Magma Copper Co. has notified Alta Gold Co., 2319 Foothill Drive, of its intent to proceed with the purchase of the 12,000-acre Robinson Mining District near Ely, Nev., from Kennecott Corp. Both companies expect to the deal to be completed before Dec. 31.

Magma Copper, based in Arizona, would own a 51 percent interest in the copper resources of the district, and Alta Gold would own 49 percent, according to Dan S. Bushnell, Alta Gold chairman and chief executive officer."This is what we've been working toward for nearly a year. Buying the Robinson District from Kennecott, with a company such as Magma Copper, sets the stage for major growth for our company and positions us for a productive and profitable future for the next 15-20 years," said Bushnell.

He said preliminary data from an extensive feasibility study shows a reserve of 200 million tons of copper-gold ore. The companies contemplate building a concentrating plant, which will process 30,000 to 35,000 tons of ore per day, and is expected to produce 2.2 billion pounds of copper and 1.2 million ounces of gold.

A plant to process near-surface oxide copper deposits and old mine dumps also is planned. This plant could recover an additional 500 million pounds of copper.