A comparison of centrifugal gravity separators for the beneficiation of the Nechalacho deposit

摘要

The Nechalacho rare-earth element (REE) deposit is located in the Northwest Territories, Canada. The main rare-earth minerals (REM) in the deposit are zircon, allanite, bastnasite, synchysite, monazite, columbite (Fe) and fergusonite; with quartz, feldspars and iron oxides accounting for most of the gangue. Recent studies investigating the use of a Knelson Concentrator and a Multi Gravity Separator (MGS) have demonstrated that both centrifugal gravity techniques have the potential to produce a high-grade pre-concentrate. However, both techniques resulted in low recoveries. This study investigates multiple stages of centrifugal gravity separation, operating at more ideal conditions, to evaluate and compare the effectiveness of a Knelson Concentrator and an MGS for the beneficiation of the Nechalacho Deposit. Gravity products produced from each technique were analyzed by XRD to determine the mineral phases present in the concentrates. Gravity separation results were compared with dense media separation to evaluate each technique. Future work will utilize QEMSCAN to identify the effect of particle size, mineral liberation and association characteristics, and mineral particle SG distributions on separation.