Patent ID: 9695054
Date: 2017-07-04
CPC Classifications: C01B

Claim:
1. A process for preparing precipitated silica, the process comprising: reacting a silicate with at least one acid using the following steps, whereby a silica suspension is obtained: separating precipitate from the silica suspension; and drying the precipitate, wherein step (ii) comprises adding, for x minutes, a dilute acid followed by adding, after x minutes, a concentrated acid, where x is between 10 and 25, and wherein the acid used in step (iv) is a concentrated acid, wherein the concentrated acid, independently in each of steps (ii) and (iv), is selected from the group consisting of sulfuric acid with a concentration of at least 80% by weight, acetic acid with a concentration of at least 90% by weight, formic acid with a concentration of at least 90% by weight, nitric acid with a concentration of at least 60% by weight, phosphoric acid with a concentration of at least 75% by weight, and hydrochloric acid with a concentration of at least 30% by weight.