Extracting from low grade ores

Key Benefits

Leaches 97-99% copper on-site in 6-8 hours
Leaches >70%gold in 6 hours
No needfor ultrafine grinding
Operatesat atmospheric pressure and autogenous heating – low CAPEX/OPEX compared to autoclaves
Lower environmental impact

Ore deposits are becoming increasingly complex to treat and grades continue to deteriorate in known reserves. For instance, approximately 15-20 per cent of the world’s current gold production involves refractory ores that must be pre-treated prior to downstream recovery by cyanidation. Ores are refractory for many reasons but commonly because gold occurs as tiny inclusions or submicroscopic gold within a sulphide mineral matrix. This mineral matrix must be physically and chemically altered to liberate the gold for subsequent leaching.

What we offer

Reduce processing cost for gold and copper extraction

Many existing gold refractory operations have low-grade stockpiles that are waiting to be processed at the end of the mine life. By adding Rapid Oxidative Leach® (ROL®) pre-treatment to an existing operation, it can become viable to process these low-grade stockpiles earlier, rather than processing them at the end of the mine life. Reducing the cut-off grade, you can move these ounces forward to generate cash flow earlier, which will increase the asset’s net present value.

A mechano-chemical process called Rapid Oxidative Leach® (ROL®) is the gamechanger for miners struggling to extract copper and gold from low-grade ores.

The technology leaches 97-99 percent copper directly on-site in six to eight hours, from concentrates as low as 5 percent copper. In gold, ROL has the potential to unlock the value of undeveloped refractory gold deposits with less than 3 g/t gold head grade.

Energy saving and cost-effective

Unlike other refractory processing techniques, the ROL process uses the application of mechanical energy coupled with oxidation under atmospheric conditions. The process relies on Stirred Media Reactors (SMRt) to accelerate the oxidation of sulphide minerals. This eliminates the need for ultrafine grinding, high temperatures and high pressure which makes it energy saving and very cost-effective.

In copper, the existing ore bodies are becoming lower grades, they are deeper, and they are more complicated to process. The ROL technology makes it possible to recover more copper from low-grade concentrates. Deposits unsuitable for smelting can be developed as they can be suitable for the leaching process, providing renewed business cases for new and remaining deposits.

This also applies to ore bodies with high arsenic concentrations, as they too can be handled environmentally safe and economically viable with the ROL technology.

Completely different life-of-mine plan

We broke the code for this technology in 2015 and the importance of this innovation was cemented in November 2016, when the ROL technology was among the winners in the global Top100 R&D Awards, in which the mining industry is rarely embraced. It has been tested in a pilot plant and we are working with the industry to test it at full-scale.

The result of the technology is a completely different life-of-mine plan; by lowering the cut-off grade, more ore will be converted into reserves, extending mine life.

Customer stories