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By Jim Sarvinis, Mark Berkley, David Clarry, Jason Berzansky

"Technologies developed to sequester CO2 or use CO2 for enhanced fossil fuel recovery are currently being utilized across the globe. Taxation regimes and CO2 credit trading are becoming drivers for a number of projects. Some mining companies have also identified ancillary opportunity to sequester CO2 in their by-products; recent work in the alumina industry is a prime example. In addition to process plant emissions, mining companies are becoming increasingly aware of their overall carbon footprint, including CO2 generated during the production of utility power. New power plant designs, in various stages of development, include CO2 separation and sequestration techniques. This paper summarizes the state-of-the-art for these technologies; including integrated gasification combined cycle (IGCC) power plants. A concept to use the gasification products as reductant in metallurgical processes is also described. The relevance of technology from power plant designs with post-combustion capture to the processing of off-gas generated in metallurgical facilities is also reviewed.IntroductionGlobalization and international economic growth have led to an increase in energy demand worldwide, and a corresponding increase in greenhouse gas (GHG) emissions. In 2005, 81% of global energy supply came from fossil fuels [1]; and while alternative energy technologies are emerging, it will require many decades to curb society’s fossil fuel dependence. Given the global concern of climate change and its scientific relationship with anthropogenic carbon dioxide (CO2), there is at present great interest in the development of techniques to reduce emissions of CO2. While most of these efforts are related to power generation and energy efficiency, the development of technologies for CO2 capture may offer opportunities in reducing emissions from industrial processes."

Jan 1, 2008

By J. P. Downey, T. Salisbury, M. Berlin, E. Rosenberg, G. Pinson, R. Christianson, K. Gleason, W. Gleason, S. Davis

"The Center for Advanced Mineral and Metallurgical Processing is developing membrane production technology based on autocatalytic reduction of palladium from solution onto a unique, porous substrate. Surface membranes and catalytic structures are critically important to applications that range from hydrogen purification membranes to petroleum refining. Autocatalytic reduction processes represent a cost effective method of producing stable surface layered structures that have good working lives. These attributes are particularly important in the production of palladium alloy purification membranes used in hydrogen production. Although considerable research has investigated the interaction of hydrogen and palladium alloys, the mechanisms in play while the membranes form are not well understood. Preliminary research has identified three distinct deposition mechanisms and it appears that substantial control over the resulting membrane is possible.IntroductionPalladium-based membranes separate hydrogen from other gases because hydrogen is uniquely soluble in and readily passes through bulk palladium. As currently produced, palladium-based membranes are expensive and have short service lives. These circumstances are due in part to the lack of a complete understanding of palladium or palladium alloy deposition. The Center for Advanced Mineral and Metallurgical Processes (CAMP), in collaboration with the Metallurgical and Materials Engineering Department at Montana Tech and the Chemistry Department at the University of Montana, is engaged in the development of new methods and materials for hydrogen purification membrane production.In membrane production, the palladium requirement depends on substrate surface properties such as surface chemistry, porosity, and roughness. Thin, defect-free membranes have been successfully produced on substrates of porous glass, alumina, and stainless steel. However, the differences in the thermal expansion coefficients of palladium membranes and porous glass or alumina substrates cause problems at operating temperatures. The use of stainless steel substrates is advantageous because stainless steels have thermal expansion coefficients similar to that of palladium and they are stable at the required operating temperatures (Wicke, E., Brodowsky, H. and Ziichner, H. ). Stainless steel is also readily available and relatively inexpensive."

Jan 1, 2012

By N. A. Warner

To filly secure the environmental and social acceptability benefits of making a sulphide smelting facility and its ancillary sulphuric acid plant or other means for fixing sulphur, a virtually zero gas emission operation, it will be necessary to utilise exclusively technically pure oxygen. The strategy proposed for preventing the smelter from overheating involves highly efficient energy transfer by promoting sulphur trioxide formation at a relatively higher temperature than normal. A closed-loop gas circuit uses an eductor system actuated by the process oxygen to recirculate sulphur trioxide and unconverted sulphur dioxide back to the smelter, the endothermic dissociation of sulphur trioxide becoming a major contributor to the removal of excess heat. The only gases leaving the system relate to the bleed of nitrogen impurity introduced in the tonnage oxygen.

Jan 1, 1998

By Ragnhild E. Aune, Shahid Akhtar, Reza Beheshti

"The potential use of Black Dross (BD) as a raw material for the production of refractories, fluxing agents and glasses is the main motivation of the present study. Heat treatment experiments were carried out in Ar, and under reduced pressure (20 Pa), to evaluate the salt removal efficiency. The chemical composition of the BD after heat treatment was investigated by SEM-EDS and XRD analyses. Based on the present results, it is established that the salt starts to evaporate at ˜1273 K in Ar, and under reduced pressure. The salt removal efficiency in a 20 g sample was found to increase in both cases as a function of time and temperature. Moreover, in Ar the chlorine concentration was lowered to 0.3 wt% after heat treatment at 1523 K for 10 hours. Under reduced pressure, however, 0.2 wt% residual chlorine was obtained after 8 hours at 1473 K.IntroductionIt is believed that aluminum recycling in the near future will become the main route of aluminum production [1]. Black dross (BD) that is produced during this process contains, among other things, high amount of salts like NaCl and KCl [2, 3]. Almost 800,000 tons of BD is annually land filled in United States and this number continues to grow with the increase in aluminum recycling [2]. The BD should be dumped in controlled land field and it is costly procedure [4, 5].The water-soluble compounds in BD react with water or environmental humidity and release chlorides into the water and/or generate toxic gases such as H2, CH4, NH3 and H2 S [6-8]. In the Europe, BD is considered as toxic waste and its disposal as landfill is forbidden [8, 9]. After salt removal, the BD is considered to be non-hazardous and can be buried under ground [10].On the other hand, BD do also contains many relatively valuable compounds that may be changed in to useful materials as a result of further treatment [11, 12]"

Jan 1, 2012

By Cesar O. Gomez

A procedure has been developed for mounting at random particles of mineral samples to be characterized using image analysis. The procedure is based on the generation of a random distribution of sample particles in particles of a diluent material. and the embedding of this particle mixture in an epoxy resin without disturbing the initial distribution. Two materials with atomic number similar to that of the epoxy resin were successfully used as diluents: activated charcoal and graphite. The proportion of diluent material to be mixed with the sample to have a large number of mineral particles in the field of view while keeping the occurrence of touching particles at an acceptable level was determined empirically. The randomization achieved with the procedure developed in this work was tested using as samples known mixtures of silica and pyrite particles of the same sieve class. The agreement obtained between the mass ratio of minerals used in the preparation of a particular specimen and that resulting from image analysis demonstrates that the procedure developed is successful in producing a specimen where the embedded particles are randomly distributed.

Jan 1, 1988

By M. P. Bohrer

A closed-loop hydrometallurgical process has been developed for treatment of smelter flue dust generated by copper recycling. The process is a semi-continuous operation in which zinc, iron, and copper are first extracted from the dust with a sulfuric acid solution. The lead and precious metals, initially present in the dust, remain as solids and can be recycled to the copper smelting furnace. Cementation with iron and zinc metal purifies the zinc and iron-rich liquid stream prior to spray drying. The spray-dried product, consisting of a mixture of zinc sulfate monohydrate and iron sulfate monohydrate, is a desirable micronutrient additive for use in animal feeds. Treatment of the smelter flue dust in this manner will generate a positive return on investment, as well as mitigate a potential environmental liability.

Jan 1, 1992

By Sylwia Zymankowska-Kumon, Rafal Danko, Józef Danko, Mariusz Holtzer

"Burning of ceramic materials is carried out at temperatures 900+ 1300°C, in dependence of the required functional properties. The Faculty of Foundry Engineering together with the Faculty of Material Engineering and Ceramics developed the technology of production of burned ceramic materials with using spent moulding and core sands. The mentioned above waste materials of the foundry industry fulfilled -in plastic masses intended for obtaining ceramic materials -the role of the addition weakening clay raw materials. The laboratory investigations were fully verified by the results of industrial tests. It should be pointed out that none negative effects were observed at the stage of mixing raw materials and preparation of plastic masses. The measurements of exhaust gases emissions performed during burning the products containing spent moulding sands as well as during the normal production did not exhibit any significant differences, which could have indicated the harmful impact on the natural environment.IntroductionSands are used by the foundry industry to make metal casting molds and are a mixture of silica sand, bentonite clay and carbonaceous additives or resins. During the casting process, the molten metal cause thermal decomposition of carbonaceous additives or resins, which results in the formation of potentially hazardous organics, that are emitted to the atmosphere and condense in the molding sand. Each year the U.S. foundry industry landfills about 10 million tones of sand because it is no longer suitable to make metal casting molds. A large high-silica sand content in spent foundry sands (SFSs) generates rational premises for their reuse in other than foundry practice fields. Efforts to divert the SFSs from landfills and encourage their beneficial use in manufactured soils, geotechnical applications, the construction industry (road construction, highway construction), the building materials industry (cement, bricks, limestone manufacture), in the filling of mining cavities or in landfill construction (roads on landfills, permanent covers) are make [1-7]."

Jan 1, 2013

By Thomas Niehoff, Dave Stoffel

"Energy in the form of natural gas, oil and electricity is expensive and will continue to be a rare resource in the future. Recycling of metals, instead of primary production, is a logical and crucial step towards energy conservation. Energy consumption can be impacted by using advanced combustion systems for metals recycling. Air-fuel combustion has been the conventional method to melt and recycle metals. Global competitive pressures, “greenhouse” gas emissions, and high energy prices force melt shop operations to optimize energy usage and reduce overall operating costs. Oxy-fuel combustion and process technology can be applied to metal recycling operations to meet these objectives. Linde has converted several hundred furnaces from air-fuel to oxy-fuel technology and has extensive experience in optimizing the use of oxygen in furnaces. Additionally, Linde has the process knowledge necessary to avoid costly start-up issues that can accompany the transition to oxy-fuel technology. This paper will describe the benefits and potential issues for conversion to oxy-fuel.IntroductionThe furnace combustion system is the heart of a fossil fuel fired melting process and must be properly matched to the furnace to work as one cohesive unit. Furnaces vary widely in size, shape and features. Rotary furnaces are barrel-shaped and can be designed for tilting or nontilting operation. In a rotary furnace, the products of combustion create a single or double pass through the furnace prior to exiting. Reverberatory furnaces are box-shaped and can also be designed for tilting or non-tilting operation. Reverberatory furnaces are constructed of single or multiple chambers, with or without metal bath movement, and designed for continuous or batch processing. Different furnaces are used for different feedstock materials and products.Furnace combustion systems also vary in many ways. Combustion systems can be of air-fuel or oxy-fuel based technologies, or a combination of the two, resulting in an air-oxy-fuel system. Each of these types of systems has different combustion characteristics which can produce very different results. Here we will describe specific differences in melting processes and their associated energy requirements."

Jan 1, 2009

By Gervais Soucy, François Quesnel, Pierre Hovington, Wen Zhu, Karim Zaghib, Jocelyn Veilleux

The properties of lithium titanates anodes in Li-ion batteries are highly dependent on their secondary constituents. While their main phase is usually constituted of Li4Ti5O12, significant quantity of lithium titanates compounds of various stoichiometry are often present, due to either the processing, usage or aging of the material. These may go underreported, as many of these spectrums overlap or display low signal in X-ray diffraction (XRD). Samples of nanosized lithium titanates synthetized by inductive plasma were characterized by XRD and scanning electron microscopy (SEM), as they provide a regular yet typical crystallite size and shape including multiple phases. A Rietveld refinement was developed to extract the composition of these samples. Mass balance through further annealing and differential scanning calorimetry (DSC) enthalpy measurements from phase transformations were also used as identification and validation techniques.

Jan 1, 2015

By Wang Haibei

China is the important country in terms of Ga, Ge reserves and products. These elements usually associate with lead and zinc ores such as in Fankou, Dachang and Lanping mines. Until now these metals could not be extracted from zinc residues effectively. The main reason is that it is difficult to separate zinc and iron. BGRIMM has carried out considerable research on this subject and some hydrometallurgical processes were developed. Zinc residues were pressure leached with a reducing agent such as zinc concentrates or SO2 at 110~130C. The final concentrate of H2SO4 was 30~50g/L. The metals such as Zn, Fe, Ga and Ge were dissolved into solution. In the leaching residue Pb and Ag could reach 20% and 2000g/t. The feed of solvent extraction was prepared from the leaching solution by pre-neutralization ? precipitation of Ga, Ge and acid dissolving. Then Ga and Ge were extracted by solvent extraction through P204 and G315 produced by BGRIMM. After stripping, metallic Ga was produced by electrowinning. GeO2 was produced by precipitation. The iron in raffinate was removed by the hematite process. The solution after removal of iron came back at the zinc neutral leaching stage. In 2003-2004, pilot tests were finished in BGRIMM in cooperation with Fankou Lead and Zinc Mine Ltd. And the extraction rate of Ga and Ge in the leaching stage was 94% and 83% respectively. The total recovery rate was 90% and 80%. It is estimated that the technology has a wide commercial use in the coming five years.

Jan 1, 2006

By Sridhar Komarneni

"Microwave-hydrothermal processing is a novel technique which combines the conventional hydrothermal processing with microwave field and we previously showed for the first time, that ceramic powders can be rapidly produced by this technique. This review paper deals with the synthesis of unary oxides such as Fe203, Ti02, Zr02, etc., binary oxides such as BaTiO3, SrTiO 3, PbTiO 3, SrZrO 3, KNbO3, etc., and ternary oxides such as NaTi2 (PO4)3 and pyrochlore phases of Pb(Mg1/3Nb2/3)O3, Pb(Zn1/3Nb2/3)O3 etc. and metal powders such as Cu, Ni, etc. below 195°C. This method can be adopted to the synthesis of a large variety of powders by the appropriate control of pH, Eh, temperature/pressure and concentration of chemical species. The main advantages of this method compared to conventional hydrothermal processing are (a) it increases the kinetics of reaction by one to two orders of magnitude, and (b) it can lead to novel phases especially those with layered structures.IntroductionConventional hydrothermal processing is a well-established synthesis technique which has been extensively used in the preparation of fine ceramic powders [1-5], large single crystals [6-8] and massive cement blocks [9]. Technologically important ceramic powders such as BaTiO 3, Al203 etc. made by the hydrothermal process are now commercially available. Although there are numerous methods for materials synthesis, hydrothermal method is truly a low temperature and environmentally benign process. For example, ZrSi04 (Zircon) which is extensively used in ceramic industry can be prepared hydrothermally at 150·C [10] compared to sol-gel or solid-state method [11,12] which require a temperature of about 1000·C. The hydrothermal method is environmentally benign because hydrothermal reactions are carried out in closed systems at low temperatures and the contents can be recovered and recycled after cooling to the ambient conditions. One of the disadvantages with any low temperature processing method is slow kinetics. For this reason we have combined the hydrothermal method with microwaves to enhance kinetics and we named this method as ""Microwave-hydrothermal"" processing [13- 16]. Although the combination of microwave and hydrothermal techniques has been used in the past few years to dissolve all kinds of inorganic (e.g. alumino silicate rocks) and organic materials rapidly for chemical analysis, we were the first to show its potential value for the synthesis of various ceramic powders [13-16]. In this paper, I show that this novel method is applicable to the synthesis of all unary, binary and multinary oxides by the appropriate control of pH, Eh, temperature, pressure and concentration of chemical species. In addition, this method is also found to be useful for the preparation of metal powders."

Jan 1, 1994

By Corby G. Anderson

For over a century, the Sunshine Mine in Idaho has been a major producer of silver. An estimated 335,000,000 troy ounces of silver has been mined. This has established the Sunshine Mine as the largest single source of silver in the world. Because the dominant silver containing mineral is tetrahedrite, a copper and antimony sulfide, normal metallurgical treatments to recover the precious metal are not practical. Thus, over the course of the company's history, novel, hydrometallurgical technologies have been developed on-site to handle complex, precious metal containing materials. Recently, the use of Sunshine technology has been extended to the recycle of secondary materials. As well, the use of Sunshine technology by other organizations for treatment of both primary and secondary feedstocks containing precious and base metals is an area of growing interest. This paper will provide an overview of Sunshine hydrometallurgical technologies including the applicability of Sunshine technology to the recycling of precious and base metals.

Jan 1, 1995

By J. N. Kondo, M. Hara, T. Smida, N. Ooto, K. Domen

"A porous material composed of two-dimensional anionic sheets of a layered perovskite, KSrNb30 10, was studied as photocatalyst for the production of Hz in the presence of alcohol sacrificial donors. Colloidal single and multi-layered HSr2Nb30 10 sheets were formed by intercalating ietra(n-buthylammonium) cations into the interlayeres of H+-exchanged KSr2Nb30 10 (HSr2Nb30 10), and addition of HN03 solution to the colloidal suspension precipitated the porous materials in which HSrNb30 10 sh~ets rand~mly stuck together. Original HSr2Nb30 10 before exfoliation had a BET surface area of 1 m2 g-1, whereas the surface area of a porous material prepared under optimal conditions exceeded 100 m2 g-1. The porous HSr2Nb30 10 had considerably higher photocatalytic'activitie8 for oxidation of 1-propanol and 1-buthanol than HSr2Nb39io, indicating that in the porous materials many niobate sheets are available for decomposition of these large alcohols.IntroductionQuite a research effort has gone into the design and study of porous materials. Such materials with large surface areas would have applications in highly efficient adsorbents or catalytic reactions.We have been studying photocatalytic reaction by cation-exchangeable layered metal oxides, where alkali metal cations are intercalated into the interlayers of inorganic sheets.[1,2] There are several advantages to using layered compounds rather than bulk powders for photocatalysis. Layered compound is rich in variety, in addition, modifications of them are easily performed by exchanging alkali metal cations in the inter layers for H + or other metal cations. The most important advantage is that some layered compounds have considerably high photocatalytic activities than bulk catalysts because the electrons and holes generated in each thin inorganic sheet readily reach interlayer spaces as reaction sites at the illterlayer spaces. It should be very important for further improvements· of layered photocatalysts to utilize two-dimensional inorganic sheets effectively."

Jan 1, 2000

By Moto Goto

Today, Pierce-Smith converters, coupled together with various types of smelting units, are used in most of the world's smelters. However, due to the "batch" processing nature, and problems associated with fugitive emissions during the transfer of melt and blowing stages, this arrangement will unlikely be adopted in future smelters. Modern day alternative processes include the Mitsubishi Process, Outokumpu Flash Smelting and Flash Converting Process, the Noranda Process, and the Ausmelt Process, but only the Mitsubishi Process is a "truly continuous" smelting and converting operation, producing a constant flow of blister without tapping, and is economically proven by long term commercial operations. This paper reviews recent advances in modern continuous converting technologies, with a special section devoted to operation of the "first standalone Mitsubishi C-furnace" coupled together with a Noranda Reactor, at Port Kembla Copper Pty. Ltd. in Australia.

Jan 1, 2003

By P. Cowx

The carbothermic reduction of zinc oxide rich Electric Arc Furnace baghouse dust in the Tetronics transferred arc plasma furnace to produce a non-toxic slag and a metallic zinc product is described. In particular, the operation of the zinc splash condenser coupled to the plasma furnace is examined and the effect of process variables on zinc recovery is discussed.

Jan 1, 1990

By Moto Goto

Today, Pierce-Smith converters, coupled together with various types of smelting units, are used in most of the world's smelters, However, due to the "batch" processing nature, and problems associated with fugitive emissions during the transfer of melt and blowing stages, this arrangement will unlikely be adopted in future smelters. Modern day alternative processes include the Mitsubishi Process, Outokumpu Flash Smelting and Flash Converting Process, the Noranda Process, and the Ausmelt Process, but only the Mitsubishi Process is a "truly continuous" smelting and converting operation, producing a constant flow of blister without tapping, and is economically proven by long term commercial operations. This paper reviews recent advances in modern continuous converting technologies, with a special section devoted to operation of the "first standalone Mitsubishi C-furnace" coupled together with a Noranda Reactor, at Port Kembla Copper Pty, Ltd. in Australia.

Jan 1, 2003

By Dai Yongnian

"The feasibility to vacuum distillation of a crude metal or an alloy was discussed. The equilibrium relationship between vapor phase and liquid phase in A-B system - - - - - PA/PB =BAa*/b has been derived. The separation coefficient, BA = rAPA/(rBPB) is a judgment criterion. By calculation PA/PB, the equilibrium composition diagram of vapor phase and liquid phase was drawn. By use of the equation derived by M. Olette, the relationship among the volatilization amounts of various impurities in a crude metal (yi) was further solved. 1-(X/100)= C =(1-Y1/100)1/02i . From yi value obtained in practice, 2i, Pi and then can be calcu-lated. The correct volatilization order of various impurities was obtained. These results can be applied to determine the practical conditions (temperture, vacuum degree, type of distilla¬tion furnace, times of distillation and control of product composition) in distillation of a crude metal or an alloy.INTRODUCTIONRefining and separation of various impurities from nonferrous crude metals by vacuum distillation have many the advantages of high metal recovery, impurities recovered in metallic state, flowsheet simplified, good enviromental protection, low operation costs and in complex equipment. So in recent years this method has been adopted widely.Vacuum distillation has also been studied and used in separation of various elements from non-ferrous alloys and the area of its application is being extended rapidly.At this situation, some problems have been put up: What kind of impurities can be removed from crude metals? What kind of alloys can be separated by vacuum distillation? In present paper, attemps have been made to answer these problems and combine with practical results to analyse some valuable data obtained from testwork on vacuum distillation of crude tin and Pb-Sn alloy."

Jan 1, 1988

By Natasa Mitevska

In the world, as well as in Republic of Serbia, conventional ore reserves are almost exhausted, so the problem of their shortage is more and more expressed. On the other side, there are many locations with significant reserves of polymetallic ores which present huge potential but cannot be classically processed. Each of these classes of materials has particular mineralogical characteristics which affect their processing. Because of that it is necessary to develop particular technology for each unconventional ore in order to extract valuable elements. The aim of investigation was to define technology for complex processing of the Blagojev Kamen sulfide concentrate by pyrometallurgical procedure in order to valorize valuable non-ferrous and precious metals present, and profit with absolute respect of environmental protection laws. The complex composition of the Blagojev Kamen sulfide concentrate with high content of non-ferrous (15.59% Pb, 9.05% Zn, 2.37% Cu) and precious (697 g/t Au and 744 g/t Ag) metals was the main factor for technological procedure and collector selection. Laboratory investigations are done in four series according to technological scheme: oxidizing roasting, charge preparation (flux addition and agglomeration), smelting under reducing conditions, lead bullion refining, Dore metal refining to final products. It is concluded that precious metals are concentrated in lead bullion (up to 97.95% of gold and 93.37% of silver), which has similar composition to lead bullion produced in lead metallurgy. In this case, simplified technology is used for lead bullion processing because of low content of arsenic, bismuth, etc.

Jan 1, 2006

By T. A. Larssen

The efficiency in production of manganese ferroalloys is dependent on the gaseous reduction of the higher manganese oxides in the ores used as raw materials. The materials, descending in the furnace, will meet the furnace gas that contains significant amounts of CO(g) and reduce in subsequent steps, the last step being reduction of Mn3O4 to MnO. This step may to varying extent occur at temperatures exceeding 800 °C, i.e. in the active region of the Boudouard reaction. The gas reduction of Assmang and Comilog manganese ores were investigated in CO-CO2-atmosphere at temperatures up to 1000 °C. It was seen that decreasing ore size correlates to a lower reduction temperature and increasing reduction rate. Similar effect was observed with increasing CO-content in the gas atmosphere. Further, it was found that Comilog ore obtained a complete prereduction at 600 °C, whereas reduction of Assmang ore was not complete at 800 °C for the majority of the experiments.

By Mariana H. Staia

Thermodynamic calculations based on the free energy minimization method were performed for the system Ti-Fe-Mn-0-C1-C in order to evaluate the chemistry associated with the chlorination of an ilmenitic concentrate using CCl4. In the calculations various weight ratios of FeTi03/ CC14, a , were considered, which varied between 0.32 to 0.98 at temperatures ranging from 673 K to 1273 K , at atmospheric pressure. The results obtained indicated that the operating conditions for a process in a packed bed reactor, which implies the chlorination of both Fe and Ti, are 0.39 < a < .49 at T 1173 K.

Jan 1, 1993