Distributed flotation kinetics models – A new implementation approach for coal flotation

• We have fractionated fine coal samples into particle composition classes.
• The flotation responses of the particle classes are able to be tracked.
• Contact angle as floatability indicator was estimated for all particle classes.
• Distinct flotation rate constant was estimated for each of the particle classes.

Composition-dependent flotation kinetic models with distributed flotation rate constants for predicting the flotation response of the various components of coal have been available for quite some time. However, the full potential of these models have not been realised because the floatability distribution of particles, a key requirement for the utilisation of the models, has not been readily accessible experimentally to allow the validation of these models.A new approach has been developed that allows the coal flotation feed to be fractionated into particles classes of size and composition using a microscopic characterisation tool called Coal Grain Analysis. Previous work had determined the contact angles of discrete coal maceral groups and associated minerals. Combining this information with the particle composition data from the Coal Grain Analysis methodology provides a pathway for estimating the contact angles of heterogeneous coal particles via Cassie’s Equation. The approach provides a unique opportunity to estimate the flotation rate constants for the different particle classes.