Hydrous clays, as the name implies, contain roughly 14% water of hydration that is chemically bound within its crystalline structure. Although they share this common attribute, depending upon the degree of processing, hydrous clays differ dramatically in terms of particle size, residue, brightness, and pH. We carry a wide selection of different particle size, brightness, pH, and other physical properties, for use in paints & coatings, adhesives, sealants, caulks, inks, rubber and plastic applications where sheen and viscosity control, good stain removal, brushability, inertness, and low abrasiveness properties are desired. The platy particle shape offers ease of dispersion, imparts good suspension properties, and exhibits good enamel holdout properties for both architectural and industrial coatings. Burgess has these available in Air Float and Water-washed versions, with many varying grades of each.
Anhydrous Aluminum Silicates & Surface Modified Anhydrous Aluminum Silicates are kaolin clays that are processed by water-washing methods to achieve purity, improved residues, brightness, and achieve a desired particle size distribution, and then subject to calcinations (heat treatment) to effect the anhydrous state through the removal of 14% water of hydration.
Calcined grades differ by method of exposure to heat. Conventional calcined grades are processed in vertical kilns with a substantial period of exposure. The unique calcination method is to flash calcine the material by exposing the feed clay to higher temperatures for only a few seconds duration. Both methods fully remove the water of hydration, but effect different particle shapes, specific gravity, and optical characteristics.
Surface modified grades are simply the calcined (or heat treated) material as a feed clay for chemical treatment.