The Relationship between Froth Image Features and Platinum Flotation Grade

Many endeavors have been made attempting to relate froth appearance to key performance indicators such as grade and recovery. The platinum industry have questioned the possibility of doing this based on the results of simple models trying to relate physical features (e.g. bubble size) to grade.In this study a fractional factorial design of laboratory experiments were conducted using platinum ore. The flowrate (x1), pulp level (x2), collector (x3), activator (x4), frother (x5) and depressant (x6) were varied for each experiment and videos were recorded of the froth. The analysis of the videos rendered 20 texture features from each image.The non-linear relationship between the froth texture features and grade were investigated using kernel Fisher Discriminant Analysis (kFDA). The results indicate that these features could be sufficient as input into advanced model based control systems for PGM flotation plants. Multivariate linear regression confirmed the hypothesis and performed very well when the kFDA features are used as predictors.