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By Mario Samamé Boggio

El presente texto señala los progresos recientes respecto de la siderurgia y la ferrominería en algunos países de América Latina. En el caso de Argentina, la vanguardia tecnológica radica en el aumento de la capacidad productiva y la tendencia hacia una aminoración en la tasa de crecimiento del consumo interno, crecimiento de la producción, exportaciones y en los problemas de abastecimiento interno y externo de chatarra y semiproductos. En el caso de Brasil, el sector de aceros tiene relevancia con la inauguración de la plan a de la empresa Acos Finos Piratini, en Río Grande do Sul. Esta cuenta con instalaciones de reducción directa, donde se utiliza carbones pobres de la misma zona y con capacidad para 65.000 t por año de fierro esponja. La industria siderúrgica de Colombia mostró en J 972 nuevos avances en sus cifras globales de producción de acero y en sus niveles de productividad. En Chile, la Compañía de Acero del Pacífico se dispone a construir una planta de peletización, que utilizará finos provenientes de sus minas de Algarrobo y Boquerón Chañar. En Ecuador, la empresa ANDEC, que está operando a un nivel de 30,000 t. anuales de laminados, definirá su programa para encarar la producción de barras en rollos y alambrón. Finalmente Perú, definió su programa de desarrollo siderúrgico, el cual contiene inversiones que para 1990 sumarán unos mil millones de dólares.

Mar 1, 1975

By R. L. Thoms

Compressed air energy storage (CAES) has been initiated recently in West Germany with a 290 MW peaking-power facility utilizing twin cavities with volumes of 150,000 m3 each in the Huntorf salt dome (1). The implementation of CAES in several geologic media is being studied carefully in the United States (2); however, the use of cavities for CAES in salt domes or salt anticlines and the associated long-term stability of these cavities is the specific topic of this paper (3). The cavities represent an essential element in a CAES plant, and thus should be designed and operated to perform with "stability" over the planned life of the overall facility. As employed herein, cavity stability implies the extent to which an acceptable amount of cavity storage volume can be utilized with economic maintenance over the planned life of the overall facility. In this sense stability is relative to the planned use of a storage cavity. Figure 1. depicts the salt deposits of the United States (U.S.) (4). The Gulf Coast region includes the only confirmed salt dome basin in the U.S., although salt structures also exist as anticlines in the Paradox Basin of Utah and Colorado. Because of the relatively small amount of elevation change within the Gulf Coast, CAES in salt dome cavities appears to hold considerably more potential for energy storage in this region than more traditional "pumped hydro" systems.

Jan 1, 1979

By Zhucheng Huang, Yuanbo Zhang, Kecheng Zhang, Guanghui Li, Tao Jiang

"With rapid development of Iron and Steel industry, plenty of metallurgical dusts and sludges are generated, which have not been effectively utilized because of their poor hydrophilicity and bad ballability. Agglomeration and roasting of metallurgical dusts & sludges with a new-type composite binder are studied in this paper. The results indicate that the dosage of the new binders can be decreased to 2.5 wt% from 3.5 wt% when using the wet-grinding process. Under the optimal conditions of briquetting pressure 2070 N/cm2, briquetting moisture content 13 wt%, roasting temperature 1000 °C and roasting time 40 min, the qualities of the green, dry and roasted briquettes meet the requirements of the industry production. The finished products have the compression strength of more than 2000 N/cm2, which can be used as high-quality burdens for blast furnaces.IntroductionWith rapid development of Chinese Iron & Steel industry, there are more and more serious resource shortage and environmental pollution existing. Converter sludges, containing 30% ~ 40 wt% moistures, are typically difficult for recycling [1]. Foreign processing technologies for sludges treatment are relatively advanced including cold-bonded agglomerates for blast furnace, RHF reduction for the dusts and sludges with high content of Zn and Pb, smelting and reduction. Domestic iron and steel companies use a small amount of sludges in sintering. However, the sludges have the characteristics of high moisture and containing harmful impurities, which directly affect the sintering mixture permeability and product quality [2-5]. There are also other technologies such as production of metallized pellets, cooling agents for steelmaking, etc [6]. All of these deficiencies and applied are not in large-scale."

Jan 1, 2011

By S. Sunkavalli

Acid rock drainage (ARD) is produced when sulfides are exposed to oxygen and water. Oxidation reactions typically result in a depression of pH and leaching of solutes and metals. Many oxidation models have been developed based on oxygen diffusion, but in environments with high permeability, other transport processes (i.e., convection and advection) can play an important role. Multiple sulfide mineral phases with differing oxidation rates should also be incorporated. WROC, a finite-difference model, was developed to account for these factors in predicting ARD. The program includes sulfide mineral oxidation using a shrinking core mechanism, heat transfer by conduction, heat of reaction, and oxygen transport by diffusion and advection. The model was validated using data from the literature. After validation, the WROC model was used to simulate several different waste rock scenarios including different forms of sulfide mineralization and the effect of implementing a waste rock cover. The results demonstrate that including specific sulfide mineral phases can have a significant effect on oxidation and that implementation of a cover can also aid in reducing waste rock oxidation. Key words: Arsenic sulfides, oxidation, shrinking core, waste rock, oxygen transport

Feb 27, 2013

By K White, R Hardie, J Merritt, B Kirsch, R Lucas

Constructed stream diversions are a common element of mine sites across Australia. A review of constructed stream diversion performance in the Bowen Basin funded by the Australian Coal Association Research Program (ACARP) in 1999 found over 80 per cent of constructed stream diversions failed to meet regulator and operator expectations. Since that time, improvements have been made in the assessment, design, monitoring and management of constructed stream diversions. Fundamental to these improvements has been the development of a better understanding of the regional stream systems and efforts to replicate the natural stream processes in the function and operation of constructed stream diversions.This paper discusses the history of constructed stream diversions through the Bowen Basin in central Queensland recorded in the outcomes of a series of ACARP funded research projects. Further, the paper reports on the outcomes of a current ACARP funded project that has reviewed the success or otherwise of constructed stream diversions in the region. The assessment has compared the performance of diversions that have been designed to replicate and provide for ongoing stream geomorphic processes with those diversions that were designed and built prior to the development of these design improvements. Based on these investigations we have identified design and construction successes and issues requiring further research and management attention.CITATION:White, K, Lucas, R, Hardie, R, Merritt, J and Kirsch, B, 2013. Challenges and opportunities for constructed stream diversions in the Bowen Basin, Central Queensland, in Proceedings Water in Mining 2013 , pp 73-82 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Nov 26, 2013

A rotating disc geometry was used to provide a uniformly accessible surface for a kinetic study of the cementation of cadmium, lead, and silver from dilute aqueous solutions. This work is an extension of studies carried out on the Cu-Zn and Cu-Fe systems for which the reaction rate was found to be completely solution phase mass transfer controlled.When the amount of material deposited was greater than 0·2 to 0·4 mg/cm2 there was an apparent enhancement in rate which is attributed to the formation of a roughened deposit. This same phenomenon was observed in the Cu-Zn and Cu-Fe systems. Again, the rate of reaction of each system investigated was found to be solution-phase mass transfer controlled.

Jan 1, 1971

By Yotamu Stephen Rainford Hara, Animesh Jha

The investigation focuses on a low temperature recovery of Cu and Co from a 40 wt% SiO2-(30 wt%Fe,6 wt%Al)2O3-10wt% CaO-7wt%CuO-7wt%CoO slag over a temperature range of 1173K to 1323K. The alloy phases containing Cu-Co and Fe-Co alloy formed via the carbothermic reduction of oxides: MO + C = M + CO(g), where M represents metallic copper, cobalt or iron. In the direct reduction of oxides, the recovery of metallic phase was well below 90% at 1323K, due to the kinetic barrier which was analysed and attributed to oxygen and metal-ion transport in the slag. This barrier was overcome by adding CaSO4 and carbon, which yields a matte (MS) phase via MO + CaSO4 + 4C = MS + CaO + 4CO reaction. Lime thus produced in situ participates in metal oxide/metal sulphide reduction reactions, which are analysed with the help of X-ray powder diffraction, scanning electron microscopy, and thermogravimetric analysis.

Jan 1, 2014

By C. Ndou, T. Mothupi, H. Mandende

The technological advances in efficient, rapid, and non-destructive hyperspectral core logging systems for systematic mineral mapping have led to the discovery and exploitation of new mineral deposits Hyperspectral imaging in the long-wave infrared range has been recently used successfully to identify various phosphatebearing minerals (monazite, xenotime, and britholite), with limited work on apatite associated with mafic-ultramafic layered intrusions. In this study we investigate the effectiveness of a hyperspectral imaging (HSI) system with long-wave infrared (LWIR) bandwidthsto identify apatite in the Upper Zone of the Bushveld Complex. The accuracy of the HSI results was validated by mineralogical and geochemical data. The two apatite-enriched zones detected by HSI suggesting widespread development of apatite throughout the uppermost 600 m of the Upper Zone. The lower apatite-enriched zone is approximately 40 m thick, while the upper apatite-enriched zone is about 23 m thick, consistent with previous thickness determinations by traditional logging and analytical methods. Spectral mixing observed in the response of apatite is ascribed either to the common association of apatite and olivine in these rocks, or to differences between the spatial resolution of the hyperspectral image and the size of apatite grains. The VNIR-SWIR wavelength region did not show prominent spectral features of apatite. Nonetheless, HSI in the LWIR range is effective in mapping apatite and should therefore be considered as an exploration tool. This research advances our knowledge of the reflectance spectroscopy of REE-bearing minerals, which makes it easier to detect, identify, and quantify REE-bearing silicate minerals by HSI.

Feb 6, 2023

By S C. Dominy, R C. A Minnitt

Determination of the sampling constant and liberation diameter are of importance when applying the Fundamental Sampling Error (FSE) equation to optimise sampling protocols. The method for the direct determination of the sampling constant is based on the æGy 50-pieceÆ experiment and variants thereof, which is generally known as the heterogeneity test. In the coarse gold environment, the heterogeneity test is prone to poor repeatability and bias due to the very heterogeneity that it aims to quantify. A key issue is the large sample mass that can be required in the coarse gold environment, which may reach 1 t or more. The heterogeneity test often provides an evaluation of the background gold grade heterogeneity, but understates that of the high-grade coarse-gold component. This is because the total mass of fragments is usually too small to represent the mineralisation. Despite this relatively well-known problem, heterogeneity tests are often undertaken on deposits where the presence of coarse gold is ignored, not fully realised or vastly understated. Sampling types and protocol designs are frequently based on poor quality data that do not match the characteristics of the orebody. For this style of mineralisation, an empirical approach to define ore characteristics is recommended.CITATION:Dominy, S C and Minnitt, R C A, 2012. Application of heterogeneity testing to coarse gold ores, in Proceedings Sampling 2012 , pp 143-160 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Aug 21, 2012

The oxidation of ferrous sulphate to ferric sulphate with air and oxygen in a gas lift percolator was investigated with initial Fe2+ concentrations in the range 0·01 M to 1·0 M,temperatures in the range 20-80°C, and pH in the range oto 2.The rate of formation of Fe3+ was found to be well described by the rate expressionEquation 1and a consistent mechanism is proposed.The presence of Cu2+ was found to cause an increased rate of oxidation, the effect being greater with Cu2+ concentrations increasing in the range 0·001 M - 0·01 M in 0·2 M Fe2+. The effect of other solutes containing Ni, Zn, Mn, Co, Hg, Cl, Mo, NH4, As, Cr, or Na at a concentration of 0·001 M in 0·2 M Fe2+ was negligible.

Jan 1, 1972

By A. Schönecker, P. Y. Pichon, B. Kraaijveld, Y. Meteleva-Fischer

"Ribbon-growth-on-substrate is a casting method, which offers a possibility to control heat flow, nucleation and subsequent crystal growth at the liquid-substrate interface. This technology allows for low-cost and high throughput shaping of silicon sheets with controlled crystal grain size and orientation for use in solar cells. In this work, sheets of silicon- metal silicide composite materials were produced and their microstructure was studied. It was shown that depending on the relevant phase diagram and casting conditions, a micro/nano-sized eutectic structure of the casted sheet can be formed. Such composite materials possess properties promising for various applications in energy generation, storage and conservation. The advantages, potential and challenges of the ribbon-growth-on-substrate technique for production of composite sheet materials as well as novel areas of application for such materials are discussed.IntroductionThe Ribbon Growth on Substrates (RGS) process is well known in the solar industry as a process to produce multicrystalline silicon wafers. An industrial size pilot production line for continuous casting of silicon wafer was developed by RGS Development B.V. in the Netherlands (Figure 1). A comprehensive review of this technology and properties of the produced silicon wafers were reported by Schönecker et al [1]. The principle of the RGS process is explained in Figure 2. The relatively cold substrate extracts the crystallization heat from the liquid silicon in the casting frame. This results in the growth of a silicon ribbon (Vc) in contact with the substrate. When the substrate (Vp) is transported from the casting zone into the cooling section, the crystal growth stops, the wafer can be removed and the substrate can be re-used. Last few years large work was done on the industrialization and market development of RGS wafers for the solar industry. Part of this work was discussed by Schönecker et al [2]. Although there is still a good perspective on the middle and long term solar market for the RGS wafers, the current market situation was found to be unfavorable for new entrants."

Jan 1, 2014

By R. D. Smith

The Bureau of Mines (BOM) evaluated the technology, capital investment, and annual operating costs of emission control for further reductions of lead in ambient air at the East Helena, Montana, smelter, and the Glover, Herculaneum, and Buick smelter-refineries in Missouri. This study seeks to analyze the technology available to the domestic primary lead industry for attempting to further reduce lead emissions below 1985 levels. Through enclosure of concentrate unloading and handling areas and all lead-processing buildings, followed by venting these enclosures to the atmosphere through baghouses and the application of appropriate local controls, emissions can theoretically be reduced by a total of 2,424 pounds of lead per day from 1985 levels at the three Missouri operations. Using conventional technology, aggregated additional capital costs of $250,014,000 and annual operating costs of $18,507,800 are estimated for the four operations, resulting in a total cost of $0.063 per pound of refined lead. Continuous drossing techniques would assist in meeting OSHA standards in process areas. Continuous drossing would change capital and operating costs to $258,344,800 and $16,104,700, respectively, for a total cost of $0.062 per pound of refined lead. First quarter, 1986 open market price for refined lead was $0.184 per pound.

Jan 1, 1986

By H. F. King

In 1982, the result of a 3-year study was published as "A Guide to the Understanding of Ore Reserve Estimation". The principal conclusions were that computation formed only part, and perhaps not the most important part, of an estimate and that the estimate should recognize that geological, mining engineering and metallurgical judgements formed an essential part of the eventual result. Subsequent expectation/realization studies of several mines have produced case histories which form the principal basis of the paper. These imply that geology is even a larger factor than thought earlier.

Jan 1, 1985

By Edward S. Bell, Frank Angebrandt

"Nuclear reactors must have very large heat outputs to compete with conventional sources and the only feasible applications are in the production of electric power or large quantities of process steam. This paper considers alternative fuels for electric power generation in Canada. In a publicly owned utility, nuclear stations are economic for base-load generation for unit sizes of 500 mega• watts or larger where competitive fossil fuel costs are higher than about 30 cents per million Btu. In British Columbia, Alberta and Saskatchewan, fossil fuels will continue to be in adequate supply at costs lower than 30 cents per million Btu and thus, except for the special case of Vancouver Island, power generation in Western Canada will continue to be the hydraulic and conventional thermal type. In Eastern Canada, fossil fuel prices are likely to be higher than 30 cents per million Btu and most utilities will be able to install units of 500 mw or larger, so that nuclear power plants will provide much of the base-load generation required. Base-load generation comprises about two-thirds of the energy generated by power utilities. By 1990, the total annual electrical energy load will be over 600 billion kwh, with two-thirds of this load in Eastern Canada. Allowing for additional hydraulic resources which may be developed in Quebec, British Columbia and Manitoba, hydraulic generation is forecast to provide a little more than a third of this electrical energy, nuclear generation a third and fossil-fuelled generation about a quarter."

Jan 1, 1969

By A. A. Debrah

Artisanal and small-scale mining (ASM) plays a fundamental role in the national and local economies of resource-rich countries in Africa. As such, more effort must be geared towards fostering this type of economic activity to sustain livelihoods in rural communities. Across Africa, efforts to operationalize ASM based on a sustainable development framework have been quite tedious and often ineffective. This is because most of these frameworks lacked context and an understanding of the continuum from the artisanal through small-scale and up to the junior miner, grouped under the general term ?ASM?. Driven by the need to contextualize some of the definitional issues in this niche sector, and gain a clearer understanding of their peculiar challenges, this paper aims to contribute to the debate on ASM by considering two of Africa?s resource-rich countries ? Ghana and South Africa. Since South Africa has made greater inroads in protecting the interests of small-scale miners, we thus draw comparisons from both countries? approach to ASM, outline the lessons learnt, and provide recommendations regarding the ways forward.

Jan 1, 2014

By Chengjia Shang

Aiming at greatly increasing efficiency and saving budget, higher strength and larger-diameter pipes have been developed and applied for constructing long distance pipeline projects in China. At the same time, in order to produce pipeline steel with high strength, high toughness and excellent DWTT performances, it is critical to refine austenite grain by static recrystallization rolling. Therefore, this paper focuses on the brief introduction of development of pipeline projects in China and also on the basics research in the field of static recrystallization during austenite processing of Nb-bearing steel.

Oct 1, 2019

The current genesis of pisolites and channel iron deposits (CID) has been defined in a way that presents CID as unique in the world. The published material on detrital pisolites mostly details the West Australian CID; most other global occurrences of iron-rich pisolites would seem to have an in situ genesis. An alternate theory for the origin of the Hamersley CID is suggested, involving an older greensand protore derived from volcanic ash and deposited on a glaciated Hamersley surface. This paper presents the author's observations, sampling and mapping after several years study and exploration for pisolites and CID in WA and in some locations overseas. It is not what one would call scientifically complete, and possibly asks more questions than it answers, but it is presented as a point for discussion.

Jan 1, 2009

By AIME AIME

MATTERS pertaining to mine ventilation were, taken up at the annual meeting Wednesday morning with E. A. Holbrook in the chair. In the absence' of its author, G. E. McElroy, the first paper, entitled "Economic Size. of Metal Mine %Airways," was read by title by the chairman. The second paper, "Intermittent Mine Ventilation," by Oscar A. Glaeser, was 'abstracted by Dan Harrington. It related to metal-mining practice, being inapplicable to coal mining, of course. B. F. Tillson asked how the ,quantity of air was measured and con- trolled in the different splits and Mr. Harrington stated that an anemometer presumably was used and that split- ting was controlled by adjusting the steel doors to the desired position by means of screws. George 'S. Rice asked if the fan were underground, and Mr. Harrington replied that it was. Although he had at, one time recommended that it be placed' on the surface, certain factors led the management to keep it underground, a. location that has several advantages in this particular case.

Jan 1, 1932

By J. O. G. Sanderson

Introduction In this paper it is proposed to review the history of petroleum geology in western Canada, to discuss some of the main events which have affected its progress, to mention its relationship to the petroleum industry, and, finally, to appraise its present status and possible future importance. It will be useful first to consider the meanings of the terms petroleum geology, petroleum geologist, and the petroleum geology of a terrain. Petroleum Geology. - In simplest terms, geology is the science of the earth. Hence petroleum geology is the science of that portion of the earth that encloses pools of petroleum. The systematic delineation and study of stratigraphic geology began about 1820. The systematic development and study of petroleum geology started about 1910. It is a relatively immature branch of geology. Petroleum Geologist. - This term may be applied to a fully qualified geologist who is engaged for a time, be it a job, a contract, or a lifetime, in the work of finding and developing deposits of petroleum and related substances. No man may properly be called a petroleum geologist who is not first a fully qualified geologist.

Jan 1, 1946

By T. H. Jeffers

To help maintain an adequate supply of minerals to meet national, economic, and strategic needs, the Bureau of Mines investigated the feasibility of extracting copper from coarse native copper ore with ammoniacal ammonium carbonate solution by a simulated in situ leaching procedure. A 5.9-metric-ton (6.5-ton) sample of minus 30.5-centimeter (12-inch) conglomerate-type ore analyzing 1.96 percent copper was leached in a column for 556 days with a solu-tion that contained, in grams per liter, 2.2 NBs and 1.9 CO[3=]. The copper extraction was 71.4 percent, and reagent consumptions were, in kilograms per metric ton of ore, 1.1 NBs and 0.85 CO[3=] (in pounds per ton of ore, 2.2 NH3 and 1.7 CO[3=]). The pregnant leach solutions contained about 1.4 grams per liter copper, which was readily extracted from these low-tenor liquors with a 1:19 mixture of an organic extractant and kerosine. Copper was stripped from the loaded organic with depleted electrolyte containing 150 grams per liter H2S04, and the copper was recovered by electrowinning with antimonial lead anodes. Conditions also were established for minimal lead transfer to the cathode copper.

Jan 1, 1979