Method for preparing precipitated silicas containing aluminium

摘要

A method for preparing precipitated silicas is described. A precipitation reaction between a silicate and an acidifying agent is also described, wherein a precipitated silica suspension is produced, and, subsequently, separation and drying of the suspension is conducted, in which, inter alia, one of the following three operations (a, b or c) is performed: (a) simultaneously adding a compound of aluminium and a basic agent, (b) simultaneously adding a silicate and a compound of aluminium, (c) simultaneously adding the acidifying agent, a silicate and a compound of aluminium.

主权项

1. A process for preparing silica comprising aluminum, the process comprising conducting a precipitation reaction between a silicate and an acidifying agent, via which a suspension of precipitated silica is obtained, followed by a separation and drying of this suspension, wherein:
the precipitation reaction is performed in the following manner:
forming an initial feedstock comprising a silicate and an electrolyte, wherein a concentration of silicate (expressed as SiO2) in said initial feedstock is less than 100 g/L and a concentration of electrolyte in said initial feedstock is less than 17 g/L,(ii) adding the acidifying agent to said feedstock until the reaction medium has a pH value of at least 7,(iii) simultaneously adding an acidifying agent, a silicate and at least one aluminum compound B to the reaction medium, and drying a suspension with a solids content of not more than 24% by weight.