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By Allan MacRae

Freeport-McMoRan Inc. operates an ISASMELTTM furnace for the smelting of copper concentrate at the Miami Smelter in Claypool, Arizona. In May 2017, the furnace was restarted after incorporating newly designed copper cooling elements from just above the tap hole to the underside of the roof. The objective of the improved cooling design was to extend campaign life by eliminating existing failure mechanisms with the wall refractory. In addition to upgraded bathline coolers and complete coverage of the gas offtake transition, or ‘kettle’, with plate coolers, a novel arrangement of coolers was installed in the remaining freeboard area. The shell required significant cutting and re-stiffening, as well as extensive modification of the cooling water piping. Based on performance observed to date, it is expected that smelter throughput will be increased due to extended ISASMELTTM refractory campaign life.

By Wenzhou Yu, Cong Zhang, Wenhui Ma, Gang Wang, Kuixian Wei

"A novel technique was successfully developed for nickel further purification by vacuum directional solidification. The removal effect of impurities in nickel was studied based on theoretical analysis and experiments. High removal efficiency of impurities in nickel can be realized according to theoretical analysis. The experimental results show that the vacuum directional solidification treatment could increase the nickel purity from 99.96% to 99.996%. Since vacuum directional solidification could effectively remove the impurities from nickel with low contamination and low cost, it is a potential route to obtain high-purity nickel for commercial application.IntroductionNickel is widely used in metallurgy, machinery, petroleum industry, chemical industry, construction industry, light industry, and other industries for its ductility, medium hardness, ferromagnetism and high chemical activity. Nickel-based alloy is an important material for the key parts of aircraft, tanks, submarines, radars, nuclear reactors and aerospace fields [1-5]. Generally, nickel contains Si, P, S, Fe, Cu, Zn, As, Cd, Sn, Sb, Pb, Bi, Al, Mn, Mg and other impurity elements, which may hinder the commercial application of nickel. Therefore, it is necessary to refine the crude nickel for the high purity nickel."

Jan 1, 2014

By Thais Cristina da Costa Caldas, Alline Sardinha Cordeiro Morais, Carlos Maurício Fontes Vieira, Sergio Neves Monteiro

"This work has as its objective to evaluate the firing behavior of a kaolinitic clayey body from Campos dos Goytacazes-RJ incorporated with flat glass waste (FGW) from civil construction. Incorporations of the waste, with a particle size less than 74 µm (200 mesh), were performed in the red ceramic in the following amounts: 0, 2.5, 5 and 10 wt%. Specimens were prepared by uniaxial press-molding and then fired at 850 and 1050°C. The characterization of FGW was done by X-ray Fluorescence. The physical and mechanical properties evaluated were: linear shrinkage, water absorption and flexural rupture strength. The microstructure of the fired ceramics was evaluated by optical microscopy (OM). The obtained results showed that the flat glass waste can be used as a component of ceramic bodies once it was noticed tolerable modifications of technological behavior.IntroductionBrazil is one of the world’s largest producers and consumers of clayey ceramic. Campos dos Goytacazes is located in the north of the State of Rio de Janeiro, southeast of Brazil, it’s known as a large producer of red ceramics. It is estimated that the production of bricks can reach 1 billion pieces per year [1].Nowadays, recycling processes became more and more important, due the generation of wastes in large scale and the preoccupation with environmental. The amount of glass waste has been exponentially growing with the growth of the population. It is estimated that the amount of discarded glass as bottles, construction windows, packing and other glass waste represented in 2006 an amount of 7.5% of the total weight of the world´s domestic garbage [2]."

Jan 1, 2012

By T. Nagano

Mitsubishi Metal Corporation started the development work of a new process for continuous production of copper in 1961. After a series of experimental and semi-commercial operations, the first commercial plant of the Mitsubishi Continuous Copper Smelting and Converting Process was put into operation in March, 1974. The new plant, which has a design capacity of 4,000 metric ton copper per month, was built within the premises of Naoshima Smelter, replacing the old No.1 reverberatory smelter there. The SO2-rich exhaust gas from this new plant is blended with the off-gas of the No.2 reverberatory furnace for production of sulfuric acid and the overall emission of sulfur at Naoshima has been greatly reduced. The operation of the continuous plant has been satisfactory and several advantageous features of the Mitsubishi Process have been proven on a commercial scale. This paper first gives a brief description of the history of the development work and the characteristic features of the process. The paper then describes the new commercial plant and operating data obtained so far.

Jan 1, 1976

By John W. Ahlrichs

Microscope, electron microprobe and x-ray diffraction have been used to provide quantitative evaluation of products from the mill, smelter, refinery and other metallurgical processes. Phase compositions and their quantities are necessary for an adequate understanding of the various products obtained throughout an operation and in laboratory testing. By careful evaluation, important information can be gained in improving recoveries and increasing grades at various stages of processing. Four case histories are discussed in this paper. Quantitative microscopic counting techniques are applied to mill products to determine degrees of locking and liberation of the economic minerals. Rapid, but accurate evaluation aids the metallurgist to develop or improve the grinding and flotation circuits. In the smelter, the identification and quantification of the phases are important for predicting reaction mechanisms and kinetic trends. Mineralogic techniques have been applied to conventional smelter products, and to those obtained in laboratory tests for newly developed innovations to smelting. Small, but important, values of gold occurrences in ore are difficult to determine. Evaluation of gold usually requires special separations into various mineral concentrates, followed by assays and mineralogic determinations of the products. Numerous occurrences of solid solution constituents can be treated as by-products, but often they are deleterious to metallurgical treatment. Most solid solution problems can be unraveled by the mineralogist's tools.

Jan 1, 1981

Microstructural investigation has shown that grain splitting or deformation banding ( DB ) develops progressively with increasing strains during cold rolling. Of particular significance to simulating texture development in cold rolled BCC polycrystals is the operation of higher order slip systems other than 110 and, the occurrence of DB in the rolling plane since the latter allows a new relaxation of the shears. Deformation banding ( DB ) model includes grain subdivision in the rolling plane and applies the Relaxed Constraints ( RC ) mechanism for the other shears. An energy criterion for deciding whether deformation banding occurs or not has been postulated, referred to as Deformation Banding Criterion ( DBC ). This paper reports the results of the investigations into the effects of different slip systems, i.e., those based on 110, 112 and 123 slip planes and their combinations using RC, DB and DBC models, in developing simulated BCC rolling textures.

Jan 1, 1999

By D. M. Hausen

The term "auriferous pyrite" relates to an association of gold with pyrite in a variety of textural forms that affect metallurgical treatment. Extraction of the gold depends not only on the grain size and distribution of the gold in the pyrite, but also on the crystal size and surface area of the pyrite. Occlusions of medium to coarse gold may be liberated by moderately fine grinding. The amenability of finely dispersed (submicroscopic) gold depends in part on the activity of the pyrite surface for oxidation. Two types of auriferous pyrite at Carlin, Nevada, have been examined by optical microscopy and SEM methods before and after aqueous oxidation test work to show how differences in morphological features can affect rates of oxidation and amenability to gold extractions by methods of chlorination and low temperature oxidation.

Jan 1, 1981

By Alice Barreto Bevitori, Felipe Perissé Duarte Lopes, Denise Cristina Oliveira Nascimento, Sergio Neves Monteiro, Isabela Leão Amaral da Silva

"The piassava fiber is one of the most rigid natural lignocellulosic fibers, which has since the last decade been investigated as possible reinforcement for polymeric composites. In the present work, the tensile properties of polyester composites reinforced with piassava fibers with thinner diameters were investigated. Composites with volume fractions up to 30% of continuous and aligned piassava fibers were tensile tested at room temperature to evaluate the ultimate strength, elastic modulus and total strain. For each volume fraction, individually separated fibers with the smaller diameters were tested. The results indicated that the tensile properties tend to improve with increasing volume fraction of the thinner piassava fibers. The role played by the fiber/matrix interaction was analyzed by scanning electron microscopy.IntroductionA significant change in the transportation sectors mainly the aerospace and automotive, occurred last century with the introduction of stronger and lighter materials. The most relevant example was the polymer composite reinforced with synthetic fiber. They are nowadays replacing conventional materials such as the aluminum alloys in airplane body owing to superior specific strength. in recent years, however, environmental problems in a global scale are imposing a reversion in the use of synthetic fiber specially the glass fiber. In spite of its higher specific strength, this fiber and its polymer composites can neither be recycled nor incinerated in a thermal plant to generate electricity [1]. Moreover, the fabrication, processing and transportation of a glass fiber composite are associated with C02emission, the major responsible for global warming [2].A possible substitute for glass fiber without the above-mentioned environmental problems, could be a natural fiber. In fact, natural fibers obtained from cellulose-rich plants, also called lignocellulosic fiber, are already being used in several engineering fields, particularly the automobile industry [3-6]. Figure 1 illustrates an automobile and its many components made of lignocellulosic fiber composite [7]."

Jan 1, 2011

By Zhonglin Ye, Yifeng Shi

"This paper has outlined forms of Au & Ag losses in copper smelting process and methods for increasing Au & Ag recovery, analyzed factors influencing Au & Ag recovery in copper converting process, presented Au & Ag behavior in copper electrorefining process, and reviewed effect of current density/electrolyte circulation rate during electrolysis and surface finish of cathode on Au & Ag losses. Measures and research direction for decreasing Au & Ag losses in electrolysis have also been introduced. Based on Au & Ag behavior in copper electrorefining process and previous studies by others, new approach for increasing Au & Ag recovery in copper smelter has been discussed. And brief comparison has made between continued multiplication method and equilibrium method application in the case of calculation of Au & Ag recovery in copper smelter.IntroductionAs gold and silver are the major by-products from copper smelting process, efficient Au & Ag recovery has become one of the key approaches for copper producers to increase economic efficiency. With similar physicochemical properties, Cu, Au and Ag belong to the first subgroup of elements in the same periodic table. Au and Ag will be enriched into Cu phase firstly when both matte-slag phase and copper-matte phase appear in copper smelting process. However, great changes have taken place in Au & Ag proportions into individual phase due to changes of physicochemical conditions in each smelting process. Metallurgists at home and abroad have carried out a great deal of pilot plant tests and laboratory tests in order to increase Au & Ag the former Soviet Union with regard to Au & Ag losses in copper smelting process in the 1970s and 1980s, and he proposed solutions to increase Au & Ag recovery in copper metallurgical plants. As more than 20 years passed, Jingchun Lu's paper, Discussion on Increasing Au & Ag Recovery in Copper Smelting System, remains as a literature of the most comprehensive study. Based on Jingchun Lu's literature, the authors of this paper discussed new approaches to increase Au & Ag recovery in copper metallurgical plants with combination of many researches done by other researchers for over 20 years."

Jan 1, 2013

By Carlos M. Fontes Vieira, Ruben J. Sanchez Rodriguez, Carlos E. Gomes Ribeiro

"The worldwide demand for ornamental stones in building construction is motivating the use of their wastes, generated during fabrication, to produce compound stones. This work has as its objective to investigate the production of an ornamental compound marble (OCM) under vacuum and compression processing of a polyester matrix composite with addition of marble waste as load and as filler. Square OCM composite plates were subjected to compression and flexural mechanical tests. Samples were analyzed to obtain the density and water absorption. The OCM composites presented properties within the expected range of an artificial stone.IntroductionMarble is a limestone, composed mainly of calcite, more or less crystallized by metamorphism that ranges from granular to compact in texture. It has a density 2.7 g/cm3 and its porosity is approximately 0.4%. The UNI 8458 standard defined marble as: ""every crystalline rock constituted mainly by minerals with a Mohs hardness equal to 3-4"". In marble production around70 - 75% of whole extract material is lost in byproducts generation [1,2].In function of large volume of residues generated, the ornamental stones industry has attracted ever more the attention of environmentalists [3].Actually the marble can be pulverized to obtain calcium carbonate for industrial applications. It is also possible to obtain a thinner powder to produce concretes [l]. Some authors study the use of stone residues in concrete mortars and ceramic bricks, getting better properties to these materials [3,4].The marble residues can be also used in engineered stones, or ''agglomerated"" stones, production. The most common engineered stones in the market consist, like a polymer concretes, in polymer matrix composites incorporating petreous components. In the formulation of the engineered stones, the particulate or granular petreous components are the result of fragmentation or trituration processes to which natural stones were submitted to [ 5]."

Jan 1, 2014

By Minna Rämä

Iron containing leach residues like jarosite and goethite from electrolytic zinc production contain many valuable metals and harmful substances. These metals and substances should be removed in order to obtain an acceptable, stable and reusable product, and maximize economic feasibility as well as minimize environmental footprint. In this work, the processing of jarosite leach residue was studied in laboratory scale experiments under oxidizing and reducing conditions at high temperatures. First, the pretreated material was melted and oxidized to produce a melt of metal oxides. Second, the oxide melt was reduced in CO–CO2 atmosphere. Target after the reduction step was to obtain a clean slag and a liquid metal or speiss phase that collects the valuable metals, such as silver. The kinetics of the thermal processing were studied for determining optimal times and conditions for the aforementioned process steps. The preliminary results show that the process is thermodynamically feasible, and the desired phases can be obtained in the experimental conditions investigated.

By B. R. Davis, Neale R. Neelameggham, R. E. Brown

The element Calcium element has a unique place in the production of etals, intermetallics and other compounds. The unusualness arises from the fact that we have several possible reductants – metallic calcium, calcium carbide, calcium cyanamide and calcium hydride. A review of how metallic calcium is manufactured and utilized is presented. The difficulties involved in producing the metal in large quantities and price implications are noted. . Fundamental thermodynamics of how these act as reductants are shown, along with the historic application of these in metal production during the past century and a half. Alternate applications as to how to control the cost of the reductant is indicated, such as the numerous attempts in making low cost titanium utilizing direct or indirect calcium reductant.

Jan 1, 2014

By Florian Kongoli

Converters have been playing an important role in the extraction and processing of metals ever since the first type of converter was invented about 100 years ago. Historically their operation has been mainly based on the experience of talented operators rather than on strict control and optimization technologies. However, in the new realities of unavoidable necessity to increase productivity and in the conditions of diversification of primary materials from various geographical areas, improving control and optimization techniques have become indispensable. In this paper a review of the authors? previous work in terms of improving control and optimization of converter operational practices related to magnetite content and precipitation, slag and metal blows, problematic and dangerous elements such as As, Sb etc. has been described by highlighting the advantages that the new control and optimization methods and tools bring to everyday converter practices. Several examples are given and future work is underlined

Jan 1, 2005

By R. Leiby

Prior to March 1992, the only component of the lead acid battery that was not recycled by East Penn Manufacturing Company was the sulfuric acid electrolyte. This acid was unusable in new batteries because the iron level was found to exceed new product specifications. The development of a liquid ion exchange process to remove the iron from the acid allows East Penn to currently recover over three million gallons of sulfuric acid annually. The process is based upon the use of an iron selective liquid ion exchange material or solvent to extract iron from the sulfuric acid electrolyte followed by regeneration of the solvent. Equilibrium and kinetic data for the extraction and regeneration steps were collected in order to scale up the process to commercial scale. An electrochemical process for the treatment of the acid used in the regeneration step was, also developed which significantly reduces the volume of strip acid required in the process.

Jan 1, 1995

By Ross W. Smith

Microorganisms are increasingly finding use in mineral processing and hydrometallurgy both for the enhancement of mineral engineering operations and for the remediation of mineral industry wastes. Some of the applications, such as biologically assisted leaching of sulfide ores and biooxidation of refractory sulfide gold ores, are established commercial processes. Others, such as the use of organisms for the removal of heavy metal ions from dilute aqueous streams, are nearing commercial application. Other uses of microorganisms are potentially possible. These include use of microorganisms in leaching non-sulfide ores, the flocculation or flotation of minerals and remediation of toxic chemicals discharged from mineral engineering operations.

Jan 1, 1993

By R. Craig McClung

Contrary to other sulfide minerals, where recovery is principally liberation controlled, the recovery of molybdenite is more complex. It is this complexity that initiated a geometallurgical investigation of molybdenites from Bingham Canyon. The aim of this investigation was to determine the effect mineralogy and/or mineralogical attributes have on recovery. All samples were analyzed using normal mineralogical techniques. The results reveal the presence of two distinctly different types of molybdenite. These have been identified as the two polytypes of molybdenite: i.e. hexagonal (2H); and rhombohedral (3R). The 2H-polytype occurs as textbook-shaped particles in quartz-molybdenite veins that are located in the current pit bottom. The 3R-polytype occurs as disseminated, “ball”-shaped particles with a dull or frosted appearance and are concentrated along the margins of the current pit. Concerning their metallurgical behavior, each type exhibits unique metallurgical properties that are consistent with those reported in the published literature. The 2H-polytype is easily ground and kinetically “faster” floating with surface attributes that are amenable to higher rates of recovery. This results in the production of a high quality concentrate under normal operating conditions. The 3R-polytype, by comparison, is difficult to grind and kinetically “slower” floating with surface attributes that are less amenable to recovery. Therefore, in deposits with higher concentrations of the 3R-polytype, modifications to the normal operating parameters may be necessary to improve recovery. This investigation highlights the necessity for understanding the mineralogical characteristics of any economic mineral(s), as these will have a direct impact on recovery.

By Christoph Zschiesche

Managing complex material streams within a lead smelting/reduction process has a long history at Aurubis. After modernization of the secondary lead smelter in 1991, Aurubis operates an electric furnace and a Peirce Smith converter to process complex secondary materials. This process links the copper and the lead metallurgy allowing Aurubis to properly combine primary and secondary process lines to optimize the processing of complex raw materials and smelter intermediates. However, combination of copper and lead metallurgy processing requires a continuous evaluation as raw material quality and composition varies. This paper describes Aurubis lead smelter processing and provides some fundamental considerations to optimize the lead processing, in particular with aspects related to speiss formation

By Regina Krachler, Herbert Ipser

"The principles of the derivation of statistical-thermodynamic models to interpret the compositional variation of thermodynamic properties in non-stoichiometric intermetallic compounds are discussed. Two types of models are distinguished: the Bragg-Williams type, where the total energy of the crystal is taken as the sum of the interaction energies of all nearest-neighbor pairs of atoms, and the Wagner-Schottky type, where the internal energy, the volume, and the vibrational entropy of the crystal are assumed to be linear functions of the numbers of atoms or vacancies on the different sublattices.A Wagner-Schottky type model is used for the description of two examples with different crystal structures:For B'-FeAl (with B2-structure) defect concentrations and their variation with composition are derived from the results of measurements of the aluminum vapor pressure; the resulting values are compared with results of other independent experimental methods.For Rh3~ (with an NiAs-derivative structure) the defect mechanism responsible for nonstoichiometry is worked out by application of a theoretical model to the results of tellurium vapor pressure measurements. In addition it is shown that the shape of the activity curve indicates a certain sequence of superstructures.In principle, there are no limitations to the application of statistical thermodynamics to experimental thermodynamic data as long as these are available with sufficient accuracy, and as long as it is ensured that the distribution of the point defects is truly random, i.e. that there are no aggregates of defects."

Jan 1, 1996

By Jürgen Antrekowitsch, Thomas Griessacher

"Heavy metal containing residues are typically hazardous wastes because on the one hand, a deposition gets more and more complicated and on the other hand, the large amounts of metals like Zn, Cu, Fe and Pb represent a significant value. Thus, a post-treatment of these materials with the recovery/recycling of the metals and stabilization of the waste is not only ecological but often also economical. The therefore typically applied recycling processes utilize pyrometallurgical steps, where carbon or carbon monoxide from fossil coal and coke is used as a reducing agent, which results in large amounts of CO2 emissions. An alternative option is the application of a hydrogen-rich gas emitted in biomass utilization processes as a carbon-neutral reducing agent. Investigations in a retort process which were done at different temperatures and times showed excellent results concerning the achievable reduction rates and final contents of the heavy metals for various residues.IntroductionNowadays heavy metal containing residues like electric arc furnace dust (EAFD), dust from cupola furnaces, waelz slag, etc. are declared as hazardous wastes in a growing number of countries due to the leachability of the heavy metals in these residues. For that reason it is no longer possible to landfill these materials or use them for road construction or disposal works. Some land filling activities, carried out until now, have only been realizable because of some process modifications or cost intensive post-treatment steps of these residues. But the disposal capacities for such materials are decreasing, therefore increasing the prices. The second point for the growing disposal limitations is the stringent environmental legislations and regulations, which restrict the number and amounts of materials which can be dumped [1 – 5].From the other point of view these heavy metal containing residues usually have high contents of zinc, lead, iron, etc., which represent a significant value and therefore a big potential to recover these metals. This is why in recent years the number of recycling processes and the amount of recycled heavy metal containing residues have continuously increased. These recycling processes have the target to recover the valuable metals from the residual materials in the form of a saleable product as well as the stabilization of the slag produced in these processes [5, 6]."

Jan 1, 2011

By Ikuhiro Sumi

A new steelmaking process, in which manganese ore was intentionally reduced, was developed to achieve a higher manganese Yield using a combined blowing converter. In this study, manganese behavior was discussed through the introduction of a model. Apparent reduction rates of manganese were calculated by the two terms that were determined experimentally, with SOkg and 2S0ton combined blowing converters. The model calculated manganese changes during the operation. We applied the model to the actual operation and found that manganese behavior was predicted fairly well by this model.

Jan 1, 1996