Abstract: An improved method and composition for producing aluminum hydroxide crystals from precipitation liquor, involves the addition of an emulsified crystal growth modifier comprising a C8-C10 fatty acid, precursors, salts or blends thereof. The emulsified crystal growth modifier also facilitates an upward shift in particle size distribution of aluminum hydroxide and an upward shift in oxalate ball size.

Abstract: An improved method and composition for producing aluminum hydroxide crystals in a Bayer process pregnant liquor, involve the addition of an emulsified crystallization modifier comprising a C8-C10 fatty acid, precursors, salts or blends thereof. The alkyl chain of the fatty acid crystallization modifier is free of functional groups. The modifier yields a commercially viable product in the presence and absence of a hydrocarbon oil which dissolves the fatty acid. Further, the modifier, prepared in either an emulsified form or as a fatty acid neat, facilitates formation of oxalate aggregates greater than 200 ?m which may be readily screened out with minimum trihydrate loss.