The Sihayo Pungkut Gold Project is located in northern Sumatra, Indonesia.
The project has a total JORC 2012 resource of 1.4 million ounces gold within which is contained a combined proved and probable ore reserve of 554,000 ounces gold.
However, Sihayo has a large volume (over 4 million tonnes) of high grade material (circa 3.5-4 g/t gold) in the resource which delivered very low recoveries (low 50% range) in the feasibility study.
Encouragingly, testwork using pre-treatment with caustic soda and nitric acid have delivered a substantial increase in gold extraction.
Sihayo achieved 92.8% gold recovery using nitric acid leach followed by cyanide leach with carbon, compared to only 58.3% recovery using conventional cyanide leach.
Further testwork has been initiated across the remaining low recovery composites to optimise the processing route for the application of alkaline leach and to determine its commercial viability.
Although the most positive results have been received from the use of nitric acid, its viability is questionable due to environmental and safety concerns.
Sihayo is continuing to investigate other pre-treatment options as well.
The company’s share price has increased by 58% during the past three months, last trading at $0.019.
Sihayo Gold Ltd has higher gold recoveries from Indonesian project
Published: 11:00 17 Nov 2016 AEDT