Ferric chloride leach process

For operations producing 30,000 tons or less of copper annuaHy, hydrometaHurgy offers an alternative to smelting that avoids problems associated with sulfur dioxide recovery and environmental controls. Techniques include the Anaconda oxygen—ammonia leaching process, the Lake Shore roast-leach-electrowin process, and ferric chloride leaching processes for the treatment of copper sulfides. AH the facHities that use these techniques encountered serious technical problems and were shut down within a few years of start-up. 

W.J.S. Craigen and Canmet/MSL Staff, The CANMET Ferric Chloride Leach Process for the Treatment of Bulk Base Metal Sulphide Concentrates , MSL Division Report. MSL 89-67, June 1989. 

Atmospheric processes have also been studied. As examples, the FCL process (Ferric Chloride Leach) extensively investigated and developed by CANMET (2), and a nitrate-based process (3) could be cited. The ability of ferric ions to oxidise various sulphide minerals, in particular sphalerite, has been known for years, and this was the basis for the FCL process. One of the perceived difficulties of the FCL process is the use of a chloride medium, and there are several incentives to operate in a sulphate system, not the least of which is the fact that the sulphate system is extremely well established. 

Fig 9.5 - Aqueous ferric chloride leaching and electrolysis (Minemet process). 

Wong, M M, Haver, F P and Sandberg, K G, 1980. Ferric chloride leach - Electrolysis process for the production of lead, in Proceedings Lead-Zinc 80 Conference, pp 445-454 (The Minerals, Metals and Materials Society (TMS) Warrendale and American Institute of Mining, Metallurgical and Petroleum Engineers (AIME) ... 

Oxidi ng Solutions. In many leaching processes the mineral must be oxidized, as for instance, in the leaching of copper sulfides by ferric sulfate or ferric chloride solutions. 

Minemet A hydrometallurgical process for extracting metals from sulfide ores by leaching with ferric chloride solution. Developed by Minemet Recherche, France. 

Monk-Irwin An unsuccessful predecessor of the Sulfate process for making titanium dioxide pigment from ilmenite. Invented by C.R. Whittemore at McGill University, Montreal, in the early 1920s and subsequently developed by J. Irwin and R.H. Monk in Canada and B. Laporte Limited in Luton, UK. Ilmenite from the deposit at Ivry, Quebec was reduced by heating with coke, leached with ferric chloride solution, and then roasted with a mixture of sulfuric acid and sodium sulfate. The resulting cake, containing titanyl sulfate, was dissolved in water and hydrolyzed, and the titania hydrate calcined. Some of the product was extended with barium sulfate. The project was abandoned in 1928. 

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... 

Cymet (2) [Cyprus Metallurgical] A process for extracting copper from sulfide ores. Copper is leached from the ore using aqueous ferric and cupric chloride solution ... 

In the modern Hunt-Douglas process the ore is leached with dilute sulphuric acid, and the copper converted into cupric chloride by addition of ferrous chloride or calcium chloride. The use of the calcium salt entails removal of the calcium sulphate by filtration. The cupric salt is precipitated as cuprous chloride by reduction with sulphur dioxide, and the precipitate is converted into metallic copper by treatment with iron, or into cuprous oxide by the action of milk of lime. In this process the amount of iron needed is proportionately small, ferric hydroxide is not precipitated, and silver is not dissolved. 

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