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By Larry B. Fiske

Elimination of dust and processing of fines for both thermal and metallurgical coals is addressed. The efficiency of treatment with lignosulfonates compares favorably to oil in thermal coal. Effect of treatment with various lignosulfonates upon cokability of metallurgical coal was determined by Free Swelling Index, Gieseler Plasticity and Arnu Dilatation.

Jan 1, 1992

By Nobuyuki Masuda

In Japan, the municipal solid waste, which amounts to 50 million tons, is generated every year and most of it is incinerated. The fly ash from the municipal waste incineration (the primary fly ash) contains heavy metals, such as lead and zinc, etc., and dioxins. In case of melting, the fly ash from the process (the secondary fly ash) contains high concentration of heavy metals (e.g., Zn; 1-20%, Pb, 1-10%). Metal Mining Agency of Japan launched a four-year project in 1999 to establish the integrated technologies to recover the valuable metals from, and to decontaminate, the primary and secondary fly-ashes in the practical scale by utilizing the existing metallurgical processes and facilities, along with the energy saving. The segregation, flotation and chemical treatment are applied to the treatment of the primary fly ash. The secondary fly ash is treated with MY (Mitsui-type blast furnace) Process after the chlorine removal to recover the heavy metals in the ash, In this paper, the segregation and flotation process for primary fly ash and MF process for secondary fly ash are explained. The main results of experiments done from 1999 to the mid of 2001 to design the pilot plants and to optimize the operating conditions are described. The main results of the experiments are as follows: - The segregation reaction of Cu was confirmed by the experiment on the treatment condition of 800 and 900`C with adding oil cokes and water to the primary fly ash, and 99.98% (toxicity equivalent) of the dioxins were decomposed by the treatment. - Washing tests of secondary fly ash to feed MF resulted that more than 70% of chloride were removed, but still lower than expected, and agglomeration tests were successful by the results of the sufficient strength of briquettes produced though a little more binder for the agglomeration is required than usual operation. - Smelting experiment by downsized MF showed that valuable metals, such as zinc and lead, are recoverable in the furnace dust. Recovery ratios, Zn: 58% and 67%, Pb: 74% and 83%, are accomplished.

Jan 1, 2002

By A. Siegmund, Gerhard Martin

The recycling of metal containing scrap is a common practice in the industry and has a long tradition. . In rec~nt years, this philosophy has been transferred to organic materials, in particular to thermoplastic polymers. BSB . Recycling GmbH, a company with a long experience in the treatment and recovery of lead from battery scrap,· had recognized this exploitation at an early stage and challenged it by a consequent continuation of the idea to recycle materials other than metals without degradation and maintaining the quality. These efforts resulted in an economic and environmentally acceptable solution producing high quality polypropylene compounds at BSB beside lead and lead alloys from battery scrap. The raw material fair the production of polypropylene compounds is shredded plastics from the separated casings of spent lead-acid batteries. The production of polypropylene with specific physical and mechanical properties is carried out by the accurate dosing of organic as well as inorganic additives. The result of the procedure is a novel product group "Seculene PP", a registered trademark of BSB Recycling GrnbH.

Jan 1, 2000

By Masayasu Kawahara

"The extraction and separation of nickel, cobalt and copper were investigated with a solvent impregnated resin which was produced from UX84-I and XAD-4. The extraction behavior of metals with the solvent impregnated resin is similar to that with solvent extraction. The extraction ability of solvent impregnated resin improves when using finer particle resin and with a higher concentration of extraction solvent.IntroductionSolvent extraction is well known-as a method for separation of metallic elements in solution. However there are problems with intermediate phase and solvent loss. Ion exchange resin is also used in hydrometallurgy, but it is not fit for separating a large quantity of metals. Amberlite XAD-4 resin is known as a absorption agent of organic matter in water. It is expected that the resin which has the ability of extracting metals can be made by absorbing organic extractant on XAD-4 resin In this study, solvent impregnated resin (SIR) was produced from LIX84-I and XAD-4, and extraction and separation of nickel, cobalt and copper were conducted using SIR. The extraction properties of SIR were investigated, and a comparison between ordinary solvent extraction and SIR was made.Experimental ProcedureAmberlite XAD-4 was used as absorption resin for the organic extractant in this study. The physical properties of XAD-4 are shown in Table I. Amber lite XAD-4 has a large surface area and shows good ability to absorb organic matter in water, but the: resin does not have the ability of exchanging metallic ion."

Jan 1, 2000

By Gabriel Riveros, Ariel Balocchi, Andrzej Warczok, Daniel Smith

Blister copper from converting of copper matte is processed by fire refining prior to electrorefining. The fire refining consists of two steps: copper oxidation with impurities slagging and copper reduction. The classical batch process is carried out in vascular or reverberatory furnaces called anode furnaces. A new process for continuous copper fire refining has been proposed. The copper flows through two reactors in cascade, where is oxidized and reduced. The flow of a liquid copper through a ceramic packed bed increases the surface area and the rate of oxidation as well as the rate of reduction in the packed bed of charcoal. Mathematical modelling allowed for the design of a laboratory scale demonstration installation and industrial-pilot installation in Hernan Videla Lira Smelter (Paipote). The results have demonstrated the process feasibility and flexibility in operation.

Jan 1, 2009

By JiaPeng Xu, Brian Lo, Uday B. Pal, Yihong Jiang, Soumendra N. Basu

"The Solid-Oxide Oxygen-Ion-Conducting Membrane (SOM) electrolysis process has been successfully tested on a laboratory scale, producing silicon directly from silica in a cost-effective and environmentally friendly way. A yttria-stabilized zirconia (YSZ) tube, closed at one end was employed to separate the molten salt containing dissolved silica from a liquid metal anode placed inside the YSZ tube. When the applied electric potential between the liquid tin cathode in the molten salt and the anode exceeds the dissociation potential of silica, oxygen ions are pumped out of the molten salt through the YSZ membrane and oxidized at the anode while the silicon cations in the flux are reduced to silicon at the liquid tin cathode. The presence of high-purity silicon crystals on the surface of liquid tin cathode was confirmed by scanning electron microscopy (SEM) and energy dispersive x-ray spectroscopy (EDS). Silicon crystals were extracted from tin cathode by chemical etching.IntroductionPhotovoltaics (PV) generate electrical power by using solar cells, and dramatically reduce the emissions of greenhouse gases (GHG). Through 2006 to 2011, it grew the fastest of all renewable technologies with operating capacity increasing an average of 58% annually [l]. However, the cost of manufacturing solar-grade silicon (SoG-Si) for high-efficiency solar energy production represents a major barrier to achieving the industrial goal for solar power of $1/Wp (watt at peak exposure) which would enable widespread grid parity. The current contract price of silicon to PV manufacturers is $50-$60/kg, with the spot market in 2007-2008 showing prices as high as $300/kg [2]. This makes the development of low cost and environmentally friendly manufacturing of high purity silicon very important."

Jan 1, 2013

By Banqiu Wu

Zirconium carbide powder has been synthesized from zircon concentrate and methane using a high temperature plasma reactor, a non-transferred DC plasma torch was used as heat source. A high temperature filter consisting of graphite felt was designed, built and operated to separate the zirconium carbide from silicon carbide during the process. Characterization of the collected powders was done by wet chemical analysis using Atomic Absorption (AA), Scanning and Transmission Electron Microscopy (SEM and TEM) and by X-Ray Diffraction (XRD). It was found that the zirconium carbide purity was around 95% with silicon carbide being the primary impurity. The powders had particle sizes between 30 and 80 nm. The effect of several experimental variables are presented as well as temperature and velocity profiles calculated in the reactor.

Jan 1, 1997

By Aline Maria dos Santos Teixeira, Francisco Manoel dos Santos Garrido, Joao Alves Sampaio, Marta Eloisa Medeiros

"Rocks for crops is a natural practice for soils fertilization which consists on adding rocks to the soil while water decomposes the rock, through chemical weathering, and gradually releases nutrients to the soil solution. This practice can be considered an alternative to the low production of potassium fertilizers in Brazil. In this context, the phonolite rock was characterized in order to evaluate its application as an alternative source of nutrients to the Brazilian agriculture. The phonolite studied is an igneous, volcanic rock with alkaline character that is chemically composed of a high grade of potassium due to the presence of feldspar minerals. In order to quantify the minerals present in the sample, characterization was carried out using several techniques such as X-ray diffraction, X-ray fluorescence and scanning electron microscopy.IntroductionBrazilian soils are generally acidic and nutrient poor due to the tropical climate in which high temperatures and intense rainfall favor a rapid decomposition of the rocks that from the soil. And as agriculture is one of the main bases of the country's economy, large amounts of fertilizer are used to make the soil productive.Although Brazil has large reserves of potassium, the demand for potash fertilizer is higher than the national supply, which makes the country dependent on fertilizer imports, especially in the form of potassium chloride. Thus, we must look for economic alternatives to traditional fertilizer [1].Stonemeal is a natural practice for soil fertilization that consists in adding basic or ultrabasic rocks to the soil so that water, through chemical weathering, decomposes the rock while it gradually releases nutrients."

Jan 1, 2011

By Jukka S. Sulanto

Outokumpu has applied its well -known copper Fl ash Smelling Process also for smelting su1phide lead . concentrates. The lead in the Flash Smelting Furnace slag is recovered by reducing the oxygen potential of the slag in an electric furnace by injecting reductant into the slag bath. A series of tests have been carried out in a 1000 KVA electric furnace? adjacent to a pilot Flash Smelting Furnace. The furnace has been fed continuously with molten Flash Furnace Slag. The feed rate has varied from 0.5 to 3.1 MTPH (0.55 - 3..4 STPH) depending on the feed rate and the quality of concentrate to the Flash Smelting Furnace. The inlet slag contained 15 to 40% of lead and the cleaned slag 1. 5 to 3. 0%. The lead recovery from sol id raw material was tested in the same continuous process by feeding lead calcine into the furnace. Feed rate was 0.7 to 0.95 MTPH (0.8 - 1.05 STPH) and the calcine contained 33 to 34% of Pb. Several reduction agents and procedures were tested. The process proved to be suitable for continuous recovery of lead from solid oxide raw materials.

Jan 1, 1990

By W. Zhao

Several years ago, Reddy and Blander presented upriori model for calculating the sulfide capacity of binary silicate melts. It is modified now to apply to CaO-AlO 1.5 melts at different temperatures and compositions. Our predictions are in very good agreement with the available experimental data. From a comparison of binary calcium aluminate and calcium silicate systems, higher sulfide capacities are obtained in aluminate systems. The sulfur can be removed from hot metal more effectively by adding aluminate melts.

Jan 1, 1995

By P. A. Botha

The coal seams in the Waterberg basin occur in correlates of the Vryheid and Volksrust Formations as developed in the main Karoo basin. In the Vryheid Formation, five thick seams of predominantly dull coal are present, whereas a multitude of thin, lenticular seams (a few millimetres to 2 metres}, predominantly of bright coal, are developed in the overlying Grootegeluk Formation. During exploration, the coal seams were divided into 11 zones. Analytical data on float and middlings fractions (RD less than 1.40 and between 140 and 1.80, respectively} were used mainly for stratigraphic correlation of the zones in the Grootegeluk Formation. The affinities of the major and trace elements for different mineral phases and/or organic material are discussed on the basis of correlation matrices and vertical variation diagrams. Titanium and vanadium clearly show some degree of organic affinity. P 205' AI203 and alkaline-earth elements are also positively correlated by the presence of goyazite in the coal. This type of investigation gives an indication of the degree to which undesirable elements like P and S can be removed during coal beneficiation, of which coal zones are unsuitable for the production of metallurgical coal on account of a high content of these elements, and to what extent the blending of different coal zones is required to keep the concentration of these elements within acceptable limits.

Jan 1, 1991

By Chikabumi Yamauchi, Masami Tashiro, Toshiharu Fujisawa, Hiroyuki Snano

"Rare earth metals usually contain large amount of oxygen because of their reactiveness, and therefore oxygen removal is one of the major problems on the purification of rare earth metals. In the present research work, halide flux treatment at high temperature under inert gas atmosphere was applied to the oxygen removal from neodymium. NdF3 was used as a halide flux. Deoxidation reaction and its mechanism were discussed based on the experimental results. Halide flux treatment is very effective for oxygen removal from rare earth metals.IntroductionSolid Sate Electrotransport (SSE) process has been successfully applied for the elimination of interstitial gaseous impurities from chemically active metals[l]-[5]. However, to achieve a higher effectiveness of the SSE process, it is required a very low initial impurity content in the metal. In case of rare earth metals, it is known that they usually contain large amount of oxygen that should be lowered as much as possible before applying the SSE process. In addition, if effective oxygen removal is achieved by simple process, it is significant also from the industrial viewpoint. In the present work, the application of a halide flux treatment is investigated to remove oxygen from neodymium by using NdF3 as a flux. At first, deoxidation reaction and its mechanism were discussed based on the phase diagram of the Nd-NdF3-Ndp3 quasi-ternary system. Based on the results, oxygen content in deoxidized neodymium was calculated theoretically and it was verified by deoxidation experiments."

Jan 1, 1998

By Itavahn Alves da Silva, Jose Dimas de Arruda, Amanda Aparecida Fátima Arruda, da Silva de Souza, Carlos Antonio da Silva, Varadarajan Seshadri, Samuel

The knowledge of the flow field inside a continuous casting mold is essential to improve operational efficiency of the process and also to achieve better inclusion control. Physical modeling, PIV technique and CFD have been employed to assess the velocity distribution in the metal- slag interface region in a slab mold. The analysis of results shows how higher casting velocity and lower immersion depth of submerged nozzle can lead to higher turbulence in the slag-metal interface. The effects of density difference between slag and metal and interfacial tension between the phases have been highlighted.

Jan 1, 2016

By Reinhard F. Dobner

After a short introduction about the HK's secondary smelter process and explanations concerning the anodes produced the regulation and buffering of bleed will be described and the principles of technology for processing of bleed will be presented. Modernization aspects, especially installation equipment, and the different types of evaporators used will be described in detail. Besides, experience made with acid-resistant materials - stainless steel, enamel, plastics - will be reported. Environmental aspects such as water and air pollution will be outlined briefly and in conclusion the quality of products obtained as well as quality control will be presented.

Jan 1, 1997

By Yuzo Hiroshige, Masayuki Kyoi, Tomonori Saeki, Masahide Okamoto, Toru H. Okabe, Yu Miyamoto, Tomohiko Akahori, Takeshi Nemoto

We report Hitachi's approach to establish the recycling process for rare-earth metals in magnet. We have developed a process to disassemble the used electric products to collect the magnets, a process to remove the surface plating film of the magnet, and processes to separate rare-earth metals from the magnet. All processes are operated without chemical solutions in order to minimize the environmental impact due to the waste water emission. For the disassemble process, we have developed an equipment to generate continuous shock on the electric products to loosen screws. A sand blast technique is applied for the plating removal process. Rare earth metals in the magnets are extracted by immersion of the magnets in molten magnesium. The extracted rare-earth metals are separated from Mg by evaporation of Mg. The overall yield of recovery is 86.8 %. The purity of the final rare-earth metal is 98.8 %.

Jan 1, 2014

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 Jiangtao Li, Zhongwei Zhao, Xingyu Chen, Xuheng Liu

The method of ultrasonic-assisted leaching was used to extract vanadium from the stone coal, with alkali as leaching reagent. The effects of ultrasonic power, concentration of alkali, reaction temperature, liquid-solid ratio and reaction time were investigated, respectively. The optimal ultrasonic leaching condition for vanadium extraction is as follows: ultrasonic power 230W, concentration of alkali 5%, liquid-solid ratio 3:1, reaction temperature 90℃ and reaction time 1h. The leaching rate of vanadium reaches 76.4% under the optimal condition, which is 12.2% higher than that of non-ultrasonic leaching. The reason on enhancing the leaching rate of vanadium by ultrasonic leaching was discussed. It is indicated that the ultrasonic cavitation can increase the surface area of mineral, which is beneficial to facilitate the reaction rate. Keywords: stone coal; vanadium; alkaline leaching; ultrasonic

Jan 1, 2014

By C. D. Adams, R. T. Tuenge, C. N. King, J. A. Samuels, B. F. Espinoza, R. C. Dye, C. F. Schaus, D. C. Smith, N. M. Peachey

"Recently, doped calcium thiogallate (CaGa2S4) phosphors have been investigated for use in electroluminescent flat panel displays. The current technique used for the deposition of thin film calcium thiogallate is sputtering. Unfortunately, this requires a high temperature annealing process to provide the desired crystallinity of the phosphor. Recent efforts have focused on the possible use of metal-organic chemical vapor deposition (MOCVD) to produce the CaGa2S4 layer. The use of MOCVD provides an attractive alternative to sputtering since it does not require heating above the strain point temperatures of the glass substrates used for the display panels. To accomplish this, the deposition of both Ga2S3 and CaS is investigated as these compounds are intermediate steps in the development of the phosphor deposition. Uniform, crystalline films of both Ga2S3 and CaS were deposited and the process shows promise for successful deposition of the CaGa2S4 phosphor.IntroductionThe lack of a satisfactory blue phosphor having sufficiently high luminances at low power has hampered the development of high resolution flat panel displays. Recently, a new series of blue emitting materials have been investigated for use in thin film electroluminescent (TFEL) devices. l ,2,3 These phosphors are based on a series of alkaline earth thiogallate host materials of the form MGa2S4:RE where M can be either calcium, strontium, zinc, or barium and RE is a rare earth ion. A full-color VGA TFEL panel using CaGa2S4:Ce as the blue phosphor has recently been fabricated and tested. l This FPD provided a luminance of 10 cdlm2 at 60 Hz. The enhanced blue in this display allowed its color capabilities to approach those of the conventional CRT.The method of depositing the phosphor onto the display panels in these test devices has been sputtering. Unfortunately the phosphor as deposited does not possess the crystalline properties required for optimum luminance. The crystalline structure is achieved by subsequent annealing of the deposited material. Although this post deposition anneal provides the desired crystal structure, it occurs above the strain point temperature of ordinary glass. Consequently, the implementation of these phosphors requires the use of glasses capable of withstanding high temperatures, adding to the cost of the final display unit."

Jan 1, 1994

By K. V. Sreenivas Rao

Solidification experiments have been conducted to study the effect of interface heat flux and air gap formation on cooling rate of the casting during solidification of Al-4.5wt%Cu alloy. The thermal history of the casting and mold during solidification is recorded using thermocouples connected to computer interfaced data logger. The measured temperatures in the mold are used as input to the IHCP (inverse heat conduction problem) algorithm for simulating multiple heat flux components at the boundary. It is observed that the filling effects induce spatial variation in the thermal field in the mold and casting regions and greatly influence the cooling rate of the casting. The study demonstrates the use of IHCP and in-situ measured thermal profile in analyzing the cooling rate and microstructure.

Jan 1, 2008

By J. Smuts

The mixed-valence iron silicate ISCORITE (Fe7Si010) was identified recently in a number of ironmakingmater1als, some of which were first produced more than a century ago. Although the existence of iscorite was not reported before 1967 and published phase diagrams do not make provision for it, the morphology of the phase in all the materials that were examined suggests that it is stable under a variety of conditions. It is shown that is-corite can accommodate various foreign cations in its lattice where they can replace Fe and/or Si. The morphology of is-corite in a number of materials of different origin is shown in relation to iron oxides and silicates in optical and SEM/BSE images.

Jan 1, 1991