Preparation method for white carbon black

The invention discloses a preparation method for white carbon black. The preparation method comprises the following successive steps: 1) adding 30 m3 of water into a reaction vessel and then adding sodium silicate with a Baume degree of 26 DEG to allow the concentration of sodium silicate in the reaction vessel to be 0.9 to 1.0 wt%; and 2) adding sulfuric acid with a concentration of 98% and sodium silicate with a Baume degree of 26 DEG into the reaction vessel at the same time, wherein 13.7 m3 of sodium silicate with a Baume degree of 26 DEG is added at a uniform speed within 90 min and the addition amount of sulfuric acid with a concentration of 98% is controlled so as to allow a pH value to be 9 to 10, continuing adding sulfuric acid with a concentration of 98% so as to allow the pH value to reach 4 within 30 min, terminating reaction and carrying out precipitation, filtering, washing, drying and calcining so as to obtain the white carbon black. Compared with the prior art, the invention has the following advantage: the tensile strength of the provided white carbon black can reach 22 to 24 MPa.