Patent ID: 8142752

Claim:
A preparation method of a talcum product with high purity degree consisting essentially in: first, a suspension is made consisting of 10 to 20 weight % of mineral talc and 80 to 90 weight % of water; the resulting suspension is homogenized and heated to a temperature of 50° to 70° C.; hydrochloric acid in a concentration of 37 weight % is added in an amount of 1 to 6 weight % to the heated suspension under continuous stirring; after achieving pH 3 to 5 and increasing the temperature to no more than 85° C., concentrated sulphuric acid in an amount of 1 to 5 weight % is added to the suspension; the suspension is further maintained at a temperature of no more than 90° C., then it is chilled to ambient temperature; from the suspension, a sediment is separated; the sediment is washed with water to reach pH 5 to 6; and the sediment is dried at temperature 140 to 160° C., thereby preparing the high-purity talcum product.