黃磷副產磷鐵渣制備電池級磷酸鐵.

Battery grade iron phosphate was prepared through three processes of nitric acid dissolution, coprecipitation and calcination. In the first stage, iron phosphate slag was dissolved with strong oxidizing acid to obtain iron phosphate solution containing iron and phosphorus. In the second stage, the pH value of iron phosphate solution was adjusted by ammonia water to make the solution precipitate into iron phosphate. In the third stage, the final product anhydrous iron phosphate was obtained through calcination. The calcined products were evaluated by XRD, SEM, particle size distribution and molar ratio of iron to phosphorus. The process research shows that the best process conditions in the first stage are solid-liquid ratio 1∶12, nitric acid concentration 7.6 mol/L, dissolution time 5 h, dissolution temperature 90 ℃,under which the dissolution rate of ferrophosphorus slag is 96.39%. The optimum technological conditions in the second stage are the molar ratio of iron and phosphorus in the solution is 1∶1, the reaction temperature is 80 ℃, pH=1.0, time is 4 h, and the molar ratio of iron and phosphorus in the prepared FePO4 is 0.97. The optimum calcination temperature is 500 ℃,and qualified iron phosphate is prepared. [ABSTRACT FROM AUTHOR]