Process for improving the rheological properties of a suspension of precipitated silica
AssigneeRhone-Poulenc Specialites Chimiques "Les Miroirs"
InventorJean-Noel Jas
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Abstract
The present invention provides a process for improving the rheological properties of a suspension of precipitated silica by the addition of an aluminum compound, thereby producing a sprayable suspension or slurry with a pH of greater than 3.5, a solids content of at least about 15% by weight, which may be spray dried to form silica in either powder or microbead form. In a preferred embodiment, the aluminum compound added to the suspension is in the form of sodium aluminate.
Claims38
A process for making a sprayable suspension of precipitated silica comprising the steps of:
- a. providing an aqueous suspension of precipitated silica having a solids content of at least about 15% by weight;
- and
- b. adding to the aqueous suspension an aluminum compound to produce a sprayable suspension having a pH value greater than 3.5.
A process for making a sprayable suspension of precipitated silica comprising the steps of:
- a. forming a precipitated silica suspension;
- b. filtering the precipitated suspension to form a filter cake with a solids content of at least about 15% by weight;
- c. slaking the filter cake to form a sprayable suspension;
- and
- d. adding sodium aluminate during any of steps (a) through (c) to produce a sprayable suspension having a pH greater than 3.5.
A process for making a spray dried product comprising the steps of:
- a. providing an aqueous suspension of precipitated silica having a solids content of at least about 15% by weight;
- b. adding to the aqueous suspension an aluminum compound to form a sprayable suspension having a pH value greater than 3.5;
- and
- c. spray drying the suspension.
A process for making a sprayable suspension of precipitated silica comprising the steps of:
- a. forming a precipitated silica suspension;
- b. filtering the precipitated suspension to form a filter cake with a solids content of at least about 15% by weight;
- c. slaking the filter cake to form a sprayable suspension;
- and
- d. adding sodium aluminate during any one of steps (a) through (c) to provide a sprayable suspension with a pH value of greater than 3.5.
Dependencies are inferred from the claim text.