Patent ID: 11884551
Assignee: RHODIA OPERATIONS
Field: Chemical engineering (Chemistry)
Classification: CPC C  B | IPC B  C

Claim 19:
20. A process for preparing the precipitated silica of claim 1, said process comprising:
(i) providing a starting solution having a pH from 2.00 to 5.00,
(ii) simultaneously adding a silicate and an acid to said starting solution forming a reaction medium such that a pH of the reaction medium is maintained in a range from 2.00 to 5.00,
(iii) stopping the addition of the acid and of the silicate and adding a base to the reaction medium to raise the pH of said reaction medium to a value in a range from 7.00 to 10.00,
(iv) simultaneously adding to the reaction medium at least one compound of aluminium, the silicate and the acid, such that the pH of the reaction medium is maintained in a range from 7.00 to 10.00,
(v) stopping the addition of the silicate and of the at least one compound of aluminium while continuing the addition of the acid to the reaction medium to reach a pH of the reaction medium of less than 6.00 and obtaining the precipitated silica of claim 1.