Process concentrates, Arbiter

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. 

An example of this type of configuration is the Arbiter Process (2) for ammoniacal leaching of copper concentrates. The lixiviant consists of aqueous ammonia flowing counter-currently and oxygen sparged crosscurrently. 

Copper SX has also been successfully achieved using leach systems other than sulfuric acid. The Arbiter plant in Anaconda, Montana, treated an ammoniacal leach liquor from a sulfide concentrate using LIX 64N (Anon 1973). More recently, BHP Minerals (now BHPBilliton) developed the Escondida process in which copper concentrates are leached with anunonia and ammonium sulfate, and then purified by SX... 

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