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By Hongli Wen, Guangkun Shen, Qiong Deng, Xuling Chen, Min Gan, Xiaohui Fan

"In this research, pyrite cinder which contains 53.51% Fe and 0.54% Pb was processed by magnetic roasting separation to obtain a concentrate with 64.62% Fe and 0.56% Pb. The concentrate was then leached with hydrochloric acid to remove lead. Several technological parameters which may influence the removal efficiency were investigated: the mass fraction of hydrochloric acid, pulp density, the leaching time and temperature. On the conditions that the mass fraction of hydrochloric acid of 5%, pulp density of 30%, the leaching time of 30 minutes and leaching temperature of20°C, the lead content in the concentrate was reduced to 0.19%. The product was suitable for agglomeration and pelletization. Through the analysis of the lead distribution and phase change during the whole process, the mechanism of lead separation from pyrite cinder was analyzed.IntroductionPyrite cinder is rich in iron, which defines its most extensive and effective use as raw materials for iron making. However, some pyrite cinders contain much non-ferrous metals, which is detrimental for the iron making process. Lead, one of the harmful elements, will destroy the blast furnace lining. Besides, it causes pollution of the environment[1]. Therefore it is necessary to remove excessive lead before entering the blast furnace. To separate the lead from pyrite cinder, much research was done, including flotation, high temperature evaporation and leaching. High temperature evaporation consumed too much energy. The flotation was difficult to obtain high- grade iron ore concentrate[2]. Majority of the leaching was direct leaching of pyrite cinder, which was also difficult to get high-grade iron ore concentrate[3]. This article explored the magnetic roasting method to get high-grade iron ore concentrate, acid leaching method of the concentrate to remove excessive lead, providing guidance for the efficient utilization of pyrite cinder."

Jan 1, 2013

By Natasa Mitevska

In order to ensure the minimal copper concentration in the reverb furnace slag, the graphical optimization method is used and the optimal slag composition of the reverberatory furnaces No.1 and No.2 in the RTB BOR, Copper Smelter and Refinery (Serbia) is obtained: (Si02) .. 38.0%; (FeO) .. 40.0%; (Fe3O4) = 5.0%; (CaO) = 5.0%; (Al2O3) .. 6.0%. Keywords: Optimization, Reverb Furnace Slag, Graphical Method

Jan 1, 2003

By Tsunehisa Nishimura

Stable operation of the blast furnace needs adequate control of the lower part. To clarify the behavior of the lower part of the blast furnace with accurate consideration of the property of slag and its flow characteristic, a new mathematical model has been developed. Using this model, the effects of the change of operational conditions on the behavior of the lower part of the blast furnace were studied. Further, means to control of the lower part of the blast furnace, especially effective means to maintain adequate temperature, were discussed. And desirable slag property and composition, especially the method to control FeO concentration dripping from the bottom of the cohesive zone to avoid a decrease in temperature of the lower part of the blast furnace was estimated.

Jan 1, 2006

By F. Kongoli

Viscosity is an important parameter of copper smelting and converting processes. It affects the settling of matte or metal droplets in the slag, distribution of elements etc. Despite this importance, confusion exists on the viscosity of copper smelting slags as a result of disagreements found among the measured viscosity data of several authors especially in the slags of high ferric iron content and close to magnetite precipitation. In this work a critical review of the existing data on the viscosity of copper smelting slags has been first carried out and the effect of oxygen potential on the viscosity of copper smelting slags has been clarified through a coupled quantification of viscosity and liquidus temperature. The confusion in the literature has been clarified and the importance of the relation between the viscosity and the liquidus temperature is discussed.

Jan 1, 2003

By F. Kongoli

Viscosity is an important parameter of copper smelting and converting processes. It affects the settling of matte or metal droplets in the slag, distribution of elements etc, Despite this importance, confusion exists on the viscosity of copper smelting slags as a result of disagreements found among the measured viscosity data of several authors especially in the slags of high ferric iron content and close to magnetite precipitation. In this work a critical review of the existing data on the viscosity of copper smelting slags has been first carried out and the effect of oxygen potential on the viscosity of copper smelting slags has been clarified through a coupled quantification of viscosity and liquidus temperature. The confusion in the literature has been clarified and the importance of the relation between the viscosity and the liquidus temperature is discussed,

Jan 1, 2003

By Brian Cochran, C. Edward Eckert

"EXECUTIVE SUMMARYINTRODUCTIONThe commercial incentives for using molten aluminum in casting operations are numerous and substantial. Although these incentives apply broadly to both shape castings (foundry) operations and wrought alloy production, the merit of a particular motive is indeed downstream processing sensitive. Melting cost reduction is a universal incentive that impacts on essentially all aluminum products. At a natural gas burner cost of $4.50 per therm, for example, the reverberatory furnace energy cost is at least $0.01 per pound of aluminum melted, exclusive of melt loss, fixed costs, and other expenses. The Aluminum Statistical Review' cited 3.188 million metric tons of secondary aluminum that was recovered by the industry in 1995. This represents a re-melt energy cost of over $70 million. Other incentives to use molten secondary aluminum include throughput enhancement, metal chemistry assurances, environmental considerations, and the avoidance of an in-house scrap processing operation.A traditional disincentive to use molten secondary aluminum is metal quality. If a particular secondary processing operation was successful in achieving and preserving an acceptable metal quality level prior to shipment, the subsequent metal transfer and ladle delivery events would frequently obviate these efforts. For example, a metal superheat on the order of several hundred degrees is required for an unheated transfer ladle to travel 3 to 4 hours to a customer location. The rate of the y-alumina formation reaction approximately doubles for every 120°F increase in temperature, therefore, the effect of excess superheat on melt loss and metal quality is considerable. Linear oxidation reactions, such as magnesia formation in magnesium containing alloys, are influenced to an even greater extent by temperature.The typical quality detractor events are:"

Jan 1, 2000

By Wei-Tong Du, Xiao-Ping Liang, Yu Wang

The structural properties for ternary molten CaO–SiO2–B2O3 system with varying B2O3/SiO2 ratios at a fixed CaO content were calculated by molecular dynamics (MD) simulation. The simulation results revealed that with the increasing of B2O3/SiO2 mol ratio, the bond length of B-O was approximately constant at 1.35 Å, and the coordination number for B (CNB-O) was observed to vary from 3.40 to 3.51, and the average angle of O-B-O increases from 105° to nearly 120°, implying that the geometric stability of structure is reducing sharply. AlsoQ3 andQ4 tetrahedral species (tetrahedron with three and four bridging oxygens respectively) decrease with the increasing of B2O3/SiO2 mol ratio, and the proportion of (Q3 + Q4) decrease linearly from 0.6 to nearly 0, suggesting that B2O3 may behave as a network-breaking basic oxide in the CaO–SiO2–B2O3 system.

Mar 1, 2017

By W. L. Dalmijn, E. A. Schokker, N. Fraunholcz, P. C. Rem

Many processes developed for the mechanical processing of Automotive Shredder Residue (ASR) suffer from high processing costs. We offer a distinct concept for low-cost mechanical processing still allowing high value-added recycling of the recovered materials. The basic idea behind this approach is to produce saleable pre-concentrates at the lowest possible costs that can be further processed in existing separation facilities. Our process includes screening, size reduction and magnetic separation. Preliminary studies showed that fibers in ASR are magnetic due to adhering rust particles allowing separation into a fiber fraction and a non-magnetic rigid fraction by high-intensity magnetic separation. The fiber fraction is most suited for thermal processing. The rigid fraction mainly consists of plastics and rubbers with up to 10 wt.-% of non-ferrous metals, some inert material and copper wires. This fraction is very well suited for mechanical processing by, e.g., sink-float separation in existing metal separation plants. The non-metal fraction can be processed further to recover the plastics and rubbers. The process proposed in this study is expected to be substantially cheaper than full thermal processing. In addition, as it mainly relies on existing separation facilities, it can be applied in the short term.

Jan 1, 2000

By Michael J. Nicol

One of the preferred methods for the recovery of gold from refractory gold ores and concentrates involves pressure oxidation in acidic solutions. The main refractory gold-containing minerals are pyrite and arsenopyrite and there is evidence that the presence of even small amounts of chloride can inhibit the oxidation of these minerals and also substantially reduce the recovery of gold. In this paper, the results of a study of the anodic (oxidation) and cathodic (reduction) behaviour of pyrite electrodes in acidic sulfate solutions containing ferric ions at different chloride concentrations and temperatures up to 200oC and pressures of 2000KPa are presented. The electrochemical studies have been complemented by pressure oxidation experiments on a refractory gold concentrate. Results have shown that, as the chloride concentration increases, the anodic reactivity of pyrite is largely unaffected but the rate of the cathodic reduction of iron(III) decreases. The rate of oxidation of a sulfide concentrate and the recovery of gold by cyanidation of the residues decreases at high concentrations of chloride.

Jan 1, 2003

By Katragadda Sarveswara Rao

"In view of the increasing importance of processing lean ores as potential future resources, efforts are being made worldwide to develop suitable technologies for the recovery of both nonferrous, base and precious metals. There are various types of low grade ores present in many countries. Gradually, the mineral reserves for production of metals have undergone complex changes with regards to their grades and particularly the physical and chemical properties of the minerals to be separated from each other. So, there is a need for new processing routes or the upgrading of existing technologies to recover metal values that are otherwise unutilized. Accordingly, an overview of the different types of mineral resources and economical processes, based on ore horizons, consumption of energy and reagents and environmental concerns, is made in this paper. In addition, the paper provides a summary of metallurgical and engineering challenges to be overcome when implementing new technologies and concepts with regard to base metal extraction and sulphur removal efficiency.IntroductionLow grade multimetal complex sulfide ores are likely to become an importance source for nonferrous as well as precious metals in the near future. The principle metallic minerals are chalcopyrite, sphalerite, galena, pyrite, pyrrhotite, arsenopyrite, tetrahedrite, boulangerite and cassiterite. Such ores are located throughout the world as multi-pocketed reserves which have present complex challenges with regard to their grades and particularly the physical and chemical properties of the minerals to be separated from each other. Their compositions can vary widely from one deposit to another and even from one location to another in the same deposit, and this poses a problem for the recovering metals present therein. Successful aqueous processing of complex sulphide ores depends on the composition and mineralogy of the raw materials and on their leaching behaviour."

Jan 1, 2012

By Corale L. Brierley

Bioheap leaching, commercially applied for secondary copper ores and agglomerates, is rapidly gaining popularity. Bioleaching of chalcopyrite concentrates is imminent. Copper bioheap leaching encompasses the bioleaching of acidified and agglomerated coarse, secondary copper ore, stacked on permanent or on/off pads. The stacked ore is irrigated with raffinate containing bacteria. LME-grade cathode copper is produced by SX/EW. Low capital and operating costs, rapid start-up, environmental benefits, operational simplicity and a good performance record make bioheap leaching an attractive technology. This paper looks at the state-of-the-art of copper bioheap leaching and chalcopyrite concentrate leaching, the risks, the benefits, costs, bioheap performance and the future prospects of copper bioleaching.

Jan 1, 1999

By Klara Kodrikova, Vera Kasparkova, Michaela Uhlirova, Karel Kolomaznik

"Potentially hazardous wastes from leather industry (blue shavings) are processed into various biostimulators within two steps. The first step takes place at high pH (11-12) and hydrolyzation is implemented with potassium alkali, in the second step the pH is lowered to 9 with phosphoric acid after enzymatic dechromation occurs. The resulting hydrolyzates were analyzed in the sense of molecular weight distribution and tested as biostimulators on rape (Brassica napus). The hydrolyzates can be also directly used as universal NPK fertilizers. It has been proved that the nitrate content in the edible parts of tested vegetables (radish, lettuce, and cucumber) was approximately 200 times lower compared to the vegetables fertilized with an inorganic nitrogen fertilizer. The harvests of vegetables fertilized with the hydrolyzate and the inorganic nitrogen fertilizer were almost the same.IntroductionDuring processing raw hide into leather (tanning processes), only 20% of the collagen material is used for the final product. The remaining 80% ends up as waste, both tanned and non-tanned. Non-tanned waste such as calcimine can be used for production of artificial collagen casings for sausages, gelatine and also in pharmaceutical industry as collagen capsulates. Further processing and recycling of tanned leather waste (especially chrome shavings) is more complicated. Although many technologies producing various quality collagen hydrolyzates have been developed and tested in laboratories, few have been implemented on industrial scale. A promising turn came in the works of ERRC USDA [1,2]. They worked out an enzymatic dechromation technology (hydrolysis) and achieved a considerable decrease of the amount of relatively expensive proteolytic enzyme, which solved the difference between the quality and price of the final product. The American experience of enzymic hydrolysis were applied on industrial scale in the Czech Republic, where a plant was built with daily processing capacity of 3 tons of chrome shavings. The experience of real operation was published in [3] and the cooperation between the Czech Republic and USA partners resulted in a patent [4]. The main asset of the patent was the use of volatile organic bases in the hydrolysis process giving high quality and cheap hydrolyzates with low ash content."

Jan 1, 2008

By Y. Sako, E. Nomura, K. Muraguchi, K. Shibata

In 1998, Mitsui Mining & Smelting Co., Ltd. (MMS) produced 70,000 tonnes of lead, 231,000 tonnes of zinc and 214,000 tonnes of copper. MESCO, Inc. has been in charge of the automation and mechanization of smelting facilities promoted by MMS as well as the construction of facilities for chemical production and electronics materials plants, by which MESCO has contributed to the development of MMS. Initially, MESCO developed a casting machine for refined lead in the early 1960's, and thereafter, it developed a casting machine for refined zinc, a stripping machine for zinc tankhouses and energy saving facilities. In the field of copper smelting, it has also developed automation and mechanization facilities.

Jan 1, 2000

By Ruben Alvarado

The need to increase business competitiveness while complying with environmental requirements represent the great challenge that the Caletones smelter has decided to face in a new development project with a compromising and willing alliance with its workers. To date, the project is at the feasibility stage, with start up scheduled for the middle of the year 2002. The processing capacity of the Teniente Converters will be increased to levels up to 2400 tpd of chalcopyrite-based concentrates containing 30% Cu, by means of more intensive use of oxygen and improved stabilization of the overall operation. Productivity increses in the converting of white metal and the pyrometallurgical treatment of slag are also planned. As a result of related strategies, the productivity of the supporting facilities, included the capacitiy of the sulfuric acid plants, will be increased. An intensive and well-designed labor-upgrading scheme will allow the transformation of every worker into an expert in his working areas, thus becoming an active driving force in technology development. Mechanization, appropiate infrastructure, and complete process control and instrumentation will give to the skilled and motivated personnel the necessary tools in order to attain the highest potential ever reached with the Teniente technology. The necessary investment for this project based on the adding facilities to the existing plant is only a third of that required to reach the same objective for a greenfield plant, thus yielding a very high return on investment.

Jan 1, 1999

By Moo Eob Choi

A new process for converting sulfur dioxide to elemental sulfur by a cyclic process involving calcium sulfide and calcium sulfate without generating secondary pollutants was developed at the University of Utah. In this process, sulfur dioxide is reacted with calcium sulfide to produce elemental sulfur and calcium sulfate. The latter is reduced by hydrogen to regenerate calcium sulfide. In the present work, the effects of different pelletization conditions for the initial reactant calcium sulfate on the strength and reactivity of the pellets were determined. These conditions include the type, amount, and impregnation method of catalyst, binder amount, and sintering. Experiments were also performed to determine the effects of temperature in the range of 973-1173 K, pellet size, cycle repetition, and water vapor or carbon dioxide content in sulfur dioxide stream on the reaction rates of the cyclic process. Nickel-catalyzed fired pellets produced by the use of molasses or cement as a binder showed good reactivity as well as high compressive strength during the cyclic tests. The binder amount did not significantly affect the reaction rate.

Jan 1, 2006

By K. S. Jeong

Since the start-up of the Onsan Smelter in 1979, LS-Nikko Copper has grown into a competitive smelter through continuous development. Several environmental improvements have been carried out, in particular, intensive investments in reducing SOx emissions, such as de-sulfurization plants, fugitive gas capturing and TMS(Tele Metering System). In addition, in recent years LS-Nikko Copper has spent more than 10 million USD every year to improve environmental conditions. In order to be a global leading smelter in every aspect especially environmentally, LS-Nikko Copper plans to inspire environment-friendly minds, co-operate with shareholders, and participate in global conventions. This paper describes the environment improvements carried out at Onsan and briefly introduces a sustainable vision for a green smelter.

Jan 1, 2006

By Hirokazu Narita

The extractability for Pd(II) using MOTDA and DHS and their durability against a mixed solution of HNO3 and HCl was investigated by solvent extraction and FT-IR measurements. Both MOTDA and DHS selectively extracted Pd(II) over Pt(IV) from 0.75 M HNO32.25 M HCl solutions. The extraction rate of Pd(II) with MOTDA was much greater than that with DHS. In the durability test, the extraction percentage of Pd(II) and the FT-IR spectra were measured using MOTDA and DHS after stirring with 0.75 M HNO32.25 M HCl solutions. The extraction percentage of Pd(II) with MOTDA hardly changed during the two-month stirring; however, that with DHS decreased with an increase in the stirring time. The FT-IR spectra showed the sulfoxide formation by the oxidation of the sulfide in DHS, but not in MOTDA. Consequently, it was found that MOTDA is more durable than DHS.

Jan 1, 2006

By Robert G. Robins

Precipitation of ferric arsenate is an effective method for removing arsenic(v) from hydrometallurgical process solutions. The solubility and stability of this compound. FeAs04.2H20, has received some attention in recent years and the reported solubilities of amorphous and crystalline material have varied considerably. This paper reviews previous studies and reports some recent work with a consistent model to explain the variable results. Free energy data for ferric arsenate and its associated dissolved complexes are presented.

Jan 1, 1990

By Shubin Wang

Copper(II) and nickel(II) are often recovered from ammoniacal alkaline solutions by solvent extraction using hydroxyoxime extractants: both copper(II) and nickel(II) are extracted from ammoniacal alkaline solutions and, from the loaded organic phase, nickel(II) is selectively stripped with a dilute acid followed by copper(II) stripping with an acid of higher concentration. Since a small portion of ammonia is co-extracted with copper and nickel, the extracted ammonia should be scrubbed using a dilute acid before metal stripping. In the present study, a mechanistic model has been developed in order to support design and control of this process. The equilibrium distribution ratios of copper(II), nickel(II), and ammonia at 298 K using LIX® 84-I (active component, 2-hydroxy-5-nonylacetophenone oxime) as the extractant are successfully correlated by considering the relevant equilibria. Based on these results, quantitative prediction of equilibrium distribution ratios in the process has been made possible, and suitable conditions for the efficient separation of copper(II) and nickel(II) are discussed.

By W. Petruk

The silver-rich cobalt-nickel arsenides ores of the Cobalt area in Ontario, Canada were mined for silver from about 1904 to 1985. The ores contained about 8 oz to 100 oz Aglt and about 1 wt% Ni and 2 wt% Co. They were processed by gravitational techniques, screening and flotation to produce separate silver and Fe-Co-Ni arsenide concentrates. The silver concentrate was smelted, and in some cases the arsenide concentrate was sold to custom smelters which recovered silver and other metals. The ores display a wide variety of textures and contain many minor and trace elements. This paper presents an evaluation of mineral characteristics that have a bearing on extractive metallurgy and smelting of this type of ore.

Jan 1, 1993