Karen Harverson
Gencor’s Impala Platinum (Implats), the world’s second- largest platinum producer, is looking at projects to increase the amount of platinum it recovers from ore.
This is cheaper than increasing the amount of ore
The group produces more than a million ounces of platinum a year from both Merensky and UG2 ores.
Implats is investigating a R100-million project to regrind its Merensky ore which could increase the platinum yield per ton by two percent to three percent.
The company already regrinds its UG2 ore and last year spent more than R80-million on a new regrind plant which resulted in an eight percent increase in platinum yield per ton.
“We don’t expect the same increase from Merensky ore as its mineral structure differs and more platinum group metals (pgms) are liberated in the primary grind, so there is less to recover in the regrind stage,” says operations director Steve Kearney.
He says the anticipated increase of two to three percent should be sufficient to justify setting up a new regrind plant for the Merensky ore but a more detailed investigation is required.
A trial project will be undertaken in the next six to 12 months during which two of the 15 mills currently used in the primary-grind process will be converted to regrind a portion of the seven million tons a year of Merensky ore Implats processes. A similar amount of UG2 ore is treated.
“If successful, we’ll convert additional mills to regrind circuits for the Merensky ore and put in new mills to take up lost capacity,” says Kearney.
He says although the project is new for Implats, other platinum producers have been regrinding both Merensky and UG2 ores for some time.
Further down the pipeline, the company may consider recycling the contents of its tailings dams which have 250-million to 300-million tons of discarded material.
Kearney says that although this is marginal at present, a surge in the platinum price could make a project to regrind the tailings feasible.
‘The recovery processes used in the past, as in the case of the gold-mining industry, were not as efficient as they are today and there are significant amounts of platinum to be reclaimed in the tailings.”
At the announcement of the group’s annual results last week, chairman Michael McMahon said attributable income for the 1995 financial year had increased by 55 percent to R264-million. This was mainly due to firmer prices for platinum and a six percent weakening of the rand against the dollar which led to a 17 percent increase in revenue per ounce of platinum.
He said growth prospects for platinum had been dampened by the rapidly increasing use of palladium in the autocatalyst market. “Nevertheless, every year, demand for platinum has steadily increased.”
Platinum contributes 64 percent of the group’s turnover while palladium contributes only 11 percent.
McMahon said the principal uncertainty in the platinum market was the capacity and willingness of the Russians to sell into price rallies and to dampen upward
He said previous plans to expand to 1,2-million ounces of platinum a year had changed and the intention was to produce about 1,1-million ounces a year in the future unless there was a significant strengthening in the precious metals markets.
The proposed merger announced in June 1995 with Lonrho’s Western and Eastern Levels was still on track and technical and financial studies were due for completion in September this year.