| Abstract |
A process for the preparation of a precipitated silica comprising the steps of a) reacting a silicate of an alkali metal M with an acidifying agent, whereby a suspen~ion of pre~ipitated silica. is obtained, b) separating the suspension and c) drying this suspension, characterized in that the precipiLaLing is carried out in the following manner: (i) an initial stock is fonned comprising a part of the total quantity, of the silicate of an alkali metal M invoived in the reaction, the silicate concentration, expressed as Sia2, in the said stock being lower than 20 gil, (ii) the acidifying agent is added to the said initial stock until at least 5~o of the quantit)7 of M2O present in the said initial stock is neutralized, (iii) acidifying agent is added to the reaction mixture simultaneously with the remaining quantity of silicate of an alkali metal M such that the ratio of quantit)' of silicate added (expressed as SiO2)/qUa11tit)' of silicate present in the initial stock (expressed as Sia2) is between 12 and 100. |