Effluent treatment process—pH refinement for sulphate removal
AssigneeMintek
InventorMartha Hendriette Kotze
Life of this patent
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Abstract
Disclosed is a method of decomposing ettringite, to form amorphous aluminium trihydroxide, which includes the step of lowering a pH of a slurry containing ettringite to a value between 8 and 8.5.
Claims4
A method of decomposing ettringite, which includes the step of lowering a pH of a slurry containing ettringite to a value between 8 and 8.5 to form amorphous aluminium trihydroxide and gypsum crystals in suspension.
A method of recovering amorphous aluminium trihydroxide from a slurry which contains ettringite, wherein the method includes the steps of lowering the pH of the slurry to a value between pH 8 and pH 8.5 to decompose and form a supersaturated calcium sulphate-containing stream, with gypsum crystals in suspension, and separating aluminium trihydroxide from the stream in a solid-solid separation process.
Dependencies are inferred from the claim text.