Definitions for "Black liquor"
One of the many sources of power used by paper mills is gained from the incineration of black liquor. This liquor is essentially liquified lignin which has been removed from the cellulose fibre during the cooking stage.
The residual lignin-containing chemical in the digester after the wood chip has been pulped.
The liquid material remaining from pulpwood cooking in the soda or sulfate paper-making process.