Copper leaching

In Situ Leaching. Copper and uranium ores are sometimes leached ia place by circulatiag acidified mine water through the underground deposit. This process is known as solution mining. 

One, the CLEAR process, was investigated by Duval Corporation near Tucson, Arizona (29). It involves leaching copper concentrated with a metal chloride solution, separation of the copper by electrolysis, and regeneration of the leach solution in a continuous process carried out in a closed system. Elemental sulfur is recovered. Not far from the Duval plant, Cypms Mines Corporation operated a process known as Cymet. Sulfide concentrates undergo a two-step chloride solution leaching and are crystallized to obtain cuprous chloride crystals. Elemental sulfur is removed during this stage of the process. 

Another process, which also generates elemental sulfur as a by-product, has been patented by Envirotech Research Center in Salt Lake City (29). In the Electroslurry process, a ball mill finely grinds a chalcopyrite concentrate, which reacts with an acidic copper sulfate solution for iron removal. The Hquor is electrolyzed and the iron is oxidized to the ferric form. This latter step leaches copper from the copper sulfide for deposition on the cathode. Elemental sulfur is recovered at the same time. 

Less than 1% copper leaching was detected under the reaction conditions and it was demonstrated that the leached copper does not contribute to... 

The present description pertaining to copper refers to solvent extraction of copper at the Bluebird Mine, Miami. When the plant became operational in the first quarter of 1968 it used L1X 64, but L1X 64N was introduced in to its operation from late 1968. The ore consists of the oxidized minerals, chrysocolla and lesser amounts of azurite and malachite. A heap leaching process is adopted for this copper resource. Heap-leached copper solution is subjected to solvent extraction operation, the extractant being a solution of 7-8% L1X 64N incorporated in kerosene diluent. The extraction process flowsheet is shown in Figure 5.20. The extraction equilibrium diagram portrayed in Figure 5.21 (A) shows the condi-... 

Copper leaching Copper concentrate, sulfuric acid Uncontrolled leachate Heap leach waste... 

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. 

CLEAR [Copper Leach Electrolysis And Regeneration] A process for leaching copper from sulfide ores by boiling with aqueous cupric chloride ... 

Table 11.5 Production Capacity of Acid Leach Copper SX-EW Plants (2001) L... 

Leach caps have a significantly lower amount of Cu than in enrichment blankets due to downward migration and precipitation of leached copper in the form of chalcopyrite (CuFeS2) chalcocite (CU2S) and cuprite (CuO). 

Chevrel phase compounds, AxMo6Ch8 (Ch = S, Se or Te), may also be considered as intercalation compounds. Mo6S8 can be prepared by acid-leaching copper from CuxMo6S8. 

BioCOP [Biological COPper] A bacterial process for leaching copper from its ores. BioCOP uses an agitated tank for oxidation and leaching of copper sulfides. Developed by BUP Billiton and Codelco, which operated a demonstration plant in Chuquicamata, Chile, from 2003. Several plants have been operated commercially in Chile since then. 

Dynatec A pressure oxidation process for leaching copper from sulfide ores. Low-grade coal is added to disperse the molten sulfur produced. Being piloted by Dynatec Corporation at Fort Saskatchewan, Canada. 

HydroCopper A process for leaching copper from sulfide ores, using dilute aqueous cupric chloride. The copper is precipitated from the leach solution by sodium hydroxide, and the precipitated cuprous oxide is reduced to the metal by hydrogen. An intergrated chlor-alkali cell provides the sodium hydroxide and hydrogen. Planned for demonstration in Finland in 2003. 

Friedrich et al made several fundamental studies of the leaching process which led to a better understanding of the morphological development of the leached copper structures (ref. 9) and the kinetics of the leaching reactions and the relationship to the phase composition of the alloys (ref. 10). In two other papers (refs. 11,12) they characterised the surface of fully leached and partially leached alloy particles using physical and chemical adsorption and endeavoured to relate catalyst activities to surface area and pore morphology. 

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