Testing of pre-concentration tin and tungsten ore at Rafaella Resources’ (ASX:RFR) Santa Comba mine in Galicia, northwest Spain, has resulted in “exceptional” ore sorting results, the company says.
The results allow Rafaella to review several opportunities to simplify its Santa Comba processing plant, and thereby streamline its capital and operating costs for the project.
“The benefits of this simplification will be significant once the metallurgical studies are completed,” managing director Steven Turner said.
The test work delivered higher rates of recovery and yields for the process plant, enabling the plant to discriminate between ore-bearing rock and low-grade barren rock.
“The results from the ore sorting test-work have exceeded the company’s expectations,” Turner said.
A 50 per cent reduction in process tonnage for the Santa Comba project reduces its environmental impact with a far lower volume of waste generated, and lower energy consumption, Rafaella noted.
Test work shows higher tungsten recovery rates
Two bulk samples that came from assayed drill cores crushed into two size groups were tested in the plant.
One sample was of average grade tungsten ore at 15 per cent, and the other low-grade tungsten at 0.05 per cent.
Tomra Sorting Solutions, which carried out the test work, said in its report that significant upgrades of tungsten and high recoveries were achieved in all sample test runs.
Tungsten ore recovery from a feed grade of 0.133 per cent tungsten reached 90 per cent in the process test, with a product grade of 0.25 per cent tungsten, and a yield of 48 per cent.
The test results showed a 50 per cent rejection of unmineralised rock and an approximate doubling of feed grade that could significantly lower planned capital and operating spending for the project.
Strategic metal with alloy and military applications
Tungsten is a strategic metal with the highest melting point of all metals, and has major applications in machine tools (drill bits and cutting tools), as a toughener in steel alloys.
The project’s grade recovery curve shows a potential for more than 90 per cent tungsten recovery with an increased yield of up to 55 per cent of feed mass.
As a result of the test work, the company can undertake bulk ore mining at Santa Comba to reduce operational costs and maximise ore recovery, the company said.
For a throughput of 1 million tonnes of feed ore, and 500,000 tonnes a year of pre-concentrate, two XRT processing units would be required, Tomra said.
Rafaella acquired the Santa Comba project last year.