Tailings dewatering and dry disposal: Case studies of the successful application of full-function, automated filter presses

Tailings slurry storage and management continues to be a significant consideration for the safe and environmentally complaint operation of a coal processing facility. Further, as the scarcity of, and stringent application requirements for, raw water sources increase in this country, it is becoming ever more important to critically account for every litre of water lost from a processing plant. These requirements, among others, have driven the need for development of techniques and technologies to minimise water losses from every stream exiting a coal plant. A major contributor to such water losses arises from the slimes slurry which has traditionally been stored in tailings dams. Typically, significant quantities of water are lost from these facilities due to evaporation and seepage, placing pressure on raw water make-up sources as well as polluting, rivers, dams and ground water. One solution at the forefront of this technological development drive is the incorporation of filtration technologies into the slimes slurry streams. Competent, low-moisture filter cake can then be safely and compliantly stored in dry facilities or, in the case of a filtered froth flotation concentrate, blended and sold as additional tons along with the coarse product. The filtrate water is then directly returned to the processing plant, eliminating water losses to the environment. This paper considers 3 case studies of the successful application of plate and frame filter presses.