TESTS have shown that waste rock from Augur Resources’ proposed Randu Kuning mine at Wonogiri Gold Project in Central Java is highly suitable for a variety of stone aggregate uses. A preliminary market assessment shows that this rock could be sold into the regional aggregate market, turning waste into an asset.
General ASTM standard rock quality tests were completed at PT Geoservices laboratory in Bekasi, West Java, on four bulk rock samples and three sub samples made from two waste rock composite samples collected from drill core within the conceptual open pit.
Results indicate that the waste rock has the properties required to be highly suitable for a variety of aggregate uses including concrete. Specific concrete design test work has not been completed as this is best done by the individual producers.
The regional market study provided important information about current aggregate use within a 100km radius of the Wonogiri property. A total of 60 users and suppliers were visited during the survey and information compiled. The results suggest that aggregate production from a modest 150 tonnes/hour crusher could be absorbed into the regional market for a variety of uses without price disruption.
It is also clear from the market study and related discussions with industry consultants that there is a strong demand for high quality aggregate throughout Java to supply ongoing and planned infrastructure projects as part of an extensive transportation upgrade initiative by the Indonesian Government.
Augur is evaluating several aggregate production scenarios including initial production from standalone quarries outside the conceptual Randu Kuning open pit. This could provide a low capital cost opportunity to get early cashflow with which to advance development of Randu Kuning mine.
Meanwhile, extension of the Wonogiri IUP exploration licence for two years ending January 2017 will allow for remaining feasibility work and environmental permitting to be completed at Randu Kuning without the associated added costs of having a Production IUP.
Ongoing metallurgical test work by Augur on whole bulk grind samples of Randu Kuning ore composites has returned 54.3% recovery of gold by gravity and 86.6% gold, 70.7% silver and 87.7% copper recovery by gravity plus flotation of gravity tailings. The test work also confirmed that tailings material will be non-acid forming and will be a net acid consumer, which indicates there will be no acid mine drainage concern for tailings.