Improving filtration efficiency with ATA® rapid dewatering technology

Filtration of tailings slurries is a growing area of interest as operations are increasingly moving to stacked disposal. Fine particles can migrate to the filter cloth and cause blinding, resulting in extended filtration times leading to larger filtration plant sizes. This capital constraint can make tailings filtration uneconomic. ATA® rapid dewatering technology builds a granular structure in tailings slurries that enhances hydraulic conductivity. ATA is a three-component system in which fine and coarse tailings fractions (either produced using a hydrocyclone or resulting from different plant processes) are each treated with complementary polymeric reagents and recombined to create anchored particles that capture fine particles while increasing the dewatering rate. This paper compares the filtration efficiency of two different tailings slurries conditioned with ATA. Iron ore tailings from Brazil and copper tailings from Australia were conditioned with ATA prior to conducting gravity drainage tests, followed by filtration with both vacuum and pressure filtration. The impact of ATA as a prefiltration dewatering process was benchmarked to conventional thickening for the copper tailings. ATA conditioning showed improved filtration rates resulting from enhanced fines capture for both types of tailings. It was also shown that ATA unlocks a lower-cost flow sheet towards dry stackable material, enabling the use of vacuum filtration as the primary dewatering method where pressure filtration would normally be considered due to the ultra-fine particle size distribution. The paper presents an overview of the flow sheets developed and tested to achieve dry stackable tailings using these two different tailings streams and provides an overview of the techno-economic impact of the ATA® technology on these two case studies.