In-Line Pressure Jig Preconcentration Plant at the Pirquitas Mine

摘要

Gekko Systems Pty Ltd engaged in the test work, design, manufacturing and commissioning of the preconcentrationrnplant at Silver Standard Resources Inc's Pirquitas mine in the north western Jujuy province ofrnArgentina. Testing of the ore at coarse feeds of between 2 and 12mm returned probable recoveries of up torna total of 95% silver into 50% of the mass fed to the InLine Pressure Jigs (IPJ's). The plant has beenrndesigned and built based on the test results to include a preparation screen to bypass the fines that arernnaturally higher in grade and repulping of the coarse which is then pumped to three parallel trains of 2-stagernIPJ roughing-scavenging. The target 50% yield to concentrate passes over a dewatering screen and thernsolids are returned back to the mill feed conveyor. The IPJ tails are transferred to a dewatering screen andrnsolid rejects are stockpiled off the end of a transfer conveyor. All dewatered underflow products arernprocessed via hydrocyclones to recover dirty water for use back into the IPJ circuit and return entrained finesrnto the fines bypass line.rnWith the sulphide orebody being processed, the results from operations to date have shown that plantrnperformance is matching the original laboratory sulphide ore testwork data. The objective of the preconcentrationrnstep is to both reject gangue and achieve grades between 300-400g/t Ag to the float circuit asrnflotation recoveries are maximised within this range. The plant currently achieves overall upgrades ofrnapproximately 150% of feed grade with the IPJ only circuit producing an average 180% increase fromrncalculated feed grade.