Thickener experiences at Langer Heinrich Mine

Abstract

Langer Heinrich Mine (LHM) reports on the operational experiences of thickeners supplied by several vendors. Modifications that were made to mitigate challenges presented by the thickener operation are discussed. The in-house modifications to the Lightnin® thickener improved capacity, reliability and performance, and the modifications of which, are ongoing. The ANDRITZ Delkor (Pty) Ltd thickener modifications were successful and the thickeners are performing to specification. Indications are that the Roymec Technologies (Pty) Ltd thickeners will perform to specification. The Magra Ultrasep 2000 High Performance Thickener is still in the commissioning phase at the time of writing. The project is being developed in stages. Stage 1 was commissioned in 2006, Stage 2 followed in 2009, and Stage 3 is currently in the commissioning and ramp-up phase. Nine 25 m Lightnin thickeners and clarifiers were installed as part of Stage 1. The thickener functions were the following: one pre-leach thickener, six CCD thickeners, one clarifier, and one 'vanadium' thickener. The 'vanadium' thickener was converted to a clarifier during the ramp-up of Stage 1. Stage 2 development required an additional four 35 m thickeners. The 25 m Lightnin pre-leach thickener was replaced by a 35 m thickener, a 35 m thickener was installed as the CCD 1 thickener and two 35 m thickeners were installed as CCD 5 and CCD 6. These 35 m thickeners were supplied by ANDRITZ Delkor (Pty) Ltd. The Lightnin thickener configuration was changed to run as three sets of two parallel thickeners and performed duty as CCD 2 A & B, CCD 3 A & B and CCD 4 A & B. The 25 m Lightnin pre-leach thickener functioned as a standby pre-leach unit. Stage 3 upgrade required an additional two 35 m CCD thickeners; CCD 4 and CCD 7. These 35 m units were supplied by Roymec Technologies (Pty) Ltd. This necessitated a change in configuration of the Lightnin CCD thickeners. The Stage 3 configuration is comprised of two sets of three parallel thickeners; CCD 2 A, B & C and CCD 3 A, B & C. The chosen tailings deposition for the Stage 3 upgrade is a paste system comprising of a 12 m Magra Ultrasep 2000 High Performance Thickener, supplied by Magra Process Engineering (MPE), as the paste thickener, the pumping system designed by Paterson & Cooke (P&C) and a tailings storage facility (TSF) designed by Metago Environmental Engineers. A fourth stage expansion is currently in the bankable feasibility study (BFS) stage. https://papers.acg.uwa.edu.au/p/1263_13_Cooks/ Thickener experiences at Langer Heinrich Mine M. Cooks et al.