Minara Resources Murrin Murrin nickel-cobalt project is located 60 km east of Leonora in Western Australia’s Goldfields region. The remote site is extremely dry, water for the process plant, cooling towers and drinking water is sourced from a number of bore water fields and treated in a reverse osmosis (RO) plant with 600 membrane elements to meet potability requirements. It is then treated by ion exchange to meet the site process requirements. Silica scaling inside the reverse osmosis membrane trains was causing a recovery rate 15% lower than the design spec. Hatch developed a specialised cleaning regimen that regained 10% and significantly improved equipment lifespan and plant uptime.
The client came to Hatch with a serious problem: a high concentration of silica in the feed water was limiting the RO permeate recovery process. The RO trains designed for 80% recovery achieved only 65% because of silica scaling on the membranes, which subsequently had a lifespan of only six months. Traditional cleaning products were insufficient and required RO trains to be off-line for long hours with little improvement.
Hatch developed a specialised cleaning regimen including MT3100, a customised cleaning product using very low concentration hydrofluoric acid (HF) to manage silica scale buildup and increase membrane life. MT3100 efficiently removes silica scaling in less than one hour.
The solution increased RO trains recovery rate to 75% and extended average membrane life to 35 months—with some lasting 80 months. This translated directly into lower operating and parts costs, significantly less plant downtime and an overall productivity increase. Minara saved A$2.4 million in the first two years and a total of A$10.2 million over 10 years.
Since the cleaning process and MT3100 product design involved hazardous chemicals, rigorous safety measures were covered, including:
•Product form (solid, liquid) and concentration
•Container type and size
•Clean-In-Place (CIP) system reviews
•Job safety analysis, operating procedures
•Personal protective equipment
As result of this rigor, an exceptional record of zero lost time incidents was achieved over 12 years and 9,800 hours of service work.
The long-term nature of this project enabled development of a ‘one-team’ approach between Hatch and Minara personnel, with a shared commitment to value and safety that has been fundamental to the project’s success.