Glasshouse testing of mixed metal dust (MMD) recovered from recycled alkaline batteries has been successfully completed.
The uptake of zinc and manganese is in line with expectations for oxide materials for a short duration glasshouse trial.
Lithium Australia managing director Adrian Griffin said: “Sustainable and ethical supply of critical materials is a global challenge.
“Recycling all the metals within spent batteries is something that’s rarely done effectively, which is why it remains a target for the company.
“We have not limited ourselves to recycling only lithium-ion batteries but, rather, have included alkaline batteries in a bid to eliminate all such items from landfill.”
Shares have been as much as 8% higher in early trade to 5.5 cents.
Closing the loop
Annual sales of alkaline batteries in Australia total around 6,000 tonnes and in 2019, the nation’s Battery Stewardship Council estimated that, at the end of their useful life, 97% of those were disposed of in municipal waste streams and reported to landfill.
Lithium Australia aspires to 'close the loop' on the energy-metal cycle in an ethical and sustainable manner.
As part of its commitment to a circular battery economy, and thus its environmental and social governance responsibilities, the company has assessed the use of zinc and manganese recovered from recycled alkaline batteries as micro-nutrient supplements in fertilisers.
Mixed metal dust assets
Alkaline MMD is produced by the company’s wholly owned subsidiary Envirostream Australia Pty Ltd at its spent-battery recycling facility in Victoria.
Envirostream collects the spent alkaline batteries from pick-up points at numerous locations, including Bunnings, Officeworks and Cleanaway.
After sorting, these batteries are mechanically shredded, with the cathode and anode active compounds, collectively referred to as MMD, separated.
That material contains high levels of zinc and manganese and minor amounts of graphite and potassium with the zinc and manganese of the most interest as fertiliser micro-nutrients.
Griffin added: “We’re cognizant of the environmental implications of burying such ‘waste’ and encourage all consumers to join us in recycling every spent battery for the benefit of the environment now for the sake of the future.”
Tested in glasshouse
This material was tested in glasshouse pot trials under the direction of the company’s consulting agronomist.
Nine tests were conducted on a quadruplicate basis to statistically assess MMD performance as a fertiliser against control samples.
Control tests included:
- No micro-nutrients;
- Zinc as fertiliser grade ZnSO4;
- Manganese as fertiliser grade MnSO4; and
- A combination of zinc and manganese as sulphates.
Conclusions from the trials:
- Plant dry matter yields were comparable across all samples (controls and MMD); and
- Uptake of zinc and manganese from the MMD was observed; however, and as expected, it was slower in comparison to that of fertiliser-grade sulphate products over the compressed duration of the glasshouse pot trial.
Next stage of assessment
Results were encouraging enough for the company to commit to the next stage of assessment with blended fertiliser agglomeration testing planned with an ammonium phosphate-based fertiliser such as monoammonium phosphate (MAP) or diammonium phosphate (DAP).
The next stage may also include larger-scale field trials to assess alkaline MMD dust performance against conventional treatments.