Process for preparing precipitated silica

A process for preparing precipitated silica, comprising a reaction of an alkali metal M silicate with at least one acid, whereby a silica suspension is obtained, followed by separation and drying of said silica suspension, in which wherein the reaction of the silicate with the at least one acid is performed in the following manner:

• steps:
• (i) forming an initial aqueous stock comprising an alkali metal M silicate, the silicate concentration expressed as SiO2 in said initial stock being less than 20 g/L,
• (ii) adding an acid to said initial stock to form a reaction medium, until at least 50% of the amount of M2O present in said initial stock is neutralized,
• (iii) simultaneously adding an alkali metal M silicate and an acid to the reaction medium, such that the ratio of the amount of silicate expressed as SiO2 added in step (ii) to the amount of silicate expressed as SiO2 present in the initial stock is greater than 4 and at most 100, and
• (iv) stopping the addition of the silicate used in step (iii) while continuing the addition of an acid to the reaction medium until a pH value in the reaction medium of between 2.5 and 5.3 is obtained,
• wherein in said process, in at least part of said step (iii), the acid used is a concentrated acid 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.