U.S. REPORT Asarco building new SX-EW plant

At a capital cost of US$54 million, Asarco (NYSE) says it plans to build a new solvent extraction- electrowinning (SX-EW) plant at its Silver Bell mine in Arizona. The new facility, which should be completed by 1993, will be capable of producing 18,000 tons of copper cathode every year.

President Richard Osborne said Asarco decided to build the plant to “take advantage of the existing 58 million tons of oxide ore reserves at Silver Bell and about 22 million tons of new reserves acquired near Silver Bell in 1989.”

Electrowinning, which replaces conventional smelting and refining techniques, is growing increasingly popular among copper producers. In fact, a new study by the Commodities Research Unit estimates that electrowinning will account for about 20% of total refined copper production by the year 2000.

Silver Bell was opened in 1952 as Asarco’s first domestic open pit copper sulphide mine. Although it closed briefly in 1984 because of high operating costs, the mine now produces about 5,000 tons of copper precipitates every year.

Asarco has also committed an extra US$26 million for expansion at the Ray mine at Hayden, Ariz., including $16 million for additional mining equipment.