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Massive Landslide In Kennecott Copper Bingham Canyon Mine, Oquirrh Mountains, Salt Lake City, Utah, United States
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Left behind is a molten copper sulfide called matte. The 70-percent-copper matte is water-quenched to form a sand-like solid, then injected, with oxygen, into a flash-converting furnace that produces molten, 98.6-percent-pure copper. This copper is then cast into 700-pound (320 kg) anode plates and shipped by rail to the refinery.
At the refinery, the anode plates are pressed flat and interleaved with stainless steel cathode blanks. Automated robotic vehicles place the prepared anodes in cells containing an acidic electrolyte. When the cells are electrified, the anodes slowly dissolve, freeing copper ions that are deposited on the cathode as 99.9-percent-pure copper.
Impurities and precious metals settle to the bottom of the electrolytic cells as "slimes." A chlorination leaching process recovers the gold and silver, which is melted in induction furnaces.
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