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By Richard D. Hangi

Process mineralogy techniques are uniquely applicable to industrial problems related to the extractive metallurgy of nickel, cobalt, and associated metals. Reflected 1ight microscopy, together with selected determinations by scanning electron microscopy-energy dispersive spectrographic analysis and electron probe microanalysis, provides the means to identify the ore minerals cobalt and nickel ores, determine the abundance of each ore mineral, assess the extent of intergrowth between the cobalt and nickel minerals and other ore and gangue minerals in the ores and concentrates, and predict the potential success of cobalt and nickel extraction by grinding, flotation, pyrometallurgical, and hydrometallurgical treatments. In addition, the extent of locking of the cobalt and nickel minerals with each other and with the gangue minerals can be directly observed by reflected light microscopy. Where ores have been treated by hydrometallurgical procedures, reflected light microscopy can serve to determine the causes of excessive leach consumption. Finally, the partitioning of cobalt and nickel between high-temperature synthetic phases produced by pyrometallurgical treatment can be precisely determined by process mineralogy techniques. Case histories from cobalt and nickel deposits illustrate the value of applied mineralogical techniques in the study of cobalt and nickel ores, beneficiation, hydrometallurgial, and pyrometallurgical products.

Jan 1, 1993

By John M. Gaines

Lead concentrates from the Viburnum Trend in Southeast Missouri are sintered, prior to smelting, to bind the particles together, homogenize the feed, and reduce the sulfur content. About 20% of the sinter at some plants is classified as bad sinter. A total of 130 samples of good and bad sinters were studied by reflected light microscopy, scanning electron microscopy-energy dispersive analysis, and electron microprobe analysis to characterize their differences in mineralogy and textures. Good sinters consist predominantly of hardysonite, franklinite, lead silicate matrix, and large crystals of calcium-magnesium-iron silicate, together with minor amounts of lead oxides, lead-zinc silicate, metallic lead, specular hematite, magnetite, lead-iron-bearing zincite, and zinc-lead-magnesium-bearing wustite in a tightly intergrown mesh of crystals and with an evenly distributed porosity of about 15-20%. Bad sinters contain larger amounts of lead silicate matrix, galena, metallic lead, and lead oxides, but smaller amounts of hardysonite, franklinite, and calcium-magnesium-iron silicate, lack intimate intergrowth of the phases, and have lower (0-5%) and unevenly distributed porosity.

Jan 1, 1992

By B. Mishra

Calcium and lithium gallides have been synthesized by powder metallurgy techniques in the stoichiometries that can be used as reduction alloys for the Rocky Flats Plant Salt-Scrub (SS) process. The SS process is performed to recover valuable metals from salts generated in the electrorefining and the molten salt extraction processes. Combustion synthesis has been optimized for variable heating rates up to the reaction ignition temperature and for green densities of the powder compacts in terms of the ignition temperature and the exothermic heating of the product in an effort to develop LiGa and CaGaz alloys. The problems arising from the melting point and density differences of calcium, lithium and gallium have also been studied. The SS alloy compositions were produced by mixing, pressing and sintering the metal-powders. The efficiency of the intermetallic alloy, Ca-17 wt. pct. Ga, as a reductant and the effect of gallium on salt clean- up has been discussed. Measurement of actinide recovery has been studied with cerium as the surrogate for the actinide metal. The development of an alloy for SS reduces a major contaminated waste disposal problem besides recovering the valuable reactive metal.

Jan 1, 1993

By Michael G. Mayer

Since its invention in 1859 various designs of lead batteries have evolved to meet commercial needs for traction applications and standby power. In recent years major developments have taken place in lead alloys and the chemistry and mechanical design of industrial lead batteries. These are reviewed in relation to their commercial application together with the new type of maintenance free gas re-combination lead-acid batteries which are opening so many new markets for lead.

Jan 1, 1990

By Francis Vanbellen

Umicore Precious Metals Refining operates an integrated precious metals smelting and refining plant in Hoboken, Belgium. Once a smelter and refiner of complex concentrates, the plant today?s feed consists exclusively of industrial and consumer recycled products, making it the world?s largest recycling facility for precious metals. Unlike the fairy tale of the Frog Prince, it took much more than a princess? kiss to successfully realize this makeover. A completely renewed plant has been built over the past decade. The most visible technological innovation was the commissioning of the Pb-Cu smelter. Its flexibility towards very different types of feed makes it perfectly suited as main entry to the Hoboken flow sheet. A new Cu-leaching & electro winning plant and precious metals refinery make up the Precious Metals Operations (PMO) whose targets are fast throughput and maximized yields for gold, silver and the platinum group metals. The Base Metals Operations (BMO), flexibly process the by-products from the PMO, valorizing ?impurities? like indium, tellurium, selenium and others. Off gas and waste water treatments ensure compliance with strict environmental standards. Precious metals recycling is an art that goes beyond mastering a unique flow sheet. Umicore Precious Metals Refining offers a complete recycling service, taking care of sampling and assaying, metals management and logistics. The quality of this integral service is recognized through the attribution of ISO certifications for our operational activities, sampling and the environmental care. And it?s an art that follows Michelangelo?s experience: ?Art is 5% of inspiration and 95% of transpiration.?

Jan 1, 2006

By V. M. Lsoitko

Statistical methods of technological mineralogy are used to model processing flowsheets in order to improve ore dressing efficiencies. The procedure involves determining geological and mineralogical characteristics of ores, classifying ore types and metallurgical procedures, and developing computer programs to interpret essential mineralogical parameters from on-stream analysis data. The on-stream analysis data include magnetism, radioactivity, luminescence and assays. The data are interpreted by computer and appropriate adjustments are made automatically in the plant.

Jan 1, 1989

By M. Tangstad, H. Mølnäs, J. D. Steenkamp

"Temperature affects several aspects of pyrometallurgical systems, including thermodynamics and reaction kinetics. Reliability of temperature measurements in laboratory and plant applications is thus important from process, safety and financial perspectives. This case study briefly introduces different techniques utilized for temperature validation, and demonstrates temperature validation on laboratory scale utilizing the wire-bridge method. Pt/Ptl3Rh thermocouple hot junctions were constructed by mechanically connecting thermocouple wires through a pure metal bridge consisting of copper, gold, nickel or palladium wire. When heating the wire-bridge thermocouple alongside a regular Pt/Ptl3Rh thermocouple, temperature offsets were quantified as the wirebridge thermocouple short-circuited at the melting points of the pure metals. At the melting points of gold (1064°C) and palladium (1555°C), average measured temperature offsets were -2.1°C ± 2.3°C and 0.2°C ± 0.4°C, respectively. Results from the copper and nickel wire-bridges were inconclusive. The paper concludes with a discussion on the potential industrial applications of the technique.IntroductionThermocouples are probably the simplest of all temperature sensors, but are widely utilized due to simplicity, versatility and ability to handle a variety of experimental conditions and industrial applications. Additionally, thermocouples are often the only option in research laboratories requiring high temperature measurements, and a high level of reliability is usually required from thermodynamic, kinetic as well as safety points of view.The study presented here originated from a test program where the compatibility between different types of carbon-based refractory materials and industrial slag produced in silicomanganese furnaces were investigated on a laboratory scale utilizing the static crucible test[l]. Due to the nature of the silicomanganese production process, the compatibility tests were to be conducted at 1600CC[2]. Details of the experimental set-up utilized for the compatibility tests are discussed in the Experimental Set-up and Method Statement section later in this paper."

Jan 1, 2012

By Denise Corrêa de Oliveira

Common dry batteries use zinc as the negative electrode. Producers commonly use additives such as mercury to prevent corrosion and to increase the mechanical resistance of the zinc anode. Alkaline batteries also contain it, as an anti-corrosive agent. When mixed with the common municipal solid waste, heavy metals as zinc and mercury pollute soil and ground water supplies, moving to the food-chain and affecting human health. Due to these possible damages, this kind of waste must be properly disposed, or recycled. Thus, even in low amounts (ppm) in batteries, mercury has to be eliminated or, at least, its content should be reduced. This work presents the use of pyromettalurgical processes, to reduce mercury content and recover zinc. The tests involved batteries treatment at temperatures from 300° to 1000°C. Mercury is eliminated up to 650°C, and zinc is evaporated at higher temperature treatment. C

Jan 1, 2001

By R. M. G. S. Berezowsky

Treatment of Hudson Bay Mining and Smelting Co. Ltd. (HBM&S) zinc concentrate in the Sherritt zinc pressure leach process produces a residue containing elemental sulphur, residual sulphides, precipitated iron species, si1ver and gold. Flotation of the residue recovers most of the elemental sulphur and residual sulphides to the concentrate, leaving iron oxides and bask sulphates in the tailings. The tailings also contain most of the sflver and some gold. Direct cyantde leaching of the oxide tailings (220 g/t Ag, 1.4 g/t Au) was capable of leaching most of the gold, but only a minor portion of the silver. This paper reports testwork, conducted by Sherritt on behalf of HBM&S, to define a process for a high recovery of the precious metals from the oxide tailings. A si1ver enhancement treatment, consisting basically of digestion of the residue with lime at 90°C to render the silver amenable to enhanced recovery by subsequent cyanidation, was selected as the most promising approach. Batch silver enhancement and cyanidation tests showed that treatment of the oxide residue with 80 kg/t CaO at 90°C for 1 to 2 h increased the silver extractability in subsequent cyanidation from <20% to 96%. A 96 h continuous miniplant test (1 kg/h solids feed rate), of a circuit including a silver enhancement treatment step followed by conventional cyanidation and carbon in pulp silver and gold recovery, confirmed metal recoveries to the carbon of 90% Au and 96% Ag. Reagent consumption rates were 1ess than 100 ?kg/t CaO and 5 kg/t NaCN.

Jan 1, 1990

By J. R. Rendón

Cylinders of commercial aluminium alloy 6063 were homogenized under different conditions. The experimental results indicated that the general mechanical behaviour as related to curves of 0.2% yield strength, ultimate tensile strength and Brunnell hardness versus homogeneizing process is the same in both cases. The mechanical properties as compared to those required by plant specifications, tend to be better with increasing values of % Mg2Si in the alloy, as expected. The electron microscopy investigations revealed that in both homogeneizing processes the resulting microstructure consist of significant spheroidizing of the alpha phase (AlFeSi) and fine-needle type structure of beta phase. The alpha phase was also present in a Chinese type scripture. Furthermore, the slow cooling within the furnace resulted in the nucleation and growth of Mg2Si precipitates generally along the grain boundaries.

Jan 1, 1997

By René Winand

Due to chemical and electrochemical behavior of the most common additives in copper electrorefining i.e. gelatine, thiourea and chloride ions, it is essential to simulate as far as possible true industrial practice while performing laboratory experiments. The three additives must be studied simultaneously, and added continuously to the electrorefining cell. Ratio electrolyte volume to cathode area; ratio bleed flow to cathode area; hydrodynamic conditions; residence time of electrolyte in the cell; current density; electrolyte and soluble anode must be as near as possible to industrial ones. Experiments performed in the author&apos;s laboratory show that under these conditions, reproducible results can be obtained at normal industrial current density and at high current density as well. Problems are however still encountered when developing a sensor for additives monitoring, due to electrolyte redox potential and to substrate influenced thin layer deposition.

Jan 1, 1995

By Michaela Dina Stanescu, Emilia Visileanu, Eftalea Carpus

"The recovery and reintroduction into the economic circuit of the textile material resources must be considered as component parts of the strategies of harmonizing the relationships between the economic growth, consumption of natural resources and environmental protection of the existing socio-economic system.The waste recovery for ensuring a sustainable development is a major concern of all industrial researches. In the textile domain, the concern in this matter is becoming more evident. An important role in manufacturing textile products it has the notion of eco-design, which has grown considerably over the last twenty years with increasing awareness of environmental and social problems in the industry.Introduction“Humanity must learn from the global financial and economic crisis experience""- is the conclusion of the policy makers who should develop a strategy designed to reinvigorate the economy and make possible an"" intelligent, sustainable and favourable to inclusion” growth, by a better coordination of national and European policies.The new vision for social market economy is based on three priority areas: smart economic growth, the development of an economy based on knowledge and innovation; sustainable economic growth, the promotion of a competitive economy with low carbon emissions and an efficient use of resources, as well as an inclusive economic growth, the promotion of an economy with high degree labour employment, which would generate social cohesion. The recovery and reintroduction into the economic circuit of the textile material resources must be considered as component parts of the strategies of harmonizing the relationships between the economic growth, consumption of natural resources and environmental protection of the existing socio-economic system.The waste recovery for ensuring a sustainable development is a major concern of all industrial researches. In the textile domain, the concern in this matter is becoming more evident. It is obvious that at the origin of pollution there are the technological processes of textile processing with impact on air, water, soil, as well as the storage processes. In all phases of obtaining a product, a series of secondary products and textile wastes with impact on the environment occur. The product used becomes also a factor of environmental pollution, which in most cases fails to assimilate."

Jan 1, 2012

By Hitoshi Iijima, Fumitaka Tsukihashi

"Fine powder of tantalum is used as materials of electric condenser. It is important to control the distribution of particle diameter of tantalum fine powders for the commercial use. In this study, fine powders of tantalum were produced by reducing tantalum chloride vapor with hydrogen gas at 1673 and 1773K. The tantalum chloride vapor was reduced with hydrogen and the produced fine particles of tantalum were collected to observe the distribution of particle diameter. The effects of reaction temperature, partial pressure of hydrogen gas and vaporization temperature of tantalum chloride on the distribution of particle diameter and reaction efficiency of reduction were determined. The mechanism of reduction reaction of tantalum was discussed.IntroductionThe ultra fine powder shows various different physical properties from that of bulk materials. Therefore, the application of ultra fine powder to various fields such as magnetic material, electric material, catalyst, etc is anticipated. The control of shape of powder, size distribution, property of agglomeration, purity is required for the practical use of ultra fine powder. Although the ultra fine powders of ceramics are produced by various methods, the ultra fine powder of metals are produced by the evaporation in gas atmosphere, plasma evaporation process, chemical vapor deposition process, and reduction and precipitation in liquid phase depending on the metal and productivity. The chemical vapor deposition process has features that pure metal powder can be obtained and the control of the distribution of powder size is easy. [1,2,3,4,5]"

Jan 1, 2000

By Filiz Sahin

This paper presents a synthesis of TiB2 via carbothermal reduction method using a mixture of TiO2, B4C and C prepared in molar ratio of 2:1:3. Reduction experiments were carried out in a high temperature graphite furnace in a graphite crucible under argon atmosphere at different time (0, 15, 30 and 60 min.) and temperatures (1400, 1500 and 1600 °C). The products obtained were investigated using XRD technique.

Jan 1, 2008

By K. J. Cathro

A hydrometallurgical process is described for the recovery of copper from chalcopyrite concentrates. The process is based on a cupric chloride leach, the concentrate having first been "activated" by heating it with sulphur at a temperature near 400°C. This activation process converts most of the iron of the chalcopyrite to pyrite, which is insoluble in the cupric chloride leachant. The copper is converted to the mineral idaite, which dissolves readily in hot cupric chloride: at 106°C, 98% of the copper is extracted in a three-stage countercurrent leach, the leaching tirqe being 1 hour per stage. The sulphur of the chalcopyrite appears as elemental sulphur, which is recycled for the activation of further concentrate, the final leach residue consisting of pyrite, plus the gangue present in the original concentrate. The copper extracted can be recovered by electrowinning, using a diaphragm cell. Current efficiency (one-electron basis) is about 70% but the cell voltage is only about 1 V, so that power consumption is three times lower than for the conventional sulphate electrowinning process. The leachant is simultaneously regenerated in the anode compartment. The behaviour of minor elements in the concentrate has also been studied.

Jan 1, 1976

By M. L. Sorokin

The thermodynamic of nickel production from laterite ore and from sulfide concentrate can be analyzed using PO2 - PS2 diagram of the Ni-Fe-S-0-SiO2 system. The procedure of the diagram computation is suggested and the diagrams for various temperature and Fe/Ni ratio are calculated. Three-suffix Margules equations are used for the calculation of the thermodynamic properties of three solutions: liquid matte, liquid slag and solid Fe-Ni alloy. The diagrams are used for the considerations about direct one-stage metallic nickel production.

Jan 1, 1994

By J. H. Meza V

La Caridad operated at only 65% of design capacity during the first five years of operation. After the first major shutdown and repairs to the furnace in mid- 1992, the smelter quickly reached 95% of design capacity. Converter operation is now more efficient; blowing times have decreased from about 1.7 to 1.2 min/ton of matte. Anode copper production is now 15000 tons/month. The increased efficiency provided by better coordination and scheduling ensures La Caridad&apos;s ability to operate at present and expanded production capacity while simultaneously meeting environmental control standards.

Jan 1, 1993

By V. P. Bystrov

Vanyukov process has been developed and investigated in Russia over the last 25 years. It has been established that various kind of material could be treated in Vanyukov process. The results of the pilot plant trials as well as industrial experience are presented in this paper.

Jan 1, 1993

By Ajay K. Singh

The surface quality demands for galvanized and galvannealed steel sheets by the automotive and appliance industries have been getting increasingly stringent over the past few years. Intensive efforts by Hot-Dip-Galvanizers to meet these demands have resulted in substantial improvement to the hot dip coating process. However, elimination of zinc bath contaminants which directly affect the coated strip surface quality continues to remain a tough challenge. As part of our effort to improve the zinc bath cleanliness, Inland Steel Company has developed a test method to quantitatively measure the contaminants in incoming zinc spelters and establish a specification for incoming zinc quality. The test is currently being used for auditing the incoming zinc quality. The zinc suppliers are also using this test for quality control purposes. The purpose of this paper is to describe the test method and how it has improved the galvanizing operation at Inland.

Jan 1, 1992

By Shaohua Ju

Siderite ore is abundant around the world, due to its inert properties of low grade, mudding when milling and low magnetic, and it is very hard to be beneficiated. Nowadays, decomposition by roasting becomes the main process for utilization of the siderite ore. The methods of energy input for roasting are normally electrical heating, coal or gas combustion. Because traditional roasting methods owns some disadvantiges, such as low energy utilization, high cost and/or large exhaust pollution, only about 10% of the siderite ores in China were used as iron concentrate. In this work, the possibility of roasting siderite ore with microwave energy is studied by both laboratory and pilot experiments. The result of laboratory experiments showed that the optimized condition is roasting for 20 min with a power density of 3 W/g, and the Fe content of the final sample obtained is about 59.12%. The pilot experiments result showed that the decomposition is thoroughly, and the main phases of the roasted material are magnetite and wustite, and the energy consumption of the roasting process is 695.8 KWh/t.

Jan 1, 2014