Discovery approves Botswana metallurgy

Posted by Daniel Gleeson on 14th November 2007

Discovery Metals has completed a comprehensive new study into the most cost effective way to process ore from its Dikoloti nickel deposit in north-east Botswana, using a state-of-the-art heap leach bio-oxidation process.

The study was based on GeoBiotics LLC’s proprietary GEOLEACHTM process, which has been developed as a method to recover base metals from sulphide ores as an alternative to stirred tank leaching and other competing technologies.

Following the positive results of the study, Discovery has contracted Snowden Mining Industry Consultants to revise the Dikoloti scoping study financial model as the bio-oxidation process has the potential to lower capital and operating costs for development of the project, in comparison to traditional flotation processing techniques. 

Highlights from new metallurgical test work:

  • The Dikoloti nickel mineralisation is amenable to heap leach bio-oxidation processing using the GEOLEACHTM process
  • Greater than 74% nickel extraction from the ore was achieved after 160 days;
  • 99% of the extracted nickel can be recovered from the bio-oxidation solution as a nickel sulphide, by use of sodium sulphide precipitation
  • The heap leach approach using GEOLEACHTM should have capital and operating costs which are significantly lower than conventional flotation processing.

Discovery Metals Managing Director, Jeremy Read, said the metallurgical test work using the GEOLEACHTM process had shown that bio-oxidation was a technically feasible method for processing the Dikoloti nickel-copper mineralisation. 

“The positive results from the GEOLEACHTM bio-oxidation test work are a big step forward for the project. We have now identified a processing technique which could lead to Dikoloti being developed as a stand-alone operation,” Read said.

“We are currently having the scoping study financial model for Dikoloti revised, based upon a bio-oxidation heap leap operation. Once the results of this financial review are known, we will make a final decision on how to progress Dikoloti to the next project development phase.”