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By J. G. Cullain

In conjunction with the over-all goals of energy conservation at Inco Metals Company, a program of improvement in compressed air utilization was established. Air flows were monitored and compared to calculated requirements to establish efficiency by area. With the cooperation of area management, measures were implemented to reduce nonproductive usage. At the operation, annual savings in power consumption alone were 80,000 dollars. The program is being extended to other mine areas within the Division.

Jan 1, 1979

Mineral Resource Throughput Management is based on the extraction of the maximum potential value from an ore reserve with the emphasis to generate maximum ROI and ROR (return on reserve). A steel producing company in India implemented MRTM to significantly improve their ROI and ROR. The value chain of this company consists of their own iron ore and coal mines, ore washing plants, sinter plants, steel plants, and sales and marketing division. The target for the mines was to produce at a stable and predictable rate and at specific quality requirements. These requirements were set to improve productivity and ROI of the steel plant. The implementation constituted the alignment of the reserve potential, total production chain, human resources and management culture at the mines with the requirements of the steel plant. Many typical mining practices were challenged and changed. Production targets regarding lump vs. fines ratio, consistent product tons, quality targets such as Fe, Al content and moist, and standard deviation on the quality targets were not achieved. A reverse distribution model with release mechanisms to satisfy the demand were developed and implemented at the mines. A stable and predictable flow of mine product with quality standards well within the required standard deviation targets were achieved. The contribution from the mines to significantly improve the Net Profit, ROI and ROR of the company were reached.

Jan 1, 2007

By EFFC/DFI Concrete Task Group

Concrete technology continues to advance rapidly and modern mixes with five components – cement, additions, aggregates, (chemical) admixtures and water – often have characteristics which differ significantly from the older three component mixes – cement, aggregates and water. Recent trends have favoured higher strength classes and lower water/cement ratios, resulting in greater dependence on admixtures to compensate for reduced workability and to meet the (often competing) demands for workability in the fresh state and setting time. The application of testing methods which reflect the true rheological properties of the concrete has not developed at the same rate as the mixes themselves and it is still not uncommon for the slump or flow table test to be used as the only acceptance test for fresh concrete.A joint review of problems in bored piles (drilled shafts) and diaphragm walls cast using tremie methods by both the European Federation of Foundation Contractors (EFFC) and the Deep Foundations Institute in the United States (DFI) identified a common issue. The review determined that many of the problems were caused by (or in part due to) the use of inadequate concrete mixes with inadequate workability, or insufficient stability or robustness of the mixes. It further identified the primary causes as inadequate concrete specifications and inadequate testing procedures. The consequences of these problems are often significant and it has been recognised that spending more time and money on getting the concrete right is the most cost effective approach.A joint Concrete Task Group was set up by EFFC and DFI in 2014 to look at this issue and this guide is the output from that Task Group. A research and development project, funded by the Sponsors of this guide, is being carried out by the Technical University of Munich in conjunction with the Missouri University of Science and Technology. This project includes desk studies, laboratory testing, and onsite testing at worksites in Europe and the US. The research work will be completed during 2016.

Jan 1, 2016

By Cristina Muñoz Fernández, Sonia Balcázar

Los mecanismos operacionales de atención de quejas y reclamos a nivel de mina (MQR) son procesos formales que las empresas ponen a disposición para permitir a personas o grupos plantear inquietudes y buscar la remediación y reparación de los impactos reales o percibidos de sus actividades. Con el objetivo de impulsar el desarrollo y fortalecimiento de los MQR del sector minero en la región andina, entre agosto del 2021 y enero del 2022, la Deutsche Gesellschaft für Internationale Zusammenarbeit (GIZ) financió un estudio de análisis y comparación de los mecanismos operacionales de atención a reclamos en la minería en Bolivia, Ecuador, Chile, Colombia y Perú, que sirve como base del presente trabajo técnico.

Sep 30, 2022

By M. Bavand-Vandchali, F. Golestani-Fard, S. Khalili, S. Rowshanfekr-Fallah

In the secondary metallurgy of steel, the availability of ladles plays an important role in decreasing the production cost. The refractory lining, therefore, should satisfy optimized quality to grant higher heats. This paper reports the results of an investigation carried out in Iranian Mobarakeh Steel Company in order to increase the lining life of ladles by employing different types of MgO C and Al203 - Mg° - C. The zoning concept was used in replacing the conventional refractories either in slag line or the lower parts of ladle. The number of heats could be improved to almost two times as before. The results are explained in terms of refractory quality as well as zoning approach. The economical impact of this improvement will also be analyzed.

Jan 1, 2004

By Luis Palacios Valdivieso

Ante la crisis minera desarrollada en la mina Condestable, se evaluó los factores técnicos, operativos, social y laboral que intervienieron en su decadencia. En este sentido, el objetivo del presente trabajo radica en describir los recursos de estrategia gerencial minera para superar las dificultades de productividad minera a través de cinco temas: cambios en los métodos de explotación, variación de la concepción geológica, proceso metalúrgico, optimización de rendimientos de los recursos y política sociolaboral. Asimismo, se muestra el programa de inversiones que la empresa ha logrado superar paulatinamente ante la crisis del precio del cobre.

Nov 24, 1993

By Juan Carlos Salas

In this paper, a collaborative R&D model which has been successfully applied by a global mining companies association is presented and analysed both from the conceptual and practical point of view and an example of these collaborative initiatives, the Copper Technology Roadmap recently generated by a group of the most relevant copper mining companies, is presented, including an analysis of strategic opportunities and challenges in the Latin American region.

Sep 9, 2007

By Lois G. Schwarz

I did a project (Sungai Piah) as a consultant to your firm in Malaysia, where we were faced with a similar situation as sketched out in your question. The following is what we did for the grouting of the primary holes, which were both located upstream of the plug as well as downstream: We used a hydrophobic MDI based semi-rigid polyurethane prepolymer in the first phase of the grouting operation when grouting under water flow conditions. Then in the second phase and also for the contact grouting we used a two component water compatible polyurethane elastomer. And then for deeper formation grouting, when all the water flow had been stemmed in the vicinity of the plug, we used a regular (balanced stable) cement based grout. So it may not exactly answer your question, but we first used hydrophobic grout because it is very efficient to grout a formation through which water flows. We didn't stop all the leaks day-lighting downstream of the plug or all water running through the formation near the plug, but the flow of water through the rock formation adjacent to the plug was reduced by 99.9%, after completing the urethane grouting. This facilitated the placement of cement based suspension grouts without wash-out.

Feb 10, 2003

When studying minerals degrees at university, all the emphasis is towards sending the graduates into the bush to work at a remote mine; however, that is not the only option available to new graduates. There are positions in equipment supply companies, commercial laboratories, research organisations, engineering companies and contractors of many types. The aim of this paper is to show metallurgy graduates that there are non-mine site based career options available to them that offer outstanding career development. This is illustrated by outlining the research being undertaken by Magotteaux Australia and by telling the story of a graduate metallurgist working in MagotteauxÆs small research group. Magotteaux is an international supplier of grinding media and wear resistant components for the mining industry. The Australian research group is focused on determining the effects that the choice of grinding media has on subsequent processing, for example flotation and leaching, by using newly developed tools and techniques.

Jan 1, 2006

The original and most basic relationship between mining company and explosive supplier was a simple one of consumer and product supplier. The divide between the two was quite clear-cut with neither taking much interest in the activities of the other. The explosive supplier had little understanding or share in the outcome, efficient rock breakage and therefore impact on mining and milling. Likewise, the mining company did not encourage the improvement or development of products. The transactions were limited to product and funds. This environment does not encourage any form of knowledge sharing, trust or optimisation of the mining process.Conversely, there are now a variety of relationships to the point that the mining company may simply be an asset manager whereby all æoperationalÆ aspects are contracted out. For the drill and blast aspect this takes the form of a æRock-On-GroundÆ contract whereby the explosives company takes on design, drill, load and fire responsibilities and is paid a rate per volume of broken rock. This removes the majority of risk to the mining company derived from having to produce broken rock and guarantees the cost of a portion of the overall unit cost of mining. The onus is now on the explosives supplier to break rock to a specification as efficiently as possible.There exist a number of variations between the æbasic supplyÆ and æRock-On-GroundÆ. These contracts may also include value sharing to encourage the explosive supplier to optimise the mining operation to maximise profit.This paper looks at some of the drivers for the change in explosive supplierûconsumer relationships and examines the æprosÆ and æconsÆ of a few of the options.

Jan 1, 2004

By Douglas F. Scott

This case study provides an example of how social marketing was applied to meet the needs of business customers. Federal regulations require that all companies develop a written program to track hazardous chemicals at their sites. The HazCom Writer, created by the National Institute for Occupational Safety and Health (NIOSH), is a software tool designed to help companies prepare their required Hazard Communications (HazCom) written plan and list all hazardous chemicals at the company's worksite. The social marketing goal was to provide a product for small- to medium-sized companies to use for federal HazCom rule compliance. The HazCom Wm'ter is a direct NIOSH response to customer and stakeholder needs (including the Mine Safety and Health Administration, the mining community, and Occupational Safety and Health Administration- regulated companies).

Jan 1, 2009

By Omotayo Kalejaiye

The Siwek 20-L chamber is widely used throughout the world to evaluate the explosibility of dusts. This research evaluated the quality of dust dispersion in the Siwek 20-L chamber using Pittsburgh coal, Gilsonite, and purple K dusts. A Pittsburgh Research Laboratory (PRL) optical dust probe was used to measure optical transmittance through the dust cloud at various locations within the chamber. A total of 540 tests were performed, with triplicate tests at five nominal dust concentrations and six locations. The two standard dispersion nozzles (rebound and perforated annular nozzle) were compared. The transmissions corresponding to the normal ignition delay period were used to: (a) determine variations in spatial uniformity of dispersion obtained with both nozzles; (b) make comparisons between the experimental transmission data and those calculated from theory for the three dusts; and (c) make comparisons with transmission data measured in the PRL 20-L and Fike 1-m3 dust explosion chambers. The uniformity of dispersion for the three dusts was similar with both nozzles, despite the differences in nozzle geometry and mode of operation. Transmission data of the three dusts were all significantly lower than those calculated from theory. This was discovered to be, in part, due to significant reduction in particle size that occurred during dispersion. By measuring particle sizes before and after dispersion, values of 60%, 50%, and 20% reduction in particle size (based on the surface-weighted mean diameter) were obtained for Pittsburgh coal, Gilsonite, and purple K, respectively. Transmission data from the PRL 20-L, Fike 1-m3 and the Siwek 20-L chambers indicated comparable results in terms of uniformity of dispersion. However, transmission data from the Siwek 20-L chamber were significantly lower than those of the PRL and Fike chambers. Again, this was attributed, in part, to the significant reduction in particle size that occurred during dispersion in the Siwek chamber. The design of the outlet (dispersion) valve of the Siwek 20-L apparatus charge vessel was largely responsible for the particle break-up. The contribution to particle break-up by the dispersion nozzles and the high level of turbulence in the chamber were found to be minimal. This is a significant finding in that the dust particle size tested for explosibility in the Siwek chamber is considerably smaller than the original dust sample.

Jan 1, 2010

By K. B. Rojiani

Surface mining activities disturb large tracts of land resulting in the potential for greatly increased downstream sediment loads. The Surface Mining Control and Reclamation Act of 1977 places increased emphasis on the protection of the environment from the adverse effects of surface mining operations. Surface mining activities must be planned to minimize disturbance to the hydrologic balance, erosion and sediment contributions to receiving streams. Sediment ponds must provide a sediment storage volume equal to the accumulated sediment volume from the drainage area as determined by the Universal Soil Loss Equation (USLE) or other empirical methods established by the regulatory authority. It has thus become extremely important for the mining industry to secure more accurate estimates of potential erosion losses and sediment yield. Accurate estimates of sediment yield are required for the planning, design and successful operation of sediment control systems such as detention ponds and other alternative control structures and for evaluating the effectiveness of land management practices. The principal soil loss prediction procedure available for use is the LISLE. The USLE procedure is inadequate for use in predicting soil loss from surface mine regions for a number of reasons. These include: 1. The USLE was developed to estimate average average annual loss from agricultural soils. It cannot predict accurately soil loss for specific storm events. In surface mine regions a major portion of the soil loss occurs during the initial six months to one year of active mining. Accurate estimates of soil loss over short periods are thus required for the design of control structures. 2. The slope length and gradient factors used in the USLE were obtained from data or cropland having slopes ranging

Jan 1, 1983

By Richard Klimpel

The laboratory ball mill grinding of coal/water slurries is described for three coals. Emphasis is placed on the measurement of specific rates of breakage for various operating conditions. Corresponding rheological information is also presented based on data collected using a rotational viscometer. A rheological explanation of the influence of various slurry fluidity conditions on the specific rates of breakage is presented. This rheological approach has proved useful In both the identification of suitable chemicals for increasing breakage rates in coal/mineral slurry grinding and in the plant scale implementation of dense slurry grinding systems.

Jan 1, 1982

By Raphael Lemos

Durante o ano de 2008 foram observados diversos “Gap’s” no processo de lubrificação, tais como: alto consumo de graxa, lubrificação em excesso, degradação de sistemas centralizados, ausência de procedimentos, mão-de-obra sem o conhecimento adequado, entre outros. Dessa forma, o processo de lubrificação foi separado em cinco grandes grupos de atuação, sendo eles: seleção de lubrificantes, gestão do processo de lubrificação, sistemas centralizados, contaminações e vazamentos. Foram aplicadas as ferramentas do MASP (Método de análise e solução de problemas) sendo a primeira delas o "Brainstorming", nos valendo das observações realizadas no Laminador de tiras a quente nº 2. Em sequência foi definido e implantado o plano de ação. Os resultados obtidos após as ações foram: a redução do tempo de parada associada a problemas de lubrificação dos equipamentos do LTQ#2, redução média de consumo de graxa no laminador de - 6.277 kg/mês, quando comparamos a média de consumo do período de Novembro de 2010 a Outubro de 2013, frente ao consumo atual no período de Novembro de 2013 a Outubro de 2014, totalizando uma redução média de aproximadamente - 75.321 kg nos últimos 12 meses.

Aug 16, 2017

By I. C. Edwards, G. E. Agar

INTRODUCTION Many research efforts over the past years have been devoted to the study of energy consumption in comminution and the characteristics of the broken material. The old "laws" have been superseded by more general methods of analysis1,2,3 but these methods have not received much attention outside the laboratory. The work to be described here was done in order to obtain scale-up information on wet rod milling of sylvinite. EXPERIMENTAL A 30 x 51 in. Denver rod mill with a scoop feeder was used for these tests. Ore was fed from a variable speed screw conveyor into the feed box along with saturated brine. The mill was filled to approximately 45% of its volume with 2400 lbs of a mixed rod charge. The minimum possible feed rate was 2.5 tph and the practical maximum for this mill was 8 tph. Individual tests were run by setting the solid feed rate, then adjusting the brine flow rate to give the desired pulp density. After steady state, as evidenced by constant discharge pulp density, had been reached, samples of the discharge were taken at 15-minute intervals. These samples were filtered, washed with alcohol, dried, then screened on Tyler screens using a Ro-tap shaker. The sylvinite feed was regular plant feed that had been scalped at 20 mesh and was tapped from the coarse ore bins. It had been previously passed through a roll crusher set at 3 inches and after scalping was essentially minus 1 in. plus 20 mesh. RESULTS The screen analysis of samples from each series of tests was plotted on double logarithmic scale paper to determine the reliability of the series. In some cases, a faulty sample or screening procedure dictated that the results of one test be discarded. The criterion is a simple one — if the slope of one plot was noticeably different from the others in the series, it was discarded. The only cases that caused difficulty were those in which the brine was not thoroughly displaced from the solids. When this occurred agglomerates were easily identified on the screens and the whole of the sample was retained on 3 or 4 screens. There were no border line cases. The number N given in Table 1 is the number of size analyses that were pooled to form the data shown in Fig. 1. While examining the reliability of the sizing and sampling by plotting the data, it became apparent that there was no significant difference between grinds made at 50 and 60% solids. For the analysis given here, these tests were regarded

Jan 1, 1967

By Douglas Kathol

Coal in the 1990?s Exit of the integrated oil company [Shell Arco Mobil Exxon Mapco Kerr McGee Hansen Nerco Sun] Continued decline in coal prices Significant mergers & acquisitions (M&A) activity ?Most properties traded, some twice ?Significant consolidation ?Massive recapitalization ?New industry leaders ?Frustrated expectations

Jan 1, 2002

By D Lautier, A A. Ndiaye, A Galli

Traditionally gold producers had built up hedge books to protect themselves against adverse changes in the commodity price, but diversified mining groups were staunchly opposed to hedging in any shape or form. The situation has evolved over the past few years. Gold miners have been reducing the size of their hedge books in line with the rising gold price. Commentators have talked about ædouble-digit dehedgingÆ and have suggested that this is the final countdown for gold hedge books. It sounded as if the era of hedging by mining companies was drawing to a close. But as appearances can sometimes be misleading, we decided to find out what mining companies were actually doing. Companies listed on stock exchanges are now obliged to give details of their derivatives holdings in their annual reports. Two or three years ago there was no such obligation. Our reality check was based on the latest annual report issued by three multinational mining groups; two with diametrically opposed views on hedging (Rio Tinto and Barrick) and the third (BHP Billiton) with an intermediate position. This snapshot of their derivative positions at a point in time revealed that Barrick and BHP Billiton have substantial derivatives positions (worth billions of dollars) to protect against adverse changes in foreign exchange rates and interest rates. Moreover Barrick has recently started hedging against increases in fuel prices. Despite its opposition to hedging, Rio Tinto has derivative positions worth several hundred million dollars, but these are primarily a legacy from various mergers and acquisitions over recent years or were entered into as a condition of project financing. Lastly we were surprised to discover that Barrick was holding asset-backed commercial paper (ABCP). So the idea that mining companies donÆt hedge their risks is just another urban myth.

Jan 1, 2009

By D. A. Stout

Mr. Chairman and Members of the Rocky Mountain Coal Mining Institute: Your Secretary has asked me to write upon a subject' which is a most interesting one, and which has a very wide scope. In view of the great need for further decreasing costs at its coal mines, the Colorado Fuel and Iron Company began early in 1924 to experiment with methods of mining which had not previously been. tried out at its mines, and which were selected because of the greater possibilities for the concentration of the work, better grouping of workmen, and increased tonnage per workman, with a resultant increased efficiency, better supervision, and lowered costs. Because of the great competition of the day, means and methods must be provided by which fewer mines can be made to produce larger tonnages and at a lower cost. Western physical conditions are such as to make our problems far more complicated and not so easy of solution as compared to many of the eastern fields where conditions are more favorable for the operation of the mines. The dry condition of our Western mines on account of a relatively low humidity, and with additional gaseous conditions, makes the problem still more difficult to solve. A study of new methods was necessary before adoption, and this was particularly true of the method of extracting the coal. Where mechanical means are used, particularly in the coking coal mines of this state, due consideration must be given to the type, and machines or conveyors should not be installed solely on the basis of their performance elsewhere, without the knowledge of local influencing factors. In trying out the newer methods of extraction at our mines, very careful consideration has been given to the question of safety and the adoption of any new methods must provide adequate means of protection to employes, and be approved by' the State Coal Mine Inspector. In any large industry there are a few outstanding operating costs, and usually the leading ones in their order are labor cost, material cost, and power cost. The things which we, hope to accomplish: 1. Reduce labor costs. 2. Reduce material costs. 3. Reduce power costs by the con 4. Reduce the amount of powder used per ton of coal produced. 5. Increase the lump percentage (particularly at the domestic mines). 6. Reduce accidents and annual compensation payment. 7. Reduce haulage costs. 8. Reduce cost for track work. 9. Reduce cost for timber and timbering, and increase the recovery of timber at a considerable additional saving. 10. Reduce the brushing costs. 11. Reduce the amount of rock hauled to the outside. 12. Reduce the cost for drainage. 13. Reduce the cost for ventilating. 14. Reduce cost of inspection and supervision. 15. Reduce the cost for shot firing. 16. Reduction of number of working places. 17. Grouping of men with increased sociability. 18. Increased tonnage per man. 19. Reduction in total number men employed. In the consideration of the methods used and now working successfully, there were three points which were considered outstanding, to make them wholly successful: ventilation, roof control, and transportation. For making the experiments, those mines were selected where conditions

Jan 1, 1925

By René G. del Villar, Jules Thibault, René del Villar

"Some key control variables of industrial processes, associated with product quality, often cannot be measured directly or frequently enough to establish adequate control. In such cases, it is possible to use available measurements to provide a prediction for these process variables and use them in a control strategy, thereby giving rise to what is now commonly called a softsensor.In some industrial grinding circuits, the on-line particle size analyzer is shared between various sampling points. Therefore, for a given location, the actual measurement is only available every 10 to 20 minutes, a delay which is unacceptable for automatic control purposes. To alleviate this problem, a softsensor based on an artificial neural network has been investigated. First, the structure of the neural network and different schemes for the training process are analyzed. Then, the performance of the neural network softsensor is compared with other inferential methods such as ARMA models and Kalman filters.IntroductionGRAHM, French acronym of the Research Group on Computer Applications in the Mineral Industry at Laval University, began in 1990 a research project on Knowledge Based Automatic Control (KBAC). This project, sponsored by a consortium of eight mining companies and the federal and provincial governments, seeked to screen advanced (knowledge-based) methods for data processing (filtering, mass balancing, etc) and automatic control (model-based) for their use in the mineral processing operations and the transfer of the project results to the sponsor companies.In parallel to more academic research work, a number of case-studies have been undertaken with the cooperation of partner companies. Among such works, a very successful one has been the design and installation of a new control strategy for one of the Kidd Creek (Falconbridge Ltd.) grinding circuits. This project was related to the evaluation of a number of control strategies and the implementation of one of them, as selected by the plant management, in the concentrator.A total of sixteen control schemes were evaluated on one of the dynamic phenomenological simulators developed at GRAHM, a trademark of this research group [ l]. The calibration of the simulator models was done based on industrial data gathered by GRAHM and Kidd Creek personnel. Then, the simulator was used to test the performance of various PID-based control schemes, designed to achieve the control objectives set by the Kidd Creek personnel. The best scheme proposed called for controlling the cyclone overflow particle size by manipulating the water addition rate to the cyclone feed box and the circulating load by manipulating the circuit ore feed. The particle size analyzer (PSI-200) available for monitoring the product size, was unfortunately shared (multiplexed) among various streams of the plant, which meant a 14 min delay between two consecutive readings for any particular stream. This induced the plant personnel to choose an alternative control strategy, one which controlled the cyclone feed density instead of the cyclone overflow particle size."

Jan 1, 1996