The mining industry globally has moved to reduce water in metallurgical tailings sent either underground, for support, or to tailings storage facilities (TSF) on surface. This strategy has been driven by two primary considerations: 

» Safety - Reducing water results in greater stability in stored tailings; and

» Environment - Recovering water limits impact on the environment, as it reduces the amount required from outside sources. 

Weir Minerals have developed a proprietary dewatering process called TerraFlowing to address both the value proposition of tailings inherent in the tailings, and tailings storage. This webinar, led by Nils Steward of the Weir Technical Centre, describes the test work and results achieved in the development of the technology to a viable dewatering process for the mining industry.

Watch the video: TerraFlowing - An innovative and flexible method for tailings management 

Date: May 27, 2020 Time: 4 pm EDT

About TerraFlowing

The process incorporates a two-stage cyclone dewatering process followed by centrifugation of the final stage of cycloning overflow. In this process three dewatered tailings streams are produced; a primary cyclone underflow, a secondary cyclone underflow and a centrifuge pulp. These three streams can be combined or used in different configurations.

This three-stage system offers the flexibility to make provision for variations in mineralogy and particle size distribution(PSD) as well as the opportunity to recover “Tailings as a Resource.”

This ability to deal with feed variations in PSD and mineralogy and deliver variations in PSD, tailings solids concentrations and recoveries is owing to the ability to vary the cyclone and centrifuge configurations and operation.

This flexibility further allows for optimisation of power utilisation. In many instances water is an annual issue; during the rainfall season water recovery is less important than dry seasons. During the rainy season the need to operate the process at maximum water recovery, associated with maximum power consumption, is less necessary and power can be conserved.

Two main TerraFlowing process outcomes have been identified corresponding to:

» A maximum solids recovery at maximum solids concentration of the two cyclone and centrifuge streams.

» A recovery of a tailings stream for TSF embankment construction with the remaining cyclone and centrifuge streams being combined for deposition within the TSF.

Water recovery can be up to 85% with a 78wt% solids concentration final tailings product from combining the three streams in the maximum solids concentration case. Transport of this final stackable tailings product will be by positive displacement pumps, conveyors or trucks.

For the case where the primary cyclone underflow has been shown to deliver a PSD suitable for TSF embankment construction, through geotechnical investigation, the remaining secondary cyclone underflow and centrifuge pulp is suitable for beaching deposition within the TSF. The water recovery in this process is up to 75%.  Transport of these tailings products can be through centrifugal pumps.

TerraFlowing is an opportunity to not only store a thickened product but also recover the value in the tailings through the construction of tailings storage facility embankments or the manufacture of structural concrete products, as well as shotcrete for reinforcement and support.

Presenter 

Nils Steward, General Manager Operations and Development at Weir Minerals, is an internationally recognised expert in the field of backfilling and tailings handling solutions. The Weir Technical Centre, opened by Nils, specialises in developing process, tailings and pipelines solutions to meet mining and minerals industry needs. Work at the Weir Technical Centre by Nils and the team has been focused on bringing a cost-effective and flexible dewatering system to the mining industry to improve tailings transport, storage and safety.

Watch the recorded webinar