Augur completes rock tests at Wonogiri gold, copper project
Thursday, April 30 2015 - 07:06 AM WIB
ASX-listed Augur Resources Limited said Thursday it has completed testing of two waste rock composite samples during the quarter at the Wonogiri gold and copper project in Indonesia?s Central Java Province.
The rock represents generally unmineralized (<0.2 g/t Au) `waste rock? collected from drill core within the conceptual open‐pit.
The company also said that general ASTM standard rock quality tests were completed at PT Geoservices laboratory in Bekasi, West Java, including; point load, density, soundness, abrasion, organic content, porosity, water absorption and alkali/silica reactivity.
?The results of these tests indicate that the Randu Kuning waste rock has the properties required to be highly suitable for a variety of stone aggregate uses including concrete. Samples tested had good density (2.6‐2.7 t/m?), low absorption (0.8‐0.9), low porosity (2.2%) and low water soluble sulphate and chloride (<0.04) with excellent soundness (4.37‐5.03) and Los Angeles abrasion (12.5‐13.7). Specific concrete design testwork has not been completed as this is best done by the individual producers,? Augur said in a statement.
To advance its understanding of the aggregate business, the company has engaged an experienced aggregate geologist to advise on related technical matters.
A regional marketing study was also initiated during the quarter, the company said. The objective of the study is to gain information about current aggregate suppliers and users within a 100 kilometers radius of the Wonogiri property. The results of this work will be reported during the June 2015 quarter and will form the basis for devising an aggregate business plan.
A third round of testwork on a sulphide composite sample compiled from drill core from within the conceptual open‐pit commenced during the quarter to investigate optimization of previous testwork with the objective of identifying a preferred process flow sheet for recovery of both gold and copper. This work will evaluate gravity concentration, intensive leaching and selective flotation and should be completed during June 2015 quarter. However, preliminary results for the minus 53 micron grind size indicates 54.8 percent recovery of gold by gravity concentration using a Falcon concentrator, with a combination of gravity concentration and flotation of the gravity concentrate tails indicating 86.6 percent recovery of gold and 87.7 percent recovery of copper.
?These preliminary results are consistent with previously reported results that a combination of gravity separation and cyanide leaching could potentially recover up to 90 percent of the contained gold whereas sulphide flotation test results suggest that up to 89.0 percent recovery of gold and 93.4 percent recovery of copper could be achieved to produce a high quality marketable concentrate with grades of up to 21.2 percent copper and 90.6 g/t gold,? the company explained.
The Wonogiri project, located in central Java, previous test work has demonstrated that a finer grind size allows for better gold recovery and, based on the current testwork, suggests the minus 53 micron grind size to show the best recovery, the Augur statement said.
The statement added that conversion of the Wonogiri IUP from Exploration license to Exploitation license is progressing well with expected completion second half of 2015.
Editing by Reiner Simanjuntak