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By Christoph Aichinger

The optimization and improvement of a modern integral iron and steel works gets more and more difficult as each individual plant is already operated at its best efficiency and at the lowest operational expenditures. However very often the individual plants are considered as stand-alone units and there are losses and inconsistencies on interfaces and take over points, which could be avoided and by that improving the overall performance of the iron and steel works as a holistic unit. Primetals Technologies looked into this subject extensively in the recent years and is now ready to offer new tools and services in order to assist operators to find further potential for improvement in processes, which seem to be fully developed at first sight.

Aug 17, 2017

By Anderson Alves Cunha

Diante do cenário macroeconômico internacional, o setor mineral busca soluções inovadoras e sustentáveis para seus processos produtivos. Uma dessas soluções é, sem dúvida, aumentar a recuperação do mineral de interesse presente no rejeito proveniente de operações de beneficiamento de baixa recuperação metalúrgica. A substituição de matérias primas naturais por resíduos abre uma gama de oportunidades para melhorar a gestão de recursos não renováveis, contribuindo significativamente para o desenvolvimento sustentável e competitividade do negócio. O presente trabalho tem o objetivo de definir qual a faixa granulométrica, existente na lama, é mais adequada para concentrar e produzir pelotas, considerando a composição química, perda por calcinação, mineralogia e quantidade de elementos deletérios. Para isso, foram utilizadas técnicas de caracterização tecnológica, como: classificação granulométrica (peneiramento a úmido e cyclosizer), fluorescência de raios X, difração de raios X e microscopia óptica. Os resultados do trabalho permitiram identificar uma faixa granulométrica com alto teor de ferro e alto grau de liberação dos minerais de ferro, porém com teores de quartzo acima que um pellet feed comercial. Sendo assim, um determinado tratamento de concentração ou um blend será necessário para adequar quimicamente o material, para posterior obtenção de pelotas com baixo custo.

Aug 17, 2017

By Elena Kalinin Toss

Inúmeras indústrias necessitam de sistemas de tratamento de água que favoreçam o processo de descarte de seus efluentes, além do aproveitamento do reuso de água. A mineração e siderurgia podem apresentar rejeitos com metais, que necessitam de tratamentos econômicos e sustentáveis. A biossorção é um exemplo de técnica que vem ganhando interesse em diversas áreas da pesquisa. O objetivo do estudo foi avaliar a porcentagem de remoção de íons de níquel de uma solução monoelementar de cloreto de níquel II (NiCl2+) em pH 2, 4 e 6. Para isso, utilizou-se um sistema de batelada, e 1g de consórcio bacteriano liofilizado (sem ser autoclavado) isolado de amostra de terra. Os resultados indicaram que a eficiência da biossorção foi maior para o pH 6, e que o consórcio bacteriano foi eficiente na remoção de íons de Ni2+.

Oct 30, 2017

By G R. Ballantyne, G Lane

Dry milling circuits that include high pressure grinding rolls (HPGR) or vertical roller mills (VRM) and air classification have replaced dry ball milling in cement production, but how do they compare to wet milling and classification circuits in mineral processing plants? Two case studies are presented that compare the energy efficiency, wear, liberation and capital cost of dry and wet milling circuits. In both case studies the VRM and HPGR consume half the energy of a wet tumbling mill for the same duty. However, the dry classification system tends to significantly erode the energy benefits. A number of improvement opportunities are presented that have the potential to improve the energy and capital efficiency of dry milling circuits. These improvement opportunities focus on the dry classification system that consumes significant energy in heating and fan power requirements and requires a large proportion of the footprint.

Aug 24, 2022

By G P. W Suyantara, Y Tanaka, T Hirajima, Y Aoki, K Sasaki, H Miki

The effect of sodium sulfite (Na2SO3) on the flotation behaviour of bornite and tennantite is reported in this work. Flotation tests were performed using pure minerals of bornite and tennantite under various concentrations of sodium sulfite at pH 9. The flotation results indicated that sodium sulfite exhibited a depressing effect on the floatability of bornite in the presence of 0.1 mM PAX. However, tennantite remained floatable after the addition of sodium sulfite in the presence of 0.1 mM PAX. The flotation tests using mixed bornite and tennantite confirmed the flotation results of single minerals. Surface characterisation using X-ray photoelectron spectroscopy (XPS) was performed to explain the flotation results. A mechanism is proposed based on the XPS analysis results.

Aug 24, 2022

By B. Strickland

The decision to accelerate development of Stillwater Mining's East Boulder Mine was made in March of 1998. It required the completion of conceptual designs by July of 1998. This was accomplished through teamwork and close cooperation of mine personnel, engineering firms and vendors, all working toward the common goal of developing an efficient and workable design. Early in the project, representatives of Stillwater Mining, Kilborn International, Parsons Brinckerhoff Transit and Rail Systems, Continental Conveyor, and H.A. Simons met to develop methods to bring the mine into production at a highly accelerated rate and to solve potential bottlenecks, including the movement of personnel, materials, and muck through a 5.6 km (3-1/2 mile) adit. This interaction, including companies not normally associated with the mining industry, led to innovative approaches and designs produced by Kilborn Engineering and Stillwater Mining.

Jan 1, 1999

By W. C. Brice

Minnesota's mineral resources are widespread and diverse (Figure 1). In addition to the nation's largest iron and manganese reserves, the state contains sizeable vanadium, copper, and nickel resources. Recently it has been determined that the proterozoic unconformities in Minnesota have a favorable potential for uranium deposits. Finally, major potential exists in Minnesota's archean greenstone belts for gold, silver, and copper-zinc massive sulfides. Many of the state's mineral resources have been found in environmentally sensitive areas. This is not surprising since the natural forces associated with the formation of mineral deposits are often the same processes that create unusual landforms. For example, much of the state's copper-nickel is found within and adjoining the Boundary Waters Canoe Area (BWCA) and Lake Superior. The history of mineral development on the Mesabi Iron Range has also created culturally sensitive areas. Early iron mining development required the workers to live close to their jobs, and mine wastes were dumped as near the mine as possible. Few, if any, foresaw the time when taconite would be economic to mine. Therefore, it is not unusual to find valuable taconite resources located under towns and waste dumps on the Mesabi Iron Range.

Jan 1, 1980

By Wayne E. Tuomi

The mining industry is faced with a pressing problem; that is, to develop more efficient methods of extraction, handling and upgrading-techniques that will do the job faster and better than ever before. New techniques require new machines, or applications of new and improved materials that can be used to modify and improve existing machine and equipment designs. The traditional approach has been to increase productivity by increasing equipment size. Prognostication indicates that the trend toward larger equipment sizes and capacities will continue as one answer to the challenge imposed by future increases in mineral demands. But what is the limit on the continued growth of equipment size? Until about 1930, there was a very definite limit-a limit imposed by the strength of the steels and the power plants then available. The equipment engineer had come to an impasse: even though it was easily possible, for instance, to triple the size of a bucket, it had become impractical to correspondingly enlarge the boom, the counterweight, and the power plant.

Jan 3, 1967

By Mara Kosovac, Sujan K. Kundu

The Iron Ore Co. of Canada (IOC) has developed a computerized plan analysis method for its open-pit iron mining operations which will eliminate much of the tedious manual drafting of pit design plans performed by engineers and geologists at its two major operational areas near Schefferville, Que., and Labrador City, Nfld. The new technique permits analysis of section or bench plans for a specific ore body, based on drillhole information; preparation of a three-dimensional unit profit matrix for pit design purposes, and storage of extensive ore-block information for other applications. Other advantages include enhanced design accuracy through reduction of human errors normally associated with preparation of large data masses, and by elimination of errors inherent in planimeter-prepared ore block diagrams.

Jan 7, 1978

By T. P. Clendenin

THE northerly two thirds of Mexico falls into five main physiographic divisions, illustrated on the accompanying map. In form, these divisions are a series of strips, paralleling the northwest-southeast axis of the country.

Jan 10, 1951

By S. Shairp

Copper is an impurity as well as a necessary reagent in the processing of zinc sulfide concentrate at Hudson Bay Mining & Smelting Co., Limited's (HBMS) zinc pressure leach plant. Copper is present in the zinc concentrate as chalcopyrite, which consumes reagents necessary for zinc leaching. A small percentage of copper precipitates in the autoclaves, discharge lines, and flash tanks, requiring maintenance of the equipment and disposal of the solids. Copper also precipitates in the neutralization stages and is removed to low levels in a specific copper removal stage of purification. Yet some copper, as copper sulfate, is required, along with potassium antimony tartrate, in the final purification stage to improve cobalt removal from the zinc sulfate solution prior to electrowinning. The behaviour of copper experienced at HBMS's zinc pressure leach plant is discussed.

Jan 1, 2008

By Launa Mallett, Charles Vaught, Michael Brnich, ROBERT PETERS

Interviews of 48 miners who escaped underground coal mine fires revealed that none of them had ever, before that incident, worn their self-contained self-rescuer (SCSR) either in training or in a real emergency. Consequently, they were ill-prepared to use this emergency breathing apparatus. One persistent problem stemmed from the fact that miners had no notion of breathing resistance, nor of the fact that it would get more difficult to breathe the longer they wore their device. As a result, many of those who were interviewed had simply removed their mouthpieces and breathed ambient air. This is obviously behavior that should be trained out of the workforce. Unfortunately, because of high costs and difficult logistics, miner training is unlikely to ever include donning and wearing an apparatus on a regular basis. In order to give workers a better idea of what to expect from their devices, therefore, the National Institute for Occupational Safety and Health researchers developed a tabletop (paper and pencil) simulation based upon actual predicaments evacuees had reported encountering. The simulation is designed to emphasize important points related to donning and wearing a self-contained self-rescuer in a mine fire escape, and, by doing so, to bring miners' expectations more in line with what their actual experiences would be. The simulation was field tested in six training classes at three different mining operations. In all, 99 individuals were involved in completing the exercise and rating its properties. In their ratings 88% of the respondents indicated they thought the scenario could definitely happen in real life, and over 80% agreed they had learned something new. From the field test data it was concluded that the simulation had authenticity and potential value as a teaching tool. The simulation was therefore used in a pre-test/post-test control group experiment to determine whether it led to improvements in miners' scores on a true-false test of their SCSR's functional capabilities and proper usage. Eighty-three miners were included in this part of the study. As expected, miners who had participated in the training exercise scored significantly higher on their post-test than miners who had not.

By F. O. Garrabrant

Power is furnished to the Climax Molybdenum Co. by the Public Service Co. of Colorado over two 100,000-volt lines to a bank of three 3333-kva. transformers 100/13.8 kv. These transformers are so designed that with the addition of forced cooling their capacity may be increased 331/3 Per cent at 12,000-ft. altitude. Under present conditions, these transformers are operated at 140 per cent of their rating with forced air cooling. On the secondary side of this bank there is a 15-kv., 1200-amp. Westinghouse oil circuit breaker provided with automatic reclosing relays allowing three successive short circuits before lockout. From this breaker 13.8-kv. power is transmitted to a central switching station (Fig. I) where all circuits radiate to the different operations of the property. Each circuit is protected by a 23-kv., 600-amp. oil circuit breaker with by-pass and isolating disconnecting switches.

Jan 1, 1947

By John B. Draper

The 1980 Mine Dewatering Act was enacted to protect water rights and to allow mine dewatering to proceed where impairment of a water right might have otherwise created a bar to mine development. In New Mexico, new appropriations for beneficial use are subject to the State Engineer's jurisdiction and are granted only upon a showing of non-impairment. Before 1980, mine dewatering was not considered a beneficial use, nor was it considered waste. The Act brings mine dewatering under the jurisdiction of the State Engineer, makes it subject to the same requirements as an application for appropriation for beneficial use, grants the right to replace the water of users whose rights would be impaired by mine dewatering without a plan of replacement, and extends the right of replacement to non-mining appropriations of water for beneficial use, Application of the Act requires determination of the definition of impairment (the threshold of significant impact on existing water rights), hydrologic evaluations to determine the impact of the proposed dewatering, and preparation and execution of a plan of replacement to avoid impairment of existing rights.

Jan 1, 1983

By K. Sharman

Quintette Coal Limited (managed and 50% owned by Denison Mines Limited) operates an open pit coal mine located in northeastern British Columbia, in the foothills of the Rocky Mountains. (See Fig. l). Mining commenced in 1982. The mine currently produces 4.75 million tonnes of medium volatile bituminous coal per year from three pits (Mesa, Wolverine and Shikano), using a truck/ shovel operation. (See Fig. 2). Conveyors and trucks transport run-of-mine coal to the heavy media/froth flotation process plan t, where it is cleaned and loaded into rail cars for delivery to the Ridley Island port at Prince Rupert, British Columbia. All coal is sold to the Japanese steel industry under a long term contract. The coal seams mined at Quintette are contained in the Lower Cretaceous Gates Formation. Mineable seam thicknesses vary from 0.6 m to 10 m. The regional structure of the area is typical of foreland fold and thrust belts, with open to tight folds and imbricate thrust faulting. The range of structural features found in the three pits, and their effect on mining, forms the subject of this paper.

Jan 1, 1991

By P. E. Wingrove

The Kayford, Boone and Nicholas Division of Bethlehem Mines Corporation operates a modern coal preparation plant in Van, West Virginia. Since the start-up of the Van Plant in 1976 until the summer of 1980, the refuse handling system proved to be a costly maintenance problem and a material handling bottleneck. During the 1980 two-week miner's vacation the original system, which included two screw conveyors and a drag conveyor, was replaced by an installation utilizing two Flexowall steep angle belt conveyors. This paper describes the technical and economic analysis that led to the new installation and reviews its first year operating performance. The Van facility is a heavy media plant designed to handle 127 mm x 0 raw metallurgical quality coal from the Powellton seam at a maximum feed rate of 590 TPH (metric tons per hour). Depending on mining conditions, the clean coal recovery rate averages between 50 and 65%. The plant is set up with three types of cleaning circuits. Coarse material (127 mm x 12 mm) is cleaned in heavy media baths. Intermediate size material (12 mm x .5 mm) is cleaned in heavy media cyclones. Fine coal (.5 mm x 0) is cleaned in a hydrocyclone1 froth flotation circuit.

Jan 1, 1981

By Emily Wortman-Wunder

As the 2011 president of the Society for Mining, Metallurgy, and Exploration, Inc., I am pleased to present the 2011 issue of the Transactions of the Society for Mining, Metallurgy, and Exploration, Vol. 330. A significant portion of the contribution that we as a professional society make is the publication of professional and technical papers that accelerate the advancement of scientific knowledge and enable the transfer of technology. Communication within the mining community is the key to a successful society. This technology exchange continues a tradition that dates back to the 1871 meeting of 22 mining engineers in Wilkes-Barre, PA, that resulted in the founding of AIME; those individuals envisioned that these transaction volumes “would form a most valuable and greatly needed addition to our professional literature.” This volume fulfills that pledge. The 2011 Transactions is the second Transactions to take advantage of new publication technologies. It appears solely in electronic format. The decision to go to an all-digital format for this longstanding publication was a difficult one, but one which will better serve the mining community. Based on the feedback from the 2010 Transactions in e-book format, I believe that the transition to the all-digital format was the proper decision. The 2011 Transactions contain some of the most interesting research from the past year, including a 10-year profile of roof and rib fall trends from the National Institute of Occupational Safety and Health (NIOSH) and a new cross-disciplinary application of the tools of epidemiology to assess and mitigate risk in coal mines . This 2011 Transactions comprise of a total of 82 technical papers (626 pages including index), including all 19 papers published in 2011 in the Technical Papers Section of Mining Engineering magazine (Vol. 63) and all 32 papers published in 2011 in Minerals & Metallurgical Processing (Vol. 28). Additionally, this volume contains 31 papers that are being published for the first time in this issue. The papers presented in this volume were written by some of the most distinguished professionals in the industry worldwide. All 82 technical papers were peer-reviewed. The process of review and publication requires much hard work by authors, reviewers and our publications staff. As the 2011 president of SME and on behalf of all our members, I would like to extend our gratitude to all whose volunteer efforts contributed to the publication of this volume.

Jan 1, 2011

By G Reynolds, L Lu

Queensland Pacific Metals (QPM) is developing its flagship Townsville Energy Chemicals Hub (TECH) facility to produce nickel and cobalt sulfates from imported high-grade nickel laterite ore for nickel-cobalt-aluminium and nickel-cobalt-manganese Li-ion batteries. The TECH facility is expected to use a patented leaching, recovery and recycling process called the DNi Process™. It uses the nitric acid leaching process for extracting nickel, cobalt and other valuable metals from laterite ore. Apart from the nickel and cobalt sulfates, the TECH Project will also produce high purity alumina, hematite (~640 ktpa) and other by-products. The hematite by-product precipitated from the DNi Process™ (hematite precipitate hereafter), is high in Fe and particularly low in impurities. QPM is working to identify potential applications for these high-purity by-products to generate additional revenue and to achieve its zero-waste ambition. As such, QPM has engaged CSIRO to evaluate various agglomeration options to produce low-cost, hematitic products suitable as ironmaking feed materials. This paper will first reveal the unique characteristics of the hematite precipitate arising from the TECH Project and then examine the sintering and pelletising processes for preparing the hematite precipitate as an ironmaking feed.

Sep 18, 2023

By G Reynolds, N A. Ware, L Lu

Queensland Pacific Metals (QPM) is progressing its Townsville Energy Chemicals Hub (TECH) project to produce nickel and cobalt sulfates for advanced battery materials. Apart from the nickel and cobalt sulfates, the process also generates a hematite by-product (~640 ktpa). The hematite byproduct precipitated from the process, hereafter ‘hematite precipitate’, is high in Fe and particularly low in impurities. However, it is a fine <20 μm crystalline, hydrometallurgical precipitate and is produced as a filter cake containing a high moisture content of about 15 per cent. This is considerably different from natural hematite ore and is expected to change its performance during sintering. In the present study, laboratory scale sintering tests were undertaken to evaluate the potential impacts of substitution of the hematite precipitate for traditional magnetite concentrates and further for Australian hematite-goethite ores in a simulated industry base blend. Substitution of hematite precipitate for magnetite concentrates was found to slightly increase the sintering temperature required to achieve the strength of laboratory sinters. However, further substitution of hematite precipitate for Australian hematite-goethite ores slightly reduced the sintering temperature required to achieve the laboratory sinter strength. These results reflect the reduction in Al2O3 contents of the blends and are consistent with the trend observed in industry and pilot scale facilities. The reduction in sintering temperature generally correlates to a reduction in fuel rate in the larger scale sintering process. The pore structure of selected laboratory sinters was further examined and discussed in conjunction with sinter strength. The pore structure images highlighted the relative difference between the blends with the most obvious difference being seen at 1290°C which correlates well with the laboratory tumble index (TI). The laboratory sinter samples showed an increase in porosity and irregularity of pore shape, as hematite substitution increased demonstrating the correlation between a more porous structure and a lower TI.

Sep 18, 2023

By R. Gebrekristos

It is commonly accepted that three types of aquifers exist in the Bushveld Complex: (a) alluvial aquifers in areas of river courses, (b) weathered bedrock aquifer formed by the in-situ weathering of the bedrocks, (c) fractured aquifers underlying the weathered aquifers controlled by the regional and local fracturing of the crystalline rocks. Hydrogeological studies conducted in the Critical Zone of the Bushveld Complex in the western limb show that the UG2 pyroxenite layer is of a particular interest and has a unique aquifer property. It yields much of the groundwater inflow into some mines and can be classified as the most important aquifer in the vicinity of the mining zone. The UG2 pyroxenite aquifer is restricted to the dipping UG2 pyroxenite unit. The unit weathers more intensely than the surrounding norites and anorthosites and is characterized by deeper weathering horizons (two to three times deeper than the surrounding rocks). For much of the UG2 mining area between depths of 35 ? 80 m, stoping of the UG2 takes place approximately 5 ? 7 m below the UG2 pyroxenite aquifer, and usually there is no groundwater inflow into the mine workings. However, unsealed deep exploration boreholes intersecting the UG2 pyroxenite and reaching underground mine workings, or mine roofbolts penetrating the weathered pyroxenite aquifer from underneath, can result in significant groundwater inflows into the underground workings. The reason as to why the UG2 pyroxenite weathers more than the norites and anorthosites has not been fully studied but is suspected to be due to the bedding planes of the unit and mineralogical composition of the particular pyroxenes forming the unit, which result in preferential physical and chemical weathering under atmospheric conditions. The weathered pyroxenes form sand-sized, rounded grains with improved effective porosity and permeability suitable for the storage and passage of groundwater. The orientation of the pyroxenite aquifer can easily be determined as it dips with the Bushveld layered strata. No-flow boundaries can be assumed on the hanging- and footwall of the pyroxenite aquifer and the flow rates can be estimated using 2-dimentional analytical equations. However, this must be confirmed with strong conceptual models since the existence of a fracture network connecting the pyroxenite aquifer with the overlying weathered and/or underling fractured aquifers can complicate the system, lowering the accuracy of analytical models and necessitating the utilization of numerical models.

Jan 1, 2012