Wheat Straw Black Liquor Treatment And Recovery,

AbstractPulp and paper industry is one of the major industries being blamedfor cOntril)uting serious pollution to the environment.. ~Vastcwater produced during ptLpermaking has four characteristics: u) high concentration; b) deep color; c) containing a great amount of fiber float; d) pollutIng a vast, sea of water. The most serious pollution in the wastcwater from papcrinaking is black liquor. During recent years, administrative and supcrvisory efforts have been undertaken by governmental agencies for abatement against the cxtrcnle]v serious pot lution problenis created by the effluent discharges lrotn the Pu [p and paper iii.i [Is. Thcat st. raw chum i ca recovery projects with the pul ping capacity of 75OOt/d have been put i nt() product ion gradual I y in recent years. it is proved that the technology of such size clieiiiicai recovery is basically mature. Chemical recovery is the most economic and effective way to eliminate the pollution of black liquor.The chem I cal recovery o I wheat straw I)LI I ping is a i nl.egrn Led eng I fleet I ng relating to each process oI pulping system and one ol. the major lc tor t.ssilicon iiiterfercnce?The main contents of the thesis are expounded as follow:1 Doing research on the relationship among viscosi ty, temperature, concentration as well as PH.2 i.t is concerned with the difficult problem of vaporizing wheat straw pulp black liquor and absorbs the method which adds caustic soda for decreasing viscosity through elimination of silicon liquor so that improves the vaporability of it.3 Confirming the position where adds caustic soda.4 Confirmation of the amount of adding caustic soda.The resultin~ draws ~the conclusion that adding caustic soda can decrease viscosity by 60% and eliminate silicon interference basically so the alkaline recovery rate is proved.