Study on P_2O_5 enrichment in medium-low grade phosphate rock

This research focuses on new enrichment method of P2O5 and RE2O3.By using diluted sulfuric acid as leaching agent,weathering factors such as temperature,liquid-solid ratio,concentration of sulfuric acid and action time were studied.On the basis of preliminary experiment,single factor and orthogonal test,weathering process of phosphate rock was simulated to explore the optimal conditions of P2O5 and RE2O3 enrichment.The results show that the optimal enrichment conditions are as follows: temperature is around 40±3 ℃,sulfuric acid concentration is 2%,liquid-solid ratio is 4∶1 and the action time is 40 min.Under the selected conditions,the grade of P2O5 in phosphate rock was enhanced from 26.13% to 31.91%,obtaining an enrichment rate of 22.12%,and meanwhile,RE2O3 grade was also enriched form 0.054% to 0.152%.