developments in the processing of refractory & complex gold ores
developments in the processing of refractory & complex gold ores
developments in the processing of refractory & complex gold ores
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GEOCOAT PROCESS<br />
• Developed by GeoBiotics, USA.<br />
• Potentially lower cost option for <strong>gold</strong> locked <strong>in</strong> <strong>refractory</strong><br />
iron/arsenic and base metal sulphide <strong>ores</strong>.<br />
• Involves coat<strong>in</strong>g <strong>of</strong> flotation concentrate onto a suitable<br />
substrate, e.g. crushed barren rock or low grade ore, <strong>the</strong>n heap<br />
bioleach<strong>in</strong>g with <strong>in</strong>oculation <strong>of</strong> naturally occurr<strong>in</strong>g bacteria.<br />
• Nutrients added to <strong>the</strong> circulat<strong>in</strong>g solution and low pressure air<br />
for bioleach<strong>in</strong>g and cool<strong>in</strong>g <strong>in</strong>jected <strong>in</strong>to <strong>the</strong> base <strong>of</strong> <strong>the</strong> heap.<br />
• The residue is unloaded and <strong>the</strong> oxidized concentrate removed<br />
by trommell<strong>in</strong>g or wet screen<strong>in</strong>g. The concentrate residue is<br />
neutralized <strong>the</strong>n subjected to conventional cyanidation.<br />
• The support<strong>in</strong>g substrate can be recycled or, <strong>in</strong> <strong>the</strong> case <strong>of</strong> low<br />
grade ore, replaced with fresh ore as needed.<br />
• Operated commercially <strong>in</strong> South Africa 2003-2006.<br />
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