due to nonequilibrium conditions. If this is true, would it be justified, then, to conclude that "the remarkable growth of the alloys in the vicinity of 40 to 60 pct Be indicates the formation of a high-melting point phase, probably accompanied by a considerable change in volume due to a large alteration of the crystal structure from that of the original compounds"? If some compound formation has taken place already during the first sintering at 950" to 1350°C, more compound would be formed by repressing and re-sintering of the 1100" samples. This treatment, however, results in higher, rather than lower, densities. In general, the density-composition curve of alloy systems containing one or more intermediate phases is characterized by a more or less defined contraction (decrease in specific volume, increase in density) over the "theoretical" density. Does not discrepancy exist between the two statements that "growth of the alloy indicates the formation of a high-melting phase . . ." and "even at 1350°C, no indications of sintering have been observed"? 5. I am not sure that the explanation given for the fact that fig. 4 did not reveal as much eutectic as the top portions of the mixture with 2 pct Be, is correct. The density of the melt containing only 5 pct Be or even perhaps less, is not too much different from that of the nominal composition. The reason might be also that there was already some separation of the components in the pressed compact. 6. I do not understand why the microstructure of the bottom regions of the compact with 5 pct Be (fig. 6) is so different from that of the top regions (fig. 5). The compact was melted on sintering at 1100°C. Its composition lies close to the eutectic point. There should be at least some lamellar structure in the bottom regions too; otherwise, the composition of top and bottom must have been very different after sintering, because the eutectic is said to extend as far as the composition ZrBe2. In case the white and gray areas of fig. 6 are both gamma, and the black areas undissolved zirconium, this composition would be close to the phase coexisting with zirconium, that is, ZrBe2, according to the hypothetical diagram, or a compound richer in zirconium. 7. Figs. 9 and 10 are not mentioned in the text. 8. The great difference in microstructure of the composition 20 pct Be of figs. 8 and 14 on one side and fig. 15 on the other side proves that sintering at 950" and 1100°C results only in partial reaction of the powers. 9. The mixture with 60 pct Be (fig. 19) seems to consist of two phases, rather than one phase, one interspersed in a matrix of another. 10. The statement that the eta phase "may be an intermetallic compound or the product of a peritectic or monotectic reaction" seems to be misleading, because the product of a peritectic or monotectic reaction in this region of the system must be an intermetallic compound. 11. If there is some solid solubility of Be in alpha and beta-Zr, it would be expected to be higher in beta-Zr (b.c.c.) than in alpha-Zr (h.c.p.). The temperature of the polymorphic transformation of zirconium then would be lowered, rather than increased. In accordance with this, Battelle has found that the transformation point of titanium is decreased by beryllium. 12. In case the phases present in alloys with 80, 90, and 95 pct Be are identical (which appears to be correct), it is striking that the relative amounts of both phases (eta and beryllium) are not too different within this wide range of composition. With 60 to 65 pct Be

Jan 1, 1951

By S. C. Schaeker, A. W. Schlechten, A. H. Larson

PARRAVANO and Malquori' studied the equilibrium of H2S-Hz with molybdenum and its lowest sulfide which they believed to be MoS2. Mc Cabe' has shown that its composition is actually Mo2S3 and determined its dissociation pressure by means of Knud-sen effusion measurements. Stubbles and Richard- son3 have recently studied the equilibrium of gas mixtures of H2S-HZ with the two-phase solid mixtures of Mo-MozS3 and Mo2S3-MoS2. The latter investigators found that M02s3 deviated slightly from the stoichiometric composition, but they did not determine the homogeneous region of the disulfide phase. Morimoto and Kullerud, studied the Mo-S system by quenching, microscope, and X-ray methods and concluded that the disulfide is stoichiometric. The present investigation was concerned with the measurement of the sulfur vapor pressure variation with composition at 1100°C in the homogeneous region of "MoS2". These measurements were made by reacting: 1) molybdenum powder (99.97 pct Moj with sulfur vapor, and 2) MoS1.g9 (formed by reaction of Mo + H2S) with sulfur vapor in a quartz capsule. Conditions were controlled to form an equilibrated phase within the homogeneous region of the disulfide. The quartz capsule was sealed off initially under a vacuum and the residual gases were gettered by titanium powder contained in one end of the capsule. A mixture of Mo + S or MOS,., + S was in the other end. The section containing the titanium powder was heated for 24 hr at 700°C and then removed by flame sealing. The end of the capsule containing the charge was then heated to 1100°C. The other end of the capsule was maintained at a temperature which would produce the desired sulfur pressure in the capsule (liquid sulfur distilled from the charge mixture was retained in this end). After equilibration, the capsule was removed from the heating assembly and rapidly air-cooled. It is assumed that equality existed between the total sulfur pressures (PT) in the two ends of the capsule and not between the partial pressures of the different molecular species (S, SZ, Three separately controlled heating elements were used to maintain the proper temperature gradient over the length (approximately 12 in.) of the capsule. A thermocouple-Wheelco "Capacitrol" system was used for temperature control of the two end heating elements within 2"C. The center heating element was controlled directly by a " Power -stat". Separate controlling and measuring thermocouples were used for both end heating elements. Pt-Pt(l0 pct Rh) thermocouples were used for 1100°C and Chromel-Alumel thermocouples were used for lower-temperature control and measurement of the assembly. Silver foil was wrapped around the end of the capsule containing the liquid sulfur to insure a constant temperature zone. The thermal gradient over the entire length of the capsule was measured to: 1) ascertain that the length of the constant temperature zone of the liquid-sulfur end and the sulfide end was sufficient, and 2) ascertain that the liquid-sulfur zone was the zone of lowest temperature. The data obtained in this investigation are shown in Fig. 1 and Table I. The total sulfur pressure (PT) and p(S2) were calculated from the data of Braune et UZ.~ The compositions of the equilibrated disul-

Jan 1, 1964

By Saravarim A.

"The aim in flotation systems is to control the grade and recovery of the product., numerical method or sampling and analysis is used to achieve this goal. Weakness of measuring instruments, lack of process knowledge, deficiencies in management and data processing in the control of flotation cells, has led the academic and industrial units to use numerical models. In this regard, using the results obtained from the experimental design carried out in the DTP line of Gol Gohar industrial and mining complex, a regression model was developed based on the analysis of variance. To present this model, after variance analysis of factors and interactions, all models were investigated and the final model was created based on 75% of the data. The model was tested with the remaining 25% of the data to confirm the goodness of the fit. The coefficient of determination for training and testing resulted 71% and 74%. Moreover, a feed forward back propagation neural network with different layers and neuron was used to model the results. The best network structure was 6-27-1 and the coefficient of determination for this network was 99% and 98% for training and test respectively. Given the complexity of neural network models and the relatively low accuracy of the regression model, neural network has a priority assuming we have access to a specialist. In addition, the results obtained from neural network can be used as expert systems to control and optimize the flotation cells.INTRODUCTIONThe primary objective of the flotation cell control is to maintain the product's (in this case tailing) recovery and grade, which represents the index for process efficiency and product quality. Continuous estimation of these indexes requires a significant amount of maintenance, and calibration of the continuous analyzers, in order to maintain an acceptable level of accuracy. Weakness of measurement equipment, lack of process knowledge and the general deficiency in management and processing of data in the flotation cell control, will lead industrial units to use smart methods such as mathematical models, regression and neural networks in near future (Panahi, Abdollahzadeh, & Sam, 2010). Artificial neural networks are inspired by the very complex structure of human brain in which millions of nerve cells solve problems or store information by communicating with each other. The duty of neural networks learning. It should be noted that learning in artificial neural networks is limited, and what is practically considered is the computing power of the network. A neural network consists of units called neurons, and has the capacity to handle a set of input data to produce a desired output data set. Each of these input and output data sets can be assumed as a vector (Soltanmohammadi & Noparast, 2006)."

Jan 1, 2016