Ore refining could become a whole lot greener by using renewable energy to drive the production of specialty metals.
The Australian Renewable Energy Agency (ARENA) has granted $490,000 to mining and metals company Element 25 (E25) to explore the viability of using wind and solar power in electrowinning manganese metal.
Electrowinning is an upgrading process used in the production of Electrolytic Manganese Metal (EMM). In effect, an electric current passes through a metallic salt solution, depositing manganese in an electroplating process.
Used primarily in specialty steel, manganese is a vital element in the production of lithium ion batteries, like the Tesla Powerwall 2. In addition to manganese, the electrowinning process produces other valuable metals, such as copper and zinc.
It’s a highly energy-intensive operation. Element 25, a WA mining and metals company, currently relies on gas-fired power to produce manganese at its Butcherbird mine site.
Renewable energy refining maximises profits
Element’s Butcherbird mine is considered the perfect test bed for making metals with renewable energy. With plentiful sunshine, wind, and manganese ore, its long mine life makes it particularly suited to take the lead on alternative power generation.
A pre-feasibility study of the site found that although plentiful natural gas at Butcherbird provided a robust base case, the best economics favoured a combination of wind, solar and gas.
ARENA’s funding will allow E25 to test the viability of Intermittent Dynamic Electrowinning (IDE). This process produces EMM under dynamic conditions – ie, intermittent renewable sources.
Analysis without IDE indicated that up to 60 per cent renewable penetration is possible, with gas making up the remainder. However, analysis with IDE shows up to 90 per cent renewable penetration is possible, with significantly improved economics.
Renewable energy refining to export emissions-free metals
The project has the capacity to be expanded to other types of metal processing. If so, a new market in exporting emissions free metals would become available to other Australian companies.
In addition, it could create a new industry in domestic ore refining, using low-cost, abundant sources of renewable energy.
“Making metals with renewable energy makes sense,” said E25 executive director Dustin Brown.
“If successful, this work will pave the way for other Australian companies to integrate renewable energy into their resource projects.”