The government will this month float a tender of an expression of interest to resuscitate the gold roasting refractory plant in Kwekwe as it moves to increase output of the yellow metal.
BY TATIRA ZWINOIRA
Speaking to delegates at the Zimbabwe Mining Investment Conference 2018 yesterday in Harare, Mines and Mining Development minister Winston Chitando said there was need to exploit gold to produce more tonnage of the mineral as it was located everywhere not just along the Great Dyke.
“Gold in Zimbabwe exists not only throughout the Great Dyke, but in every province of Zimbabwe. However, I will only talk about two issues or initiatives that government is pursuing. If we come around the Midlands area towards the south, a lot of the gold or a significant amount of gold is refractory in nature, I am sure miners know what I mean,” he said.
“You will find because of the metallurgical challenges faced by the refractory nature of that gold, a significant amount of it is not being exploited. So, government, including the MMCZ (Minerals Marketing Corporation of Zimbabwe), will be floating a tender of expressions of interest by the end of March (this month)for a joint venture to establish a plant in Kwekwe which will be the centre for the processing of refractory gold.
Chitando said the roasting plant that used to be operating in Kwekwe has been down for some time and the implication was that those who were relying on that plant to process their refractory gold were no longer producing.
“Bringing that unit into play, the roasting refractory plant in Kwekwe will unlock a lot of gold production where the gold is refractory in nature,” he said.
He said if refractory gold was pursued, the gold deliveries target of 30 tonnes for the year would be surpassed.
Refractory gold ore is one that has ultrafine gold particles disseminated throughout its gold occluded minerals and is naturally resistant to recovery by standard cyanidation and carbon adsorption processes.
These refractory ores require pre-treatment in order for cyanidation to be effective in recovery of the gold.
Roasting is the process used to extract gold from the refractory gold ore.
According to scientists, roasting is the only commercialised process in Zimbabwe for the pre-treatment of refractory gold feed stocks for the subsequent cyanidation leaching results in 75% gold recovery and is characterised by high gold values in the residue.
The roasting plant in Kwekwe, which has been idle since 2000, is owned by MMCZ.
There is an estimated 350 000 tonnes of refractory ores located in the Midlands region moving down southwards of the country which if exploited would increase the targeted 30 tonnes of gold delivered for the year.
Investment plans to recover refractory gold comes as the mineral is one of the country’s major foreign currency earners, raking in $1,28 billion last year and constituting 24% of the total foreign currency earnings.