Surface treating mineral particles to reduce halide adsorption

摘要

Mineral particles are surface treated with an alkali metal silicate, hydrogen peroxide, an acid, or an organophosphorus compound. A preferred surface treating method utilizes sodium silicate in aqueous solution at pH greater than 9, followed by neutralization with acid to precipitate a silica coating onto surface portions of the particles. The mineral particles are preferably alumina particles. The surface-treated alumina particles may be incorporated into fluoride dentifrices or compounded with halogenated hydrocarbons and polymeric resins to form flame-retardant polymer compounds.