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By G. B. Atkinson

The Bureau of Mines investigated a method for increasing the leaching rate of bulk superalloy scrap to facilitate recycling and recovery of critical metals such as Ni, Co, and Cr. Three superalloys were investi- gated, the cast-nickel-base superalloy IN-738, the wrought-nickel-base superalloy Rene-41, and the cast-cobalt-base superalloy Mar-M-509. Superalloys melted with 20, 30, 40, and 50 pct Al metal to form inter- metallic compounds were easily crushed to a convenient particle size and reacted rapidly with acid solutions which dissolved the metals. For example, leaching 1/2-in pieces of unalloyed IN-738 with excess 6N HC1 at 95° C for 2 h dissolved about 0.5 pct, while leaching 10 g of minus 20-mesh 30 pct Al-70 pct IN-738 with excess 6N HC1 at 95° C for 2 h dis- solved 96.2 pct.

Jan 1, 1983

By Helmut Ehnes

Over 330 million accidents at work happen world wide every year, only counting those leading to more than four days absence. More than 350,000 end fatal. Two million people more die every year due to work-related diseases. To sum this up: around 2.4 million people die every year because of work conditions. Among many risky industries, mining stands out. While mining represents just 1% of employees globally, it unfortunately represents 8% of all occupational fatalities. Mining operations go along with a variety of hazards. Not only in large operations, as they first come to mind, but also in the manifold small scale mines, with an estimated 13 million labourers worldwide exposed to substances such as dust, mercury and other chemicals, while also dealing with poor ventilation, inadequate space and overexertion. But is the number of severe accidents and diseases inevitable or can we change this situation? We can make mining sustainably safer, but we need a successful strategy to do so. A high potential lies in Vision Zero. Vision Zero is a prevention strategy for a safe future without fatal or serious occupational diseases, work accidents and traffic accidents. First defined as early as in the 19th century by Eleuthère Irénée du Pont, its very successful elements were adopted by many European countries first aiming at road safety, then extended to safety and health at work. Vision Zero?s holistic elements cover technology, workplaces, rules, and people as fields of action. By focussing on severe and fatal accidents, its application increases the level of safety and health overall.

Aug 1, 2013

By Y. Nien Wang, Moe Amini, Heiner Sander, Max John

INTRODUCTION As the population increased along the coast route (California Route 1), and the people’s need to have guaranteed access increased, the landslides and related road closures began to have serious adverse economic impacts. Landslides were causing major long-term road closures about every 10 years on average. In 1983, ground movement at Devil’s Slide caused Highway 1 to be closed for an extended period of time which caused significant economic loss to the surrounding coastal communities. A number of options for bypassing the slide area were considered, and the Martini Creek inland bypass was selected for design. Subsequent litigation led to the creation of the Devil’s Slide Tunnel Study in 1996. The results of this study indicated that a tunnel alternative would be competitive with the inland bypass. The final decision was left to the citizens of San Mateo County, who approved the tunnel alternative in the November, 1996 election After completion of environmental studies and the processing of legal challenges, the final environmental document was finished in 2001. The preferred tunnel alternative was designated to proceed for final design and construction. PROJECT DESCRIPTION The Devil’s Slide Tunnels consists of a separated two-lane road, one lane in each direction, which passes through twin tunnels and over twin bridges and then connects with the existing non-separated, two-lane road at each end. The total length of the project is approximately 1900 meters consisting of four main project divisions, which are described below, going from south to north. 1.Operations and Maintenance Center (OMC) area, 2.Southern approach roadways to the South Portals (250 meters), including the South Rock Cut,

Jan 1, 2005

By N. L. Piret

In copper smelting minimization of solid waste generation is receiving increased attention with more stringent environmental legislation and lower disposal space availability. Copper smelting slags generally being valorizable, solid waste generation is attributed to the presence in the feed of unvalorizable impurities which do not report to the slag and to the unavoidable formation of contaminated dilute acid solutions which need neutralization. As to unvalorizable impurities, solid waste minimization is achieved by rejecting them in the highest possible concentration. Dilute acid is mainly due to the formation of SO3 in the smelter gases and to the discard of decopperized bleed-off electrolyte. Its generation is substantially lowered by preventing SO3 formation, by converting the dilute acid to a valorizable product, e.g., by thermal decomposition for H2S04 recovery or by precipitation as chemical gypsum, and by suitable treatment of the bleed-off electrolyte for impurity removal. Industrial processes are evaluated and alternatives are discussed.

Jan 1, 1994

By H. C. Roland Kammel

Stannous sulfate electrolytes are widely used nowadays in electrolytic tin production. Characteristic features of this electrolysis process are that dense cathode deposits can only be obtained by additions of organic additives and that so called ?black mud is formed on the anode surface which leads to an increase in cell-voltage. In order to prevent excessive cell-voltages or oxygen evolution the black mud has to be removed periodically. Studies in laboratory scale have been performed about the effect of different organic additives on electrolytic tin deposition and the formation of surface layers on pure and industrial tin anodes. Results reveal that organic addition agents are effective in reducing cathode roughening as well as extending the covering time of the anode ?by black muds.

Jan 1, 1985

By J. M. Dahl, L. H. Van Vlack

STAFF: Editor, Gerhard Derge Associate Editor, Paul G. Shewman Carnegie lnstitute of Technology Schenley Park Pittsburgh, Pa. 15213 Editorial Assistant, M. A. Redmerski Production Editor, Otto T. Johnson THE METALLURGICAL SOCIETY: Jack H. Scoff, President; Richard C. Cole, Post-President; Harold B. Emerick, President-Elect; Ralph L. Hennebach, Treasurer; Robert W. Shearman, Secretary; Donald A. Parks, Assistant Secretary; Leslie S. Wilcoxson, Assistant Secretary. PUBLICATIONS COMMITTEE OF THE METALLURGICAL SOCIETY: R. E. Lund, Chairman; T. E. Dancy, H. B. Emerick, P. R. Gouwens, R. E. Grace, J. H. Jackson, H. H. Johnson, A. E. Lee, Jr., R. R. Nosh, R. D. Pehlke, and Paul Queneau. Review and selection of monuscripts is under the supervision of the following Publications Committees: Extractive Metollurgy Division: R. E. Grace, Chairman; G. M. Bell, D. W. Bridges, J. M. Cigon, G. W. Healy, T. A. Henrie, R. D. Holli-day, C. E. O'Neill, C. S. Sami s, A. W. Schlech-ten, and Charles Shull . Iron and Steel Division: R. D. Pehlke, Chairman; T. P. Floridis, Arnulf Muon, G. R. St. Pierre, E. T. Tuckdogon, L. H.Von Vlack, and J. M. Uys. Institute of Metals Division: H. H. Johnson, Jr., Chairman; J. B. Clark, Vice Chairman; M. R. Achter, G. F. Bolling, J. O. Brittain, G. P. Conard, II, L. A. Girifolco. G. T. Hahn, J.P. Hirth, L. Himmel, G. T. Horne, George Krauss, C. F. Leitton, Jr., J. D. Livingston, R. D. Monning, H. M. Otte, S. V. Radcliffe, R. E. Reed-Hill, H. C. Rogers, O. Sherby, M. T. Simnod, G. R. Speich, E. A. Steigerwold, R. A. Swolin, W. A. Tiller, W. R. Upthegrove, J. B. Wagner, Jr., Derek Walton, H. W. Weart, W. W. Webb, and D. WiIsdorf. Published monthly by the American lnstitute of Mining, Metollurgicol, and Petroleum Engineers, Inc., 345 East 47th Street, New York, N. Y. 10017. Telephone PLAZA 2-6800. Subscription $30 per year for non-AIME members in United States and North, South, and Central America; $32, foreign; $7.50 for AlME members. Single copies, $6.00, single copies foreign, $6.50. The AlME is not responsible for any statement mode or opinion expressed in its publications . . . Copyright 1965 by the American Institute of Mining, Metallurgical, and Petroleum Engineers, Inc. . . . Registered cable address, AlME New York . . . Indexed in Engineering Index, lndustrial Arts Index, and Chemical Abstracts . . Second class postage paid at New York, N. Y., and Ann Arbor, Mich. Volume 233, Number 1.

Jan 1, 1965

By Frederick C. Trutt

Research performed on arcing faults and their interaction; with electrical insulating materials within coal.-mine power-system enclosures is described. This work was performed at The Pennsylvania State University from 1 December, 1976 through 30. November, 1977. Results presented are interim in nature and future research is planned to integrate the simulations which have been constructed, as well as to apply developed experimental procedures to the evaluation of electrical insulating materials for use in coal-mine enclosures. The thrust of this research has been divided into several primary areas. These include the development of a theoretical procedure for computation of three-phase and line-to-line arcing fault currents as a function of time, formulation of an arc model based upon thermal-arc plasma properties so that arc voltages and energies may be computed, development of a simulation for pressure and temperature rises when an arc interacts with an electrical insulating material within an enclosure, experimental evaluation of electrical insulating materials in terms of their tendency to support an arc as well as their potential contribution to enclosure pressure rises, and integration of the above research areas to form overall procedures for theoretical and experimental evaluation.

Jan 1, 1977

Mineragraphy is a coined term to signify the field of microscopic investigation of ore minerals. The term is not euphonius and is sometimes regarded as superfluous because the subject is no more than an enlargement of the scope of petrology. In the past the practical field of petrology has been largely limited by the instruments which were designed for the study of rocks and' the microscopical properties of the transparent minerals. The addition of mineragraphy has been brought about by the use of the reflecting microscope and a totally different technique.The use of the petrological microscope, as it has been employed in the training oi geologists and mining engineers for nearly half a century, has been justified many times, not only in its application to general geological problems, but also in the more restricted field of the exploration and examination of ore deposits. It provides information of the gangue minerals and rocks associated with an ore body which is of great value in some mining fields. In cases where ore deposits occur selectively in certain favourable types of rock, the recognition and delineation of these rock types is a useful guide in prospecting. The Boulder Belt at Kalgoorlie forms one of the most striking examples in Australia where important significance is attached to different rock types, and the petrological microscope is essential to their elucidation.

Jan 1, 1932

By M. K. Roberts

The approximately 2800 Ma old Ventersdorp Contact Reef is a unique Witwatersrand orebody, from which about 6% of the world?s gold production is derived. A major portion of this production is mined at depths exceeding 2500 m and deepest levels of mining are at about 3600 m. The orebody?s hangingwall consists of volcanic rocks. This differs from the older Witwatersrand orebodies, which have quartzitic hangingwalls. The thickness of the Ventersdorp Contact Reef is generally about 1.20 m, but is highly variable, at an average dip of about 18°. A pronounced unconformity beneath this orebody is also expressed by varying footwall rock type characteristics and frequent rolling of the reef plane. These rolls follow topographic variations of the palaeo-surface. More geological than rock mechanics studies were performed on the Ventersdorp Contact Reef prior to 1992. Recently, however, a multidisciplinary team comprising various rock engineering and geological disciplines has delineated geotechnical areas by a novel technique. Geotechnical areas are defined by distinct footwall/hangingwall rock assemblages. The presence of three footwall and two hangingwall rock types results in the definition of six geotechnical areas across a distance exceeding 60 km, including about 10 gold mines. Distinct rock mass behaviour has been documented in three of the six geotechnically defined areas. Different rock mass behaviour is expressed by features such as mining-induced fracturing, closure rates, fall of ground characteristics and seismic character. Some geological features override the rock mass behaviour as defined for the individual geotechnical areas. These are undulations of the orebody or the frequency, characteristics and attitude of major discontinuities. It is concluded that the concept of geotechnically subdividing orebodies is not only important for facies delineation and the associated grade, but also needs to be considered for safety aspects, in determining factors such as the appropriate support to be employed.

Jan 1, 1999

By Georgia J. Lysay

The Kemess Mine tailings impoundment is retained behind an earthfill and rockfill dam that, when complete, will measure about 140 m in height with a crest length in excess of 1 km. Due to weak foundation conditions, the dam must be raised at a very flat downstream slope approaching 7H:1V. This requires an enormous volume of fill to construct the downstream shell of the dam, which has a low permeability clayey till core and is raised via the centerline construction method. For the initial years of annual dam raising, from 1996 through 2002, the downstream shell of the dam was constructed with non acid generating waste rock from the open pit, 7 km distant and requiring an uphill haul with obvious cost implications. To reduce costs, and to reduce waste haulage constraints on mining schedules, feasibility studies were initiated for raising of the downstream shell using cycloned tailings sand as opposed to open pit waste. This required inclusion of flotation cells for removal of residual sulphides from the tailings to produce the non acid generating product mandated for the downstream shell of the dam. These studies were positive, and cycloned sand construction was initiated in December of 2002. This paper describes the experience gained with cycloned sand construction for the dam. Unique aspects include environmental controls given the sulphide-bearing ores, preparation of the existing shell of the dam for subsequent placement of hydraulically placed cycloned tailings sand, on-dam settling ponds, water management issues, reclamation of the sand dam for erosion control commensurate with the wet climate, and use of the system to construct an above-water beach of non acid generating tailings to increase the closure security of the structure. A particularly unique aspect of the Kemess experience is hydraulic fill operations extending throughout the coldest winter months, as compared to other operations where such placement has traditionally been considered non-viable through the winter months

May 1, 2007

By Fernanda Borba Simões

Na produção de biocombustíveis a partir de óleos vegetais produzidos via craqueamento térmico-catalítico, é realizada a desacidificação do produto final para sua viabilidade, podendo ser efetuada pela adsorção. Os adsorventes são diversificados e vão desde zeólitas até o uso de resíduos industriais. Este trabalho buscou testar a lama vermelha previamente ativada quimicamente e termicamente como adsorvente de ácidos graxos livres presentes no gasóleo leve produzido a partir do craqueamento do óleo de palma com índice de acidez inicial de 55,1257 mg de KOH/g. A lama vermelha foi utilizada em cinco condições: seca sem tratamento, ativada quimicamente (pré-tratada a 400°C/2h) por solução de HCl a 37%, de H2O2 a 4%, de HCl a 1,5 M e de KOH a 1,5 M. Na cinética de adsorção, a lama vermelha ativada por solução de HCl a 1,5 M mostrou-se mais eficiente que os demais adsorventes, pois reduziu o índice de acidez do biocombustível de 10,7574 mg de KOH/g para 9,1752 mg de KOH/g no tempo de 50 minutos. Quanto à eficiência dos adsorventes restantes, no que tange a desacidificação, apenas a lama vermelha seca e a ativada quimicamente por KOH a 1,5 M apresentaram remoção dos ácidos graxos livres perceptíveis.

Aug 16, 2017

By Jonnie M. Estes

A two-constant equation is presented for helium from 30° = T = 1,473° K. This equation is developed by modifying a generalized equation of state originally presented by Redlich and Kwong (20).3 The modification consists of setting B = 0.06372 Tc/PeT. This modified equation represents the compressibility factors of each of 80 isotherms tested in this temperature range to less than 1 percent average deviation.

Jan 1, 1967

MR. RIGG: Gentlemen, I would like to welcome you all to the symposium this morning. My name is Jack Rigg, and I m a special assistant to Hollis Dole, Assistant Secretary of the Interior for Mineral Resources. Hollis is not in town this morning, and I am here to pinch-hit for him. The first order of business this morning is remarks by the Honorable Russell Train, Under Secretary of the Department of Interior. Mr. Train. MR. TRAIN: Thank you, Mr. Rigg. Lest you think that Hollis Dole is not interested in this symposium, let me just say that fie is flying back from Australia just to be here. He is heading up a United States delegation in Australia meeting on resource problems in the Pacific. And I believe he will be here about noon.

Jan 1, 1970

By A. E. Hall, R. N. Taylor, J. G. Taylor

The introduction of tunnel-boring machines to South African gold mines has created problems and challenges which accompany any new technique. This paper describes the experience gained in this field, especially in the design and erection of a tunnel borer and in boring and environmental conditions.

Jan 1, 1978

By Moacir Medeiros Veras

A tecnologia de sensor-based sorting faz uso de sensores high-tech para pré-concentrar seletivamente partículas de minérios que tenham teores toleráveis para planta de beneficiamento, rejeitando as partículas que são totalmente estéreis ou rejeitos. A pré-concentração de carvão assistido pelo método Dual Energy X-Ray Transmition possibilita separar seletivamente o carvão com melhor quantidade de matéria orgânica das rochas silicáticas com maior densidade. O objetivo desse trabalho foi investigar a afinidade da tecnologia de sorting na pré-concentração do carvão mineral da Carbonífera do Cambuí/PR assistido por sensor de raios-x. Os testes foram realizados em dois lotes cujo range granulométrico foi -4”+2” e -2”+1”. A pré-concentração foi feita em 2 cortes de separação, o primeiro para retirar o rejeito e o segundo para obter 2 tipos de produtos. Os resultados indicaram que 52,15% da massa foi rejeitada, concentrando 47,85% do material de carvão na fração média -2”+1”. Na fração grossa -4”+2” foi rejeitado 62,51% da massa e concentrado 37,49% de carvão. As análises imediatas dos pré-concentrados mostraram que na fração grossa houve redução de 44,57% de cinzas totais e houve aumento de 4,59% para 8,29% de enxofre [S], enquanto na fração média a redução foi de 36,98% de cinzas totais e de 1,19 % [S].

Oct 30, 2017

By Elard Rodríguez Véliz

El objetivo del presente texto es mejorar el rendimiento de las brocas a través de una serie de análisis realizados durante el programa de perforación comprendidos entre los años 1974-1977. Para ello, se utilizó una metodología que implemente un código que elimine ciertas brocas utilizadas desde 1974 al 31 de diciembre de 1977, dado que el anterior no se adecuaba a las características. Posteriormente se realiza un cuadro comparativo del motivo del deshuso del anterior código, se señalan sugerencias y resultados del análisis de brocas, así como los factores de las fallas de las mismas.

Nov 20, 1978

By Tadashi Aiura, Yasuhiro Miura

"A small amount(0.2mass%) of Scandium(Sc) was added to the 7.NOl and 5083 Al alloys as a refiner and stabilizer of microstructure, and the resulting microstructures were discussed in comparison with the effects of the conventional additives. The followings are summarized: 1) in the as-solidified structure, a ·decreased tendency of constitutional supercooling and increased solubility of Mg were recognized for the Sc-added 5083 alloy. Sc is a -better microstructure refiner for the 7N01 alloy than Zr, in a sense that it does not suppress the favorable effect of· coexisting Ti. 2) Sc effectively suppresses recrystallization both in the 5083 and 7N01 alloys. 3) The rod like primary Al3Sc crystals formed during solidification, as well as the fine dispersion of Al3Sc precipitates formed by subsequent heat treatment, can act as a strong recrystallization suppresser. IntroductionThe 7N01 and 5083 alloys are the most popular industrial Al alloys and they are widely' used for various structures because of their superior properties. Fine macro and micro structures of the materials are required for obtaining acceptable sec resistance,consistent appearance of anodized surface and good weldability, as well as good mechanical properties. In order to produce fine grain structures, transition metals, such as Cr, Zr, and Mn, have been conventionally added.It has been reported that Sc is an efficient refiner [l, 2] and can be an alternative for the conventional and also suppresses recrystallization in Al alloys [3,4]. Scandium is the lightest transition element and forms an equilibrium intermetallic phase. The equilibrium phase, Ll2-Al3Sc, is coherent with the matrix, and of _spherical shape. A fine dispersion of the spherical precipitates is obtained by quenching and aging after solutionizing annealing. The authors have already reported a part of the experimental results on the effect of Sc on the as homogenized microstructure of the 5083 alloy [5]. In the present study, the effects of Sc on the macro and micro structures of the industrial high strength Al alloys(7N01 and 5083) for extrusion are investigated, and the superior role of Sc as a grain refiner is shown"

Jan 1, 2000

By M R. Stevens, W Mori, G B. Boswell

The Onemana prospect is located on the eastern Coromandel Peninsula, North Island, New Zealand. Systematic exploration involving surface geological mapping, geophysics, rock and soil geochemistry, reverse-circulation and diamond drilling has identified a number of important features of a fossil hydrothermal system at Onemana. This relatively intact gold mineralised system is hosted within a sequence of rhyolitic volcanics and volcaniclastics, overlain by lake sediments, sinters and hydrothermal eruption breccia. The system lies within a graben/half graben bounded by major NE-trending faults which form the approximate boundaries to hydrothermal alteration. Rock and soil geochemistry indicate a broad zone of anomalous gold, silver, arsenic, mercury and antimony. Overlapping elevated rock and soil gold anomalies indicate strongest mineralisation occurs over two zones of hydrothermal brecciation named 'Breccia Knob' and 'Western Ridge'. Geophysical data obtained from Gradient Array Resistivity and Ground Magnetics have been used to produce anomaly maps. The terrain corrected resistivity plot shows a number of well defined linear resistivity anomalies which are believed to represent large silicified and quartz veined bodies at relatively shallow depths. The strongest of these anomalies correspond with 'Breccia Knob' and 'Western Ridge'. Reverse-circulation and diamond drilling targeting these resistivity and geochemical anomalies has confirmed wide intervals of quartz veining, silicification and gold mineralisation. Petrologic data based on drill samples indicates the existence of a laterally extensive gold bearing epithermal system. Hydrothermal alteration is thought to have been caused by strongly convecting, two-phase (boiling), near-neutral chloride fluids which persisted at high temperatures (170 - 220¦C) to the paleosurface. A geological model is postulated of a large, complex, hydrothermal system developed in a shallow lake or marginal lake environment created by rifting and graben development within a recently extinct rhyolitic volcanic centre. Geothermal activity alternated between relatively quiescent periods of unrestricted fluid upflow and sinter development interspersed with violent hydrothermal eruptions caused by near surface silica capping and overpressuring above a major fluid conduit centred under 'Breccia Knob'.  Opportunities for precious metal mineralisation are evident from drilling to date. Upflow of near-neutral chloride fluids to shallow depths favours the presence of strongly mineralised stockworks at relatively shallow depths. Periodic hydrothermal eruptions would have caused fracturing and rapid depressurisation of the hydrothermal system, strongly favouring the precipitation of gold from solution both near surface and within feeder-vein systems at depth.

Jan 1, 1995

By B. Tiryaki

Longwall shearers usually suffer from excessive pick and pickholder consumptions and severe wear of the back plate of the clearance ring section of shearer drums. In practice, most of the drums were seen to be withdrawn from the face due to the abovementioned problems, while vane picks and their holders were intact due to the improper lacing design of the clearance ring picks. However, few underground investigations and their results on the effect of lacing arrangement of clearance picks on the service life of shearer drums have been published. Nevertheless, the pick consumption characteristics of shearer drums were not investigated in detail, since these are fewer pick consumptions with shearers when compared to roadheaders. This paper is concerned with the comprehensive in situ trials on the effect of lacing of clearance ring picks on the lifespan of shearer drums, and the pick consumption characteristics of longwall shearers at Cayirhan Coal Mine in Turkey. The lifespan of shearer drums employed with shearers in this mine increased 70 per cent, while the consumption rate of clearance ring picks decreased threefold through using an alternative lacing for clearance picks, indicating the significance of utilizing proper design techniques for clearance ring picks for the service life of shearer drums. Statistical analyses carried out, using the raw pick consumption data, implied that the clearance ring picks experienced much higher loads than vane picks, revealing that special attention must be paid to designing clearance ring picks. An average maximum consumption value of 41 was determined for clearance ring picks, with corner-cutting picks having the most replacements, while it was 35 for vane picks, on three-day based pick replacements.

Jan 1, 2004

By Dave Price

"Canada is scheduled to become the 4th highest diamond revenue producing country in the world by year 2004 with the already operating Ekati Mine and the anticipated operation of the Jericho Mine in 2002 and the Diavik Mine in 2003.This paper provides an overview of worldwide diamond production statistics and a brief introduction to a diamond processing plant. The dense medium separation (DMS) extraction process is presented and this process is discussed in more detail with respect to the extraction of diamonds in terms of feed preparation, dense medium, dense medium cyclones, ferrosilicon recovery and dense medium cyclone operating efficiencies.INTRODUCTIONThe Ekati Diamond Mine in the Northwest Territories started commercial production of diamonds in the 4* quarter of 1998. At full production, the mine is anticipated to produce annually some 3 million carats of diamonds. The Jericho Mine in Nunavut Territory and the Diavik Mine in the Northwest Territories are anticipated to come into production in the 1'' quarter of 2002 and 1st half of 2003 respectively. The combined annual diamond production of these three mines will total approximately 10.34 million carats by 2004, making Canada the 4~ highest diamond revenue producing country in the world.A diamond processing plant initially utilizes crushing, scrubbing and screening in the beneficiation process to liberate diamonds from kimberlite ore and size the product for further treatment through DMS. Alluvial diamond operations do not require initial crushing and scrubbing but incorporate a feed preparation and sometimes a recrush facility with the DMS plant. The heavy sink product from the DMS, which contains diamonds, is further upgraded through x-ray separation and high intensity magnetic separation prior to producing the final diamond product.DMS is a relatively simple separating principle. A mixture of particles of different density is immersed in a dense fluid, so that particles having a density lower than that of the fluid will float while those of heavier density will sink. The translation of the float-sink principle from a laboratory method to continuous industrial practice offers the prospect of very precise mineral separations based on density differences alone."

Jan 1, 2000