作者: Darrel James Wilson , Steven Philip Rosenberg , Wayne Tichbon , Catherine Ann Heath
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摘要: A process for the removal and causticisation of sodium oxalate and/or sulphate from a Bayer liquor containing carbonate one or both in an alumina refinery is described. The based on observation that to efficiently causticise solutions, it first necessary remove aluminate ion solution, optionally with recovery some later step. This effected by removing ions through formation carbonate-bearing hydrocalumite sulphate-bearing hydrocalumite. may then be treated sufficient lime any residual all present so reacted solids thus formed can separated safely disposed of. include pre-causticisation step which causticised reduce concentration ions, prior ions. invention provides effective practical method soda sulphate. efficiency utilisation also dramatically increased about 20 % 80 (if not objective) wherein losses minimised. substantially lower than usually achieved processes oxalate-crystallisation.