摘要 |
In order to control the sodium oxalate level in the liquor employed in the Bayer process for the production of alumina, a part of the spent liquor recovered from alumina trihydrate precipitation stage is concentrated by evaporation to render it supersaturated with respect to sodium oxalate. The thus concentrated liquor is then sprayed onto a packing in an enclosed space under conditions such that the supersaturation of the droplets at impact on the packing exceeds a critical supersaturation. The sprayed liquor deposits sodium oxalate on the packing and is recovered for recirculation to the process circuit. |