Meeka Metals (ASX: MEK) has commenced a $6 million upgrade of processing facilities at its Murchison gold project in Western Australia to boost throughput and accelerate gold production.
The work includes the installation of an additional crushing circuit, wash plant and Steinert multi-sensor ore sorter to unlock up to 200,000 tonnes per annum of additional mill capacity, increasing throughput to approximately 800,000tpa.
Preliminary testing at Steinert’s facility in suburban Perth using sample ore from the Andy Well underground development confirmed it would be highly-amenable to sensor-based sorting.
The ore sorter demonstrated the ability to sort 85% of contained gold ounces into 50% of the rock mass, producing a high-grade product with materially-increased head grade, as well as a low-grade product for stockpiling.
Andy Well Ore Sorting
Ore sorting will initially be applied to Andy Well ore, with high-grade gold-bearing quartz material separated for immediate processing and low-grade ore stockpiled for processing at a later date.
Based on an average Andy Well production rate of 400,000tpa at 3.8 grams per tonne gold, as outlined in a December definitive feasibility study, ore sorting is expected to produce 42,000 ounces gold from the high-grade product and 7,000oz from stockpiled ore.
Managing director Tim Davidson said the processing upgrade would deliver a meaningful increase in annual gold production.
“Ore sorting unlocks an additional 200,000tpa of milling capacity and effectively doubles the head grade of Andy Well ore entering the plant,” he said.
“The test work results were excellent, and gave us strong confidence in the ability to consistently separate the high-grade gold-bearing quartz from lower grade material that will be stockpiled for later processing.”
Mill-Constrained Operation
Meeka’s Murchison processing plant has nameplate capacity of 600,000tpa; however, with feed from Andy Well and multiple open pit operations, the operation has become mill-constrained.
Ore sorting addresses this constraint by reducing the mass of lower-grade material requiring immediate processing by concentrating the gold into a higher-grade, lower-mass product.
Key benefits include additional processing capacity, increased processing head grade, increased gold production, reduced processing costs per ounce, lower tailings deposition and reduced plant wear.
“We expect this high-return, quick-payback investment to be operational in the September quarter providing additional processing capacity for ore from our open pits and our second underground mine at Turnberry which will start-up this year,” Mr Davidson added.
Commissioning of the ore sorter is targeted for the September quarter.
