Lightweight particulate cementitious materials and process for producing same
AssigneeVenture Innovations, Inc.
InventorsJack C. Cowan, Roy F. House, Andree' H. Harrington
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Abstract
Disclosed is a process of manufacturing a lightweight particulate cementitious composition particularly adapted to the sorption of liquids comprising adding to a foamed cement slurry a particle forming agent, and aging the treated foamed slurry for a period of time sufficient for the particles to form and harden for subsequent handling. The bulk density, particle size distribution, and concentration of the agent are selected such that the cementitious composition has the desired density and such that at least 65% of the particles obtained after aging have the desired particle size.
Claims21
A process of preparing a lightweight particulate cementitious composition comprising a water absorbent material coated with a cementitious material, which comprises:
- (1) forming a foamed aqueous slurry containing water and a cementitious material in a water to cementitious material weight ratio from about 0.2 to about 1.2, the slurry containing from about 0.1% to about 5%, by weight of the water, of a foaming surfactant, and from 0% to about 20% based on the weight of the cementitious material, of a plasticizer for the cementitious material;
- (2) mixing with the foamed slurry up to about 120%, based on the weight of the cementitious material, of a water absorbent particulate particle forming agent selected from the group consisting of clays, heat expanded perlite, exfoliated vermiculite, porous silicates, ground vegetable materials, water absorbent polymers, and mixtures thereof;
- and (3) aging the treated foamed slurry for a period of time sufficient for the particles of the lightweight particulate cementitious composition to form and harden for subsequent handling without crushing the particles, whereby the water absorbent particle forming agent is coated with the cementitious composition;
- wherein the particle size and concentration of the particle forming agent are selected such that at least 65% of the particles of the lightweight particulate cementitious composition have a particle size less than 3 mesh, U.S. Standard Sieve Series;
- and wherein the cementitious material is Portland cement.
A process of preparing a lightweight particulate cementitious composition comprising a water absorbent material coated with a cementitious material, which comprises:
- (1) forming an aqueous slurry containing water and a cementitious material in a water to cementitious material weight ratio from about 0.15 to about 1.0, the slurry containing from about 0% to about 20%, based on the weight of the cementitious material, of a plasticizer and from about 0.1% to about 5%, by weight of the water, of a surfactant;
- (2) foaming the aqueous slurry by either (a) vigorously mixing the slurry and entraining air therein, (b) mixing with the aqueous slurry a pre-formed foam containing from about 1% to about 10% by weight of a foaming agent, or (c) both (a) and (b);
- (3) mixing with the foamed slurry up to about 120%, based on the weight of the cementitious material, of a water absorbent particle forming agent selected from the group consisting of clays, heat expanded perlite, exfoliated vermiculite, porous silicates, ground vegetable materials, water absorbent polymers, and mixtures thereof;
- and (4) aging the treated foamed slurry for a period of time sufficient for the particles of the lightweight particulate cementitious composition to form and harden for subsequent handling without crushing the particles, whereby the water absorbent particle forming agent is coated with the cementitious composition;
- wherein the particle size and concentration of the particle forming agent are selected such that at least 65% of the particles of the lightweight particulate cementitious composition have a particle size less than 3 mesh, U.S. Standard Sieve Series;
- and wherein the cementitious material is Portland cement.
Dependencies are inferred from the claim text.