Polyaluminosilicate process
AssigneeEka Chemicals AB
InventorJohn D. Rushmere
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Abstract
A method for the production of water soluble polyaluminosilicate microgels by the reaction of dilute polysilicic acid solutions with dilute solutions of alkali metal aluminates.
Claims14
A method for the production of water soluble polyaluminosilicate microgels which consist essentially of aggregates of very small particles of silica, surface aluminated and having a surface area of at least about 1000 meters.sup.2 /gram, said aggregates being formed into chains and crosslinked into three-dimensional networks, comprising the steps of
- (a) acidifying a dilute solution of alkali metal silicate containing about 0.1 to 6 wt. % SiO.sub.2 to a pH of between 2 and 10.5 to produce polysilicic acid, followed by
- (b) reacting a water soluble aluminate with the polysilicic acid before the polysilicic acid has gelled such that a product with an alumina/silica mole ratio greater than about 1/100 is obtained;
- and then
- (c) diluting the reaction mix before gelation has occurred to the equivalence of about 2.0 wt. % SiO.sub.2 or less to stabilize the microgels.
An aqueous mixture comprising a water soluble polyaluminosilicate microgel which microgel consists essentially of aggregates of very small particles of silica, surface aluminated and having a surface area of at least about 1000 meters.sup.2 /gram, said aggregates being formed into chains and cross-linked into three-dimensional networks, and being present in the equivalence of about 2.0 wt % SiO.sub.2 or less and having an alumina to silica mole ratio of greater than 1 to 100.
Dependencies are inferred from the claim text.