Govt seeks partners for Kwekwe roasting plant

Published: 08 May 2014

Government is seeking partners in the treatment of the Kwekwe roasting plant calcine dump and the establishment of a facility to recover gold from refactory gold concentrates with the view to boost the country's gold production.

Approximately $140 million could be realised from the calcine gold dumps.

In a statement, secretary for Mines and Mining Development Professor Francis Gudyanga said at least 3750 kilogrammes of gold was trapped in the dump.

"As a result of low gold recoveries there are calcine gold dumps at the roasting plant with already milled material at the surface estimated to be 625 000 tonnes at an average of 10g/t.

"Based on work previously done elsewhere, 60 percent gold recovery from the dump can be achieved through a process route involving a combination of ultra-fine grinding with acid pre-treatment prior to cyanidation. On this basis the dump potentially has at least 3750 kg recoverable bullion gold," he said.

In refractory ore, gold is locked up within the crystal lattice of sulphide minerals as very fine particles.

The only way to recover refractory gold is to break down the crystal structure of the sulphide mineral and the traditional method of doing this has been roasting.

Getting a partner to inject capital in the roasting plant will usher in new technology that can efficiently and effectively extract the refractory gold from the dumps. Extensive reserves of the refractory gold exist in Zimbabwe, particularly in the Kwekwe, Kadoma and Gwanda greenstone belts.

"Presently, the refractory gold ore belt runs from Chegutu in Mashonaland West Province to Gwanda in Matabeleland South Province. Gold mines in other provinces are roughly expected to hit some refractory patches as they continue their mining," said Gudyanga.

The plant was established in 1937 to toll treat refractory gold ore concentrates from various mines in the country.

But the plant stopped operating in 2000 and Government transferred ownership of the assets to Minerals Marketing Corporation of Zimbabwe on condition that the corporation would pay all the liabilities that the roasting plant had. Government has assumed the responsibility of resuscitating the plant.
- BH24

Tags: Gold,