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By N. H. Emmons

THE work of a consulting engineer or manager, when controlling mining-operations, requires that he have all the information concerning the mine in as concise a form as possible, and as the ore-reserves and their depletion and enlargement are the vital points to be studied, it is well to have them kept up to date and in some convenient form. The present paper describes a method adopted by me, which shows in a very clear manner the ore-reserves in a mine. The case illustrated is that of a vein near enough to the vertical for the vertical elevation of the mine to be the main working-map. A flat ore-body would be represented on a similar plat, but instead of the horizontal thickness of the vein being shown in the circles, the vertical thickness would be inserted. Fig. 1 represents an ideal longitudinal elevation of a mine, plotted in the ordinary way, using 100-ft. blocks and section-lines. In a mine where the block-numbers are posted by the engineer underground, the system of keeping the ore-tonnages extracted from the different blocks is easily maintained, and the actual tonnages of ore extracted can be kept so that the surveyor can have a check on his estimate from time to time. The ore-reserve sheet, Fig. 2, should be the same size as the map it is to accompany. Each square is used for the description of the ore-reserve in the block it corresponds to on the elevation. Where the section-lines cross the levels a circle is drawn, in which are written the widths of ore at that point, these widths being used in the calculations of each block cornering in the circle. It has been found convenient to show the figures in black in the lower half of the circle when the actual widths of ore are known, and when it is necessary to make up the figures of probable ore, as at the time of making

Jun 1, 1912

By B. Morrison

"The Kiruna Electric System is a recently developed inclined ore haul age system for underground mining operations. Although an initial investigation was carried out at the Swedish underground iron ore mine LKAB almost three decades ago, it was not until 1981 that the resources of LKAB, ASEA and Kiruna Truck AB were combined to investigate, and subsequently develop an ""all- electric truck"" for the mining industry.It has long been appreciated, that major economical advantages could be realized by a mining operation through an extension of the cost-effective life of the existing ore hoisting system by the use of ramps to haul ore up to the main haulage level. Diesel truck s have been used and are being used for ramp haulage. Their use however, is limited due to ventilation and operating costs restraints.There are numerous instances of orebodies, located within a couple of hundred metre s of surface, or below an existing hoisting facility, being developed by ramp access while the shaft is being sunk. Development of an orebody via ramp access has many advantages to a mining operation where mechanized mining is to be practiced. These advantages are both practical and economical; generally falling within the over-all umbrella of the phrase ""cash flow"" mining.The decision to sink a shaft is a major committment by any mining company, regardless of size and financial reserves. Extensive diamond drilling, both shallow and deep must be carried out before a decision can be executed. This constitutes a major financial expenditure over an extended period of time.The decision to sink a shaft must be weighed against the reliability of geological interpretation of the deep diamond drilling results, the stability of the mineral market and potential fluctuation in ore prices and interest rates."

Jan 1, 1989

By E. Eccleston

The ConRoast process for the production of platinum group metals involves the use of a fluidized bed reactor for the removal of sulphur from ore concentrates by roasting prior to smelting in a DC-arc furnace. Test work was carried out in 2007 at Hazen Research in Golden, Colorado to provide the data necessary for a commercial roaster to be designed by Technip. This paper discusses the rationale behind the test work, the goals for calcine composition to be used as smelting furnace feed, the results of various roaster operating parameters in terms of calcine composition (particularly residual sulphur and the fate of trace elements), and the impact of the results in terms of a commercial roaster design.

Jan 1, 2009

By Jake Hutchison, Wade Hutchison

The opposition to the project has risen as a result of some political pressures and from public perceptions about the project’s necessity and its impact on the neighborhood. As a result of this controversy, the Underground Conservation Hall was quickly termed “Bredesen’s Bunker” by the Media. Close exposures for blasting, required by the Conservation Hall construction project, have been regulated by specifications that regulate seismic monitoring, pre-blast and post-blast inspections. Planned blasting for the project included blasting to a depth of 30 feet (9.14 meters) within 35 feet (10.67 meters) of the front of the newly renovated Tennessee Executive Residence. Excavation for the project found more competent rock at higher elevations than identified in test drilling which required blasting within 2 feet (0.61 meters) of the side of the Residence.

Jan 1, 2009

By W. P. Johnstone

The computer assisted generation of geological models to represent the geometry of, and grade distribution within, orebodies is a rapidly growing area of the geological profession. Such models are increasingly used as a necessary starting point in determining the mineability of mineral deposits in terms of practical mine design and economic considerations. The transition from traditional techniques such as field or underground mapping and the manual calculation of grade and tonnage estimates, as well as related activities such as the interpolation of cross-sections, the use of stereographic projections, core logging and hand contouring, to computerized applications, is by no means complete. In fact, many geological professionals deliberately avoid the use of computer simulations based on the perception that the resulting models are simplistic and that their construction is not founded on sound geological principles. The purpose of this paper is to assess current thinking on this topic by considering; (a) an overview of advances in the drafting of geological maps, (b) the theoretical basis for multi-dimensional geological modelling, (c) the case for combining traditional and modern techniques, and (d) the benefits to the mining value chain.

Jan 1, 2003

By Jon C. Volkwein

The canopy-air curtain was originally developed by the Bureau of Mines to surround the operator of a continuous mining machine with a zone of clean air. This report describes the application and testing of a canopy-air curtain on a gathering-arm loader, as well as some of the problems associated with providing a zone of clean air to a standing, semimobile operator. The area of air-curtain coverage and effects of air velocity are discussed. In its present form, the canopy-air curtain provides a 50 percent reduction in respirable dust to the operator.

Jan 1, 1981

By Blaisdell J. L, MacPherson G

The present communication records the results of a research investigation conducted in the Porcupine Gold Mines in Timmins, Onto. Soon after silicosis became a compansable disease in Ontario under the Workmen's Compensation Act in 1926, the attention of mine operators and physicians was drawn sharply to the prevalence and importance of this condition in the mining industry. A number of examining centres were established in Northern Ontario by the Workmen's Compensation Board, and the yearly X-ray examination of miners was made compulsory.Although working conditions were soon improved, the mining industry realized that they were confronted by a problem demanding basic research for its final solution. The late Sir Frederick Banting had, for a number of years, been interested in silicosis, and it was upon his suggestion that an experimental investigation was undertaken at the McIntyre-Porcupine Mines Ltd., Schumacher, Ont., in November, 1932. A preliminary report of this investigation was published in 1937 by Denny, Robson and Irwin and a further report by the same authors in 1939.Accepting the theory that silica exerts its injurious effect upon animal tissue through a slow transformation into silicic acid in the presence of body fluids; these authors assumed that if the solubility of the silicious material retained in the lung could be sufficiently reduced, the usual fibrotic response would be modified or would not occur. A search was therefore undertaken for some non-toxic compound that would fulfil this purpose. After investigating ma:qy substances, Denny and Robson discovered in 1936 that the presence of small amounts of aluminum powder almost completely inhibited the solubility of silicious material in vitro. An intensive study of the mechanism involved later showed that the reduction in solubility was due chiefly to a coating of the silica particle with a thin film of a gelatinous hydrated alumina which on drying formed the crystalline alpha aluminum monohydrate boehmite (AI203.H20). The presence of this absorbed layer on the surface of the quartz was indicated by -staining it with aurin (ammonium salt of aurin tricarboxylic acid) and proved by Germer and Storks by means of electron diffraction patterns.Inhalation experiments with animals were at once begun, using pure quartz dust with and without aluminum powder. (See original communications.) These observers showed that while typical silicosis was produced in about 5 months in the control animals receiving silica dust alone, the...

Jan 1, 1945

By Miguel Vera Barrientos

Dado que el desarrollo de labores mineras se ve influenciado por el conocimiento del macizo rocoso puesto que otorga mayor seguridad a las personas, equipos e instalaciones en operaciones interior mina, el presente texto plantea un método sistemático para la rectificación de muestras de roca intacta con tablas de valores empíricos y escalamiento de los resultados.

May 1, 2015

By John J. Sammarco

The U.S. Bureau of Labor Statistics reports that the mining industry has the highest average annual fatality rate (31.9 per 100,000 workers) among all major American industry. To address this, a major research program to reduce hazard exposure of miners with computer-assisted mining equipment was initiated by the U.S. Bureau of Mines.1 One application involves the manual process of extracting and hauling coal where operators, in the tight confines of a mine, can be struck or caught by mobile machinery. The approach to remedy this problem uses a guidance system on the haulage equipment so that it follows the machine that extracts coal. This, in essence, involves sensor-based docking of the machines. Sensors that can survive the hostile mine environment of dust, methane gas, and water, play the key role. Computer analysis of the mining machine's movements and empirical machine characterizations were conducted to establish operating requirements and spatial limitations to ensure proper loading of coal into the haulage equipment. These data served in the selection of a sensing system. Various technologies such as scanning laser systems and ultrasonic sensors have frequently been used in other applications but were found unacceptable. However, a near infrared (IR) sensor employing active targets met the requirements. The sensor has a nominal 75° conical field-of-view and a range from 0.1 to 18.0 m. For the single target mode, nominal range accuracy was 4.3% at a distance of 3.56 m. Correction algorithms were generated reducing the error to 0.6%. Airborne dust testing showed less than 0.8% accuracy (worst case) degradation at levels exceeding (by a factor of 7.5) concentrations permitted by Federal law. The sensor can track multiple active targets providing five degrees-of-freedom (DOF) measurements. Using four targets, the nominal range accuracy was 0.4% without correction algorithms. A guidance system for the haulage system to follow the mining machine does not exist commer¬cially. Such a system can reduce fatalities and injuries by current haulage mining equipment, and is a viable alternative to current haulage control.

By D. K. Weatherley, T. P. Oladele, L. B. Bbosa

Comminution is a critical stage of mineral processing which aims to reduce the size of ore particles through breakage, consequently increasing the likelihood of liberation of valuable minerals. Several factors, such as pre-existing cracks, mineralogical composition and particle size, are known to affect ore breakage behaviour. While investigating the contributing role of each factor is essential to improve understanding of breakage, isolating individual factors by experiment is typically impractical. Numerical techniques such as the Bonded Particle Model-Discrete Element Method (BPM-DEM) have been developed as a means of studying closely controlled breakage conditions. This study evaluates this technique in modelling the effect of pre-existing cracks breakage behaviour for synthetic ore specimens during impact breakage in a short impact load cell (SILC). Synthetic ore was modelled as a collection of discrete entities connected by brittle-elastic beams. Model parameters were calibrated against macroscopic material properties of a conventional homogenous synthetic ore. The extent of pre-existing cracks within specimens was prescribed by varying discontinuities between the connecting entities. An approach with the insertion of seed points was used to model the mineralogy of the specimens. Results showed that pre-existing cracks resulted in a decrease in the fracture force as the crack density increased. Additionally, the irregularity of fracture patterns within rock specimens after impact became more apparent as the crack density increased. The findings were used to emphasise some of the attributable causes of the variation observed between ore hardness characterisation tests and in situ ore behaviour. Keywords: Element Method; Bonded Particle Model, synthetic rock sample; rock fracture, preexisting cracks

Jan 1, 2020

By AIME AIME

IN accordance with the provisions of Art. XII, See. 3, of the By-laws of the American Institute of Mining and Metallurgical Engineers, the Board of Directors hereby give notice of their intention to amend the By-laws as follows : Art. V, Sec. 2. Amend by substituting the word "senior" for ('first" before the words "Vice-president" in line two of the third paragraph of said section which relates to the calling of special meetings of the Board in the absence or disability of the President.

Jan 1, 1930

By D. E. Ranta, Jean-Michel Rendu

It is generally recognized that geologic input is required for the results of a geostatistical study to be meaningful. However the link between geology and geostatistics is often complex and not well understood. A geostatistical evaluation can be divided into four phases: Background discussions, computation, reserve reporting and reserve audit. Each one of these phases is described, as well as the role the geologist should play during their completion. This role will vary depending on the geology of the deposit being studied, the geostatistical method chosen and the computer hardware and software being used. The geologist's acceptance of the results is needed if the geostatistical model is to have any credibility. The most significant obstacle to a meaningful study comes from the difficulties geologists and geostatisticians often encounter when attempting to communicate with each other.

Jan 1, 1992

By Paulo Eduardo Melo da Cunha

Com um cenário de constante mudança na área e logística, uma demanda cada vez maior por transporte rápido, eficiente e a baixo custo, muito se tem exigido dos gestores de logística na solução, otimização e implementação de soluções criativas para desatar o nó logístico existente hoje no país. A falta de infra-estrutura tanto interna, quanto externa tem dificultado o trabalho e comprometido os resultados globais das empresas. Muitos trabalhos já foram realizados, mas as constantes mudanças, aumento dos volumes transportados em cada modal, a falta de planejamento governamental, tem exigido novas formas de trabalhar. Um relacionamento mais próximo dos fornecedores de transporte, com grande envolvimento dos clientes e áreas comerciais é fundamental para os bons resultados e é desta forma que buscamos otimizar o fluxo ferroviário para a região da grande BH.

Jul 29, 2018

By Yasushi Sawada

An experimental investigation was carried out to study the rates of reduction of iron oxides dissolved in liquid Ca0-SO2-A203 slags by Fe-C droplets at temperatures ranging from 1325 OC to 1550 OC. The %FeO in the slag was varied from 5.5 to 18. Flash X-ray images were employed to observe the behavior of Fe-C droplets in the slags during the reactions and for determining the slag-gas-metal interfacial area. Effect of P205 in the slag and sulfur in the droplet was also investigated. The reduction rates were determined by measuring the volume of CO evolved as a function of time and the estimated slag-gas- metal interfacial area. The reduction rates have increased with increasing %FeO in the slag and the slag temperature. The experimentally established relationship between the reduction rates and FeO (wt%) in slag is given by

Jan 1, 1992

By M. J. Nicol, T. Moyo

Ammoniacal solutions are an effective lixiviant for the oxidative dissolution of some mineral sulphides. A detailed study of the anodic dissolution of chalcopyrite in ammonium sulphate-ammonium hydroxide solutions has been carried out using cyclic voltammetry, chrono-amperometry and rest potential measurements. The role of the copper(II)/copper(I) redox couple in the oxidation process has been evaluated. Rest potentials have been found not to be affected by oxygen but to increase with an increase in initial copper(II) concentration. Pseudo-steady-state anodic current densities measured in the absence of copper(II) ions at the rest potentials obtained in the presence of copper(II) ions increase with increasing concentration of copper(II) ions, confirming the positive effect of copper(II) ions on the rate of dissolution of the mineral. Cyclic voltametric and chrono-amperometric data show that in the absence of initial copper(II) ions, the rate of dissolution in the presence of dissolved oxygen is significantly lower. These results confirm that the effective oxidant for the mineral under the conditions of the study is copper(II) and not dissolved oxygen. Coulometric measurements have been used to establish the stoichiometry of the anodic reaction at different potentials.

Jan 1, 2014

"Chairman: Professor J. C. Griffiths Rapporteur: Mr J. P. G. PRETORIUSPapers:Mine-mill production scheduling by dynamic programming by R. J. Roman Optimization of a large mining venture by J. C. Paynter, B. K. Loveday and C. G. Robinson Economic surface mining of multiple seams by T. V. Falkie and W. E. PorterIn introducing his paper, Mr Roman said that whereas in manufacturing plants the yearly production levels were usually chosen to produce the largest annual cash flow, in a mining operation, the raw materials (ore) were exhaustible so that the production had to be scheduled to maximize the total net present worth of the operation. This optimum production schedule could be determined by using dynamic programming. The required information was readily available to management at most mines. The 'possible operating range' of production rates lay between the rate with the highest profit per ton. and that with the highest profit per year. The optimum production rate started typically at the top of this range and decreased slowly as the deposit was depleted.Dynamic programming was used to determine several production schedules for a hypothetical mine-mill complex. The effects of changes in the ore grade estimates, size of deposit and acceptable rate of interest on the production schedule were taken into account. Apart from the fact that the net present worth of the overall profits was larger than that obtained by conventional methods, it appeared from the cases studied that the amount of metal recovered was also greater.Dr it P. King commented that this was a very interesting application of dynamic programming. He pointed out, however, that the market price of the metal was likely to vary significantly and randomly during the life of the mine, and he suggested that the problem should, therefore, be reformulated as a stochastic dynamic programming problem.If the price of the metal rose to abnormally high levels, a much higher than normal production rate could be expected. The results of analyses given in Table 5 showed that the production rate was a function of market price. In his view the stochastic problem could be solved just as easily as the deterministic problem.In reply to a question by Dr King as to whether the function relating recovery to production rate (Table I) was based on real data, the author replied that it was based on the results of an analysis conducted at the Union Carbide Corporation's Pine Creek tungsten mine in California.Dr D. M. Hawkins stated that costs were incurred when the production rate was altered, for example, in appointing or laying off staff, and that in practice it may be necessary to take these costs into account in finding the optimum production rate. Mr Roman replied that, while normal administrative costs were accounted for, the additional costs incurred in appointing and laying off staff were not taken into account."

Jan 1, 2014

By D. Holdridge, D. Liao, S. Waterfall, N. Strobl, S. Sun

High melting point inclusions, such as spinel, alumina and AlO rich calcium-aluminates, have a strong tendency to agglomerate on the tundish stopper rod and Submerged Entry Nozzle (SEN) during the steel casting process, and eventually to cause SEN clogging. Calcium treatmen by wire injection during steel refining during Ladle Metallurgy (LM) is commonly used to modify these troublesome inclusions to lower melting point inclusions. However, too much Ca injection (Ca over-treatment) can cause operational issue (e.g. slide gate plate erosion),as well as increase Ca cost. Therefore, it is desirable to add an appropriate amount of Ca to avoid either under-or over-treatment. Based on inclusion analysis with an ASPEX® computer controlled scanning electron microscope (ASPEX) instrument, AlO and AlO rich calcium-aluminates were identified as a major cause of SEN clogging at ArcelorMittal Dofasco Electric Arc Furnace (EAF) steelmaking stream. A Ca treatment index was developed to improve the inclusion modification. The improved inclusion control has reduced SEN clogging and enhanced steel quality.

Mar 1, 2017

POSITIONS VACANT (Under this heading will he published notes sent to the Secretary of the Institute by members or other persons.) In the course of the next few months, a mechanical engineer, who has specialized in the design and erection of copper-smelting plants, including steel work, power equipment, etc., may be required by a company operating abroad. Man speaking German preferred. No. 23. ENGINEERS AVAILABLE (Under this heading will he published notes sent to the Secretary of the Institute by members or other persons introduced by members.) Member, 31 years of age, married, graduate of Massachusetts Institute of Technology, desires position with malleable iron or steel firm. Nine years' experience as chemist and metallurgist in malleable, gray iron, and steel. No. 123. Member, metallurgist, desires position with company making steel, castings, or tool steel. Has had six years' experience with the electric furnace, making steel castings and tool steel, also heat treatment of same. No. 124.

Jan 9, 1914

By E. C. Tarpley

An acid-extraction procedure developed in Germany for determining mineral matter in coal was investigated by the Bureau of Mines to determine its application to American coals. It was found to be suitable for all ranks of coal from anthracite to lignite if modified slightly for coals containing considerable quantities of calcium compounds, such as calcite or calcium humate. The precision of the method is satisfactory, and the results are probably closer to the true content of mineral matter than those obtained by empirical formulas. The method requires considerably more analytical data than the Parr or approximation formulas but is no more time consuming than obtaining the necessary data for the King, Maries, and Crossley formula (theoretically the most comprehensive empirical formula used). An appendix to this report includes a detailed description of a recommended procedure.

Jan 1, 1959

By P. Saunier, S. Fourmont, R. Stafford, A. Jung, J. Mlynarek

The safe and economical storage of tailings generated by modern day mining operations is possibly the single largest challenge faced by miners today. By nature, tailings are a waste product that have little to no economic value. Yet, their physical and chemical contents can pose incredible environmental hazards if not stored correctly. The variety of factors that are met when designing Tailing Storage Facilities (TSFs), means that in most cases, a low-cost solution is sought to accomplish storage, meet environmental regulations, and adhere to industry best practices. TSFs can be large dam face structures or smaller structures like retention/evaporation lined ponds. Water management is potentially the single largest factor that miners and designers must contend with when constructing a TSF. Water is a necessary component in the process of extracting ore but can be difficult and expensive to remove once it is mixed with solid tailings particles. As a result, the most common disposal of these water containing tailings, called a slurry, is to simply discharge into an embanked TSF (Vick, 1990). These structures, just like any other water retaining dam, can breach releasing contents downstream. Despite modern advancements in TSF design, there have been numerous dam failures that have resulted in tragic loss of life and ecological devastation. Most notably in the last decade, the Brumadinho and Mariana Dam disasters in Brazil killed 278 people in downstream communities when TSF dams failed in 2019 and 2015, respectively (Rotta at el., 2020). Similarly, in 2014, the Mount Polley tailings spill in British Columbia was the second largest tailings spill on record and caused extensive damage to adjacent watershed ecosystems when the TSF embankment was breached (Byrne at el., 2018). While there were indeed numerous unique and underlying factors present in each of these structural failures, a shared element in the devastation was the large-scale release of unstable liquefied tailings

Mar 2, 2022