Low intensity magnetic separator modelling: a pseudo liberation approach

With the objective of developing a wet, low-intensity magnetic separator model, a number of plant data were analysed. Although the particle size versus mineral recovery relationship for a given stage of magnetic separation in a plant appeared to be reasonably stable, it was found that magnetic separation could not be classified as a deterministic process on this basis. Accurate modelling required size-by-size liberation information. Detailed analysis of available data led to the development of a model based on tdhe pseudo liberation concept, which could be used when such liberation is not available. The underlying idea is the fact that separation of gangue particles becomes more difficult and magnetite recovery increased, as the feed grade to a magnetic separator gets higher. Feed grade to a magnetic separator was considered as a compact parameter defining the liberation state of feed. A three-dimensional relationship between feed grade, particle size and mineral recovery was constructed using available data from a given plant, which allow calculation of a particle size mineral recovery relationship for a feed grade, hence liberation state. The model was incorporated into Usim Pac and used for plant simulations. Although the model was not fully validated by implementing simulation-based modifications in a plant, results of simulations appeared to be reasonable. (C) Institute of Materials, Minerals and Mining and Australasian Institute of Mining and Metallurgy. Published by Maney on behalf of the Institutes.