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By E. O. Stensholt

The Hybinette electrorefining process for production of cathode nickel was in use at Falconbridge Nikkelverk A/S, Norway, until 1975 when conversion to the new chlorine leach process was started. In 1978 the conversion to electrowinning had been completed, but further major improvements to the process have been made up to 1987. After a major expansion program in 1985 - 87 the refinery has a nickel capacity of 54 000 mt Ni/year. The main feed materials to the process are converter matte from the Falconbridge smelter in Sudbury, Ontario, Canada, and from the BCL smelter in Selebi-Phikwe, Botswana. A typical composition of the mixed feed to the refinery is: 40 - 45% Ni, 25 - 30% Cu, 20 - 22% S, 2 - 3% Fe and 1.0 - 1.5% Co. The matte is chlorine-leached in the first process step, nickel being dissolved selectively in a train of leach-cementation tanks. Essentially all copper and sulphur that was present in matte appears in the leach residue as CuS. In 1986 an autoclave treatment stage was added to the process to improve nickel extraction from the leach residue. The resulting strong nickel chloride solution is purified by the process steps (1) precipitation of iron and arsenic, (2) solvent extraction of cobalt and other minor elements and (3) precipitation of lead and the remaining impurities. The nickel solution is then fed to the tankhouse, where various nickel products are produced by electrowinning. The chlorine gas that is produced during the electrolysis is returned directly to the chlorine leaching tanks to dissolve more matte. After stripping from the loaded organic phase and solution purification cobalt is also produced by electrowinning. The copper sulphide leach residue, which contains some nickel, is dead- roasted in fluidized-bed roasters. The sulphur is recovered and sold as sulphuric acid. The calcine is leached in spent copper electrolyte, from which cathode copper is produced by electrowinning. Precious metals and the remaining base metals are recovered from the copper leach residue. The Falconbridge chlorine process is very versatile. It can accept a wide range of impurities in the feed and still produce metals of exceptional purity.

Jan 1, 1988

By B. Yawney

A copper-nickel sulfide concentrate was leached in water at about 2000C under oxygen pressures of about 0.35 MPa. Oxidation of sulfide to sulfate was virtually complete in about 30 minutes, resulting in greater than 95% copper and 98% nickel extractions. Leaching temperature was shown to be the most important factor affecting metal extractions. Measured rates of oxygen consumption were used to develop batch kinetic data. Mini-plant continuous pressure leaching tests agreed with batch leach results. A proposed overall flowsheet is briefly examined.

Jan 1, 1976

By J. G. Reid

Nickel is second only to aluminium, of all non-ferrous metals, in energy required to convert the ore to metal. Nickel Laterite ores, which constitute the feed source for approximately 40% of world nickel production, are at a particular disadvantage because of the absence of sulphur, as an energy source, in the ore and because lateritic ores general 1 y are not amenable to beneficiation. The dramatic escalation of oil prices which commenced in 1973 and continued for a decade meant that Nickel Laterite refineries using oil as a primary energy source were placed at a distinct disadvantage relative to refineries utilizing nickel sulphide concentrate feeds. By the late 1970's the continuing large difference in oil and coal prices caused Greenvale to consider converting certain high oil consuming areas of the refinery to coal. These investigations confirmed that the areas of ore drying and power generation, which together consumed 50% of total Plant oil requirements, could be economically converted from oil to coal firing. Construction of the coal conversion facilities commenced in October 1980 and the first ore drying air heater came on line in August 1981. Construction was completed with the commissioning of the coal fired boiler in June 1982. This paper outlines the additions required to receive and utilize coal in ore drying and power generation and how the changeover was completed with minimal process disruption.

Jan 1, 1988

By G. Bjorling

After complete dissolution of chalcopyrite concentrate in sulphuric acid in presence of nitric acid the excess of the latter is expelled by a surplus of concentrate and the last traces of nitrate removed in the mother liquor after crystallization of the copper and iron sulphates. Zinc accumulates in the mother liquor from which it can be removed by solvent extraction of zinc sulphate as a pair of ions. After dissolution of the sulphate crystals in water the neutral solution is oxidized in an autoclave at 140°C where iron sulphate is thermally hydrolyzed; the iron-free solution is taken to copper electrowinning and the cell acid after partial evaporation recirculated with the mother liquor to the leaching circuit. Total recovery of copper is about 96%; other metals like zinc and iron are concentrated in industrially usable products. At a copper price of about 70 c/lb, the method appears to be profitable also in a small unit.

Jan 1, 1976

By Zhou Jiemin

In order to fully understand the behavior of the rectangular six- electrode electric smelting furnace and improve its design and operation, a three-dimensional mathematical model has been developed which incorporates the electrical and thermal flows into numerical solutions, assuming a steady state regime. The model has been used to simulate the performance of the 16500 kVA nickel matte smelter at Jinchuan in China, and various factors have been investigated. The results of computation are in agreement with the measured data obtained from this furnace and its physical model. Application of this model is described and the calculation on the Jinchuan smelter shows that the operation expenses can be reduced by optimizing the furnace geometry and some operating parameters.

Jan 1, 1991

By E. Gutierrez-Miravete

A computational method for the simulation of mold filling processes is described. The method is based on the representation of the flowing or deforming medium as a collection of mutually interacting parcels of material. Instantaneous positions of individual material parcels are calculated by numerical integration of the dynamic equations, subject to appropriate initial and boundary conditions. So far, the method has been used to produce qualitative simulations of some flowing and deforming systems encountered in mold filling technology, and our findings are summarized herein. In all cases, individual material particle motions can be followed in detail, allowing critical examination of potentially problematic mold design features.

Jan 1, 1992

By Hang Goo Kim

A mathematical analysis based on equilibrium modeling has been developed to describe the distribution behavior of minor elements such as Pb, Zn, Bi, Sb, and As among gas, slag and recovered copper phases during the reduction of copper oxide in slag cleaning with CO gas. The results show that large fractions of the impurities transferred to slag during smelting or converting are recycled to the recovered copper metal. It is also shown that there is a limit to the recovery of copper from slag because iron oxides are also reduced to form a copper-iron alloy at low oxygen potentials. The effects of various operating parameters such as temperature, the activity of FeO, the initial amounts of the elements in the slag and CO content in process gas, on the behavior of these minor elements are discussed. The predicted results were compared with the results of a pilot plant operation in which pulverized coal was used as a reductant. Consistent trends between the two cases were obtained.

Jan 1, 1992

By R. W. Lawrence

A method by which it is possible at an oxidation potential below 680 mV SHE to achieve quantitative conversion of sulphide sulphur to elemental sulphur instead of sulphate in a biological leach of chalcopyrite and bornite has been investigated. The process chemistry, biological phenomena and process flowsheet options are discussed. Several copper concentrates have been evaluated and have been found to be amenable to th process. Results to study the progression of chalcopyrite decomposition during the leach are presented and mineralogical factors affecting the requirement for silver addition are discussed. A chloride addition method for improving silver recovery is described. The results of a small scale continuous leach test have demonstrated that continuous operation can be carried out with high copper extraction and stoichiometric conversion of sulphide sulphur to elemental sulphur.

Jan 1, 1985

By Richard L. Summers

The shaped charge has proven in various military and industrial applications to be an effective penetrator of materials. Upon initiation a detonation wave traverses the explosive billet, collapsing a metallic liner and creating a jetting process. From multiple non-simultaneous flash radiographs of the jet in free flight, the observer can study the collapse, formation, and growth of a shaped charge jet. Digitization of a particulated jet's position and shape from the radiograph into electronic storage files provides the experimentalist with an efficient basis for data reduction. With the aid of a simple personal computer, one can in a matter of minutes generate a wealth of information concerning jet formation after initiation and thus gain insight into the quality of its manufacture, design, and assembly. This paper will in detail explain the methods in place for fully automated data reduction of radiographic films. Methods of computer aided digitization of particulated jets and analysis of physical jet characteristics and performance will be discussed.

Jan 1, 1992

By J. M. Toguri

The viscosity of the molten FeO-Fe2O3-Si0z system in the composition range of interest to copper smelting has been investigated using a rotating cylinder technique. The silica content of the slag was varied from 20 to 35 wt percent while the oxygen pressure of the system was varied from 10-7 10-11 atm. The temperature range investigated was from 1200 to 1350°C. It was found that the viscosity of the slag generally decreased with increasing temperature and increasing oxygen pressure. As the silica content was increased, the viscosity was found to increase.

Jan 1, 1976

By Kimura. E.

Continuous estimation of phosphorus content of molten copper is required to produce phosphorus deoxidized copper in a continuous casting operation. The phosphorus content of molten copper was related to its electric resistivity, which was measured by the four-probed technique with a specially-shaped cell. In a laboratory scale, the linear relationship between the above factors was confirmed in the temperature range of 1083OC through 1200°C. The phosphorus concentration range measured was from 40 to 500 ppm. The phosphorus content was monitored successfully by measuring the electric resistivity of the molten copper in the distributor of a continuous caster in an industrial scale.

Jan 1, 1992

By J. L. Sanchez

Using a special double-zone transpiration reactor, the vapor transport chemistry of vanadium pentoxide in the presence of water vapor has been investigated. Three possible volatile hydroxides above V,O,(s) are reported in the literature: VO,(OH),, V,O,(OH),, and VO(OH),. In the present study, it was established that VO(OH), is the principal gaseous hydroxide species formed. The predominant reaction was found to be: { } The vapor pressure of VO(OH), was measured as a function of temperature, water pressure, oxygen pressure and flowrate. The results have been used to determine the Gibbs free energy of the above reaction as a function of temperature: { } The results of the present work were combined with thermodynamic data reported in the literature to obtain expressions for the AGO for the reaction above V,0,(1) and the AGO of formation (units in cal/g-mole).

Jan 1, 1993

By René Bustamante

A GPSS/H simulation is beeing done for a traditional smelter of copper, which envolves a reberberatory furnace, a set of Peirce Smith converters (PSC) and a refining furnace. The objective is to try different plant layouts, being the handling of liquid material at high temperature one the mainly concern, this envolves a study of the ladles and cranes used. Some of the modifications that can be evaluated through the model is the role of oxygen potential when tonnage oxygen is used, number of cranes, PSCs in operation, etc.

Jan 1, 1992

By Aarne Kopanen

In recent years, various renovations have been carried out in the production chain of the Outokumpu copper refinirg process. The anode casting shop, which is the final integral production section at the Harjavalta copper smelter built in its original form in 1945, was fourxl unsuitable for technical and capacity demads during longer periods of operation, and a new casting shop was built in 1974. The electrolytic copper refinery of Outokumpu Oy at Pori was built in 1941, and subsequently expanded in two stages. Even with its present limited scale of production it has been fom important to mechanize the main operations. This work was started in 1967 with the design and construction of the starting sheet machine connected with the cathode washing and unloading machine as a combined unit. Mechanized treatment of anodes has gained advantage particularly from the new design of a highly automated anode casting shop. In the further development of the mechanization a stripping machine for, starting sheets was designed and installed, starting operation in 1974.

Jan 1, 1976

By Kazuteru Tozcwa

The oxidation of several sulfide minerals in aqueous ammoniacal solution is discussed thermodynamically. The region in which Cu(NH3)2 4+ is stable has been estimated as a function of pH and concentration of total ammonia, {[NH3) + [NH4)}. In ammonia leaching when copper in sulfides is assumed to be extracted in the form of Cu(NH3)2 which will be rapidly converted to cupric ammine, thermodynamic data predict that such minerals are oxidized readily in the following order, CuS, Cu2S, CuFeS2, ZnS, NiS, Ag2S. This agrees with investigations on ammonia leaching of sulfide minerals, reported previously. The leaching of copper sulfide concentrate has been examined experimentally. Copper in a copper sulfide concentrate, in which the main constituents were chalcopyrite and pyrite, was effective¬ly extracted. The copper extraction was affected by factors such as (1) agitation intensity, (2) oxygen partial pressure, (3) NH3/Cu molar ratio, (4) leaching temperature and (5) addition of ammonium sulfate. From the results obtained in this work, it is concluded that mass transfer of oxygen plays the most important role in ammonia leaching of copper sulfide minerals.

Jan 1, 1976

By Steven C. Torma

The present article reviews some of the technologies available for recycling high-energy yield explosives loaded projectiles. These activities lead to reduction of military ammunition stockpiles and their conversion into commercial and industrial applications. The recycling technologies involve dismantling and separation of ammunition components into recyclable metals, plastics, paper and explosive materials. The metal 1 ic components will be sent to smelters, where they will be converted to products that can be used in a variety of industries, such as construction, automotive, housing and so on. Plastics and paper will be recycled and reused. Explosives will be recycled to be used for industrial purposes in the mining industry. Propellants (ammonium nitrate and ammonium perchlorate) can be ground to small particle size and treated to be used in the agricultural industry as fertilizer. In addition, some of the excess explosive material recovered in the demilitarization process may be incinerated to produce energy for steam production for heating purposes, or for production of electricity. Furthermore, this article reviews the developments in the bioremediation of explosive contaminated soils and industrial effluents.

Jan 1, 1994

By Ullrich Kammer

Metaleurop's secondary lead smelter at Oker produces 60.000 mtpy of lead and lead alloys. More than 8O2 % of the raw materials are spent lead acid batteries. The other 2O2 % consists of drosses, ashes, scrap lead, type metal, sludges, etc., and is processed in a short rotary furnace (SRF). Also, industrial batteries not fitting in the battery scrap treatment plant are processed in the SRF provided with gas/oxygen-burner. Till Sept. 199O2, a soda ash slag was used in the SRF-smelting similar to the rotary kiln-smelting at Oker. Facing the future problems of handling and dumping soda ash slag, Harz-Metall GmbH has improved SRF-smelting with a non¬hazardous slag, insoluble in water, easy to dump and cheap in fluxes. This slag is based on a CaO-SiO2 -Fe0-type. Aim of the slag smelting is to be within the temperature range of 2 1100° and 1200°C - the eutectic line of Olivine in the corresponding ternary system. Since Sept. 199O2 Harz-Metall GmbH has operated the SRF with an "Olivine-type slag" with good results. Although the material is a "leady" slag. HMG is optimistic of using it as a filling material for construction purposes.

Jan 1, 1993

By Guo Gongyi

An extraction chromatography by which 99.99 % pure scandium oxide can be prepared from the starting materiel containing about 70% scandium oxide has been developed by taking advantage of some peculiar properties of the complex chemistry and extraction chemistry of scandium. The purification of scandium was performed at room temperature with relatively fast rates in two chromatographic columns. The preliminary separation of scandium from impurities was done by extraction chromatography using tri-butyl phosphate as the stationery phase in the presence of citric acid, and the nearly complete separation in the presence of perchloric acid. The scandium recovery was greater than 90 %.

Jan 1, 1989

By U. M. Mutnti

In order to meet the stringent market requirements for high purity cobalt, ZCCM commissioned the VIR plant in December 1982. The plant comprises a 4.1 tonne/heat vacuum induction furnace with a rated annual capacity of 2,500 MT of barstock. In the VIR furnace, molten cobalt is held under vacuum at 1600°C resulting in the removal of more volatile impurity elements by distillation. Operations todate have demonstrated that Pb, Zn and Cd have good distillation rates in excess of 95%, leading to cobalt containing 1 ppm or less of the above elements. Removal of other impurities such as Se, Bi is about 65% with the finished product still assaying around 1 ppm of each of these elements. Vacuum refining of cobalt offers an economic route for producing higher grades of cobalt from the type of concentrates and treatment processes available within ZCCM. The consistency of VIR cobalt quality has been confirmed by ZCCM and some of its alloy customers.

Jan 1, 1988

By Y. Y. Sheng

Plume flows created by gas injection into liquid metals have been studied extensively, however the dynamics of bubbles within the plume have not received adequate attention, particularly for large, irregular bubbles, characteristic of the processing of liquid metals. The present model uses a combined Eulerian-Lagrangian approach in which an estimated void fraction distribution is used to calculate the liquid flow field with a conventional Eulerian scheme. The trajectories of bubbles are then computed in a Lagrangian manner using the estimated flow field, and experimentally measured information on bubble drag coefficients', lateral migration due to lateral lift forces and interaction with turbulent eddies, and variation in bubble size due to break-up. Turbulence in the two-phase zone is modeled with a modified k-e model with extra source terms to account for the second phase which have been recently determined by the present authors. The computed void fraction and turbulent liquid flow field distributions are in good agreement with experimental measurements.

Jan 1, 1993