Rapid beneficiation of fine coal tailings using a novel agglomeration technology

Abstract

Froth flotation has been used successfully over the last century for the beneficiation of coal and mineral particles. However, the process has been affected by certain restrictions relating to the rate at which the bubble/particle concentrate segregates from the aqueous tailings and to the recovery of ultrafine particles. An alternative separation technique, which appears to have the potential to remove these limitations, is selective agglomeration using a high internal phase emulsion binder. Presented in this paper are the findings from an investigation into the continuous steady state processing of fine coal tailings using the emulsion binder. This coal was sourced from a hydrocyclone overflow and had an ash% of 42%. The results from the experiments are compared to the results obtained from a batch system. It was found that both systems achieved a high combustible recovery of 70–80% and low product ash of 15–17%, however, the continuous process needed at least 15% less organic liquid to achieve agglomeration. Moreover, filtration of the agglomerated product material subjected to further high shear demonstrated low moistures of approximately 16 wt%. Therefore, it appears that agglomeration using the emulsion binder offers a method for producing valuable products from fine coal tailings.