In an unusual practice to manufacture plant fertiliser, an Australian recycler and supplier of battery materials is testing metal dust from spent household batteries for use as crop nutrient supplements. The company conducted trials to assess the use of zinc and manganese recovered from recycled alkaline batteries as micro-nutrient supplements in fertilisers.
The Perth-based company - Lithium Australia NL - recycled everyday alkaline batteries from local pick-up points across the country. After sorting, the batteries were shredded to obtain the mixed metal dust, or "MMD". The MMD is sourced from the company's wholly-owned subsidiary, Envirostream Australia Pty Ltd ('Envirostream') at its spent-battery recycling facility in Victoria, Australia.
Using the MMD, trials are conducted on pots of wheat in glasshouses. The dust contains high levels of zinc and manganese with minor amounts of graphite and potassium. Zinc and manganese are important constituents of fertiliser micro-nutrients.
In the initial round of trials, the company grew wheat in a variety of controlled scenarios. The scenarios included using the recycled zinc and manganese separately as fertiliser sulphates, using a combination of both, and growing wheat without any fertiliser micronutrients.
The company said that the results were encouraging enough for it to commit to the next stage of assessment.
"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," Lithium Australia Managing Director Adrian Griffin said in a statement.
"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," he added.
According to the company, "Annual sales of alkaline batteries nationally total around 6,000 tonnes. In 2019, Australia's Battery Stewardship Council estimated that, at the end of their useful life, 97% of those batteries were disposed of in municipal waste streams and reported to landfill."Also Read: COVID-19 Lockdown: Environment Takes Backstage As Centre's Focus Shifts To Ease Of Businesses