Finders: Test work shows upside potential for cover recoveries at Lerokis deposit
Monday, November 20 2017 - 05:00 AM WIB
ASX-listed Finders Resources Limited reported on Monday the following progress of recovery test work completed on diamond drill core from the metallurgical drilling program at the Lerokis deposit, Wetar Copper Project, in Indonesia?s Maluku Province.
The company said in a statement that the drill program comprised eight large diameter diamond holes for ongoing metallurgical test work. The metallurgical test work was designed to confirm the mining, crushing and stacking characteristics of Lerokis ore and to optimize blends for the different mineralized domains within Lerokis. Once the program is complete, these results will be used to update the company?s financial models and optimize mine planning.
?The significance of the test work results is clear when compared to the recoveries from Lerokis used in the BFS financial model at 66 percent and the Project finance model at 50 percent,? the statement said.
The test work was undertaken in a specially designed column testing facility located at the 25,000 tpa copper cathode SX-EW plant. This purpose-built facility has been used to conduct ongoing test work on the various mineralized domains to enhance overall recoveries in the sulphide heap leach process.
The recovery results for the Lerokis mineralized domains are highly encouraging. Compared against the Lerokis BFS recovery curves, three of the four samples produced faster rates of recovery (Zone 5 PBX2, Zone 5 PBX1/2 and the Composite), with the fourth sample (Zone 1S BO) performing to expectations (40% extraction rate after 213 days of leaching). More importantly, two of the four samples (Zone 5 PBX2, Zone 5 PBX1/2) demonstrated significantly higher total recoveries when compared to the Lerokis BFS recovery curve.
The composite sample was made up of 32% Zone 1S BO, 32% Zone 5 BO, 32% Zone 5 PBX1/2 and 5% Lerokis Clay. Locations for Zone 5 and Zone 1S in the Lerokis orebody.
PBX1 is pyritic breccia located in the leached zone of the orebody and PBX2 is pyritic breccia located in the transitional zone of the orebody. BO is black ore located in the massive sulphide section of the orebody.
The lixiviant (acid solution used to irrigate the ore) used in the test work was actual raffinate from the current Kali Kuning solvent extraction (SX) operation to ensure that the testing was representative of actual operating conditions in the heap leach pads. The temperature of the test work was also carried out within the current target operational range of the heap leach pads as indicated.
?The test work is ongoing and further enhancements are anticipated through the observations of actual operational experience,? Finders said.
Managing Director Barry Cahill commented: ?These encouraging results from the metallurgical testwork program at Lerokis clearly demonstrate upside potential for copper recoveries at Lerokis over the planned operational life of the Project. Operational experience is greatly improving our understanding of the orebodies at Wetar and the metallurgical responses of the various ore types to heap leaching.?
Editing by Reiner Simanjuntak