The Renison mine in Tasmania produces about 1 million tonnes of ore per annum.

It is operated by a joint venture between Metals X and Bluestone Tin.

The JV approached equipment developer Tomra Mining to find a solution to the acidic processing water.

Tomra developed an X-Ray Transmission sorter designed specifically for the extreme and hostile conditions at the underground mine.

Ore is processed underground via a primary crushing system before being brought to surface through a shaft.

Once there, it enters the pre-concentration plant involving further crushing, screening and cleaning.

In the wet plant the product goes through primary grinding followed by bulk sulphide flotation.

Due to the acidity of available water, equipment is easily eroded.

Tomra developed a solution guaranteeing tin feed quality using two COM Tertiary XRT 1200 sorters designed to withstand the mine's harsh conditions.
Tomra technical manager Gavin Rech said this mitigated the use of acidic waters.

"Our XRT stands out for the high spatial and density resolution and its ability to do contrast sorting, identifying fine high-density tin inclusions in the ore with an accuracy that has no equal on the market," he said.

"It can separate it from the acid-forming sulphides, so that we have the ability of pulling the tin into the first product and sending the rest to the EM sorter."

The sorters were made from stainless steel and encased in a shell, rather than left exposed or made from materials traditionally used across the mine.

"[The steel use] will assist prolonging the sorters' life by protecting the unit from our high-moisture and corrosive environment," Tomra said.

According to Tomra which has produced a case study into the sorters at the mine, run of mine productivity was increased 20%.

This led to production costs falling 10% across the mining operation.