METHOD FOR RECOVERING SALT CAKE FROM WASTE LIQUOR OF VANILLIN

摘要

PURPOSE: To precipitate and separate salt cake by blending waste liquor of vanillin containing salt cake with acetone in a given volume ratio and precipitating and separating salt cake. ;CONSTITUTION: Waste liquor of vanillin production process is mixed with acetone in an amount to give a ratio of acetone/waste liquor of vanillin of 0.1-2 by volume while stirring for 0.5-3hours. The amount of acetone added and addition time are required to change depending upon water and salt cake contents in the composition of the waste liquor. Addition of batch type or semi- batch type is preferable as the adding method and continuous method can also be applied. Crystallization is executed under normal pressure to somewhat pressurized state (e.g. 1-2kg/cm²G). In the case of normal pressure, a crystallizer is equipped with a condenser, vaporized acetone is condensed with cold water and acetone is sufficiently refluxed. The stirring rate is 100-400rpm and the crystallization temperature is 20-40°C. By separating and removing salt cake in this way, the pretreated waste liquor can suitably subjected to activated sludge method and can be concentrated for burning.;COPYRIGHT: (C)1993,JPO&Japio