Study on the process of magnesium removal from phosphate rocks with high content of magnesium by chemical method

This paper is based on the background of magnesium removing from phosphate rocks cy sulfuric acid.Mabian phosphate ore was selected as the representative sample.The optimal process conditions were obtained by the orthogonal experiment design and range analysis: reaction temperature was about 55 ℃,pH value was 3.0,particle size of phosphate rock was between 150μm and 180μm,ratio of liquid phase over solid phase was 2.0∶1,and the residence time was 2.0 hours.Through the regression analysis of experimental data,the mathematical model of weight ratio of phosphorus to magnesium from the treated phosphate rock.The model could be used to explain the macro-reaction process of phosphate pretreatment.Finally,under the optimal experimental conditions,the ratio of magnesium removing from phosphate rock was 68.42%,the phosphorus loss was only 2.61% and the treated phosphate rock could near HG/T 2673-1995 standard of phosphate rock for the process of wet phosphoric acid in Grade II.