Phosphate beneficiation by calcination. Prediction of P₂O₅ in the product, mining and plant control

A method is described to predict P₂O₅ content in the product (of phosphate beneficiation by calcination) as a function of the composition of an untreated and also of a washed raw material. The method consisted of: (a) developing an on-line multielement analysis by XRF; (b) finding the elemental and mineralogical relationships in the product, by factor analysis; (c) determination of the independent variables; (d) finding the relationships between the concentrations of the impurity variables in the raw material and in the product; (e) developing a linear model to predict P₂O₅ content. The predictions are used for mining and for plant control.