摘要 |
<p>of the disclosure The invention relates to a method of carbonating green liquor and seprating sulphur from this liquor as hydrogen sulphide. Green liquor is prepared by burning the waste liquor from chemical pulping process in a recovery furnace or with corresponding method and dissolving the smelt obtained in aquous solution. Green liquor is first clarified in order to separate insoluble solids and possibly precarbonated with gas containing carbon dioxide. Then green liquor is carbonated with concentrated carbon dioxide so that proper concentration of alkalibicarbonate is obtained for separating sulphur as hydrogen sulphide in the following stage. In sulphur separating stage, alkali bicarbonate and alkali bisulphide react with each other liberating hydrogen sulphide.</p> |