An improved dewatering process for mill tailings

CIM Bulletin, Vol. 82, No. 924, 1989

T. Yalcin, Laurentian University

This paper describes the development of a process flowsheet designed to provide high dewatering rates and to bring about savings in tailing disposal costs. The flowsheet comprises a hydrocyclone, a settling cone and a thickener arranged in closed circuit. The mill tailing, after pulp density adjustment, is fed to the hydrocyclone which yields two products. The underflow product is sent to the settling cone for further dewatering. The overflow product, together with the settling cone overflow, goes to the thickener which, with the aid offlocculants, gives a clear effluent and a relatively dilute underflow. The latter combines with the original mill tailing to form the hydrocyclone feed. Solids finally leave the system in the settling cone underflow which can reach pulp densities of up to 78%, making it suitable for direct disposal or for use as mine backfill. Some discussion is included for the selection and sizing of equipment required for this process.

Mots Clés: Mineral processing, Dewatering, Mill tailings, Hydro-cyclones, Process development, Mass balance calculations, Thickeners