Evaluating the effectiveness of proprietary additives in improving the capture and sequestration of oxidized mercury in scrubber systems.

摘要

Mercury released during thermal processing (induration) of beneficiated taconite ore (referred to as green balls) can be captured by scrubber waters if it is in an oxidized form. Consequently, mercury emissions from Taconite facilities can be reduced by oxidation of the mercury released from the green balls, followed by capture in their scrubbers. Moreover, sequestration of the captured mercury from the scrubber slurry could prevent possible (re-)emission by ensuring that the driving force for oxidized mercury capture by scrubber liquids is at an optimum; and prevent recycling of captured mercury back to previous process steps.;This research investigates the ability of certain proprietary additive-based technologies to achieve oxidation, capture and sequestration of mercury in Taconite facilities. The said additive-based technologies have showed successful mercury control capabilities in coal-fired utilities, but need to be retrofitted for Taconite facilities. The additive-based technologies consist of the injection of powdered activated carbon (PAC) and ESORB-HG-11 (a halogenated PAC) into the waste gas of a selected Taconite facility and dosing of the plant's scrubber slurry with diethyl dithiocarbamate (DEDTC).