Aluminum trihydrate crystals and improved method for the production thereof

The present invention provides an improved process for the production of alumina trihydrate crystals. Through the addition of a hydroxamated polymer at various stages of the process for production of these alumina trihydrate crystals, an upward shift in the particle size distribution of the alumina trihydrate crystals occurs. In one embodiment, the hydroxamated polymer is added to a filtered aqueous solution, which comprises no more than about 10 mg of insoluble solids per liter. In another embodiment, the hydroxamated polymer is added to an aqueous solution comprising insoluble solids after precipitation of alumina trihydrate crystals has commenced. Optionally, alumina trihydrate seed crystals may be added to the aqueous solution to initiate or encourage crystal formation.