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By Chunlin Chen

Published data on thermodynamics of a number of minor elements (As, Sb, Bi, Pb, Zn, Se, Te, Cr, Sn) in liquid copper, matte and slag have been reviewed, assessed and used in development of thermodynamic solution models of melts. The behavior of antimony in alloys, mattes and slags is used as an example to illustrate the approach taken in assessment of published data and validation of the developed models with respect to the activity of Sb in condensed phases as well as the effects of matte grade, slag chemistry, temperature etc on the equilibrium distribution of Sb between melts and the gas phase. Results obtained from a comparison of different smelting processes with the modeled multi-phase equilibrium are presented and discussed. The predicted effects of slag chemistry and matte grade on the deportment of other minor elements during smelting of copper mattes will be presented and discussed.

Jan 1, 2006

By Mingchun Lu, Zhijia Liu, Xueqi Zhang, Jianliang Zhang

"In order to solve the problem of shortage of scrap, especially high quality scrap, a new substitute for scrap or DRI has been developed. The decarbonization mechanism of granular pig iron has been analyzed and the technical process and decarbonized granular pig iron have been evaluated in this paper. The research result shows that this new process is superior to direct reduction process in product quality, construction investment, operation flexibility, production efficiency etc. Decarbonized granular pig iron (DGPI) not only can be used as conventional scrap but also can be charged into EAF as high purity .burden equivalent to heavy scrap:IntroductionIn the past years, with the universal application of continuos casting technique in China, the amount of scrap generated inside steelworks has been reducing continually. On the other hand, the EAF steel proportion is increasing and this gives to the obvious change in structure of steel product. At present, the requirement on both scrap quantity and scrap quality is being paid more and more attention. Because China is a country which is devoid of scrap and poor in resource (nature gas and high grade iron ore) for developing direct reduction iron (DRI) so that sponge iron can not be produced cosmically in China and has to be mainly imported. Instead of part of scrap, some cold pig iron in cold state has been charged into EAF in China. However the high carbon content in pig iron has limited its proportion in EAF metal burden. Because the price of pig iron is lower than that of imported DRI in China, the technique of granular pig iron decarboniztion is hopeful to become effective way to produce substitute for scrap or DRI."

Jan 1, 2000

By Roberto Javier Santiago

This paper tries to make a study about the use of calcium carbide during the tapping in replacement of part of the aluminum used in the furnace tapping, analyzing theoretical consumptions and then transfering the practice to the plant.

Jan 1, 2006

By Armando Valenzuela

Arsenic has been a common impurity in copper sulfide concentrates treated pyrometallurgically in Chile, which inevitably during the smelting-converting process reports in the final copper product affecting its properties, but also affecting environment as a very toxic occupational hazard. The enforcement of air quality standards, which regulate pollutants such as sulfur dioxide, particulate matter, and arsenic, has resulted in the implementation of pollution abatement plans and emission reduction schedules mainly by state-owned copper concentrate smelters. Investments associated with these plans incorporated gas-handling systems in order to capture polluting emissions. Electrostatic precipitators recover dusts containing mainly Cu and As which are leached to recover copper, while arsenic is disposed currently in the form of ferric arsenate. Gases containing high sulfur dioxide content are treated in plants to produce sulfuric acid, which is used in various classical and new hydrometallurgical processes. Additionally, smelters have effluents treatment plants for arsenic disposal either as ferric arsenate or calcium arsenate/arsenite. This paper reviews the environmental situation of the Chilean metallurgical industry, and the present trends for arsenic management are particularly emphasized since Chile is the world?s largest copper producer.

Jan 1, 2006

By C. J. Boreiko

Traditional patterns of lead and zinc utilization are being evaluated in accordance with new paradigms that seek to ensure the long-term compatibility of global industrial activity with precepts of sustainable development and sustainable consumption. As a consequence, both industry sectors are experiencing intense scrutiny from the international community, and numerous regulatory options are being considered that may impact upon international industry practice. This paper reviews the growing expectations being placed upon industry, and highlights some of the common regulatory concerns being expressed regarding both metals despite their differing toxicological profiles.

Jan 1, 2000

By Katsukiyo Marukawa, Mashamichi Sano, Shigeta Hara

"Various subject of studies are discussed to develop ·innovative refining processes in the 21st century for cost reduction, production of high quality steel and environmental conservation. The future refining reactor should have abilities of highly efficient mixing and separation of different phases. It is stressed ·that applications of electromagnetic and ultrasound energies, and control of flow fields rate required to create the highly efficient mixing I separation reactor.IntroductionIn recent years, it seems that the research and development in the field of steelmaking has shifted its emphasis to the solidification I ingot-making process in which continuous casting plays the leading role. From a long-range point of view, however, the need for continual development of the refining process will probably increase but is very unlikely to decrease. In order to meet such demands, it is required that problems and issues of the present process should be clearly grasped and that there must be rapid progress in process elements, such as highly efficient mixing and separation of different phases.Applications of electromagnetic and ultrasound energies and flow field control will become important options for resolving the above-mentioned problems. By efficiently and skillfully incorporating these new technologies into high-efficiency mixing/separation reactors, the innovative refining process will be established in the early 21st century."

Jan 1, 2000

By F. Baldini, M. S. Borges

"The proposed method emphasizes the optimization of waste management with regard to the exploitation of raw materials incorporated in the remains of industry, as well as the economics of natural resources as an environmental impact assessment. This system [tool] allows: (a) the conversion of an environmental liability into an asset by finding a line of appropriate research for each type of waste and the development of new materials applicable to other industries, (b) the performance of internal control of the waste generated (production, storage, final destination) as well as legal conformity.Objectives:1.1 General objective:To design a collaborative system for socio-environmental management of industrial waste.1.2 Specific objective:Develop evidence of concepts;Evaluate the deployment of the inventory of waste in an industry;Enable the conversion of an environmental liability into an asset by finding a line of research appropriate to the waste: a case study;Evaluate the environmental legislation in the legal mechanisms that influence company decisions.IntroductionThe global economy is undergoing major changes, among these changes; it should be highlighted those related to technological progress and environmental quality.While the industrialized countries and higher levels of economic growth dominate modem technology, developing countries are identified by a different growth pattern, using the annual growth rate of Gross Domestic Product per capita [3, 18].Growth is when the GDP grows, in percent, over the previous year. Development, on the other hand, is when the countries change their technologies and improve their internal structure. Thus, the growth considers the accumulation of wealth, while the development is concerned with the distribution of wealth, improvement of the quality oflife and environmental quality [3, 18].As the UNESCO report shows (1999), the biggest problem is between consumption and development, what is produced and the end that is given to the product. Therefore, product and by-product have equal importance in the quantity produced [29].On one hand there is a positive relationship between indicators of economic growth and technological progress, however, on the other hand, these transformations are a paradox, confirmed by the dramatic use of environmental resources and the lack of technologies for recycling of industrial scrap."

Jan 1, 2011

By Takahiko Okura

Sulphur, with its multiple oxidation states, play critical roles in many processes, ranging from regulating enzymes in plants, to acidifying aquatic systems, and to affecting the global climate. Most of non-ferrous smelters have been contributing to reduce atmospheric emissions of sulfur dioxide to acceptable levels, converting it to sulphuric acid and/or gypsum. However, some amount of SO2 gas is still emitted from isolated smelters. Furthermore, sulphuric acid is competing with involuntary elemental sulphur in the market. This situation puts the non-ferrous metallurgical industries to develop a new sulphur fixation process. This paper briefly describes the new technologies for fixation, followed by the novel proposal to convert SO2 gas to elemental sulphur using organic materials. Finally, the feasibility will be presented technologically and economically.

Jan 1, 2006

By Satya Ganti, Bryan Turner, Bill Davis, Veeraraghavan Sundar

This work presents a three dimensional microstructural analysis of medium carbon steels, based on serial sectioning using optical microscopy. The microstructural phases considered here are ferrite and pearlite. Typically conventional 2D microscopy is used to analyze these phases (ASTM E112-13 in Standard test methods for determining average grain size. ASTM International, West Conshohocken, PA, 2013), with eddy current (Khan et al. in J Mater Process Technol Freitas et al. in Mater Sci Eng A 527(16):4431–4437, 2010) as alternatives. Medium carbon steel samples were heat treated in a furnace and either slowly cooled in the furnace, or cooled at higher rates. This resulted in different pearlitic microstructures in the samples. The analysis was conducted with Robo-Met.3D®, a fully automated metallography system for serial sectioning. Based on optical microscopy, volume cubes of hundreds of microns on edge were imaged and reconstructed to conduct grain size and phase volume analysis. The system proved capable of collecting image data with high fidelity, and controlled slice thickness in an automated manner. The resultant dataset was useful in visualization and analysis of pearlite and ferrite phases in steel samples.

Mar 1, 2018

By C. J. Lewis

This presentation concerns calcium oxide-better known as high calcium quick lime High calcium quicklime is produced by calcining high calcium limestone, mostly in the many rotary kilns located throughout the United States and Canada. This paper presents suggestions on the handling of lime based on field experience. The subjects covered are chemical analyses, transporta¬tion, lime storage, lime slaking to form a water slurry of calcium hydroxide solids, slurry transportation, slurry viscosity, and scaling of lime slurries. It is hoped that the comments on the foregoing areas will be of use to those designing or operating lime systems.

Jan 1, 1992

By Florian Kongoli

The overall productivity and efficiency of sulfide smelting plants depends considerably on the productivity and efficiency of each unit furnace operations. Furthermore, the efficiency and productivity of each furnace affects and dictates to a certain degree the process of managing the flow of materials from one unit to another. A furnace with low productivity, several technical problems or high frequency of accidental shut downs can easily become a temporary or a permanent bottle neck in the entire flowsheet and can be the cause for a low productivity and efficiency of the entire plant. As a result, controlling, optimizing and automating the individual furnace operations in order to assure a stable process but at the same time to increase productivity is an indispensable need. In this paper, the authors discuss their recent work in effectively controlling acute industrial furnace problems such as magnetite build-up and accretions, eliminating unnecessary slag foaming, decreasing slag losses etc. as well as the intensification, optimization and automation of a series of furnaces in sulfide smelting through a unique physical process modeling that correctly simulate the industrial furnace operations and avoid guessing and uncertainties. The advantages of this new approach have been discussed.

Jan 1, 2006

By V. Ramachandran

ASARCO Incorporated, a large and diverse producer of non-ferrous metals, is involved primarily in smelting and refining of copper and lead. The Company also recovers by-product metals and chemicals produced in the smelting and refining process including selenium, tellurium, silver, gold, platinum, palladium, bismuth, antimony oxide, lead-antimony alloys, and nickel sulfate. The treatment of complex concentrates, containing high level's of impurities, also results in the production of various sludges, drosses, dusts and slags. This paper addresses the interplant and intraplant transfer of these materials between the copper and lead circuits and their subsequent treatment for maximum metals recovery. It also describes the role of ENCYCLB/TEXAS Inc., a subsidiary of Asarco, which treats Asarco's by-products, as well as hazardous and non-hazardous wastes produced by other manufacturers.

Jan 1, 1994

By A. A. Shook

For relatively little capital outlay, the metal delivery control system in the BHP Copper Rod Plant at San Manuel' was significantly upgraded using the UNAC process simulation and control system (CICS Automation, Newcastle, Australia). An accurate simulation of the metal delivery process was developed with UNAC, which was then used to design a robust controller capable of dealing with plant complexities such as noise, time delays, and nonlinearities. This controller was implemented online using UNAC. Thanks to the extensive preparatory simulation, the controller worked immediately and required no additional online "tuning". Operator response has been favorable, and the UNAC control system has become part of the standard operation of the plant.

Jan 1, 1999

By Leonard J. Friedman

There have been considerable changes in systems, equipment design and materials used in the modern Sulfuric Acid process. Many of these will shape the metallurgical sulfuric acid plant for the year 2000 and beyond. Advances have come from all over the world, and include new scrubbing area designs, catalyst contacting devices, silicon stainless alloys for unlined acid systems, energy recovery from acid heat, stainless converters and heat exchangers, etc. This paper describes each of the process "advances" and presents a review and analysis indicating advantages, operating experience and limitations.

Jan 1, 1988

By Russell James Hewertson

Since 1989 Air Products and Chemicals, Inc. has converted over 40 air fuel fired furnaces to oxy-fuel and air-oxy-fuel. Advances in burner design, flow control technology and operating experience have lead to improved performance with quicker melt times and lower costs. Metal recoveries are improved by faster melting and better furnace atmosphere control, allowing lower grade materials to be processed economically. The presentation will discuss the improvements made in recent years and review data from state of the art installations.

Jan 1, 2000

By F. E. Katrak

Rare earths markets by definition usually include not only the rare earth elements, but also yttrium. They can be subdivided into a very large light rare earth fraction (about 95 percent by weight of all rare earths consumed) consisting mainly of cerium and lanthanum and a smaller fraction (with much higher unit value) consisting of selected high-purity oxides or elements such as yttrium, europium, samarium, or neodymium. CRA estimates that the noncomnunist world market for all rare earths and yttrim was on the order of US$750 million in 1986. The main focus of this paper is on the principal uses for rare earths, some CRA-developed proprietary data on their consumption by region, and the selective nature of business opportunities in the rare earth markets. We also provide forecasts on the future trends in these markets.

Jan 1, 1989

By Roberto Parra, Roberto Parada

"A novel process for minor elements control in copper pyrometallurgical production is proposed based on a theoretical analysis and the results of an experimental program. Its application can solves operational problems related to volatile elements that determine pollutants gas emissions and the final quality of anodes. The process considers a calcination of mixtures of the dust with sulfidizing agents such as dirty copper concentrate or elemental sulfur at temperature under 800 °C. The product are a clean calcine that recovers all the Cu content on the dust and a gas stream that collect the minor elements as sulfides species. The calcine can be returned to the smelter avoiding the As increasing in the circuit and so on, the capacity for the treatment of dirty concentrates for the smelter can be higher. The possibility to apply vacuum in the calcinations step can decrease the operation temperature. The solid condensed from the gas has different options for its stabilization, with the advantage that this stream represents few mass with high As content.IntroductionThe control of undesired minor elements (IVIES) in conventional pyrometallurgical copper production is especially relevant for ore deposits associated to Andes region. The concentrates that are being produced present every time higher levels of volatiles and harmful elements: group Va (As, Sb and Bi), Pb, Zn, and Sn."

Jan 1, 2008

By James D. Navratil

Ferrites have been used to separate a wide range of substances such as dissolved metal species, particulate matter, and organic and biological materials; they have been used almost exclusively for metal waste treatment applications. The versatility of the ferrite waste treatment technique is evident in the wide variety of application methods. Furthermore, ferrites can be used to remove selected impurities in feed solutions containing metal products requiring purification. A brief overview of ferrite properties and recent applications for metal recovery and waste processing will be presented.

Jan 1, 1990

By Chi Ru?an

Sollutions of ammonium chloride, nitrate and sulfate were studied in extraction of rare earths absorbed on a low-grade, kaolilnitic ore recently discovered in southern China. The results of percolation leaching tests and the recovery of the rare-earth values from these solutions are presented.

Jan 1, 1989

By Satian Niltawach

Iron sulphate jarosite through which iron in zinc sulphide concentrate feed is removed from the production circuit of conventional roast-leach-electrowin process, is chemically unstable and environmentally hazardous even if it is mixed with lime. If zinc silicate ore is used at similar chemical conditions in place of calcine in the jarosite precipitation, the resultant silico-jarosite residue having been mixed with lime is chemically stable and environmentally friendly. The recovery of zinc from silicate ore is also higher than that from calcine.

Jan 1, 1994