Resouro Strategic Metals (ASX:RAU) is using the fusion sulphuric acid leach technology, developed by YM Serviços, in the next phase of metallurgical optimization at the Tiros titanium-rare earths project in Brazil, according to a Monday Australian bourse filing.

The firm is targeting maximized product recovery, near-elimination of tailings, and risk mitigation. The process converts over 90% of the mass in feed into saleable products and displaces, by heat treatment and the use of volatile materials. It also converts anatase into rutile at the pre-heating temperature.

The process was identified as sustainable with significant risk reduction by the potential elimination of tailings from mineral processing.

The next stage of follow-up tests, supervised by YM Servicos, will begin on Monday. The budget for the first batch of tests, expected to be completed by the end of June, is $70,000.

Its shares fell 6% on market close on Monday.