Los Andes Copper says it has received additional positive results from the ongoing prefeasibility study (PFS) metallurgical test work at its Vizcachitas project in Chile.

These results show improved filtration rates for both the fine and coarse fraction tailings compared with previous testing, it said, reinforcing the decision to adopt dry-stacked tailings at the project.

An October press release regarding PFS metallurgical test work carried out by SGS demonstrated that the Vizcachitas tailings were amenable to being filtered and dry-stacked.

These same coarse and fine representative tailings samples were sent to the TAKRAF laboratories for further settling and filtration assessments. Los Andes said the TAKRAF work tested various settling and filtration parameters, including those previously tested.

The studies demonstrated that for the coarse fraction vacuum filtration, the rates improved from 1.9 t/h/sq.m to 3.4 t/h/sq.m when compared with the previous results. For the finer fraction, the settling velocities improved from 8.4 m/h to 16 m/h and the pressure filtration rates improved from 0.6 t/h/sq.m to 0.7 t/h/sq.m. The expected cake moistures for both filtration technologies were 15%.

These positive results mean that the Vizcachitas project, processing 110,000 t/d of ore, would only need to use eleven standard 162 sq.m belt filters and four 2.5 m x 2.5 m pressure filters for the tailings dewatering operation, Los Andes said, noting that other operations in the world were successfully operating with similar filter arrangements.

“Tailings filtration reduces water consumption by 50% when compared to thickened tailings disposal alternatives,” Los Andes said. “Furthermore, filtered tailings can be handled by trucks, conveyors and shovels, eliminating the need for the construction and operation of a tailings dam.

“The adoption of this technology puts the Vizcachitas project at the forefront of the environmentally responsible practices being adopted for the future of sustainable mining globally.”