Canada-based cleantech company Orbite Technologies has completed preliminary research to recover gold from fly ash after concluding that the process is feasible.
Orbite’s research indicated that extraction of gold from fly ash is feasible using the company’s waste monetisation technology.
The company also filed a provisional patent application titled ‘Processes for Recovering Noble Metals from Various Materials’ for this process.
Orbite CEO Glenn Kelly said: "In the analysis of multiple feedstocks, we identified gold concentrations that, if extractable, can significantly increase the potential value of fly ash when processed using our technology.
"Consequently, we intend further investigating and developing this aspect of our technology, and include gold recovery in the workflow for the conversion of the extraction section at our Cap-Chat facility to the chloride process."
Orbite is working on the completion of its 3t a day of high-purity alumina (HPA) production plant in the facility.
The company plans to complete preliminary engineering to convert the HPA plant’s alumina extraction unit to a demonstration facility for multi-feedstock using its chloride technology in the first half of 2016.
The work is scheduled to begin in the second half of 2016 and the extraction section would be operational in 2017.
Kelly added: "Using our technology, we currently estimate average value for typical fly ash at around $200-$250 per tonne.
"Even at observed average concentrations of 7.5ppm of gold in fly ash, a 50% recovery would increase this value to $350-$400 per tonne, while 100% recovery would increase this to around $500-550 per tonne."
Extraction of other metals, such as platinum, iridium, and palladium using this technology is expected to make a further positive contribution to the fly ash value, the company said.