Abstract: The invention relates to the use of carboxylic acid during the preparation of precipitated silica or a suspension of precipitated silica and to the precipitated silicas thus obtained, particularly with low water uptake, which can be used, for example, as a reinforcing filler in silicon matrices.

Abstract: A precipitated silica production process that includes a precipitation reaction between a silicate and an acid is described, in which the acid used in at least one of the steps of the process is a concentrated acid.

Abstract: A process for preparing precipitated silica comprising a precipitation reaction between silicate and an acid, in which the acid used in at least one of the steps is a concentrated acid, preferably selected from the group consisting of sulfuric acid having a concentration of at least 80% by weight, in particular at least 90% by weight, acetic acid having a concentration of at least 90% by weight, formic acid having a concentration of at least 90% by weight, nitric acid having a concentration of at least 60% by weight, phosphoric acid having a concentration of at least 75% by weight, and hydrochloric acid having a concentration of at least 30% by weight.

Abstract: A process for preparing precipitated silica comprising a reaction of a silicate with an acidifying agent to obtain a suspension of precipitated silica (S1), followed by a step of separation to obtain a cake, a step of spalling said cake to obtain a suspension of precipitated silica (S2) and a step of drying said suspension, wherein the spalling step is carried out at a temperature of between 50 and 120° C.

Abstract: A process for preparing precipitated silica comprising a precipitation reaction between silicate and an acid, in which the acid used in at least one of the steps is a concentrated acid, preferably selected from the group consisting of sulfuric acid having a concentration of at least 80% by weight, in particular at least 90% by weight, acetic acid having a concentration of at least 90% by weight, formic acid having a concentration of at least 90% by weight, nitric acid having a concentration of at least 60% by weight, phosphoric acid having a concentration of at least 75% by weight, and hydrochloric acid having a concentration of at least 30% by weight.

Abstract: A method for preparing precipitated silica includes the reaction of sodium metabisulfite or sodium sulfite with sand, wherein a) sand is mixed with sodium metabisulfite or sodium sulfite; b) the mixture thus obtained is melted to produce solid sodium silicate and sulfurous anhydride; c) the solid sodium silicate is dissolved in water to provide a sodium silicate aqueous solution, d) the sulfurous anhydride is reacted with the sodium silicate aqueous solution to provide a mixture containing precipitated silica; and e) the precipitated silica is separated from said mixture.

Abstract: A process for preparing precipitated silica comprising a reaction of a silicate with an acidifying agent to obtain a suspension of precipitated silica (S1), followed by a step of separation to obtain a cake, a step of spalling said cake to obtain a suspension of precipitated silica (S2) and a step of drying said suspension, wherein the spalling step is carried out at a temperature of between 50 and 120° C.

Abstract: A precipitated silica production process that includes a precipitation reaction between a silicate and an acid is described, in which the acid used in at least one of the steps of the process is a concentrated acid.

Abstract: A method for preparing precipitated silica includes the reaction of sodium metabisulfite or sodium sulfite with sand, wherein a) sand is mixed with sodium metabisulfite or sodium sulfite; b) the mixture thus obtained is melted to produce solid sodium silicate and sulfurous anhydride; c) the solid sodium silicate is dissolved in water to provide a sodium silicate aqueous solution, d) the sulfurous anhydride is reacted with the sodium silicate aqueous solution to provide a mixture containing precipitated silica; and e) the precipitated silica is separated from said mixture.

Abstract: Carboxylic acids are employed during the preparation of precipitated silica or a suspension of precipitated silica to provide precipitated silicas with low water uptake, which are useful, for example, as reinforcing fillers for silicon matrices.