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By Victor Bredykhin

The report is devoted to the investigation and improvement of processes taking place at contact of large quantities of water insoluble liquid and particles of solid phase in a pulp. Theoretical analysis and simulation of acting conditions have allowed to determine that after attaching of oleophilic particles on the «water-reagent» separation surface the break of a formed complex is taking place according to the reagent volume and for oleophobic minerals along the «solid-reagent» separation surface. As a result particles are selectively treated if the magnitude of the reagent adhesion to the surface of solid phase in water is great. The results of dispersion are influenced significantly by availability of sharp edges on the surface of real particles. They keep tree phase perimeter of moistening. It is possible to fix reagent in the form of lens whose contact angle is significantly smaller in comparison to the thermodynamic angle. In adhesion dispersion the reduction of reagent volume, covering the equal area of particles surface is possible when the reagent is in a pulp in the form of thin films on the «water-gas» separation border. The process is tested in laboratory conditions as well as at pilot concentrating mills in flotation of sulfide ores, non-ferrous metals (copper-molybdenum ore), native sulfur and coal.

Jan 1, 2006

By J. L. Bill

The capacity of the Mount Isa Mimes Limited Copper Smelter was expanded in 1998 from 180,000 tomes per year of anode copper to 265,000 tpy. It is based on the innovative Copper ISASMELT technology, which currently treats concentrate at up to 184 tph. Increasing lance-air oxygen enrichment increased the ISASMELT furnace feed rate from 102 to 184 tph. The increased feed rate was achieved without any modifications to the ISASMELT furnace. The first refractory campaign following the upgrade lasted for two years. Future campaign lives of four years or more--without water cooling-are possible. Other Copper ISASMELT furnaces are operating in the U.S.A., Belgium, and India, with additional smelters under construction in China and Germany. In addition, Lead ISASMELT furnaces are operating in the U.K. and Malaysia. The paper discusses the performance of the MIM Copper ISASMELT furnace and the Copper Smelter since the expansion, including operating data and refractory performance.

Jan 1, 2002

By Todd S. Fayram

The Gordonsville Operation of Pasminco US Inc. along with the Center for Advanced Mineral and Metallurgical Processing (CAMP) at Montana Tech studied, developed and implemented a pilot scale hydrometallurgical facility for the industrial recovery of germanium and gallium. This paper describes the joint testing and engineering program that culminated in this successful process.

Jan 1, 2003

By Linping Yu

A simplified ED process was developed for organic acids recovery from cyclohexanone waste in this paper. In this regard, the one-stage ED was investigated directly without pretreatment, such as ion-exchange or nanofiltration to removal of foulants. The current efficiency and the energy consumption in the ED process for the recovery of carboxylic acids from cyclohexanone waste is theoretically analyzed and experimentally tested. The concentration of recovered carboxylic acid is related to many parameters and still needs more work to be determined.

Jan 1, 2009

By Patrick R. Atkins

Energy issues will have increasing impacts on decision making in all facets of society over the next few decades. Industrial users of energy and producers of products that affect energy use must be fully aware of the implications of their processes and products on the energy situation. This paper describes a model that has been developed for the aluminum industry that allows scenarios to be evaluated to gain improved understanding of possible implications for our businesses. A brief overview of the model is provided.

Jan 1, 2006

By Patrick R. Atkins

Energy issues will have increasing impacts on decision making in all facets of society over the next few decades. Industrial users of energy and producers of products that affect energy use must be fully aware of the implications of their processes and products on the energy situation. This paper describes a model that has been developed for the aluminum industry that allows scenarios to be evaluated to gain improved understanding of possible implications for our businesses. A brief overview of the model is provided.

Jan 1, 2006

By A. V. Tarasov

Technology has been developed for production of elemental sulphur from off-gas from autogenous smelting processes based on reduction of sulphur dioxide with natural gas with subsequent treatment of reduced gas containing hydrogen sulfide by the Klaus method. This technology has been applied on a commercial scale at the copper smelter of the Norilsk Mining and Metallurgical Complex for treatment of off-gas from the Vanyukov smelting process (PV). In the course of further improvement of the technology a catalytic version of the process has been developed based on the use of a catalyst at the reduction stage, which permits a decrease in the natural gas requirement by 25% to 30%.

Jan 1, 2006

By Yasumasa Hattori

Fluid flow in a flash furnace concentrate burner was investigated quantitatively in order to improve burner performance. Computational fluid dynamics was utilized for researching fluid flow in a burner port mathematically then its results were reviewed in the commercial flash furnace burner and its calculation results were found to be in good agreement with the actual measurement results. Based on those results, a mathematical fluid flow model for the Sumitomo flash furnace concentrate burner has been developed so as, to improve premixing and combustion efficiency of concentrate in the reaction shaft.

Jan 1, 2002

By B. S. Boyanov

The hydrometallurgical technology for zinc production in Bulgaria is characterized by the use of considerable quantities of imported zinc concentrates and several kinds of Bulgarian ones which are quite different in chemical, phase and granulometric compositions. In this connection, 7 sulfide zinc concentrates (Bulgarian and imported ones) were investigated by chemical analysis, DTA, TGA, X-ray diffraction analysis, sieve analysis. The accomplishment of optimal mixing of concentrates and providing stabile mix composition for a long period of time of roasting in fluid bed furnace is a task of primary importance in the technological process control in zinc hydrometallurgy. This can be achieved using mathematical optimization methods.

Jan 1, 2006

By Javier Antoñanzas, Juan Carlos Múgica, Lourdes Yurramendi

The gasification of wastes containing an organic fraction is usually performed at low-medium temperature using different kind of catalysts. The off gas obtained is a mixture of carbon oxides, mainly carbon monoxide, and hydrogen and can be used for different energetic applications. The main problem is the production of tars in the off gas that has to be separated from the valuable gas flow and, finally, treated separately. An interesting alternative is the partial or total treatment of organics at high temperature. In this case, the off gas contains a higher content of hydrogen and elemental carbon as particulate matter. The energetic source to obtain a temperature in the range of 1,000 - 1,200 ºC is obtained by a plasma torch. In order to make de process attractive, an important issue to be considered is to commercialize the carbon obtained for different industrial applications.

Jan 1, 2008

By W. John Rankin

Professionals, technical and non-technical, working in the mineral and metal commodity industries need to understand the concept of sustainability and its implications for the industry. Undergraduate courses have not done this well in the past. Much has been written in this field, and there have been great advances in understanding. However, much of what has been published is superficial and sometimes misleading, and there is as yet no coherent, single account that can serve as an introduction or overview for mineral industry graduates. This paper presents an outline which can guide readers in developing an understanding of the topic and its relevance to their work. Key references are provided, particularly those accessible on the internet, which will serve to introduce the reader to the important principles and understandings. The guide should also be useful to academics preparing students to work in the minerals and metal production sectors.

Jan 1, 2010

By G. S. Nus

Technology for treating man-made metal-containing raw materials in DC electric furnaces with polarization of the bottom phase (PDF furnaces) has been developed and proven on a semi-commercial scale. PDF furnaces permit processing of man-made raw materials, i.e. current and accumulated intermediate products with rather high contents of valuable metals (i.e. slags, sludge, residues, Waelz slag, etc.), as well as secondary raw materials and virtually any type of waste using an environmentally safe technique based on sublimation of volatile metals and transfer of non-volatile metals and sulfur into the bottom phase in the furnace. Processes developed on the basis of the use of PDF furnaces make it possible to take advantage on a full commercial scale of electrolysis of molten materials, including electrochemical reduction of metals, intensification of their settling into the bottom phase and sublimation of volatile components, as well as to significantly improve recoveries of nonferrous metals, resolve the problem of excessive accretion formation in slagging processes and substantially improve the environmental situation. The low-grade discard slag obtained can be utilized in the construction industry; in particular, slag can be added to the limestone feed for cement manufacture.

Jan 1, 2006

By Biserka Lucheva, Tzonio Tzonev

"Recycling of aluminum scrap and dross is significant in the economic and energy saving, as well as in the environmental protection. Recovery of metal aluminum depends on many factors. The aim of this work is to investigate experimentally the metal recovery under different conditions. The processing of aluminum dross was carried out in DC electric arc rotary furnace. The optimal technological parameters are determined. It is turned out that the presence of crushing refractory bodies during the processing of the aluminum dross in the rotary furnace increases the degree of aluminum recovery with about 10 %.IntroductionCompact and granular aluminum dross are used for the fulfillment of the experiments, which were obtained by salt free melting of aluminum scrap. The only preliminary preparation of the compact dross is crushing them into proper size, in compliance with the size of the opening for furnace charging and removing of fraction – 1 mm. The granular dross is subjected to sieving also with the purpose to remove the fraction – 1 mm. In these conditions the content of the metal phase in the compact dross is 72 %, and in the granular – 77 %. The processing of aluminum dross was carried out in DC electric arc rotary furnace (Figure 1).The purpose of this research is to investigate experimentally the metal recovery under different conditions and to establish the dominant factors, which need to be controlled."

Jan 1, 2008

By Mingzhou Li, Lin Wu, Changren Tong, Fengli Yang, Shaohua Yang

"According to characteristics of Tm, Yb and Lu enriched oxides composition and problems in its traditional extraction separation process, the computer simulation of a optimized fuzzy extraction separation process, in which three products with high purity(>99.99%) could be obtained at same time, was carried out. Distributing Curves of every element in both organic and aqueous phases were worked out. Distribution rules of rare earth elements in every stage of the optimized extraction process were studied. The computation results of economical and technical index showed the consumption of the acid and base chemical reagents in the optimized process would be saved more than 30%.IntroductionFor the solvent extraction separation process of rare earths, countercurrent extraction process was widespread in the industrial practice. Normally, rare earth ions were extracted by the saponificated extractant and transferred into the organic phase, where the acidic extractant was saponificated by the base firstly. Then, the loaded rare earth ions were stripped from the organic phase into the aqueous phase by the acid. Therefore, the acid and the base were the main consumptions in the process, and the equilibrium acid of the stripped rare earth solution was one of the main pollution resources. Meanwhile, for the heavy rare earths, such as Tm, Yb and Lu, stripping was more difficult, and the equilibrium acidity of the stripped rare earth solution was higher, so the acid consumption increased greatly."

Jan 1, 2012

By Donald O. Voit

A BASIC language program has been written that simulates the performance of an integrated solvent extraction circuit consisting of an extractor, a reflux fed scrubber, and a stripper. The program is designed to simulate the performance of a circuit having an aqueous feed containing each of the lanthanides as well as yttrium. The Kremser equation is used to determine the separation occuring in each section of the circuit. The required input variables are the feed composition, the separation factors, the light key extraction factors and extractor feed zone distribution coefficient, the number of stages, and the reflux ratios. The program calculates the composition of the streams at each node in the circuit, the total loading, and the remaining distribution coefficients. User interaction with the program is essential. The program has no capability to determine if the calculated values are consistent with various real restraints. Knowledge of the physical, chemical, and equilibrium behavior is essential to successfully utilize the program. The number of iterations required to achieve steady-state provides insight to the circuit response times. With suitable supervision the program can be used as a simulator for operator training.

Jan 1, 1989

By Yong Hack Lee

Electric Arc Furnace (EAF) dust is generated when scraps are treated in the electric arc furnace and usually classified as hazardous industrial waste in most countries. EAF dust usually contains 15 to 25% of zinc and 3% of lead. It is usually treated in rotary kiln (Waelz process) or landfilled after a solidification and stabilization treatment. Numerous methods have been proposed as the EAF dust treatment technology, but few of them are in operation as a commercial scale except the Waelz process. Korea Zinc performed a plant test in which 600 tons of EAF dust was treated using TSL (Top Submerged Lance) technology. The TSL technology is a low cost, proven technology for processing zinc-bearing residues. The EAF dust was first de-chlorinated and fed to the TSL furnace. Finally, clean slag satisfying toxicity criteria was generated and valuable metals such as zinc and lead were recovered as fume oxide. The fume oxide was de-halogenated by sodium carbonate and sent to zinc refinery to recover zinc and lead. The recovery of zinc and lead was 90% and 93%, respectively. Most of the dioxin in the EAF dust was discomposed so dioxin less than the Korean regulation limit was detected in the offgas, which proves that the TSL technology is the best solution to treat EAF dust.

Jan 1, 2006

By Corby G. Anderson

Over the past 15 years, numerous pressure oxidation plants for pretreatment of gold ores and concentrates have been installed throughout the world. While this technology is now established, it suffers in terms of the complex engineering and operational characteristics inherent in utilization of high temperatures (i.e. up to 225oC) and high pressures (i.e. > 3000 kPag). This paper outlines the application of an industrially proven pressure leaching methodology utilizing nitrogen species catalyzed pressure leaching and alkaline sulfide gold leaching. As such, it stands as an economic and engineering advancement in pressure leaching and non-cyanide treatment of gold ores and concentrates. In particular, the technology offers significant technical and economic advantages over traditional pressure oxidation and cyanide gold recovery in the treatment of gold bearing chalcopyrite ores and concentrates. An example of this will application will be delineated in this paper.

Jan 1, 2003

By A. N. Lasseigne

Hydrogen storage capabilities of LaNi5 intermetallic compounds were investigated utilizing the combination of thermoelectric power, Beeghly Ester-Halogen digestion, and Leco hydrogen determination. Thermoelectric power has demonstrated a rapid hydrogen assessment capability and can achieve the equivalent of the pressure-composition-temperature (activity) diagram. Effective use of hydrogen storage materials occurs in the two-phase, alpha+beta region of the PCT diagram. A thorough assessment of the content of each phase in this two-phase region to optimize performance of the hydrogen storage materials is described. Practices using the combination of these three analytical practices for rapid characterization of LaNi5intermetallic alloys are discussed.

Jan 1, 2006

By Tracy T. Morris, Luis G. Navaro

"Anodic copper slimes produced during the electrolytic refining of copper are routinely batch leached to remove copper. At the Amarillo Copper Refinery, an atmospheric leaching process was converted to an autoclave pressure leaching system to improve the removal of copper, reduce the consumption of oxygen, improve leaching times and enhance tellurium recovery. The benefits of pressurized versus atmospheric leaching of slimes were soon realized by obtaining the desired level of decopperization in a shorter time and with lesser quantities of reagents. The autoclave was designed and constructed with a unique oxygen injection system that enables good control of the leaching process and with no plug-ups. Other features include a mass measuring system that balances the quantity of slimes to be leached to the desired final solution concentration based on initial feed concentrations. The end result was a more efficient and controllable leaching process for removing copper from anode slimes.IntroductionThe electrolytic refining of copper consists of an electrolytic cell filled with a sulfiiric acid based electrolyte and pairs of copper anodes and cathodes. When a current is applied, copper in the anode dissolves and is plated onto the cathode. Impurities within the anode that are more noble than copper do not dissolve and end up at the bottom of the cell and are referred to as slimes. Gold and silver are the main slimes constituents of interest because of their monetary value, but there typically are significant quantities of selenium, tellurium, lead, antimony, arsenic, bismuth, nickel, silica and tin. Copper is also present, usually as a metallic or as a reactant with tellurium, selenium, oxygen or sulfur and can range from 10 to 30% of the slimes fall."

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