Patent ID: 6960336

Claim:
A method of producing low soda alumina, comprising: (a) supplying alumina source material to a calciner and calcining the alumina source material in the calciner; (b) supplying a soda removal agent to the calciner; (c) gasifying the soda removal agent and supplying the gasified soda removal agent to the calciner while contacting the gasified soda removal agent to the alumina source material; (d) supplying exhaust gas from the calciner to a dust-collector to collect dust contained in the exhaust gas; (e) recirculating a portion of the collected dust back to the calciner; (f) externally discharging another portion of the collected dust; (g) slurrying still another portion of the collected dust while controlling slurry pH; (h) washing and filtering the slurried dust and recirculating the washed and filtered slurried dust back to the calciner; and (i) extracting low soda alumina calcined by the calciner.