Cosmic Boy Mill Recovery Enhancement Project

Location: Approximately 100 km south east of Hyden in Western Australia

Engineer/Client: GRE Engineering

Year of completion: 2018


GR Engineering designed, constructed and commissioned the Cosmic Boy concentrator plant for Western Areas in 2009. The concentrator was subsequently upgraded in capacity in 2011.The Mill Recovery Enhancement Project (MREP) Nickel Bio-Leach encompassed the addition of unit processes to the Cosmic Boy concentrator plant designed to extract nickel from partially oxidised ore types that exhibit poor flotation response in the main concentrator plant.


Tank and vat leaching involves placing ore, usually after size reduction and classification, into large tanks or vats at ambient operating conditions containing a leaching solution and allowing the valuable material to leach from the ore into solution.

In vat leaching the solids are loaded into the vat, once full the vat is flooded with a leaching solution. The solution drains from the tank, and is either recycled back into the vat or is pumped to the next step of the recovery process. Vat leach units are rectangular containers (drums, barrels, tanks or vats), usually very big and need to be lined with material resistant to the leaching media. The treated ore is usually coarse.

The GRP Solution

GRP Tank Solutions supplied eight (8) off 230,000 litres Leach Tanks and seven (7) off Chemical Tanks The Leach Tanks where manufactured in two (2) sections at our Bibra Lake WA facility with final assembly was completed on site at Forrestania WA.

All tanks were manufactured and materials selected to ensure the specific chemicals they were holding would provide long term protection.