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By H. -P. Behrendt

Muldenhiütten Recycling und Umwelttechnik GmbH is a lead smelter with a very long tradition. The first reference to the existence of smelters on this site is given by a document of inheritance dated 1318. Originally run as a primary lead smelter, which was supplied with ores from the Freiberg mining district and from overseas, it was required to change it over to secondary raw materials due the abandonment of mining in the Freiberg area in 1968. Today, Muldenhüitten Recycling und Umwelttechnik GmbH has two production lines; lead production from secondary lead and waste incineration, which are closely connected and gain advantage from each other. Installations, improved technologies, and the highly skilled personnel have contributed to satisfy all demands for a production concerning quality and environment.

Jan 1, 2000

By David B. Dreisinger

The total pressure oxidation treatment of arsenical copper ore and concentrate from the El Indio mine of Banick Gold was tested in benchtop autoclave treatment. The concentrate oxidation typically achieved ~95% copper extraction. Copper extraction was limited by the reprecipitation of a complex precipitate containing arsenic. Gold extraction by cyanidation of the oxidation residue was around 95%. Silver extractions were less than 10% due to the formation of argentojarosite in the autoclave. The total pressure oxidation of the whole ore sample was more successful. Copper extractions of 98-99% were routine achieved. Gold extraction by cyanidation was +95%. Silver extraction could be increased to as high as 95% by using the lime boil treatment. A process flowsheet was proposed based on the results achieved. Copper recovery was proposed by direct solvent extraction and electrowinning of copper by treating the dilute solution from the autoclave discharge.

Jan 1, 1999

By J. M. Floyd

Technology in use commercially and available for commercialisation for injection processing of base and precious metals in bath reactors is surveyed and compared. Differences between bath smelting and suspension smelting systems are highlighted in relation to important smelting criteria. The factors affecting the results achievable with various tuyere and lance injection bath smelting systems are discussed in relation to the various smelting, converting and refining operations involved in copper, nickel and precious metal processing steps. Process chemistry, process dynamics and heat and mass transfer rates are discussed for the different systems.

Jan 1, 1993

By Yun Li

In 1999 Yunnan Copper Corporation (YCC) decided to modernise their copper smelter and change the existing sinter plant I electric furnace process to a combination of ISASMEL T and electric slag cleaning furnace. The main aim of the project was to improve the environmental performance and decrease the energy consumption. Generally the project has been successful, partly attributable to the selection of a reliable and fully demonstrated technology. The design capacity for the ISASMELT furnace is 600,000 tonnes of dry copper concentrate per year. The furnace has been running smoothly since heat up in May 2002. YCC expended considerable effort in the preparation for plant operation. An extensive training program for key YCC personnel at the Mount Isa Copper Smelter improved their understanding of the process significantly and ensured successful hand-over of the technology. This paper describes the project history and summarizes initial operating results.

Jan 1, 2003

By C. M. Egert, S. Rajic

"We have developed a monolithic micro-spectrometer suitable for a variety of sensing applications including industrial process monitoring. The device consists of a solid structure with a volume less than 6 cubic centimeters. All optical components of the spectrometer including two aspheric mirrors, a diffraction grating, and entrance and exit surfaces are fabricated onto the surface of the structure. All light paths are internally contained within the structure. The result is a small, rugged spectroscopic sensor ideally suited for use as a process monitor. Due to its monolithic nature the device requires no post-fabrication alignment; nor can it be knocked out of alignment during use. Although many materials and thus wavelength regions were possible, the prototype device discussed here was produced in PMMA by precision diamond turning. However, lower cost manufacturing approaches involving injection molding are under development to produce an affordable sensor.Due to its rugged monolithic design, small footprint, and low cost the monolithic micro-spectrometer is ideally suited for distributed monitoring applications often required for industrial processes. It is expected that modified versions of this sensor designs will be required for specific applications so as to maximize the performance and resolution over the operating range. For example, the prototype device described here operates over a wavelength range of 500 nm to 1000 nm. The performance of this device as a real-time surface monitoring sensor will be discussed in detail. Our approach of using wavelength dependant scattering resulted in the reduction to practice of a miniature, monolithic, rugged, low-cost, micro-instrument in a sensor sized package. The process sensor applications community has been faced by the cost versus performance issue. Simple go/no-go sensors are typically inexpensive but they provide very limited and sometimes dubious data. Scaled down traditional instruments offer very good measurand information but are typically cost prohibitive, fragile, and still relatively large. This work will bridge the gap between these two extreme sensing alternatives."

Jan 1, 1997

By Robert D. Pehlke

"The evolution of oxygen steelmaking is reviewed and new operating processes are described. The developments which could impact this technology are summarized. Staged and continuous steelmaking are considered in the light of new technologies. The future opportunities for oxygen steelmaking processes are overviewed. IntroductionThe use of oxygen in steelmaking was originally brought on the scene by the development of pneumatic steelmaking. Sir Henry Bessemer in England originally conceptualized the use of gaseous oxygen in steelmaking, and then he and William Kelly in Eddyville, Kentucky independently developed the original pneumatic process which involved blowing air through a bath of molten pig iron to oxidize the carbon and silicon and produce steel. This process and many following processes, including those which would use pure oxygen gas, have been proposed.Beginning with the first commercial oxygen steelmaking vessels at Linz, Austria in 1952, the world steelmaking industry has adopted this style of processing. In general, the process has involved the use of steel scrap in amounts from 20 to 35% of the metallic charge with molten pig iron produced in blast furnaces making up the remainder. The impurities in the charge are oxidized through the use of oxygen gas injected into the steelmaking vessel.However, currently being adopted into commerical practice and on the horizon are a number of advances in this process which include the use of iron ores as a source of iron and oxygen, the use of an all scrap charge, incorporation of pre-reduced iron, the use of auxillary fuels to change the balance of cold and liquid iron-base charge materials and numerous refining techniques."

Jan 1, 1988

By Brian Lightfoot

Ausmelt Technology uses a furnace/slag/lance system in a way analogous to the way a chemical engineer would use a mixed reactor. The technology is sufficiently versatile to treat materials under a very wide range of temperature and chemical conditions. At one extreme the system has been operated at temperatures high enough and oxygen potentials low enough to make iron. At the other extreme it has been operated of temperatures as low as 800°C and oxygen potentials high enough to cupel lead from silver. This versatility permits the treatment of a great variety of wastes including asbestos, mixed organic\heavy metal wastes, incinerator ash smelter residues, waste water treatment sludges, organochlorine compounds and many others.

Jan 1, 1994

By Pradip

The selective adsorption of chemisorbing fatty acids at high temperatures together with the addition of soda ash and lignin sulfonate as depressants is the key to the industrial processing of bastnaesite ores. This paper presents the results of a fundamental investigation that indicate that alkyl hydroxamates can be an alternative collector for the beneficiation of bastnaesite ores that contain barite and calcite as the principal gangue minerals. The primary mechanism for providing sites for the chemisorption of hydroxamate on bastnaesite appears to be through dissolution of cations, formation of the respective hydroxo complexes and readsorption at the interface.

Jan 1, 1989

By G. Ríos

Atlantic Copper Metallurgical Complex in Huelva (Spain) was commissioned in 1970 with a capacity of 40,000 tpy of copper from concentrate. In 1975 the old blast furnaces were replaced by the Outokumpu FSF technology. During the last 30 years, through several expansions and technical modifications, the production has increased up to 300,000 tpy of new copper. This paper describes the developments on the control of impurities that have been made to fit new situations, such as a new artificial gypsum plant, a new electrolyte treatment plant or different secondary materials handling management.

Jan 1, 2006

By M. D. Bishop

Loss of organic solvent extraction circuits occurs through several accepted methods. Losses are commonly attributed to entrainment of the plant organic and evaporative loss of diluent. Evaporative losses of diluent have been estimated using various models or by considering all losses over and above entrainment to be due to evaporation. Other possible loss mechanisms are discussed and data on losses during weather conditions are presented. Accurate estimation of evaporative loss is vitally important to the industry due to both cost factors and environmental concerns. Data for and description of the Diffusive Flux Model are presented as an improved-method of estimating evaporative losses:

Jan 1, 1999

By Michael J. Virnig

The formation of crud is a normal part of operating a solvent extraction circuit for the recovery of copper. It periodically must be removed from the circuit. This results in significant costs in terms of manpower, downtime, and loss of circuit organic. Field studies have been carried out that show that the presence of a thermodynamic modifier in the organic phase contributes to crud formation. In an effort to better understand what factors contribute to crud formation, laboratory studies involving competitive adsorption studies with model solids have been carried out. The results of these laboratory studies will be integrated with the results of the field studies to present a better understanding of crud formation.

Jan 1, 1999

By Laurentiu Nastac

"The importance of investigating solute redistribution during the unidirectional solidification of multi-component alloys is broadly discussed in the literature. A previously developed analytical model that was experimentally validated for Al-Cu, Sn- Bi and Fe-Si dilute binary alloy systems is used in this article to study in detail the solute redistribution, the liquid/solid interface stability based on an extended transient constitutional undercooling criterion and the size of the initial transient region during the unidirectional solidification of Ti-6-4 and Ti-17 alloys. A comparison between Ti-6-4 and Ti-17 alloy systems with respect to interface stability and the size of the initial transient region is also provided. The effective partition coefficients of the alloying elements in these alloys were determined based on specially designed experimental measurements.IntroductionThe importance of investigating solute redistribution during alloy solidification is broadly discussed in the literature [1-5]. One of the relevant applications of this study would be the mathematical modeling of equiaxed and columnar solidification of multicomponent alloys. This includes the instability of the solid/liquid interface. There are several mass and heat transfer processes that involve the calculation of solute redistribution during directional solidification such as industrial directional solidification processes, continuous casting, remelting processes, Czochralski crystal growth technique, floating zone techniques, etc."

Jan 1, 2012

By W. Persson

The first installation at a copper smelter of a Semtech OPC System for continuous, on-line production control of copper converting in PS converters took place in 1994. At present OPC systems are installed at 19 PS converters. The technology presents to the operator real-time information on the progress of the process he is controlling in the form of optical process parameters, thus facilitating dynamic process control. The optical process parameters are based on time- and wavelength resolved registrations of the light emitted by the off-gas flames and identification of correlation between these parameters and characteristic metallurgical process data. The present paper provides a description of the technology as seen by the furnace operators and a summary of operating experiences made during five years of full-scale, operation at various smelters, reviews influences from the technology on smelter operational practises and comments on recent developments as regards new applications of the technology.

Jan 1, 1999

By Gary A. Campbell

This article is an analysis of world consumption of copper for the years 1976-1996. It is done to provide a comparison of what has happened over this time period with the trends of previous years in order to learn more about world copper consumption and to forecast world copper consumption trends into the new millennium. The analysis begins by documenting the geographic trends of consumption of copper for the years 1976-1996 by both region and key individual countries. Then, variables based on the intensity-of-use hypothesis and the intensity-of-use technique are selected and tested against the observed consumption behavior by using the correlation coefficient technique. The statistical results and their implications for the consumption of copper into the new millennium are discussed.

Jan 1, 1999

By Varadajan Seshadri

Torpedo cars have been extensively used for pig iron desulfurization although its geometry is not considered to be ideal as far as mixing and mass transfer are concerned. Complications arise from scaffolds formed through aggregation of flux, slag and pig iron during operation. Following industry demand a 1:6 torpedo car physical model was operated to assess the optimum refining conditions for pig iron desulfurization. Similarity between the model and prototype were established through Froude and turbulent Reynolds criteria. Mixing times were evaluated by pulse tracer addition and the kinetics of metal/slag interactions were assessed from experiments investigating iodine transfer from kerosene to water. The influence of parameters such as level of metal, gas flow rate, lance penetration, lance orientation, presence of scaffold were evaluated. Mixing times were found to be shorter than regular desulfurization time and also not very sensitive to scaffold presence. Scaffold contributes to the reduction of the useful volume only. Mass transfer at the permanent reactor is more effective when the torpedo is operated at its full capacity. The experiments also highlight the dominance of the transitory reactor as compared with the permanent reactor.

Jan 1, 2006

By Jonathan M. Berkoe

Design engineers and metallurgists have long recognized the need for better methods to calculate a wide range of fluid dynamic effects in smelters and hydro- metallurgical facilities. Examples can range from the capture of fume in the secondary hoods of a copper converter, to controlling the thermal effects of heat transfer resulting from metal and slag flows within a furnace. With the advent of relatively low-cost, high- speed computers and user-friendly, commercially available computerized fluid dynamic (CFD) programs, these calculations can now be made. Use of CFD increased the understanding of both hot gas and molten flows in smelter facilities and has already led to design improvements in converter fume control hoods as well as improved management of heat transfer in electric furnaces. This paper will present two representative CFD applications to metals industry facilities. To date, Bechtel has implemented CFD results on four continents.

Jan 1, 1999

By Chai Liyuan

Chromium-containing slag was detoxified by the method of microbial treatment using Ch-1bacteria isolated from nature by our research group, belonging to achromobacter sp. and with the characteristic of reducing high concentration of Cr(VI) in alkaline solution. The detoxifying process of Ch-1 to chromium-containing slag was studied by column-leaching techniques respectively. The results indicate that Cr(VI) in leachate can not be detected when chromium-containing slag has been column-leached for 7 days, and Cr(OH)3 content in precipitate is up to 32.8% with great value of resource recycling. Flowchart of engineering experimentation was ascertained based on the parameters of column-leaching experiments. Using the technique of pelletization of chromium-containing slag heap-leaching by Ch-1,the leaching rate of water-soluble Cr(VI) existing in chromium-containing slag reaches up to 100%, while the leaching rate of full chromium is up to 90%, when the process has been operated for 7-10 days under the conditions of 25-40C and consecutive spray by circular leachate. The content of Cr(VI) in chromium-containing slag after detoxified meet the national identification standard for extraction procedure inxicity for hazardous wastes(GB5085-1996) in China, moreover approximately 90% of Cr(VI) existing in chromium-containing slag has been recycled.

Jan 1, 2006

By M. Furuta

Tamano Smelter of Hibi Kyodo Smelting Co., Ltd. has been operating without a slag cleaning furnace (SCF) since its start-up in 1972. It has used its own developed coke combustion technology, the Tamano-Type Flash Smelting Furnace (T-FSF). The coke combustion technology that is the core of the process, along with the installation of a computer guided system and the improvement of the concentrate burner combustion in the T-FSF have all contributed to having acceptable copper loss levels in the slag without using a SCF. However, recently, because a high concentrate charge rate has been used in order to achieve a high matte grade in the T-FSF, a short settling time has been experienced and copper losses in the slag have become difficult to maintain at a lower level. Furthermore it is estimated that copper losses will further increase after the completion of the next expansion because with the aim of having a higher matte grade operation at 67% less coke will be charged and the reduction effect of the settler will be smaller. Therefore, in order to maintain the copper losses in the slag within proper levels the installation of SCF was decided. This paper, describes the operation before the introduction of SCF along with some theoretical considerations of slag chemistry.

Jan 1, 2006

By V. K. Handa

Sterlite Industries (I) Ltd. started its copper smelter in 1996 and worked through the common problems associated with smelter start-ups. Specific issues in the converter area included converter blower IGV problems, punching machine reliability, converter spitting, back collar burning, ,and short converter campaign life. With a very young and dedicated team of engineers and technicians, smelter management assigned teams of three to four members to work scientifically and systematically through each major problem area to recommend and implement appropriate solutions. The converter mouth was redesigned with respect to tuyere and metal height to eliminate spitting and back collar burning. The air line was changed in places to reduce the pressure drop. A new back-up compressed air line and vessel was installed to prevent tuyere blockage in the event of a blower trip or power failure. The converter mouth liners and bricking around the mouth was modified to eliminate metal leaking through the pouring lip Modifications to the punching machines were made to address specific problems and preventative maintenance practices were further streamlined and reinforced to ensure 100% availability of hot metal cranes, converter blowers, punching machines, and ID fans. Matte availability and matte temperatures were improved by streamlining the upstream ISA and Rotary Holding furnace areas. Implementation of a detailed training program for the converter operators significantly improved the operation and morale. Water-cooled double hoods and a third converter were installed as part of the smelter modernization plan. The new hoods dramatically improved hygiene in the crane aisle while the addition of the third converter posed new challenges for the same motivated group of crews with respect to flip flop operation to keep the idle converter hot and to maximize in-stack time, managing crane/ladle logistics, and managing revert generation. This paper describes the converter operation's journey from the initial days of long blowing times and large revert accumulations to present operations with two converter flip flop operation, and also describes the team work, constant focus on increasing productivity and reducing costs, and benchmarking.

Jan 1, 2002

By G. Archer

ASARCO, a large and diverse producer of nonferrous metals, is involved primarily in the smelting and refining of lead and copper. Lead-antimony alloys, antimony trioxide, bismuth, cadmium oxide, selenium, tellurium, silver and gold are among products which result from processing by-products of smelting and refining. The complex mixture of concentrates at some smelters and the high impurity loads at some refineries result in various drosses, sludges, dusts and slags. In this paper, the complex interplant and intraplant transfer of by-products is addressed. These by-products result in an exchange of metals between the lead circuit and the copper circuit. Examples of the transfer of by-products and the prospects for the recycle of valuable products from wastes generated by customers and unrelated processors are also discussed.

Jan 1, 1992