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By Bruce Hebblewhite

This paper focuses on the recent achievements and practices developed through the Minerals Tertiary Education Council (MTEC) initiative of the Minerals Council of Australia (MCA), in conjunction with the three partner universities involved in mining engineering education – University of New South Wales (UNSW), West Australian School of Mines, Curtin University (WASM), and University of Queensland (UQ). The collaboration between these partner universities and industry has led to the development of shared course material, cross-institutional teaching arrangements, and development of a number of flexible, distance-based delivery programs. The paper will then move on to future initiatives. Importantly, the exciting challenge is the future initiative planned to cement this collaboration by the formation of a “virtual” national school of mining engineering – Mining Education Australia (MEA). This will provide a common 3rd and 4th year program to all three universities from 2007, involving innovative teaching and learning arrangements, greater student exchange potential and a more significant input by industry into the education process. Such an initiative is not without its challenges, and has a long way to go, before becoming a reality. However, it offers greater attractiveness and marketing potential to prospective students, as well as economic efficiencies, whilst delivering a better quality, and hopefully greater quantity of graduates to industry. It can also form a launching platform for a much greater level of international collaboration, through a proposed International Mining Education Network (IMEN) which is currently being floated amongst a number of international educators.

Jan 1, 2005

By J. A. Pigott, R J. Hall

The International Nickel Company of Canada, Limited operates five underground mines on the rim of the Sudbury Basin in the northern part of the Province of Ontario. Four of the mines, the Frood-Stobie, Creigh-ton, Murray and Garson, are located on the south range of the basin with-in a radius of IO miles of the centre of the city of Sudbury. The fifth mine, Levack, is on the north range about 30 miles northwest of the city. The ores are mined primarily for nickel and copper, and the principal minerals are pentlandite, chalcopyrite and pyrrhotite. In 1960 the total ore production was in excess of 16 mil-lion tons, 95 per cent of which was produced from the five underground mines and the balance from the Frood-Stobie Open Pit. Mining at this open pit is nearing completion and underground production has been expanded to replace the open pit tonnage.

Jan 1, 1961

By S. Makni, A. Faucher, F. Robichaud, A. Bouajila

"Optimizing the ball charge in a grinding mill may be needed to maximise throughput or alternatively, to achieve proper product size in more challenging situations. Efforts to optimise the ball charge however are essentially empirical and suffer from the lack of appropriate, accessible and reliable tools. To address these limitations, a new model-based technology was developed that relies on 3D Discrete Element Method and population balance techniques: it takes on the form of a simulator that aims to significantly decrease the time required to optimise the size distribution and the grinding media load within a ball mill. This paper summarizes the research work related to the development of this simulator. The calibration of the different constituting sub-models will be highlighted. The successful use of the simulator to predict the effect of ball make-up on the grinding product size distribution in one plant is also reported.INTRODUCTION Adjusting the characteristics of the grinding media charge in grinding mills holds significant potential for optimisation of mill performance. For example, properly adjusting the ball size distribution in a ball mill can help achieving specified targets for final product size distribution and/or throughput capacity. However, several problems appear when reviewing the process and the available tools to optimise ball mill load: • The current empirical simulation tools are lacking with regard to the ability to predict the performance of grinding when changes to mill ball make-up are made; • Generally, these tools estimate the top size of the charge so it is difficult to predict the effect of mixed ball make-up; • As the quality of prediction of these tools is low, the operators try to optimise the ball charge by a ""trial and error"" method and proceeding with conservative changes. The influence of these changes on grinding performance is often less than the measurement precision and the improvements then remain imperceptible; • A change in ball make-up may require an average of about 6 months waiting period before reaching the stationary state of mill ball load. This exercise is due to be costly if applied change decreases the mill performance. In its effort towards the comminution process optimisation, COREM R&D portfolio had addressed the herein described opportunity during the last five years This paper describes the technology already developed for the optimisation of ball charge. It takes on the form of a simulator that aims to predict the evolution of the grinding media load, the grinding energy available in the ball mill and the final product size distribution. The simulator was first validated in a pilot scale ball mill and then applied in an industrial case."

Jan 1, 2012

By Shengqi Chen

The reduction smelting of nickel laterites produces slag, consisting principally of the chemical components MgO, "FeO", SiO2, and A12O3, and ferro-nickel alloy. Despite the fact that the phase equilibria for the ternary MgO-"FeO"-SiO2 up to 1500°C is well established limited experimental data are available in the MgO-"FeO"-SiO2-Al2O3 system, which is relevant to commercial operation of the process. A methodology has been developed for the experimental investigation of the liquidus temperatures for the multi-component system MgO-"FeO"-SiO2-Al2O3-Cr2O3 in equilibrium with metallic iron. Experiments have been carried out using high temperature equilibration, quenching, followed by electron probe X-ray microanalysis (EPMA). Liquidus temperatures have been determined in the silica primary phase field in the composition ranges directly relevant to the Cerro Matoso S.A. ferro-nickel smelting slag. Liquidus isotherms have been determined for temperatures between 1450 to 1600°C. The study enables the liquidus to be described for a range of MgO/FeO ratios. It was found that liquidus temperatures in the silica primary phase field decrease significantly with the addition of AI2O3. Keywords: Liquidus temperature, ferro-nickel, pyrometallurgy, smelting

Jan 1, 2004

By S. C. Richardson

The electrowinning (EW) circuit involves using DC current in the electro-deposition of metal ions dissolved in an electrolyte solution. This paper reviews a method to generate an electrical model of an EW circuit and the resulting DC current flow and voltage distribution within the circuit. Topics include: calculations of electrolyte conductivity and the equivalent electrical resistance of the electrolyte within the electrolyte pipelines connected to the EW circuit; the breakdown and classification of the EW cell voltage into thermodynamic and ohmic potentials; methods to calculate current flow and voltage distribution throughout the EW circuit; and the development of an interactive visual computer model to simulate an actual EW circuit. Stray current can pose an electrical shock hazard to employees in electrolytic tankhouses. Increased awareness and understanding of the voltage distribution and potential stray current in an EW circuit can help mitigate the risk of tankhouse workers becoming exposed to electrical shock hazards. INTRODUCTION Copper electrowinning tankhouses include rectifiers that deliver large amount of DC current to a series of electrolytic cells consisting of electrolyte solution and electrode pairs. The design also includes metallic conductors in the circuit which include the rectifier’s positive and negative busbar, inter-cell busbar, and the anode and cathode frames. The electrolyte acts as an electrical conductor that transfers current via ions between the anodic and cathodic electrodes within the cell. Electrolyte, as a conductor, is also capable of conducting DC current outside the main EW circuit through the connected electrolyte feed and return pipe systems. DC current that follows a path other than the intended path through the series of electrolytic cells is referred to as “stray current”. Developing an electrical model enhances understanding of voltage distribution and current flow in an EW circuit. This paper discusses the derivation of the various representative components of the model as well as the output from the model. An interactive visual computer simulation incorporates the model output in order to aid in the understanding of voltage distribution and current flow throughout the EW circuit.

Jan 1, 2019

This Information Circular from the National Institute for Occupational Safety and Health (NIOSH) documents and supplements the information presented in a series of workshops held during 2002 and 2003. The primary intended audience consists of all who are involved in developing and conducting miners' training. According to the Mine Safety and Health Administration (MSHA), mine operators reported 240,000 full-time equivalent workers and independent contractors reported 42,000 full-time equivalent workers working on mine property during the year 2000. Unfortunately, these workers have a relatively high risk of suffering serious work-related injuries and illnesses. The mining industry has the highest rate of occupational fatalities among all U.S. industries. The fatality rate is 30 deaths per 100,000 workers compared to 4.6 for all private industry (Morbidity and Mortality Week Report, 2001; NIOSH, 2002). Compared to workers in other industries, miners also have a relatively high rate of nonfatal lost-time injuries, and their injuries tend to be more severe (Bureau of Labor Statistics, 1999). Many miners are also exposed to significant health hazards, including coal and silica dust, diesel exhaust, and noise. More than 1000 U.S. miners die of lung disease each year (NIOSH, 1999). Mine safety and health professionals have long recognized training as a critical element of an effective safety and health program. Federal regulations (30 CFR, Parts 46 and 48) require mine operators to provide initial safety and health training to all new miners, as well as a minimum of 8 hours of refresher training each year. The time and money being spent to train U.S. miners is substantial, and so there is a strong and steady demand for new and better mine training materials and methods. A growing concern among mine safety professionals regards the training of new workers. A major change in the mining workforce is anticipated within the next decade. In major segments of mining, especially coal, relatively few workers have been hired since the 1970's. Thus, as an entire cohort of miners in the current workforce nears retirement, the replacement of these employees will require an influx of new workers. New miners may be young people who lack the ability to recognize and respond to mining hazards in an appropriate manner. They may also have had different educational experiences than their older counterparts. Many safety professionals believe that these two cohorts require different approaches to training. The papers in this report should help prepare mine trainers for the changes about to occur in the workforce and acquaint them with strategies they can use to enhance the effectiveness of their training. The first three papers present basic principles for teaching adults. The five remaining papers are intended to illustrate how these principles can be applied to the development and imple¬mentation of effective training for miners. Below is an overview of these papers. 1. Kowalski and Vaught review the process and principles of adult learning. The learning model they present includes a discussion of goals, content, delivery, assessment, and remediation. Adults are viewed as active learners, experienced-based, expert in their own right in specific areas, independent, real-life centered, task-centered, problem-centered, solution-driven, skill-seeking, self-directing, and internally and externally motivated. Basic aspects of curriculum development are briefly reviewed. For further information about adult learning, see Camm and Cullen's paper. 2. Mallett and Reinke's first paper discusses issues related to training new miners who have recently or will soon be entering the mining workforce. These new generations of miners have different learning style preferences and training needs than Baby Boomers and other older miners. Even trainers who have been highly effective in the past should reassess their training styles and their classroom materials to determine if they are prepared to meet the needs of these young new workers. This paper provides information that will help mine trainers communicate across the generation gap. 3. Mallett and Reinke's second paper provide an overview of training evaluation. Trainers and decision-makers are given a framework for planning and assessing training evaluation strategies. The authors present Kirkpatrick's (2001) model of evaluation categories and discuss how to start an evaluation plan and various ways to collect data. They do not provide detailed instruction in evaluation methodologies, but give trainers a review of the things they need to consider when developing an evaluation plan. A good evaluation plan can inform revisions to a training course, assess trainee learning, and/or answer managers' questions about program effectiveness. 4. Brnich, Derick, Mallett, and Vaught discuss a technique for incorporating worker participation into fire prevention and safe equipment operation training. This technique involves development of short (5 to 7 minutes) videotapes coupled with toolbox talks that ground the content of the videos within the context of a miner's workplace. An example of one of these training modules is presented, along with the results of an evaluation performed on its effectiveness at improving miners' understanding of what types of information they should be sure to communicate during a mine emergency. 5. Wiehagen, Conrad, Friend, and Rethi discuss on-the-job training (OJT) as a method for teaching miners safety and production skills. Much of the training is done by experienced workers. This paper describes how small investments can help improve the effectiveness of on-the-job training. Effective on-the-job training involves some structure and planning in the transfer of responsibility for task performance from the trainer to the novice. Assisting the trainer could involve helping develop up-to-date job analyses and offering strategies for teaching and evaluating job skills. This paper addresses organizational considerations supporting structured on-the-job

Jan 1, 2002

By Natália de Oliveira Roque Maciel

Atualmente uma das maiores preocupações da humanidade está relacionada as questões ambientais, o que tem motivado a pesquisa e o desenvolvimento de materiais provenientes de recursos renováveis e ambientalmente amigáveis. A despeito disso, este trabalho objetiva comparar a resistência de compósitos desenvolvidos com fibras naturais e, portanto, ambientalmente amigável e de compósitos desenvolvidos com fibras de vidro, que por sua vez apresentam impactos ambientais desde a fabricação até o descarte. Foram fabricados 13 corpos de provas para amostras contendo 0% de fibra, 30% de fibra de curauá e 30% de fibra de vidro na matriz epoxídica e ensaiado na máquina de tração. Os resultados obtidos apresentam valores bastante superiores para as amostras contendo fibras de vidro, contudo, ao relacionar a tensão do compósito com a respectiva densidade da fibra, foi possível constatar que os compósitos com fibras naturais chegam a apresentar resultados superiores aos compósitos fabricados com fibras de vidro. É possível concluir, portanto, que do ponto de vista da propriedade mecânica em questão é possível substituir as fibras de vidro por fibras de curauá.

Aug 17, 2017

By L. Hanschar, C. Bwalya, E. Mokola, K. Musonda, A. Makayi

This paper describes the installation, commissioning and operation of porous plugs featuring nitrogen gas purging in both Anode Furnaces at the Kansanshi Copper Smelter (KCS), a greenfield copper smelter which commenced operation in March 2015. The decision to install porous plugs was taken in November 2016 and the facilities were successfully commissioned on both anode furnaces in October 2017. The project was successful and has demonstrated the following process improvements: 12.2% reduction in main burner fuel consumption Larger average charge size, due to fewer accretions; 17 minute decrease in average refining cycle times Improvements in slag skimming operations Improved casting rates INTRODUCTION Porous plugs The application of porous plug technology in copper smelter anode furnaces is well established around the world. Vukovic and Gamweger (2017) and Wallner (2004) noted that the stirring and mixing action induced by the injection of inert nitrogen gas into the molten copper via porous plugs has potential benefits in the following areas: Homogenization of the temperature and composition of the molten copper resulting in Reduced fuel consumption Less tendency to overheat slag (reduced risk of refractory attack) Less slag produced with a lower degree of oxidation (lower rate of refractory wear) Less tendency for buildups to form Improved environmental performance (produce low sulphur blister at Peirce Smith converters) Elimination of buildups inside the furnace and potential for larger charges per cycle Reduced processing times and potential for shorter cycle times More efficient skimming of anode slag Shorter skimming time Less copper carry over to Peirce Smith converters Very little slag remaining in the furnace (reduced potential for buildups to form)

Jan 1, 2019

Jan 1, 1967

By John Nagy

Large-scale tests in the U.S. Bureau of Mines Experimental Coal Mine show that the explosion hazard of coal dust on shuttle-car roadways can be con-trolled by proper application of water, dry rock dust, a saturated solution of ammonium phosphate, or mixtures of water or the water-phosphate solution with rock dust. The experiments were made with loadings of 1.0 and 5.0 pounds of mine size coal dust per linear foot of entry, and with a 3-or 4-inch-thick layer of coal rubble on the floor, The data from the tests with mine-size coal and rubble are comparable. The water contents of the dust loading were determined from samples collected just prior to initiation of a gas-air mixture in an ignition zone at the face Dust samples were collected 1 inch deep from the coal-rubble deposit. One experiment was made with the dust in the coal rubble bound with latex applied as a water solution by spray. The binding action was inadequate and explosion propagation was obtained.

Jan 1, 1970

By Charles Jones

IN the winter of 1902, while occupying the position of mining and examining engineer for the Mountain Copper Co., Ltd., of Keswick, Cal., I had occasion to discuss with the General Manager, among other things, the question of the enormous waste of sulphur in smelting cupriferous, pyrite ore, and to cast about for means to utilize this waste or to render the fumes innocuous to vegetation. The decreasing rate of production of California farms, the consequent need of fertilizers, and the opportunity thus offered to utilize large quantities of sulphuric acid in the manufacture of superphosphates naturally brought the subject to the practical and commercial side of phosphates. I was informed that the company had made efforts to find phosphates in the West, without success. I advised as a start placing inquiries for phosphate deposits on the Pacific coast in the current mining ,journals. This was done, with the result that in January, 1903, from an advertisement in the Mining and Scientific Press we got track of a deposit in Rich county, Utah, through T.J . Wilson, of the Southern Pacific railroad in San Francisco. As soon as snow in the mountains would permit, in May, 1903, I undertook an examination of the property, with the result of recognizing the importance of the find, in spite of its lack of facilities for transportation at a commercial figure. On June 15, 1903, I concluded my report by saying, "This may be one of the world's deposits of phosphates." On Nov. 17, 1903, I concluded my report for the season in the following words : " I have now no hesitation in saying that I believe the Carboniferous formation so largely developed in the Wasatch mountains of Utah and the mountains of the Great Basin will prove to be one of the greatest storehouses of phosphoric acid in the world."

Jan 10, 1913

By P. C. Benedict

Introduction and Summary The Northern Empire mine is a mile east of Beardmore, and 100 miles northeast of Port Arthur, district of Thunder Bay, Ontario. Production started in March, 1934, and terminated in September, 1941. During this period, the mill treated 425,866 tons of ore, from which 153,103 ounces of gold were recovered. The lowest level from which ore was mined was the 1900, but considerable drifting was performed on the 2075 level and 800 feet on the 2415, the deepest level. The following description of the geology of the mine is recorded by the senior author but is based on the observations and complementary mapping of both authors. The vein strikes about N.72°E. and has an average dip of 80°S. (Figure 1). In stoped sections, the quartz averaged about two feet wide. On the 1725 level it was drifted on continuously for more than 7,000 feet, but in the mine as a whole practically no commercial ore was found beyond points 1,400 feet west and 1,800 feet east of the shaft. Conspicuous wall-rock alteration extended throughout this section but not much beyond its limits. There was some splitting of the vein and widening of the alteration halo on the lower levels. The average general colour of the quartz changes with depth. It may be generalized, from top to bottom, as light grey to dark grey to brownish. The brownish quartz first appeared near the bottom of the ore.

Jan 1, 1947

By A. Sobhy

Froth flotation is a widely used, cost effective coal cleaning process. However, its high process efficiency is limited to a narrow particle size range between approximately 50 to 600 µm for coal and 10 to 100 µm for minerals. Beyond this range, the efficiency of froth flotation decreases sharply, especially for difficult-to-float coal fines of weak hydrophobicity (e.g., oxidized coal). This study was aimed at enhancing recovery of an Illinois fine coal sample using a flotation column featuring a hydrodynamic cavitation nanobubble generator. Nanobubbles that are mostly smaller than 1 µm can be formed selectively on hydrophobic coal particles from dissolved air in fine coal slurry. Results indicate that combustible recovery of a -150 µm coal was increased by 5-50% for different size fractions in presence of nanobubbles, depending on process operating conditions. Other major advantages of the nanobubble flotation process include lower collector dosage and air consumption since nanobubbles are produced from air naturally dissolved in water and they act as a secondary collector on particle surfaces, thereby resulting in considerably lower operating costs. Key words: Cavitation; coal; froth flotation; nanobubble.

Feb 27, 2013

By K. G. Davies, M. J. Royea

"A major program of pillar recovery at the Sullivan mine has been assisted for the past several years by a concerted series of rock mechanics investigations. The object of these investigations is to measure the parameters of rock behaviour which influence pillar mining. This quantitative information is then used in the design of mining methods appropriate for various conditions.Instrumentation to measure absolute rock stress, changes in rock stress and the gross deformation of rock masses has been developed. Various instruments are described, as are instrument evaluation procedures and typical test results. The data from underground measurement projects have been used to modify pillar extraction sequences along re-treat fronts. Rock mechanics information from individual pillars has been incorporated into the design of mining methods to suit particular circumstances."

Jan 1, 1968

By R. Blosser

Phelps Dodge introduced a process improvement model known as Quest for Zero in 2001. In 2004, the focus of Quest for Zero shifted from corporate-led initiatives to projects led by site personnel. The Hydrometallurgical Division at Morenci focused on two (2) significant process improvements: reducing electrolyte bleed and organic losses. In September 2004, Morenci kicked off a bleed reduction project to reduce electrolyte bleed by 45%. By the end 2005, electrolyte bleed was reduced by 55% through understanding and reduction of variance. Significant process changes made during this time period include changes in acid-addition strategy, reduction of uncontrolled bleed, and optimization of bleed placement. In April 2005, the organic reduction project began with the goal of reducing losses by 15%. Operational improvements during this project included improved organic recovery systems, mixer speed optimization, and picket fence installation. By the end 2005, this project reduced organic losses by 35% and current losses are 48% lower than at the start of the project. These projects and smaller Questfor Zero projects have resulted in sustainable annualized savings of $13 million in Morenci hydrometallurgical operations. Through the use of Six Sigma tools, process variances can be controlled and reduced.

Jan 1, 2007

By Mark L. Chatman

The U.S. Bureau of Mines studied mineral resources of the Dragoon Mountains Unit, Coronado National Forest (54,264 ac), Cochise County, AZ. This study involves literature and field investigations with a focus on mine and prospect sites, which were inventoried and mapped; maps are contained in this report. Rock-chip samples were taken from mineralized zones and from some mine dumps; assays of the 477 samples are in appendixes. Mineral deposits are genetically and spatially related to Tertiary-age granitic intrusive activity. Most metallic mineral deposits are also strongly fault-controlled. Colored marble resources (270,000 st) are valued at approximately $6.5 million, if all were to be developed and sold as landscaping material in the form of-marble chips. However, with current demand, it is unlikely that regional markets could absorb all this material. Economic modeling of copper-zinc-silver skarns suggests none would be profitable to mine and capitalize at early 1993 commodity prices, mainly due to the small estimated size of the deposits (30,000 st to 40,000 st maximum). In the entire Unit, 140,000 st of inferred subeconomic skarn resources were estimated by USBM on five different skarn trends; measured subeconomic resources are negligible. Exploration by industry, 1992, was small-scale (on 2 skarn trends and 1 auriferous fault zone).

Jan 1, 1993

By K. Zabrusky

Estimation of high grade epithermal vein deposits can present challenges in correctly representing the continuity of grade within an undulating structure. One solution to this problem is to use dynamic anisotropy to follow local variations in the strike and dip of veins. Dynamic anisotropy (D.A.) allows the search parameters to change block by block throughout the model to account for the local variations. Presented here is a study of a vein that changes orientation down-dip. A traditional resource estimate using one search ellipse orientation was performed. The resulting estimated grades did not accurately reflect those of the sample data. Using a search ellipse with an average value for the two distinct dips caused the grade estimation to be less representative than desired. Rather than performing domain-based analysis with different search ellipses, the issue was corrected by using Datamine Studio 3?s D.A. function. The 3D vein trend was used to estimate the dip and dip direction of the vein in each block. The resulting D.A.-estimated model follows the two dip trends of the vein. This software makes a previously tedious task faster, and allows for more accurate estimations.

Feb 27, 2013

By G. S. Hume

Research thrives on ideas, and the theoretical considerations of today are either the discarded notions or the proven facts of tomorrow. The progress made in the past fifty years in the acquisition of knowledge of petroleum geology is no less astounding than is the tremendous increase in the production of oil on the North American continent from 61 million barrels in 1897 to 1,917 million barrels in 1947, an increase of 3,300 per cent, with production of natural gas expanding from less than 400,000 Mcf in 1897 to approximately 4,500,000,000 Mcf, or an increase of 11,000 fold in the same period. In the search for and discovery of the oil and gas fields that have yielded such prolific wealth, no idea has had a more profound effect than has the ?anticlinal? theory of oil accumulation, propounded in 1844 by Sir William Logan, the founder of the Geological Survey of Canada, after noting the position of oil seepages on the crests of anticlines in Gaspe peninsula. Sir William apparently was not much impressed with his own idea at this time, but after the Drake well discovery in 1859 and the publication by Henry D. Rogers, of Glasgow University, formerly of the Pennsylvania Geological Survey, of a paper in which he pointed out that the seepages in Pennsylvania were on anticlines, T. Sterry Hunt, an associate of Sir William Logan on the Geological Survey of Canada, published a reasonably comprehensive statement of the anticlina theory in the Montreal Gazette on March 1st, 1861. Hunt recognized the fact that the oil ?being lighter than the water which everywhere penetrates the rocks below the water level, naturally rises and accumulates along the crown of these anticlines". This was a recognition of the fact that gas, oil, and water in an anticlinal structure separate according to buoyancy or specific gravity. For some years the anticlinal theory does not seem to have attracted much attention, but when I. C. White in 1883 revived it and put it to practical use by prospecting for 'anticlinal' oil an gas structures in Pennsylvania, West Virginia, and Kentucky, its real value not as a theory but as a fact became widely recognized. Even today, the search for anticlines as oil and gas structures is being vigorously continued. In the past fifty years, however, it has become widely recognized that petroleum and natural gas collect in many different types of structures, and these have become known by the general name of 'traps'. About 1890, terrace structures were highly regarded because it was thought certain oil fields in Pennsylvania, New York, and Ohio were directly related to them. However, as Wilson (2, p. 437) has pointed out, it is recognized to day that ?'wherever the surface evidence is complete and dependable, other factors (than the terrace structure) are found to be in control'.

Jan 1, 1948

By J. Sidhom, W. Fourie

"As the mining industry continues to face difficult challenges the need to persistently focus on productivity and utilization of labor and equipment costs will intensify. With these challenges in mind, Komatsu is helping to bring mining performance and analytics to the next level.By evaluating underground haulage, a significant component of the room and pillar mining value stream, variables have been identified and sensitivities have been performed to show opportunities to balance and streamline throughput. As a result of applying operational excellence tools to the mining environment, Komatsu is seeking to optimize mining performances by limiting waste, simplifying the process, increasing productivity and machine utilization, as well as removing workers from harm’s way.These days it’s not enough to work harder; mines have to work smarter. Improving efficiency, reducing costs, increasing safety: these are no longer nice to haves, they are must haves.Starting with the best products and the right people is a first step, but then what? How do mines take their operations from average to being a top performer? By using operational excellence principles aimed at eliminating waste, simplifying processes, automating where possible and removing people from harm’s way.The fundamentals of operational excellence (OpEx) are based upon the process of define, measure, analyze, improve and control (DMAIC). DMAIC is an improvement cycle that helps with, for example, haulage optimization by: defining the issues and problems in the process as well as the areas of improvement; measuring and collecting mining operational data by time study and equipment monitoring system; analyzing through sensitivities and production modelling to determine root causes and then improving the performance and controlling the operation.Komatsu uses OpEx or lean principles inside its organization to drive efficiency, but it also helps its customers employ them to achieve new levels of productivity and safety.These same principles can be applied in most situations to streamline processes, improve operations and deliver value."

Jan 12, 2017

By F Linares, B De Waele, K Bischoff, M Lacorde, G Loveday

Recent exploration has identified the presence of detrital iron deposits (DIDs) associated with banded iron formation (BIF) units in the north-west of the Congo Craton, Gabon. The regional geology comprises a complex of granitoids and gneisses assigned to the Archaean Chaillu Complex, within which older slivers of lower amphibolite-grade greenstones are preserved including muscovite-biotite-garnet-bearing felsic schist, amphibolite and BIF. These units are typically overlain by several metres of residuum comprising colluvium, eluvium and duricrust. The residuum is overlain by a regionally extensive loess cover from 2 m to 10 m thick.The DIDs occur within the weathered residuum as mostly unconsolidated gravels with lesser canga (CAN) duricrust draped over deeply weathered hematite. Head grades are in the range of 45 to 52 per cent Fe. Fresh BIF, located from 30 to 50 m below surface, is comprised of magnetite-quartz±amphibole. The detrital iron gravels are comprised of rod- and plate-shaped clasts of hematite (martite)-maghemite-goethite composition, in a ferruginous sand to clay-sized matrix. The DID form ridges and plateaus that coincide with magnetic highs defined using high-resolution ground magnetic surveys.The field relations and petrography indicate that the detrital iron accumulations are the result of weathering (including enrichment) and erosion of primary BIF. This includes removal of quartz, further oxidation and re-cementation of BIF to form ferruginous caprock. This cap and the in situ oxidised BIF were subsequently disaggregated and liberated, and further weathered to form the detrital iron accumulations.Metallurgical test work on bulk detrital iron samples has shown this material can be upgraded to lump and fines iron ore products with grades of 62 to 65 per cent Fe using simple scrubbing and wet screening, followed by dense media separation of the -1 mm fraction, with overall mass yields from 75 to 85 per cent. The test work indicates a high ratio of lump to fines products, sometimes exceeding 50:50.CITATION:De Waele, B, Lacorde, M, Bischoff, K, Loveday, G and Linares, F, 2017. Geological and metallurgical characteristics of banded iron formation associated detrital iron mineralisation in Central West Africa, in Proceedings Iron Ore 2017, pp 259–268 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Jul 24, 2017