The mining industry is showing greater interest than ever in safe and sustainable solutions for managing tailings. We have started seeing actions within the financial and regulatory context but mostly financial and operational considerations driving the shift away from Tailing Storage Facilities (TSFs).

As levels are rising of many tailings dams, and new licenses are harder to come by, we need to find cost-effective ways to dewater mine tailings. Water scarcity is another issue bringing sustainability to the forefront and is likely to accelerate the trend away from wet tailings disposal.

One company leading the industry in tailings best practice is The Bloomfield Group in NSW Hunter Valley at its Rix’s Creek Mine. The Australian owned and operated mining and engineering business has been operating for more than 80 years. The group was committed to set out a tailings management plan to move away from tailings storage facilities at the Rix’s Creek South Coal Handling and Preparation Plant.

Since 2012, Alfa Laval has been working alongside Rix’s Creek from concept study to building a full-scale tailing dewatering plant for dry disposing of their tailing materials with solid bowl decanter centrifuge technology.

Moving away from tailings dams by using solid bowl decanter centrifuges allows the process water to be recovered from tailings at the plant which is a significant benefit in regions where water scarcity is a big issue. It is a significant long-term commitment and great effort by both companies to deliver a system which has the capability to dewater 100 per cent of the Rix’s Creek South plant coal tailings.

Mechanical dewatering allows to re-capture up to 90 per cent of the water, as the centrifuge separates the fine solids using G-forces from the contaminated process water. The solids are discharged as a cake with a low moisture content that can be dry-stacked, and used for mine rehabilitation together with mine overburden and coarse rejects. Depending on the mineral being processed and other parameters such as solids density and particle size distribution, the cake moisture ranges from 15-40 percent.  The water recovered from the centrifuges is used directly back again in the process, saving water resources as well as energy usually used for water reticulation.