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AssigneeSeabridge Gold Inc.
InventorsMaryam Mohammadi, Berend Wassink, Jianming Lu, David Dreisinger
Estimating the term…
Processes are provided for the kinetically efficient reduction of selenate species to selenide species using chromous ions in acidic solution. This reduction may advantageously be carried out in the presence of sulphate species, with selective selenate reduction in preference to the reduction of sulfate. The reduced selenate may be removed from the chromous-treated solution, for example by precipitation of a copper-selenide solid. The chromic ions formed by reaction of chromous ions in the reduction of selenate may also be removed from solution, for example by addition of a base to form an insoluble chromic hydroxide solid. The chromic hydroxide may be recycled to regenerate chromous ions, for example by electrolysis. In this way, systems are provided for continuously removing dissolved selenium from wastewater streams.
A process for continuously removing dissolved selenium species from an input water stream comprising a dissolved aqueous selenate (Se(VI)) at an initial Se(VI) concentration, wherein the process removes the dissolved Se(VI) from an acidic reduction medium by reduction of the dissolved Se(VI) with chromous (Cr(II)) ions at an initial Cr(II)/Se(VI) molar ratio of 8 or above, whereby at least 95% of the Se(VI) is reduced to form a hydrogen selenide (H2Se) product within a reaction time of less than 5 hours, to provide a lowered-Se(VI) solution having a final Se(VI) concentration that is lower than the initial Se(VI) concentration, and wherein the Cr(II) ions comprise recycled Cr(II) ions produced by the process.
Dependencies are inferred from the claim text.