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By L. N. Ertzeva

The present work is dedicated to investigation of the sulfidizing process of ore pyrrhotite concentrate with recovery of a sulfide material, enriched with non-ferrous metals, and waste pyrite, with downstream separation by a certain beneficiation method.

Jan 1, 2006

By D. Lambert

Process modeling for large deformation metal forming processes has been developed into a very successful tool in commercial applications during the last two decades. DEFOR.MTM is a well-known metal forming process simulation program used by many industrial and research institutions. Recent developments include the ability to model multiple deforming body behavior during multi-pass pack rolling and microstructure prediction during multi-pass shape rolling. This paper summarizes how DEFOR.MTM can be applied to a number of rolling processes and briefly describes preliminary work carried out using the ALE technique. Keywords: Simulation, Rolling, Pack, Shape, Microstructure, FEM, ALE, Tantalum

Jan 1, 2003

By Steven R. Izatt

IBC Advanced Technologies, Inc. (IBC) has developed a mercury selective product, which can be used by sulfuric acid producers as either a polisher, or as the primary technology for mercury removal from sulfuric acid. The Molecular Recognition Technology (MRT) separations material selectively binds Hg2+, and to a lesser extent Hg+, out of concentrated sulfuric acid. Mercury output levels of less than 0.1 ppm can be attained by the MRT system. Pilot plant tests have been successfully conducted at base metal smelting operations. A large-scale commercial plant is due for commissioning in 2003. Results from these projects will be discussed.

Jan 1, 2003

By Ross R. Bhappu

A theoretical and experimental investigation into pyrometallurgical refining of chloride leach/electrowin copper is described. The two techniques investigated were (i) vaporization and (ii) gaseous halogenation. Experiments were carried out with a packed bed of electrowon copper crystals and a boat of melted copper crystals. Nitrogen gas and Freon 12/nitrogen mixtures were used as the carrier and reac.tive gases. Vaporization was found to be effective in removing Bi, Pb and S while halogenation was effective. in removing As, Bi, Pb, S and Sb. Silver resisted all attempts at removal. Iron was removed but less effectively than the other impurities.

Jan 1, 1985

By C. M. Antony

The galvanizing process involves the use of accessory equipment in a series of aggressive environments including zinc ammonium chloride flux, molten zinc at 45S°C (850°F), and acid for stripping of adherent zinc. An Fe-Ni-Cr-Co alloy has been identified which combines excellent strength and resistance to molten zinc and acid attack making it suitable for accessory equipment. The alloy was field tested by a commercial galvanizer as basket material and was found to provide improved life compared to original low-alloy steel baskets while cross-section thickness was reduced 44%. Additionally, other associated processing cost savings were realized.

Jan 1, 1992

By Robert E. Moore

Synthetic spinel is proving to be a highly effective refractory for specific applications, but its cost limits applications. Formation of spinel from a raw material such as diaspore or bauxite could provide a simple and less costly starting material. In the study reported here, finely ground (-325 mesh) diaspore from Missouri and bauxite from Guyana and China are combined with hard burned MgO (-325 mesh) in appropriate proportions to yield spinel and spinel with secondary phases. A classical sintering and dilatometer study was completed, followed by a microstructure study to determine completeness of the reactions and morphologies of the reaction products.

Jan 1, 1993

By Robert E. Moore

Synthetic spinel is proving to be a highly effective refractory for specific applications, but its cost limits applications. Formation of spinel from a raw material such as diaspore or bauxite could provide a suitable and less costly starting material. In the study reported here, finely ground (-325 mesh) diaspore from Missouri and bauxite from Guyana and China are combined with hardburned MgO (-325 mesh) in appropriate proportions to yield spinel and spinel with secondary phases. A classical sintering and creep study was completed, accompanied by a microstructure study to determine completeness of the reactions and morphologies of the reaction products.

Jan 1, 1991

By Cem Colakoglu

In this study, nickel containing iron alloys were produced by carbothermal reduction of lateritic nickel ores obtained from Manisa - Caldag region of Turkiye in order to investigate the reaction mechanism of nickel and cobalt. In the experiments, the lateritic ore containing 1.58 wt.% Ni and 0.12 wt.% Co was calcined in a semi-pilot scale rotary furnace at 1100°C for 1 hour. Then, a mixture of calcined ore and metallurgical coke was reacted in sintered alumina crucibles using a graphite resistance tube furnace at different time (0- 60 min) and temperature (1500-1600°C).

Jan 1, 2009

By Robert A. Medower

This paper will review the operational benefits of applying contemporary control technology to balance the blast to a cupola. Reported benefits from existing installations include reduced channelling, higher pour temperature, reduced oxygen consumption, lower coke consumption & reduced emissions.

Jan 1, 2001

By W. G. Davenport

Chapter 13 evaluated the %02 in blast, industrial oxygen and oil requirements for smelting FeSrCuFeS2 concentrates~ This chapter examines high eu grade CU2S-CuFeS2 concentrates the same way.

Jan 1, 2001

By M. Arenas

A corrosion study of a bonded NdFeB permanent magnet materials alloyed with titanium carbide additions has been undertaken. The materials were produced by rapid solidification by melt spinning. Commercial epoxy was used as a bonding medium. The corrosion results were compared with those of a near stoichometric unalloyed NdFeB. Anodic polarization and potentiostatic techniques in 0.9 M Na2SO4 solutions were used to characterize corrosion behavior. It was found that the addition of 6 a10 Tic resulted in superior corrosion resistance, as indicated by lower corrosion currents and less iron dissolution at fixed potential.

Jan 1, 1997

By D. J. Brennan

A techno-economic study is in progress, examining process and product options for treating smelter gases containing various concentrations of sulphur dioxide. Key contenders have been examined within an Australian context using the following criteria: * Markets for products * Capital Costs * Operating Costs * Waste streams generated Product options considered thus far are sulphuric acid, sulphur, calcium sulphite and gypsum. The development of an appropriate overall framework for evaluating process and product options is discussed and findings thus far presented. The emerging techno-economic study offers promise as a constructive guide to future policy decisions by industry and government.

Jan 1, 1994

By M. D. Bishop

Loss of organic solvent extraction circuits occurs through several accepted methods. Losses are commonly attributed to entrainment of the plant organic and evaporative loss of diluent. Evaporative losses of diluent have been estimated using various models or by considering all losses over and above entrainment to be due to evaporation. Other possible loss mechanisms are discussed and data on losses during weather conditions are presented. Accurate estimation of evaporative loss is vitally important to the industry due to both cost factors and environmental concerns. Data for and description of the Diffusive Flux Model are presented as an improved-method of estimating evaporative losses:

Jan 1, 1999

By N. Panagiotopoulos

A low-grade (1.06% Ni, 0.06% Co) hematitic type lateritic ore from Triada, Euboea Island, Greece, has been leached with sulfuric acid at atmospheric pressure for the extraction of the contained Ni and Co values. The effect of various parameters, including reaction time and leaching temperature, acid strength, pulp density, etc., on Ni, Co extraction and Fe dissolution was determined. By leaching at 95°C for 4h with a 3N sulfuric acid solution at 25% pulp density, Ni and Co extractions were 82 and 75% respectively, and Fe co-dissolution 28%, yielding a pregnant solution containing 2.7 g/l Ni, 0.16 g/l Co, and 33 g/l Fe. Overall acid consumption was 850 kg/t ore (or 100 kg/kg Nil. Preheating of the laterites at 600°C before leaching resulted in much faster leaching kinetics for Ni, but the final extraction and acid consumption remained unaffected; Fe extraction was not influenced. Three-stage counter-current leaching at 9S°C, using 2N acid strength at each stage and 35% pulp density, reduced acid consumption to 350 kg/t ore (41 kg/kg Nil, and yielded 81% Ni recovery. Percolation leaching of -10 mm laterite at ambient temperature with 3N acid for 7 days resulted in 58% Ni extraction.

Jan 1, 1988

By Yeliz Demiraya, Onuralp Yucelb

"Production of strontium metal from its oxide was studied under the pressure of 1-5 mbar by methalothermic process. SrO with 99 % purity was used in the experiments. Effects of Al powder addition (100, 200, 300 % of stoichiometric ratio) and time were investigated on recovering of metallic strontium. Effects of BaO addition (100 %, 200 %, 300 %) was also investigated. The final residues were examined for their chemical composition. XRD, AAS and Flame Photometer were used for chemical analysis. More than 96 % of strontium metal recovery can be obtained.IntroductionStrontium is an element which is used in many advanced technology applications. Barium strontium titanat, strontium bismuth titanat, and strontium bismuth tantalat thin films are promising materials in ferroelectric and Schottky-based microelectronics technologies, especially for memory applications. Physical vapor deposition (PVD) techniques as magnetron sputtering, thermal evaporation and molecular beam epitaxy (MBE) are the most widely used methods for growth of these thin films [1-3]. In these techniques high-purity of Sr metal is used as evaporation sources and sputtering targets. Furthermore, metallic strontium is used as a ""getter"" in electron tubes, and as an alloying elements in aluminum alloys [4].The most used Sr compound is SrCO3 and widespread process used in production of SrCO3 is the hydrometallurgical carbonation of celestite. Although there are considerable amount of Selestite reserves, SrCO3 and strontinum metal are not being produced in Turkey, yet [5].Concentrated celestite (SrSO4) is conversed to SrCO3 in carbonate media. Black ash and direct conversion processes are currently used methods. There are many satisfactory studies about hydrometallurgical carbonation of celestite and decomposition of SrCO3 [6, 7]. Since strontium metal is produced from it’s oxide (SrO), SrCO3 needs to be decomposed to SrO."

Jan 1, 2011

By Mukesh K. Agarwala

Alloy composite parts were made from powders by Selective Laser Sintering (SLS). SLS is a rapid prototyping process that uses data from CADICAMICAE systems to guide a laser beam and rapidly form 3-D prototype parts from powders without any part specific tooling. In this study, Bronze-Nickel parts made by SLS were studied for their mechanical properties. To make the parts structurally sound, SLS parts were further processed by conventional isothermal sintering, without loss of shape. The resultant densification and mechanical properties were studied and related to microstructures and P/M densification models. These results were then correlated to the SLS processing parameters.

Jan 1, 1994

By Zhenglong Li

A process has been developed to recover titanium from a blast-furnace slag which contains about 20-25% Ti02 and 12% Fe. In this process. "hot" slag from the blast furnace is directed to a separate furnace where it is reheated with additives to form two simple slag phases: one is titanium enriched anosovite (Ti3O5) and the other is a titanium lean non-crystal glass phase. The modified slag is then processed by conventional beneficiation techniques to produce a marketable titanium concentrate and a usable slag material. This paper focus on separating anosovite from glass by electrostatic separation and froth flotation.

Jan 1, 1996

By Guoqiang Lv, Xi Yang, Wenhui Ma

Cast multicrystalline silicon ingots are widely used in photovoltaic manufacturing. A key issue to achieve high solar cell efficiencies is to attain an optimized temperature field during directional solidification (DS) process. This paper reports numerical investigation of multicrystalline silicon (mc-Si) ingot production using two major types of DS furnace. Specific examination is made on thermal distribution, interface shape and stress field. Evaluation is performed for the applicability of thermal system design to reduce thermal stress, improve crystal quality and enhance energy efficiency. The effects of procedure parameters and geometric configuration on temperature distribution are discussed as well to provide the viable solutions for systems optimization.

Jan 1, 2015

By Konstantina Chalastara

Mixed phase titanium dioxide (TiO2) nanoparticles synthesized through hydrolysis of TiCl4 solution at different conditions, namely concentration, pH, and residence time are characterized and evaluated as photocatalysts. The process is operated in a continuous stirred-tank reactor, CSTR giving blends of anatase, brookite, and rutile nanoparticles that were further evaluated to find the optimum mixture for a photocatalytic sorption material. The titania nanoparticles are first characterized in terms of photocatalytic activity under UV light illumination using an organic model compound (methyl orange) and after that are tested for removal of toxic selenate and selenite species from simulated effluent waters.

By Russell E. Clemons

Coarse-crystalline granite, quartz syenite, syenite, meladiorite, and anorthosite in the Florida Mountains, southeast of Deming, New Mexico, were originally mapped as Precambrian. They were remapped in 1971 and some of them described as Mesozoic intrusives. Several subsequent papers presented Precambrian and Ordovician ages. Zinc, lead, copper, silver, gold, manganese, fluorite, and barite mineralization in the Florida Mountains invite more extensive exploration. Clarification of ages of rocks and periods of alteration and mineralization are necessary for efficient exploration. Field observations combined with petrographic studies strongly suggest that all the coarse plutonic rocks are Precambrian and most were altered extensively by late Tertiary hydrothermal activity.

Jan 1, 1982