Search Documents

By Walter Kahn

Increasing consideration is being given to simplifying traditional methods of tracing pipelines and maintaining required temperatures of stored fluids. Because of their reduction in capital costs, virtual elimination of maintenance. ease of control and "cleanliness"; interest in electrical techniques has accelerated. 1,2 Resistance cable and other heaters have been given some attention. but less well known in the recent introduction of thermal conductive coatings. This paper is addressed to the use of thermal conductive coatings for heating fluid-transport piping and storage tanks. Emphasis will be given to the simplicity, efficiency, and versatility of design and application which their unique properties further contribute to the general economics of electrical heating.

Jan 1, 1965

By R. F. Mehl, C. E. Birchenall

SINCE Maxwell1 first considered the self-diffusion process in 1872 its importance in the kinetic theory of matter has been recognized. Until the discovery of isotopes in 1913, a direct measurement of this quantity seemed impossible. The only information that could be gathered indirectly was for gaseous systems for which the kinetic theory was well developed. When methods of direct observation be-came available, investigations on self-diffusion were carried out in condensed phases. In metals these data are presumably of potential importance in the study of recovery, recrystallization, creep, sintering, and related phenomena. Following the pioneer work of Von Hevesy2 and his collaborators, who determined the rate of self-diffusion in lead with the naturally occurring thorium B isotope, several metals have been investigated. Pb, Ag³, Au.6,5, and Cu6,7,8,9 are examples of isotropic crystals existing in only one phase modification. Anisotropy of diffusion has been demonstrated in Bil6 and Znll. This paper is a study of a single metal in two allotropic forms and also of self-diffusion in a body-centered cubic lattice. Despite the fact that the measurements in each of the papers cited on self-diffusion in copper seem to be internally consistent to about 10 to 15 pet, the curves reported by different authors differ by factors of 2 to 4 at the same temperatures. This uncertainty may account, in part, for the failure to establish a successful correlation between the self-diffusion rates and other physical characteristics of the metals. No satisfactory theory of metallic self- diffusion has as yet been proposed to account for all the existing data and to permit estimation in other metals. Experimental Part: Two units of radioactive iron were used in these experiments, each a mixture of Fe53 and Fe59 (12). Fe53 decays by K electron capture and the emission of an X ray with a half life of about 4 years. Fe59 emits two beta spectra, one with a maximum energy of 0.26 Mev, the other 0.46 Mev, and gamma rays of 1.1 and 1.3 Mev, with a half life of about 44 days. They were present in nearly equal concentration initially. The composite half life started at about 50 days and increased as the Fe59 decayed, leaving Fe55 relatively more abundant. After aging a year, the half life was too long to measure significant decay in a month. The absorption properties also changed with time. Because of the importance of the absorption coefficient in the diffusion calculations, it was necessary to determine this quantity frequently over the period during which these experiments were carried out. This correction was unsuspected at the time of publication of notesl3 on this work and accounts for the discrepancy in alpha iron and for part of the discrepancy in gamma iron.* * The data in the present paper supersede those given in the notes entirely. In one note the scale of log D was inadvertently reversed. In addition to the correction for the drift in absorption coefficient, the D values for gamma iron at low temperatures were high owing to insuficient correction for diffusion occurring during heating and cooling through the high temperature part of the alpha range at a rate much slower than that employed in the runs reported here. The high temperature alpha rates are much higher than the low temperature gamma rates and correspond to large equivalent times at these temperatures. These experiments were discarded and new measurements taken. Independent experiments with the same activity units indicated a radioactive contaminant in the iron, but exhaustive attempts to isolate and identify it chemically failed. These experiments? indicate † These experiments will be discussed in a later publication from this laboratory. that the contaminant represented only a trace of little importance in the diffusion results. The active iron was plated from an iron chloride solution. Enough of the solution was dropped on a 1% in. square of filter paper to wet it thoroughly.

Jan 1, 1951

State of Louisiana, Department of Conservation, Division of Minerals, 126 New Orleans Court bldg , New Orleans, La. Dr. J. A Shaw, Director The Bureau of Scientific Research of the Minerals Division has recently issued the first of a proposed series of Geological Bulletins on the geology of Louisiana, by parishes The bulletin may be had for 25 cents postage by writing to the above address: Geological Bulletin 1, Geology of Iberia Parish (1931) Other bulletins of a more general nature have been published in the past. Bulletin 13, A brief survey of the natural resources of Louisiana (1930) (revised 1931), 14, The clays of the Shreveport area (1927), 16, The clays of Monroe area (1928), 19, The clays of Alexandria area (1929). The latest (Tenth) Biennial Report of the Department of Conservation for 1930-1931, containing a review of the natural resources of the state in the report of the Division of Minerals, may be obtained on payment of 25 cents for postage

Jan 1, 1933

By Stephen Hardcastle

Supplying ventilation in underground metal mines can be one of the most energy demanding services required to support production activities. Consequently, as energy, in the form of electricity or combustible fuels can be expensive and their unit cost is expected to increase, there is significant interest in reducing the overall demands of a mine?s ventilation system through such initiatives as controlling ventilation based upon demand and exploring other power alternatives to the current usage of the diesel engine in mobile mine vehicles. However, determining the benefit of any energy saving technology is complex and not universal applicable across the industry, consequently they have not been widely adopted. For these technologies to succeed they must be strategically applied based upon sound business cases. The intent of this paper is to provide information on some of the prospective control strategies and their potential impact on the power consumption related to supplying ventilation.

May 1, 2007

By R. Hogg, T. H. Dumm

"The mathematical treatments used in the evaluation of particle size distribution from pipet-withdrawal centrifuge data are reviewed. An error in the published procedure for multiple-sample withdrawal systems is pointed out and a corrected formulation is presented. An alternative treatment, based on a piece-wise linearization of the size distribution is described. Computer simulations of the analytical and data evaluation procedures indicate that the errors in the original formulation are not generally serious and that the corrected and alternative procedures lead to very similar estimates. Except for some cases involving very narrow size distributions, the alternative approach appears to give slightly closer estimates of the size distribution. Comparisons based on actual experimental data are also described.1 IntroductionSedimentation methods are widely used for the determination of particle size distributions. The procedures are relatively simple to use and the results are essentially absolute, requiring no external calibration. Gravity sedimentation is typically applicable to particles in the size range of about I to 50 pm and generally involves measurement of the relative concentration of particles as a function of depth and time in a dilute suspension. Particle size is calculated using Stokes, law:"

Mar 1, 1989

By N. Mashaba, D. Botha

The aims of this study were to investigate the factors that influence women’s engagement in technical positions in the South African mining sector and to determine what could be done to promote their successful participation. A convergent parallel mixed-methods research design was used to ascertain the factors that facilitate, inhibit, and influence engagement. In the quantitative phase of the study, questionnaires were circulated to women employeees; and in the qualitative phase, semistructured interviews were conducted with employer representatives, most of whom were human resource personnel. Confirmatory factor analysis showed that the three-factor structure (vigour, dedication, and absorption) of the Utrecht Work Engagement Scale fit the sample data reasonably well. Although there is room for improvement, respondents demonstrated acceptable levels of engagement in their work. On the other hand, the qualitative findings showed that employee engagement is impacted by unfavourable working conditions, work–life balance, and the mining industry’s male-dominated work culture. The findings showed that employee engagement should be elevated to a core human resource function. To increase the participation of women in mining, human resource professionals are encouraged to collaborate with mine supervisors, managers, and employees to develop programmes that promote employees’ absorption in and dedication to their work.

Nov 6, 2023

By Diego de Araujo Santana

O tamanho médio dos grãos é um parâmetro estrutural frequentemente estimado quando se está avaliando, principalmente, as propriedades mecânicas dos materiais metálicos. A American Society for Testing and Materials (ASTM) estabelece, nas normas ASTM E112 e ASTM E1382, metodologias para estimar o tamanho médio dos cristais de maneira manual e semiautomática/automática, respectivamente. O presente trabalho propõe, além de uma nova metodologia semiautomática, duas metodologias automáticas para estimar o tamanhão médio de grão em materiais metálicos policristalinos monofásicos, assim como um parâmetro para avaliar a morfologia dos grãos. O tamanho de grão G ASTM encontrado utilizando os novos procedimentos testados se apresentou muito próximo aos valores obtidos pelos métodos padronizados, que também foram aplicados e usados como referência para avaliação da representatividade das medidas. Desse modo, os métodos propostos se apresentam como uma alternativa viável para estimar o referido parâmetro estrutural dos materiais metálicos.

Aug 17, 2017

By A. Becker, C. Gauvreau, L. S. Collett

"A scale model was designed to simulate the airborne Barringer INPUT time domain electromagnetic system. The amplitude of the response to a vertical conductive dyke varies considerably with the conductor's thickness conductivity product (TCP). The response increases from a minimum detectable level at a TCP of about 2 mhos, rises to its maximum value at a dyke TCP of 15 mhos and then falls again so that conductors with a TCP exceeding 500 mhos would probably remain undetected. Measurements made with both standard receiver coil configurations (maximum or minimum coupled) indicate comparable effectiveness for both systems, either from the viewpoint of vertical conductor detection or from the viewpoint of discrimination against overburden anomalies."

Jan 1, 1972

By Frederick Carr

1. The application of retreat longwall mining to the North American coal mining conditions is be¬coming more advantageous as more experience is gained. The productivity results being achieved and potential possible illustrates that this system can be the keystone of future underground coal production. 2. In the American coal fields multi-entry is normally practiced as this allows profitable longwall development with existing equipment and systems. Difficulties are being experienced however in the longwall retreat phase by the col¬lapse of multi-entry roadways and excessive use of supplemental support in the following panel tailgates. In some instances the headgate of an operating face can also be in difficulty. 3. Jim Walter Resources Mining Division is developed on a mining plan that calls for three retreat longwalls at each of its four deep mines which have varying depths of cover and immediate roof and floor conditions. The #3 Mine has experienced longwall entry difficulty and there were differing viewpoints with respect to the best development systems to adopt particularly regarding the number of entries and pillar sizes. In an attempt to reconcile these different points of view J.W.R. asked Dr. Wilson to examine the problem and this paper outlines the new approach developed.

Jan 1, 1982

By Pedro Porto Silva Cavalcanti

A suscetibilidade à degradação mecânica de pelotas de minério de ferro é diretamente influenciada tanto pela composição quanto pela sua estrutura. O trabalho analisou criticamente essas relações para pelotas queimadas para a redução direta, por meio de análises detalhadas com quatro tipos distintos de pelotas, que incluíram análises químicas e mineralógicas, medidas de porosidade e distribuição de tamanhos de poros por tomografias de raios X, distribuição de poros por região da pelota por meio de microscopia, da dureza, bem como de resistência à compressão, abrasão, bem como um novo método de avaliação da resistência à fragmentação por abrasão. O trabalho mostra que há, de fato, forte correlação entre a suscetibilidade à degradação e várias dessas características analisadas. Forte correlação foi observada entre a porosidade e o tamanho máximo de poros. Boa correspondência qualitativa foi observada entre o acabamento superficial e a resistência à compressão. Resultados de um novo teste proposto de suscetibilidade à fragmentação superficial sugerem que a porosidade total e a mineralogia exercem pouca influência nesse comportamento, enquanto as características superficiais, como o acabamento e a microdureza exercem uma influência direta nesse mecanismo.

Aug 17, 2017

By Léo Daiki Shinomiya

O planejamento de cenários é uma ferramenta empregada como um mecanismo competitivo que entrega uma visão para um futuro passível de acontecer, baseado em fatos atuais e históricos. Adaptado para ser aplicado a resíduos industriais, este método de planejamento de cenários pode ser descrito em oito etapas. Neste trabalho é apresentada a 1ª etapa, que mostra o uso de pesos e critérios para definir as aplicações mais adequadas para a Lama Vermelha a partir de uma infraestrutura disponível localmente. A Lama Vermelha é gerada em larga escala pela indústria do Alumínio, somente no estado do Pará são gerados 5,4 milhões de toneladas anualmente, que impacta diretamente nos custos desta indústria em função de seu tratamento e estocagem. Os resultados guiam definições para as aplicações mais adequadas para a Lama vermelha, sendo destacado o emprego na fabricação de cerâmica vermelha e na produção do cimento.

Aug 17, 2017

By M. Tiedtke, T. Crary, P. MacPhail, M. Ounpuu

"The SGS carbon-in-pulp (CIP) / carbon-in-leach (CIL) model was used to evaluate and optimize the carbon circuit at Alamos Gold’s Young-Davidson Mine. Plants samples (pulp and carbon) were tested in a series of small scale batch experiments to determine rates of gold leaching and adsorption on carbon from a combined flotation concentrate/tailing product. The testwork data, along with existing plant data were then used to model the performance of the existing CIL plant and optimize the circuit to improve performance and overall recovery. The primary purpose of the modelling exercise was to determine the most cost effective way to lower solution losses at the plant. The modelling was also used to learn how the various parameters in the CIL circuit affect solution losses and the gold inventory tied up on the carbon. This resulted in recommendations for minor changes in the CIL flowsheet, which were successfully implemented in the plant. The approach, results and plant changes are presented.INTRODUCTION This paper presents the details from testwork conducted on samples from Alamos Gold’s Young- Davidson gold mine which is located near the town of Matachewan, approximately 60 km west of Kirkland Lake in Northern Ontario, within the southwestern part of the Abitibi Greenstone Belt. The objective of the test program (completed by SGS Canada in 2013) was to investigate and model the combined flotation concentrate / tailing carbon-in-leach (CIL) circuit and suggest ways to improve gold recovery. The metallurgical test program included mineralogy, rheology, and carbon modelling testwork. Plant information was provided during the test program and used in the optimization process. Upon completion of the testwork, plant changes were recommended and implemented at site (October 2014). Plant results from 2014 to 2017 confirmed the modelling results."

Jan 1, 2018

By H. Kurushima, S. Tsunoda

An investigation of the hydrometallurgy of Cu-Zn concentrates by The Dowa Mining Co. of Japan is described and a detailed flowsheet of the Kosaka hydro-metallurgical plant is given. Sufficient operating experience has shown that the Dorrco FluoSolids system has proven successful for recovery of both zinc and copper by roasting in a fluidized bed. At present, 2400 metric tons of concentrates per month are being treated and recoveries of 93 pct Cu and 65 pct Zn are being effected. A SURVEY of the Japanese chemical industry in 1949 revealed, among other things, that sulphur-bearing blast furnace gas from the Kosaka smelter of The Dowa Mining Co. Ltd., Kosaka, Japan, was being exhausted to the atmosphere as waste. In addition, it was costing that company an average of ten million yen ($28,000) annually for damages to the surrounding property caused by the sulphur dioxide in the gas. It was recommended by this survey that the gas be utilized for the production of sulphuric acid by the contact process. Mr. Kurushima visited the United States in May 1950 to investigate the engineering, construction, and operation of a contact acid plant. Any acid produced at Kosaka would necessarily have to be 98 pct H,SO, to prevent corrosion in railroad tank cars transporting it to the point of use. However, the production of 98 pct acid requires constant volume and SO, content of the gas. As the converter gas at Kosaka fluctuates in both volume and quality, it was decided to evaluate the smelting process with relation to other methods of recovery. This evaluation revealed a relatively new type of roaster, the Dorrco FluoSolids reactor, which was reported to be capable of roasting the copper sulphide concentrate in an excess of air with the production of an SO1 gas strong enough for acid production and a water-soluble copper sulphate calcine. The copper sulphate then could be leached from the roasted ore and electrolytic copper recovered from the leach solution in much the same manner as practiced by the Chile Exploration CO. for treating naturally occuring copper sulphate ores. Use of a reactor of this type would eliminate the need for a blast furnace and converter and, in addition, would effect savings in labor and fuel. The Kosaka ore is a microscopically fine mixture of copper, zinc, and lead sulphides. The lead and a small amount of the barite present can be separated by flotation, but any separation of copper and zinc proved extremely difficult. In blast furnace operation at Kosaka, zinc had been slagged off until a stockpile of about 12,000,000 tons containing 5 pct Zn had been accumulated. Mr. Kurushima felt that if any of the zinc in the concentrate was sulphat-ized and leached with the copper, it also could be recovered electrolytically. The Dorr Co., sponsors of fluidization technique in the metallurgical field, suggested that sulphate roasting be tested out on a laboratory scale and that, if successful, a commercial Dorrco FluoSolids system be constructed. They indicated that the results from such laboratory tests could be transposed to a commercial scale without pilot planting the roasting operation. It was therefore decided to send samples of flotation concentrate to the West-port Mill, laboratories of The Dorr Co., for testing. The objective of Mr. Kurushima's visit to the United States thus had changed from investigation of sulphuric acid plants to a fundamental examination of the hydrometallurgy of copper and zinc. Testing Program In February 1951, Mr. Tsunoda went to the United States to witness the application of the FluoSolids system to sulphate roasting at The Dorr

Jan 1, 1956

By C. F. Ellis

Interest in the composition of automobile exhaust gases has been greatly accelerated by recent studies that have indicated that these gases contribute to smog formation in urban areas. Several analytical methods have been published for the analysis of the hydrocarbons in the exhaust gases, but similar information has not been published on the analysis of the oxygenated compounds. This report presents procedures for chemical analyses of certain oxygenated compounds, procedures for sampling the exhaust gases for these analyses, and the analytical results of some experimental work in which these procedures were used. A stationary 1956 model, 170 horsepower, V-8, dynamometer-mounted engine, operated to simulate vehicular cruise conditions, was used for the study. Exhaust gases produced from a regular-grade Midcontinent gasoline during 15-40- , and 60-mile-per-hour cruise operations were analyzed by chemical methods for formaldehyde, total aldehydes, total carbonyls, total alcohols, carbon associated with the oxygenated compounds, and the oxides of nitrogen. Experimental results indicate: 1. The range of concentrations of the total of the functional groups of oxygenated compounds, expressed as moles per million moles of water-free exhaust gases, is about 90-100; the concentrations increase with engine speed. 2. Aldehydes comprise about 80-90 mole- percent of the total of the oxygenated groups, and formaldehyde accounts for about 50 mole-percent of the total aldehydes. 3. The order of magnitude of the concentration of the carbonyls is the same as that for the aldehydes, indicating that ketones are not a major group. A colorimetric test indicates that methyl ketones Constitute about 2 mole-percent of the oxygenated compounds.

Jan 1, 1961

By Jas. G. Ross

Introduction Asbestos, a mineral known and used in ancient times, has become an article of commerce only during the life of the older asbestos miners in Quebec. The diversified uses of this adaptable substance are now numbered by the hundreds. Wherever insulation or resistance to heat may be required, asbestos, either by itself or mixed with some other material, may be employed to advantage. Regarded as a curiosity for centuries, it is now in such common use that it is familiar to all. The demand for long fibre for use in the manufacture of textiles and brake-lining, and for shorter fibre for making shingles, paper, and insulation materials, serves to support the industry of mining asbestos-bearing rock and milling the fibre from it in Canada, South Africa, Russia, Cyprus, and the United States. The commercial use of asbestos dates only from 1876, in which year large deposits were discovered in the Province of Quebec, Canada. Prior to that year a small amount of long fibre amphibole asbestos was produced in Italy. Occurrence In Canada In the Eastern Townships of Quebec, along the line of the Quebec Central railway, is an area of serpentine rock. It extends westerly into Vermont and easterly to Gaspe. A part of it, the section from Danville to East Broughton, contains areas in which occur deposits of commercial asbestos fibre of the chrysotile variety. Pits have been opened on some of these deposits at Danville, Coleraine, Black Lake, Thetford Mines, Robertson, and East Broughton. Thetford is distant 68 miles from Quebec city, East Broughton lies 25 miles to the northeast of Thetford, while Danville is 45 miles to the southwest of Thetford.

Jan 1, 1927

By H Guthrie, J Hodder, J Bain, S Durkin

Australian mines have traditionally relied on diesel powered vehicles to fulfil their light vehicle needs. There are many reasons for the resources industry to review its use of diesel-powered vehicles. The international industry has developed projects to explore the use of Battery Electric Vehicles (BEV) as a more sustainable alternative to traditional diesel-powered vehicles. While the technology for cost-effectively applying modern high-performance lithium-based batteries to the mining environment has existed for over a decade it is yet to be widespread throughout the industry. Through the collaboration of Safescape, 3ME Technology and Kirkland Lake Gold, with funding from Mining Equipment technology services (METS) Ignited, the project has focussed on advancing the Australian METS sector’s capability in the rapidly approaching implementation of BEV technology. This paper reports on the collaborative approach to develop a prototype vehicle; explains the selection criteria for the various components of the vehicle; and details the risk-based approach to developing a scalable product to replace existing underground light vehicle fleets. The prototype vehicle was tested underground at Kirkland Lake Gold’s Fosterville operations in Victoria beginning in October 2019. Reporting from these trials focusses on the key factors affecting underground operations. These include driveability, safety, charging and cycle times. Gathering data around energy consumption through normal daily duties enabled a model of energy consumption and charging requirements to be developed such that various applications of the electric vehicle can be considered against existing diesel-powered vehicles. This has provided insight into the impact on daily operations, and the way forward for large scale implementation.

Mar 15, 2021

By Lucas Travi

Um dos tratamentos superficiais mais conhecidos é a nitretação a plasma, que consiste basicamente na introdução de nitrogênio na superfície da ferramenta, na forma de nitretos de elementos de liga, em solução sólida, a fim de criar uma camada protetora que aumenta a vida útil do material. A nitretação a plasma permite o controle da camada formada através do ajuste de parâmetros como temperatura, mistura gasosa e tempo de tratamento. Porém para ferramentas mais complexas é comumente utilizado um novo processo de nitretação, a nitretação a plasma com gaiola catódica que tem como principal diferencial o aquecimento homogêneo das peças, evitando assim a heterogeneidade da camada nitretada. Outra vantagem é que neste processo não é comum ocorrer o acumulo de plasma o que evita o efeito de borda. Neste trabalho, será analisada a importância da menor rugosidade superficial aliada a dureza superficial no comportamento tribológico do material no processo de nitretação a plasma com e sem gaiola catódica. O resultado dos ensaios tribológicos demonstraram que o incremento de dureza associado a uma menor rugosidade superficial obtido para a amostra nitretada com gaiola catódica promoveu uma redução no coeficiente de atrito ao longo do tempo. A rugosidade superficial média para as amostras nitretadas com gaiola catódica foi menor que as nitretadas via processo convencional, aproximando-se do valor obtido para às amostras que foram polidas.

Aug 17, 2017

By A. Fleming

The exploration process, like any other commercial activity, can only succeed if the objective of the exercise is clearly defined and persistently pursued. Successful exploration requires properties, funding, personnel and persistence. Many of us have years of experience in conducting exploration in our countries of residence. Conducting exploration in a foreign country, however, requires a number of significant other criteria.

Jan 1, 1997

By Henry F. Herley

The New Orient mine, owned and operated by the Chicago, Wilmington & Franklin Coal Co., has caused a great deal of comment and interest because of its unusual features and huge daily production. It is in Franklin County, Illinois, adjacent to the town of West Frankfort. The seam being mined is the Illinois No. 6 which in this locality is 9 to 12 ft. thick and lies approximately 500 ft. below the surface. Without fear of contradiction, it can be said that this is one of the largest coal mines in the world from a daily production standpoint. During 1928, New Orient produced 2,400,000 tons, which amounts to over 10,000 tons each day the mine operated that year. The mine is built for a capacity of 12,000 tons but has actually hoisted over 15,000 tons in one 8-hr, shift. This enormous production can perhaps be better visualized if it is realized that each day's operation depletes over two acres of coal. The general features of this mine have already been fully covered in a paper by George B. Harrington,' President of the Chicago, Wilmington & Franklin Coal Co. In a paper of the nature of Mr. Harrington's, it was unnecessary to stress any particular phase of mining conditions, consequently the ventilation problems were touched upon but lightly. In this paper an attempt has been made to describe some of the problems which have been encountered in providing adequate ventilation for the mine. Ventilating Conditions The acreage allotted to New Orient mine has a length, north and south, of approximately 6 miles, and a width, east and west, of 2 to 4 miles. A number of important considerations caused the hoist shaft, air shaft and surface plant to be located near the southeast corner of the property, instead of near the center, as is usual. During the initial phase of the mine development, the mine was ventilated through these shafts, although there was a full realization that at some future date other shafts would be required.

Jan 1, 1930

By Hiroyuki Sano, Chikabumi Yamauchi, Mitsuru Tanahashi, Toshiharu Fujisawa, Shin-ya Iwahori

"Pyrometallurgical process using Cu2O-based slag was proposed as a recycling process for copper scrap. However, it is difficult to remove nickel from copper by oxidative refining. Therefore, it is necessary to reduce the concentration of nickel in copper before the oxidative refining. In the present work, the copper enrichment stage in this recycling process, where copper scrap melt is separated into the Fe-C-Cu melt and the molten copper, was taken up and the compositions of both melts were measured. Based on the above results, the distribution ratios of nickel between the Fe-C-Cu melt and the molten copper were calculated. Furthermore, the optimum condition of copper enrichment stage was discussed from the viewpoint of nickel removal and copper recovery. The possibility of recovering 4N-purity copper by using this recycling process was confirmed.IntroductionRecycling is well known as a method for saving resources and reducing environmental damage. More than 99% of copper is used in metallic form - as metal or copper alloys[l]. High-grade copper scrap is directly re-melted and reused, while low-grade copper scrap is transported to copper smelters to be pyrorefined and electrorefined. Nevertheless, a great amount of copper is being stockpiled in the cities and should be recycled in the near future. At that time, the current recycling process will face new problems due to the increases in the recycling rate to the smelters. This includes insufficient combustion heat to melt copper scrap and ·almost no benefit in electrorefining because the scrap does not contain gold and silver. Thus, an alternative pyrometallurgical method for copper scrap refining will be required."

Jan 1, 2000