Process for combustion of the residual black liquors from the manufacture of cellulose pulp

摘要

Process for combustion of residual black liquor from the treatment of wood or of lignocellulosic matter with alkali metal or alkaline-earth metal hydroxides and/or salts employing a fluidised bed with two stages 2 and 3 containing a refractory pulverulent. The addition of calcium carbonate to the black liquor at 1 makes it possible to obtain lime at the time of combustion. This process requires a low investment and allows the concentration and the combustion of the black liquors and the caustification of sodium carbonate to be carried out in the same apparatus. After combustion the refractory pulverulent is bleached with water in 4, and this yields a soda-containing liquor. The process is particulary suitable for black liquors containing solvents or crust-forming matter such as silica.