Patent ID: 6365639
Filing Date: 2002-04-02
Classification: B01J,C09K

Abstract:
A rheology modification agent prepared by calcining at a temperature of from about 750Â° C. to about 1500Â° C., a material comprising an unwashed waste stream from bauxite processing containing at least Mg, Al, CO3 and OH ions; such that a product is formed, whose constituents substantially conform to the proportions of the empirical formula:Mâ€²mMâ€³n(OH)(2m+3n+qa+br)(Aq)a(Br)b.xH2O; wherein Mâ€² is Mg and m is an amount of from greater than zero to about 8; where Mâ€³ is Al and n is an amount of from greater than zero to about 6; wherein A is O and q is âˆ’2 and a is an amount from greater than zero to about 3; wherein B is CO3 and r is âˆ’2 and b is an amount from zero to about 1; provided qa cannot be greater than or equal to 2m+3n; further provided that (2m+3n+qa+br) is less than 3; and where xH2O represents excess waters of hydration, with x being zero or more; and, optionally thereafter, admixing with said product an aluminum oxide, a nitrogen-containing compound, or a combination thereof.