Experimental study on purifying hard-kaolin from coal tailings by flotation

To purify hard-kaolin deriving from coal tailings in Erdos area of Inner Mongolia,an ore dressing flow-sheet was determined based on the detailed analyses of ore samples properties; the optimum milling time and fineness was achieved through grinding tests,and optimized the conditions of carbon and iron removal by floatation and impurity removal by magnetic separation.The hard-kaolin was purified under the optimum tests conditions.Test results suggest that after carbon and iron removal by flotation and magnetic separation,the final kaolin containing 34.72% of Al₂O₃、0.54% of Fe₂O₃、0.50% of TiO₂ and its calcinations whiteness reached 84.24%,which meet the national standard of high quality calcinations kaolin in enamel,rubber and plastic industries.