Patent ID: 6746592
Filing Date: 2004-06-08
Classification: C01D,C01F,C25B

Abstract:
A method for the reduction of soluble aluminum species in an evaporated salt alkali metal halide brine containing up to 500 ppb aluminum species to provide a brine feedstock suitable for use in a chlor-alkali membrane cell process, said method comprising:(a) treating said brine with a magnesium salt in an amount to provide a Mg to Al molar ratio selected from 5-20 to 1 and at a Mg concentration of from 0.5 to 5 ppm, and sufficient alkali metal hydroxide to provide an excess alkalinity concentration of between 0.1-0.3 g/L alkali metal hydroxide to effect precipitation of a magnesium aluminum hydroxide complex; and (b) removing said complex to provide said brine feedstock.