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US 4,470,876 AGranted
Kraft overload recovery process
OwnerMarc F. Beaupr/e/, Emile A. Cambron +1inventors
InventorsMarc F. Beaupr/e/, Emile A. Cambron, Emily T. Cambron
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Abstract
The present invention relates to a kraft overload recovery process for the treatment of kraft black liquor (b.l.) which comprises acidifying the b.l. with an acid comprising sulfuric acid, separating the lignin therefrom, and further treating the residual b.l. for recovery of inorganics contained therein for use as a source of cooking chemical in kraft cooks.
Claims16
A Kraft overload recovery process for the recovery of black liquor resulting from a kraft pulping process in a kraft recovery system having a kraft recovery process comprising the steps of:
- (a) feeding a first portion of said black liquor to said furnace,
- (b) adjusting the concentration of a second portion of said black liquor to a concentration of at least 40% solids, and acidifying said second portion of said black liquor with an acid comprising sulfuric acid so as to form at a temperature above 57.degree. C. an insoluble coagulated layer of substantially all the lignin contained in said second portion on top of said second portion of black liquor and to form sodium sulfate,
- (c) separating said insoluble coagulated layer of lignin on the top of the rest of said acidified second portion, said rest of said acidified second portion comprising organic and inorganic components,
- (d) feeding at least said inorganic component comprising said sodium sulfate to said kraft recovery system operating at capacity.
1 more element
Dependencies are inferred from the claim text.