Characterisation of Metal Debris in Grinding and Flotation Circuits

• Published in: Minerals engineering Vol. 171; p. 107074
• Main Authors: Asamoah, Richmond K., Baawuah, Emmanuel, Greet, Christopher, Skinner, William
• Format: Journal Article
• Language: English
• Published: Elsevier Ltd 01.09.2021
• ISSN: 0892-6875; 1872-9444
• DOI: 10.1016/j.mineng.2021.107074

The metal debris displayed a wide range of morphologies [Display omitted] •A remarkable range of metal debris morphologies and sizes in the grinding and flotation circuits.•Upstream equipment fragments such as loader teeth and high speed tools reporting in concentrator.•Considerable amount of metal debris circulating in the milling circuit.•Sulphide mineral oxidation at reactive metal debris surfaces.•Limitation of flotation performance and process economics with links to metal debris de-agglomeration. An extensive body of work exists on the impact of grinding media composition on media wear, valuable mineral surface chemistry and subsequent separation from gangue species. However, the literature is limited in describing what happens to metal (either tramp metal from upstream processes, or grinding media debris) in the grinding and flotation processes. This study aims at characterisation and deportment of metal debris within the grinding and flotation circuits of three Australian concentrators. The results show a remarkable range of “metallic” morphologies and sizes, with a considerable amount of metal debris circulating in the hydrocyclone/mill circuit while fine fractions proceed to downstream flotation. Chemical and mineralogical characterisation revealed notable metal debris contribution from upstream equipment such as loader teeth and high speed steel tools, coupled with mild steel grinding media. Surface chemistry and mineral association analysis suggest sulphide mineral oxidation at reactive metal debris surfaces, causing possible limitation of flotation performance and process economics.