Kaiser Reef Limited has commenced installation of a Wolff Batch Centrifugal Concentrator (BCC) gravity circuit and ancillary equipment at the Maldon gold processing plant as part of an upgrade program at its operations in Victoria, Australia.
The Maldon plant is just 3 km from the company’s Union Hill Mine, which produced 2.1 Moz of gold, and has a processing capacity of 250,000 t/y, currently operating at between 20% and 30% of its full capacity.
The Wolff BCC comes with features such as a segmented bowl and a rotary union tailored for dirty water applications. These advancements minimise maintenance needs (eliminating the need for cranes during bowl changes) and reduce the demand for clean water, thereby reducing both capital and operational costs, according to manufacturer Gekko Systems.
The gold gravity circuit at Maldon will collect the unusually high concentration of coarse gold observed from the company’s A1 goldmine after the SAG mill. This will enhance recovery by collecting coarse gold separately and earlier from the leach feed than through the current mill flowsheet, the company says.
Kaiser has previously seen gold “held up” withing the processing plant because of gold’s very soft and malleable nature and high density. This has required regular mill liner removal to collect the entrained gold. The company expects this initiative to help enhance and smooth cash flow and also improve overall gold recovery. This equipment is currently being installed and should be operational by early August.
In addition, Kaiser has purchased a previously used Terex cone crushing unit to reduce the size of the crushed ore product from the jaw crusher prior to feeding ore into the SAG mill. The cone crusher further reduces the average rock size delivered by the Terex crusher currently in operation from 75 mm down to below 25 mm.
“Reducing the rock size reduces the time required to grind ore in the ball mill and thereby reduces the company’s energy and power costs,” Kaiser Reef says. “This will increase the effective treatment capacity rate, leading to greater operational efficiency and reduced processing costs. The calculated payback period is approximately eight months.”
These upgrades to the fully permitted Maldon processing plant advance the company’s strategy to significantly ramp up production and cashflow from its Victorian gold projects, particularly the high-grade A1 Gold Mine, Kaiser Reef says.