Cobalt is a rare and valuable mineral. It is usually found with copper deposits. Zambia has some of the world's largest deposits of cobalt but outdated equipment has restricted production. Now, reports Priscilla Ross, a private company is all geared up to take full advantage of the high prevailing prices for the mineral.
During the Cold War, cobalt was described as a strategic metal. Thankfully the Cold War has been relegated to the history books but cobalt is still a scarce resource.
Cobalt is used to harden steel, for example to make jet engine parts heat resistant. It is also used to harden cutting tools. Magnetic qualities make it useful in electronic and electrical equipment and it finds a diversity of applications in chemicals and paints. What is interesting about this minor metal is that it is usually produced as a by-product of copper but while the copper price is languishing around 65-70c/lb, the cobalt price is a handsome $18-20/lb.
With some rather good timing, the South African mining company Avmin bought the Chambishi cobalt and acid plant and Nkana slag dump from Zambia's state copper company, Zambian Consolidated Copper Mines (ZCCM) in September last year.
The Chambishi cobalt and acid plant is situated near the town of Chambishi on the Zambian copperbelt, 35km northwest of the town of Kitwe.
The Chambishi assets were purchased for $50m with Avmin owning 90% of the new company, Chambishi Metals Plc, and ZCCM retaining a 10% interest. At the time, it was the largest amount paid for any asset package in the ZCCM privatisation programme. Through the purchase, Avmin acquired a high grade on-surface cobalt and copper resource.
The two Nkana slag dumps, which contain 20m tonnes are situated at Nkana/Kitwe and consist of copper/cobalt arisings derived from ZCCM's Nkana smelter. The average metal content of the dump is 0.76% cobalt and 1.06% copper. The plant produced 1,844 tonnes of cobalt and 8,658 tonnes of copper over the past year.
When Avmin bought the Chambishi plant it comprised a roaster, leaching vessels, copper electro-winning and an acid plant. The plant dates back to the early 1970s and, according to Avmin, had been maintained to acceptable standards. The cobalt and part of the copper electro-winning circuits had been refurbished by ZCCM during the financial year prior to the Avmin takeover.
The acid plant was a conventional single pass plant with a capacity to produce 100,000 tonnes of sulphuric acid a year.