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By P J. Fourie, J R. Walklate

Gravity separation techniques have been in use in the mineral sands industry for decades; from the Reichert cone to Wilfley tables, Wright sluices and the Kelsey Jig, all attempting that elusive perfect gravity separation. Just as the gravity separation industry evolved, Richards Bay Minerals also evolved in their use and approach to gravity separation. This paper discusses the history of gravity separation at Richards Bay Minerals and briefly comments on future developments. History Primary Concentration Richards Bay Mineral?s (RBM) first mining concentrator and mineral separation plant commenced operation in 1977 to process ilmenite, rutile and zircon bearing dunal deposits along the northern Natal coast. The orebody contained a greater proportion of non-valuable magnetic heavy mineral in the SG range of 3 to 4 compared to West Australian and Florida USA deposits, making mineral separation more difficult(1). The deposit was mined using two dredges feeding a floating 2000 tph concentrator. Concentrator feed was screened and fed to two four-stage circuits consisting of primary, scavenger, cleaner and recleaner Reichert cones [see Figure 1]. The primary units were fed at a rate of 80 tph and a density of 60% solids by weight.

Jan 1, 2006

By G. B. Shea

Among the many engineering problems directly related to conservation in the petroleum industry, that of crude-oil emulsions continues to be important. Emulsions of water and oil always have constituted one of the most serious forms of waste in the oil fields, and the necessity of dehydrating emulsified crude petroleum to obtain marketable or pipe-line oil confronts operators in many fields with a major operating problem. In 1926 the Bureau of Mines published a comprehensive treatise s on oil-field emulsions dealing with field conditions, practical methods of dehydration, and physicochemical characteristics of the formation and resolution of emulsions. Although this bulletin is still available and may be obtained from the Superintendent of Documents, Washington, D. C., and although its contents are a valuable reference on the subject of emulsions, knowledge regarding the physical properties of emulsions and the phenomena of dehydration has increased greatly within the last decade. With the information gained through continued scientific research, substantial improvements have been made in the art of resolving petroleum emulsions. Moreover, in recent years there has been a growing realization of the importance of emulsion-preventive measures that has led to more critical examination of the causes of emulsions and methods of eliminating or at least reducing the degree of emulsification. Conditions causing agitation and commingling of oil and water and the formation of "cut oil" often are within the control of the producer, thereby making it possible to utilize preventive or remedial measures by which emulsification may be minimized or avoided. In fact, many companies have materially reduced their treating costs as a result of careful studies in emulsion prevention and proper handling of "wet" production. Of course, in many instances preventive measures or the correction of conditions causing emulsification cannot be achieved practically or economically, and the emulsions that form must be treated regardless of the care exercised or the money spent in attempting to prevent their formation.

Jan 1, 1939

By D Johnston

Within the first full year of BarrickÆs Cowal Gold Mine operation, the Lake Cowal Foundation Limited (LCF) has already been delivering results consistent with its goal to protect and enhance the natural environment of Lake Cowal and its catchment area. The LCF is a non-profit Environmental Trust established in June 2000 in conjunction with the development consent process for the construction of BarrickÆs Cowal Gold Mine. Its primary goal is to protect and enhance Lake Cowal, a nationally significant ephemeral wetland located 350 km west of Sydney, New South Wales, Australia. Significant concentrations of water birds visit the lake and the Australian Heritage Commission listed Lake Cowal on the Register of the National Estate in 1992. The LCF is managed by a Board of Directors from representative member organisations including the Total Environment Centre, National Parks Association, Nature Conservation Council and Barrick Australia Limited. Although largely funded by Barrick, the Foundation also attracts external funding and works in partnership with a diverse range of other groups and organisations, beyond the mine fence. The total value of currently approved projects is estimated to be in excess of $7.1 million, which includes æin-kindÆ contributions made by the local community and in particular the Lachlan Catchment Management Authority (LCMA) and local farmers. To date, LCF has been involved with the development and implementation of 30 projects with a total of 34 project partners. LCF has worked with over 60 landholders to improve Lake Cowal and its catchment, with 6180 ha of land now being managed for conservation or sustainable farming in the local area. Many landholders have been, or are involved in property planning or participating in other training opportunities. Sustainability of LCF programs and outcomes will be assured by commitments to projects within four key themes: conservation, research and research support, sustainable farming and community education and training. The LCF works independently from the mining company and has no responsibility for the environmental management within the mining lease. It is about capitalising resources generated by the mine to enhance environmental outcomes in the wider Lake Cowal catchment area by working collaboratively with the local community, industry and government authorities to ensure the long-term protection of a unique wetland ecosystem affected by landscape scale degradation.

Jan 1, 2007

By J. M. Font, R. G. Reddy

Jan 1, 2004

By Wei-ling Wang, Ryosuke O. Suzuki, Xiang-ning Meng, Miao-yong Zhu

"A finite-element thermal-stress model of continuous casting mold is conducted to predict deformation of copper plates and its change with different cooling structure. The results show that deformation behavior of copper plates is mainly governed by cooling structure and thermal- mechanical conditions, deformation amount is related to structure geometry, and a small deformation mutation occurs in cooper-nickel boundary due to different properties. The maximum deformation of hot surface centricities of wide face locate at 100 mm below meniscus and that of narrow face locate at meniscus and terminal of water slots and significant curvature fluctuations on both sides of copper-nickel boundary. The maximum deformation of centricities is increased up to 0.05 mm with thickness increment 5 mm of copper plates, and maximum deformations are only depressed 0.01 mm and 0.02 mm with increments of 1 mm nickel layer thickness and 2 mm water slot depth respectively.IntroductionIn conventional continuous casting of steel, a large amount of sensible and latent heat of molten steel dissipate in primary cooling zone and make continuous casting mold under enormous heating load giving rise to thermal stress, deformation, high-temperature fatigue and creep not only depress mold life-span, but reduce casting stability [1] Many studies focused more on heat transfer, solidification and shrinkage of solidifying shell to provide inverse proposals for optimizing cooling system and even designing new taper of mold [2,3], but it is generally useless to those of having been manufactured or being put into production. Therefore, mold-related forward problems show necessity to be discussed deeply, and stress and deformation distributions based on special thermal conditions in mold should be analyzed in order to explore suitable cooling structure of mold directly. Samarasekera et al. [4] examined heat flow and distortion of two-dimensional longitudinal sections and investigated effect of cooling water velocity, copper plates thickness and carbon content on formation of rhomboidity and longitudinal comer cracks. O'Connor et al. [5] developed a three-dimensional mathematical model to compute thermo-mechanical state in thin-slab mold and calculated temperature and deformation of mold wall to assess roles of various process parameters on impacting mold life. Thomas et al. [6] predicted temperature, distortion and residual stress in mold and indicated increased distortion requires increased remachining, which reduces mold life and increased residual stress increases the probability of a catastrophic crack failure. Park et al. [7l determined heat-flux profiles in funnel-shaped and parallel thin-slab molds based on an inverse heat conduction model and thermocouple temperature measured in-plant and put them into three- dimensional finite-element thermal-stress model to predict temperature, distortion and residual stress of mold wall. Korie et al. [SJ focused on prediction of temperature, distortion and residual stress in mold and in particular to clarify that mold life is significantly affected by temperature and its rigidity, but little effect by mechanical including clamping force, bolt prestress, friction and ferrostatic pressure. Meng et al. [9l predicted temperature and thermal stress in a slab mold and analyzed effect by cooling system geometry and casting speed quantitatively. In present study, a three-dimensional finite-element thermo-mechanical model with type-switched element is transformed from previous heat-transfer finite-element model [9l, and mold deformation is simulated in order to shed light on thermo-mechanical behavior with special thermal conditions and different mold geometry at high casting speed."

Jan 1, 2013

By S. S. Cole, C. E. Wood, T. L. Joseph

"INTRODUCTION Iron ore containing titanium was first used in blast furnaces over a century ago. It is well known that TiO2 is a slag-forming material that will increase the amount of slag produced by the usual gangue materials, silica and alumina. Increase in the volume of slag due to the presence of TiO2 and a lack of information concerning its effect on the properties of the slag have prevented the general use of titaniferous ore. Also rather com¬mon belief among furnace operators that the bottom of the furnace builds up when ores containing TiO2 are smelted has militated against the use of titaniferous ore. This building up of the hearth has been attributed to the formation of copper-colored crystals of titanium cyanonitride, which have been observed in the salamanders of blast furnaces. Until recently the availability of nontitaniferous iron ore has left little incentive to use ore containing titanium.The presence of vanadium in certain deposits of titaniferous magnetite in New York State has created new interest in problems connected with the use of titanium-bearing ore. It appears that most of the vanadium in this ore can be recovered in pig iron, which can be blown in a converter to produce a slag containing vanadium in amounts suitable for the production of ferrovanadium.The Titanium Division of the National Lead Co. recently erected a largo mill to treat ore from Sanford Hill, in Essex County, New York, about 50 miles west of Port Henry. The ore deposit was acquired from the MacIntyre Iron Co. and is often referred to as Sanford ore. It is one of the largest deposits of Iron-bearing material to be found east of the Lake Superior region and is being mined by open-pit methods."

Jan 1, 1943

By Larissa Mitie Ihara

Foram encontrados vários casos de falha de engrenagens de redutores de grande porte, aplicados em turbogeradores em usinas de cogeração. Este trabalho tem como objetivo a análise de falha dessas engrenagens bihelicoidais. Engrenagens operam sob condição de carregamento cíclico variável, logo seus principais modos de falha são fadiga de contato e por flexão de dentes. A engrenagem estudada, fabricada em aço 18CrNiMo7-6, foi utlizada em campo e apresentou fratura em dois dentes. Realizou-se uma análise de espectrofotometria para confirmação da composição química do material base. Uma análise microestrutural foi realizada utilizando microscopia óptica, revelando que a microestrutura corresponde a martensita com austenita retida. Foi feito um perfil de microdureza no plano transversal do dente, que indicou uma camada cementada efetiva de 2.150 µm e dureza de 715 HV0.1 na superficie. Foi feita uma fractografia macroscópica para determinação das caracteristicas da fratura, o que permitiu identificar marcas de praia e deltas de rio. Aliado a isso, foram feitas imagens por microscopia eletrônica de varredura, determinando o local do início da trinca. A partir dessas evidências, pôde-se concluir que o mecanismo de falha predominante foi fadiga por flexão de dente.

Aug 17, 2017

By Frank Wright

"The Icon Sullivan Joint Venture ore deposit was discovered in June, 1965 by Messrs. Paul Benard, Bob Galipeau and Mac Watson working under the direction of Mr. Andrew J. Troop, as employees of the Icon syndicate. The deposit is located on the Waconichici River as the south end of Baie du Poste of Lake Mistassini, approximately 45 miles north of Chibougamau. Property acquisition and Winkie drilling was followed by a diamond drilling program to evaluate the deposit. Stripping of the open pit area connnenced in the late fall of 1966 and the first test sample of ore was shipped to Chibougamau in December of that year.Regular ore shipments to the mill of Merrill Island Mining Corporation Limited for concentration commenced May 25, 1967. Production to December 31, 1970 amounts to 42,960,000 pounds of pay copper.The ore is chalcopyrite in white quartz dolomite, and it contains a very small amount of precious metals. The quartz dolomite assumes a flat to gently dipping attitude and is associated with a graphitic argillite contact zone on both hanging and footwall sides, in dolomitic limestone rocks. There is practically no other sulphide present in the ore.During the summer of 1969 a series of pre-concentration tests were completed and a Wemco heavy media sink float plant was installed in late 1969 and early 1970. This pre-concentrator eliminates at least one third of the ore mined in the form of barren quartz dolomite prior to ore shipment by truck to the concentrator in Chibougamau."

Jan 1, 1971

By J. Damay

El agotamiento de los recursos de alta ley, incertidumbre en la exploración y costos altos de inversión son factores que limitan las decisiones de los futuros inversionistas. En este sentido, el texto plantea técnicas de investigación operacional que el ingeniero de minas pueda evaluar y limitar el riesgo de inversión de la compañí. Asimismo, se muestran las técnicas aplicadas en el grupo "Society Le Nikel Peñaroya". Para ello, se utiliza la geoestadística, valor mínimo y de ley límite, estrategia de la explotación minera, método de clasificaciones comparativas y programas de simulación.

Jan 1, 1982

By William R. Rumbold

THE Kinta valley in the State of Perak, one of the largest of the Federated Malay States, is probably at the present time the richest alluvial tin-district in the world, Perak producing from 20,000 to 25,000 tons of tin annually, and the Kiuta valley being the chief producer. The valley runs approximately north and south, and is 30 miles long by 12 wide. It is very flat, the mountain-ranges on either side rising abruptly from the plain, that on the east being the great Central range of the peninsula, and that on the west a subsidiary range marked " Kledang " on the map, Fig. 1. The valley is drained by the Kinta river, which rises in the eastern mountain range and flows south to join the Perak river, being joined by numerous streams from both mountain-ranges. The rain-fall is heavy, averaging annually about 90 in. The whole country is covered with dense jungle, except where it has been cleared for mining-operations and a small amount of cultivation. Mining villages are scattered throughout the valley, the chief towns being Kampar, Batu Gajah, Lahat and Ipoh, the latter being the center of the mining-operations. An ideal section of the main geological features of the Kinta valley is given in Fig. 2. The valley is composed of a highly crystalline limestone, usually white in color, sometimes gray; in fact, it may be called marble. It is always highly inclined and often contorted, and in some places is interbedded with shale. On the east side of the valley, near its contact with the granite, it forms a remarkable series of limestone cliffs, which rise in some cases as high as 2,000 ft. above the level of the limestone in the valley. It is non-fossiliferous, and its geo-

Sep 1, 1906

By Melina Gamis da Silva

Em um trabalho anterior [1], as temperaturas de processamento aplicadas na laminação de tiras a quente, LTQ, da CSN foram investigados para algumas classes de aços microligados ao Nb. Os resultados deste trabalho mostraram a possibilidade da redução da temperatura de reaquecimento utilizada para esses aços refletindo em possibilidades de melhoria de produtividade. No trabalho atual, o impacto dessas mudanças na microestrutura obtida de LTQ foi investigado com mais profundidade, utilizando um software desenvolvido para prever a evolução da microestrutura em termos das frações recristalizadas, das distribuições de tamanhos de grãos e do comportamento das tensões médias de escoamento, TME.

Oct 30, 2017

Minerals are vital to any industrialized civilization. Annually, the United States uses more than 4 billion tons of new mineral materials, or about 40,000 pounds per person-about half being mineral fuels and the other half being metals and nonmetallics. Stable and economic domestic mining, mineral, metal, and mineral reclamation industries are essential to the economy. The value of United States energy and processed materials of mineral origin exceeds $200 billion annually. Although a number of minerals are imported, especially some designated as "strategic and critical," most U.S. mineral supplies are derived from the domestic mines and processing facilities that you will be seeing, reading about, and visiting as you use this visitor guide. We hope you enjoy your experiences. This pamphlet, a guide to mining and mineral operations that may be observed or visited and some other points of interest relating to minerals, is in-tended to aid tourists and students who are interested in mining. Some may wish to study our Nation's romantic past; others may plan to enter the minerals industry as a career; still others may have a primary interest in conservation practices. The pamphlet is also intended to aid State and local officials, Chambers of Commerce, and mining firms in answering some of the many questions of tourists and students.

Jan 1, 1977

By Edward Steidle

TWO years ago the Committee on Latin American Education Relations, Mineral Industries Education Division, started a study of mineral industries education in the Latin Americas. Information was obtainable only with great difficulty. Some information was available piecemeal but no complete resume had ever been assembled. Initial assistance was gained from the United States Office of Education and the Pan American Union. This, and first-hand knowledge of the writer, provided a list of colleges and universities which were believed to offer work lead. ing to a degree in one or more branches of the mineral industries. Detailed information could be obtained only by direct contact with each university through air mail service. Questionnaire letters were sent to officials of 34 colleges and universities. Twenty-one gracious replies were received. Fourteen of the colleges and universities concerned offer curricula in mining, five in metallurgy, three in petroleum, seven in geology, one in geographical engineering, one in topographical engineering, and one in geophysics. Two institutions offer advanced training in petroleum engineering. No institution offers any courses under the caption of ceramics or fuel technology.

Jan 1, 1945

"Pilot plants for pressure hydrometallurgy represent special design and project execution challenges. Over the past twenty years, Zeton has designed and fabricated a variety of world-class pressure hydrometallurgical pilot-plant facilities for the nickel industry, and this paper discusses design considerations and strategies related to such projects. Project execution methods are also discussed, and guidance is given for the selection of materials of construction and for the selection of appropriate pressure and temperature design points for pressure hydrometallurgical pilot equipment. The paper concludes with a discussion of the need for process similarity with future commercial operations and the realities of pilot-scale equipment.INTRODUCTION The process technology developer or owner and the designer/fabricator of a new pilot-plant facility are faced with some difficult technical choices even after the decision to build a dedicated plant has been taken. A pilot-plant project is usually on the critical path of a large commercial project involving investments many multiples greater than the capital cost of the pilot plant. Schedule savings in the design, manufacture, and commissioning of the pilot plant or in a rapid completion of the experimental program can be disproportionately beneficial to the overall development project. However, inappropriate shortcuts resulting in major oversights can be disproportionately problematic. A number of considerations and suggestions for both the project execution approach and the process engineering design of pressure hydrometallurgical pilot-plant facilities are presented as a guide for potential owners and operators of new pilot-plant equipment and facilities. These suggestions are particularly applicable to the nickel industry, where the majority of our firm’s prior hydrometallurgical experience was obtained. This paper is an update to an earlier publication (Martin, 2004), offering an opportunity for a new generation of metallurgists and engineers to learn the specialist requirements of pilot- and demonstration-scale plant design, which are key functions in the development and commercialization of new processes."

Jan 1, 2017

By M. L. Requa

EVERY forward step in civilization brings with it an increase in population and increasing demand for raw materials. Modern civilization, because of its industrial development, depends more and more for its well-being on ample supplies of raw materials; the higher the type of that civilization, the greater its dependence. No fact is more obvious than that the raw materials should be put to use with greatest prudence and efficiency. National life is not a matter of a decade or a century. Conservation is no longer a matter for political discussion; it is a vital element in the future welfare of all nations. Unfortunately, to the minds of many, conservation means the locking up of natural resources, their arbitrary withdrawal, bringing about, in short, a condition of industrial stagnation. This has occurred in past centuries through misdirected governmental effort. Two eminent engineers have variously defined conservation as follows:

Jan 1, 1925

By Steve Kral

U.S. mines are among the most efficient, productive and safest in the world. Much of that efficiency is due to the high-technology equipment and processes available to the industry. The U.S. mining industry can produce more material now with fewer people than it could a few decades ago. And that material can be produced more safely. However, the workforce is growing older and fewer young people are filling the holes created by retirements. Even though mining is one of the highest paid occupations in the United States, young people believe they can find jobs that pay almost as well without the risks and the often remote locations associated with mines.

Jan 1, 2002

Mining Methods LUCIEN EATON, Chairman S. R. ELLIOTT, Vice-chairman CHARLES W. WRIGHT, Secretary Alluvial Mining CLINTON BERNARD CHARLES JANIN O. J. EGGLESTON CHARLES H. MUNRO N. L. WIMMLER Open-cut Mining Iron MAX H. BARBER J. A. MACKILLICAN KENNETH DUNCAN W. R. VAN SLYKE

Jan 1, 1932

By J. B. Zadra

After the discovery of the rare-earth mineral deposit in the Clark Mountain area near Mountain Pass, San Bernardino County, Calif., two samples wore obtained through the Mining Division of the Bureau of Mines for investigation of possible method of concentration. Three other samples were received later from different locations in the same area. The rare-earth mineral in this ore had been identified by E. T. Schonk as bastnaesite, a fluocarbonate of the rare-earth metals containing cerium, lanthanum, praseodymium, thorium, uranium, etc. Associated with the bastnaesite were barite, silica, and some calcite. The bastnaesite contained a small amount of iron as a coloration and some manganese. Twenty to fifty percent of the weight of the samples studied was bastnaesite, or ten to twenty-five percent total rare-earth oxides; about half was cerium oxide. Apparently, none of this mineral occurred in pure form. Even the highest-grade particles 'wore contaminated by fine, interlocked grains of barite, calcite, and silica; barite contamination predominated, and the barite was interlocked with varying amounts of bastnaesite. While the specific gravities of pure bastnaesite and barite (approximately 5.0 and 4.50 respectively) differ enough to allow separation by gravity, the interlocking of the minerals nullified this difference. Consequently, only a partial separation could be made by gravity concentration. The extremely fine grained texture of most of the ore prevented grinding to a size that would make concentration by flotation practicable; a partial separation of barite by this means was effected.

Jan 1, 1952

By Charles A. Kelliher

In November of 1957, the Aliquippa Works started operation of the third basic oxygen furnace shop in North America. This high speed basic steelmaking method provided a very economical increase in capacity at the Works. The success of these two (2) 81-ton furnaces led to the construction of a second B.O.F. shop, producing heats of 230 tons at J&L's Cleveland Works in 1962. The experience gained operating both shops provided the background for the design of the new steelmaking complex at the Aliquippa Works. This new complex consists of a three (3) furnace shop with two (2) furnaces blowing alternately producing heats ranging from 120 to 207 tons. This variation in heat size is predicated on the requirement that approximately 20% of the shop production will be used to supply steel to a six (6) strand casting machine, producing 4' through 7" billets. The new B.O.F. shop has replaced all other steelmaking units including the #1 Shop, where operations were discontinued in September of 1968. With the advent of the strand casting facilities in September of 1969, many of the standard shop practices had to be changed to compensate for higher tap temperatures, longer handling times, and reduced ladle availability. The subsequent changes in these areas led to the evolution of the strand cast ladle practice which is described in this paper.

Jan 1, 1972

By R. M. Treco

THE thermal expansion of pure beryllium was first investigated by Hidnert and Sweeneyl in 1925 on a single cast specimen stated to be of 98.9 pct purity. A study of the coefficients of expansion by X-ray methods has recently been made by P. Gordon' on powder obtained from the Brush Beryllium Co. assaying 97 wt pct beryllium with about 2 wt pct oxygen as an impurity. The present work pertains to about the highest purity metal obtainable from the Brush Beryllium Co. This metal was in the form of lumps which were remelted and cast in a high-vacuum induction furnace. Expansion data in this paper deal with beryllium extruded into bars of rectangular cross-section 4x1/2 in. and the anisotropic expansivity of a large cast single crystal. Analysis of the cast metal after extrusion indicated a beryllium assay of 99.28 pct. Impurities were 0.170 pct Fe, 0.140 pct Al, 0.014 pct Mg, 0.086 pct Si, 0.020 pct Cu, 0.020 pct Mn, 0.007 pct Ni, 0.007 pct Ca, 0.080 pct C, 0.179 pct 0, (as BeO). Part I—Extruded Metal Thermal expansion measurements were obtained with a fused quartz-tube differential type dilatom-eter3 on specimens cut from the extruded sections in longitudinal and transverse directions. Specimens were machined to a diameter of 0.250 in. and a length of 3.000 in. One sample from each direction was vacuum annealed for 1 hr at 800°C. The dilatometer tube was placed in a vertical tube furnace having a uniform temperature zone which was twice the length of the sample. Average time for a complete thermal cycle to 500°C was 18 hr. Temperatures were observed with two chromel-alumel thermocouples attached to the sample about 1 M in. apart. The accuracy of temperature measure-ment was ± 0.25°C. An argon gas atmosphere sur-rounded the specimen to prevent oxidation of the beryllium. Samples were identified as shown in table I. Results - The original plan included measuring expansion up to 1000°C, but the first two runs on sample No. 5 showed that a permanent contraction occurred from

Jan 1, 1951