Mohamed H. Taha, Hassan El-Shall and Ahmed M.Masoud,

1 Nuclear Materials Authority, P.O. Box 530, El-Maadi, Cairo 11381, Egypt

 2University of Florida, PO Box 6135, Gainesville, FL 32611-6135, USA

Summary-The multivariate 2³ full factorial methodologies is used to study the effect of leaching time, acid concentration, liquid/ solid ratio on the dissolutionof low grade phosphate ore using hydrochloric acid solutions in terms of the maximum P₂O₅ leaching efficiency and the minimum impurities (represented by Fe₂O₃) leaching efficiency. The obtained results were statistically analyzed by using analysis of variances (ANOVA) to measure the adequacy of the fitted model. Based on the design of the experiments, the first order regression model has been constructed to approximate the phosphate leaching efficiency. According to the optimum conditions, the validity of the model has been verified, and the results clear that there is an agreement between the predicted and experimental data which con­firm the experimental adequacy of the models and the existence of the optimal conditions.