Cominco expands output capacity for minor metals

With a $2.3- million indium project and a $5.8- million germanium recovery project under way in Trail, Cominco Ltd. is set to become the lowest- cost world producer of the two strategic metals by year-end.

The germanium project, which will be completed by August, will allow initial production of eight tonnes of germanium per year, with provision for expansion to 15 tonnes. Work started on the germanium recovery circuit in 1987.

The company has been producing indium at its Trail base metal metallurgical complex for many years and, as both products will be concentrated in the same circuit, it was natural to expand indium production at the same time. Production will rise from about 150,000 oz per year to a potential capacity of one million oz of indium. Work started earlier this year and will be completed by year-end.

“The indium market is expanding rapidly,” says Klaus Goeckmann, Cominco’s vice-president marketing and sales, “and the germanium market has experienced steady growth. We forecast a strong future for both metals.”

With its own raw material input, Cominco will be a long-term, stable source for both metals. Indium is contained in lead concentrates primarily from the Sullivan mine at Kimberley. Germanium comes in zinc concentrate mainly from Pine Point and from future mines’ concentrate.

New process technology has been developed by the company’s Technical Research Centre at Trail. A concentrate will be produced containing both the germanium and indium. This concentrate will first be treated with Cominco- developed solvent extraction process to recover the indium. The impure indium will be refined in the existing indium refinery.

The residual solution will then be treated in a second solvent extraction process, similar to the first, to recover germanium. Impure germanium will be refined in a new plant being built at Trail. Products will include germanium oxide and high purity germanium metal. Some concentrate will also be offered for sale.

Both metals have high-technology applications. Germanium is used in night vision systems by the electronics industry and as a catalyst in the production of plastics. Indium is used in semi-conductors, light-emitting diodes, nuclear rods and other applications such as dental alloys and automobile windshield demisters.