Solvent extraction electrowinning process

The electrowinning process developed by Ginatta (34) has been purchased by M.A. Industries (Atlanta, Georgia), and the process is available for licensing (qv). MA Industries have also developed a process to upgrade the polypropylene chips from the battery breaking operation to pellets for use by the plastics industry. Additionally, East Penn (Lyons Station, Pennsylvania), has developed a solvent-extraction process to purify the spent acid from lead—acid batteries and use the purified acid in battery production (35). 

In addition, solvent extraction is appHed to the processing of other metals for the nuclear industry and to the reprocessing of spent fuels (see Nuclearreactors). It is commercially used for the cobalt—nickel separation prior to electrowinning in chloride electrolyte. Both extraction columns and mixer-settlers are in use. 

Increasingly more copper is being produced by electrowinning because of economics and technical advances, such as in solvent extraction processes. Certain brands obtained by SX—EW are treated as cathode quahty and are used directly by wire-rod manufacturers. Whereas in 1984 100,180 t of copper was electrowon in SX—EW plants, in 1992, 439,043 t produced by SX—EQ was electrowon (7). 

The resulting mixed-metal feeds can be processed using solvent extractants and the processes— see, for example, Figure 6 (Section 9.17.5.1.2)—often involve electrowinning of the metals from chloride solutions, providing chlorine for regeneration of the ferric chlorine leachant,... 

There has been much development of processes to electrowin Cu from chloride media,165 but to date no major plants using the solvent extraction coupled with electrowinning from chloride media have been commissioned. 

Arbiter Previously known as the Sherritt-Gordon ammonia process. A process for leaching copper from sulfide concentrates, using ammoniacal ammonium sulfate solution at 85°C and relying on air oxidation. Copper is produced from the leachate by solvent extraction and electrowinning. Sulfur is recovered as ammonium sulfate. Operated on a large scale by the Anaconda Copper Company in Montana from 1974 to 1979. See Sherritt-Gordan. 

Cymet (1) [Cyprus Metallurgical] A process for extracting copper from sulfide ores. It involves leaching, solvent extraction, and electrowinning. Developed by the Cyprus Metallurgical Processes Corporation, Golden, CO. Superseded by Cymet (2). 

The process flow sheet was first tested for direct leaching of steel mill flue dust and production of zinc metal by electrowinning. The tests were performed in a continuously operating pilot plant, producing 10-20 kg/day zinc metal. The same pilot plant was then used for treating copper/zinc-rich brass mill flue dust in a closed loop operation, recycling all the zinc solvent extraction raffinate to the copper circuit leach section. In the zinc circuit leach section, only the amount of zinc rich dust necessary for neutralization of the copper solvent extraction raffinate was used. The results obtained from the pilot plant tests indicated contamination problems within the solvent extraction loops. The estimation of economic data showed a weak return on the assets compared with the alkali route, and sensitivity toward the raw material price. 

BioNIC [Biological NICkel] A biological process for leaching nickel from its ores. It comprises bacterial leaching, solvent extraction, and electrowinning. Developed by BHP Billiton at Yabulu from 1999, but not commercialized by 2004 because no ore body of a suitable concentration and size had been identified. 

Cuprex [Copper extraction] A process for extracting copper from sulfide ores, combining chloride leaching, electrowinning, and solvent extraction. Piloted by a consortium consisting of ICI, Nerco Minerals Company, and Tecnicas Reunidas. 

The most important copper electrowinning production method is heap leaching of oxide copper ores with recovery by solvent extraction and electrowinning (SX-EW process). The general flowsheet of an SX-EW process is shown in Fig. 18. It is a low-cost method of copper recovery. This technology has recently been applied successfully to mixed oxide and chalcocite ores, notably in Chile. Currently, there are significant development efforts underway to try to extend heap leaching to chalcopy-rite ores. 

The copper electrowinning process requires concentrated solutions to improve mass transport and increase the solution conductivity. The pregnant leach solutions from leaching are too dilute and too impure for the direct production of high-purity cathodes. Electrowinning from these solutions would give impure, dendritic deposits. Solvent extraction provides the means for producing pure,... 

Fig. 18 General flowsheet of copper leaching, solvent extraction, and electrowinning process. 

Processes that use chloride leaching, solvent extraction to sulfate solution, and electrowinning from sulfate solution. 

In the Cuprex process, the copper sulfide concentrates were leached with a sodium chloride and ferric chloride solution in two stages to produce a cupric chloride solution. Copper is extracted by solvent extraction and recovered as powder by electrowinning. The process used... 

Cobalt is produced as a coproduct of nickel or copper refining. Copper-cobalt sulfide concentrates can be processed by the RLE process. Mixed cobalt-nickel sulfides can be precipitated from ammoniacal leach solutions and as mixed nickel-cobalt hydroxide or carbonate from acid sulfate leach processes. From chloride leach solutions, cobalt can be separated by solvent extraction. Most cobalt production is associated with nickel production from sulfide and laterite ores. Pressure leaching, solvent extraction followed by the electrowinning of... 

Metals are important resources and have a wide range of applications. Metals are often extracted from ores. Once the ore is mined, the metals must be extracted, usually by chemical or electrolytic reduction. Pyrometallurgy uses high temperatures to convert ore into raw metals, while hydrometalluigy employs aqueous chemistry for the same purpose. The methods used depend on the metal and their contaminants. Most metals are obtained by hydrometallurgical processes such as aqueous acids or alkalis are predominantly used to dissolve the metal oxides, sulfides, or silicates. Electrowinning and solvent extraction are frequently used to recover and concentrate the metals. A limited number of high-temperature molten salts have also been used for the recovery of refractory metals, such as titanium and aluminum, from their ores... 

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