The invention relates to a device and method for recovering
sulfuric acid in waste
sulfuric acid generated in the process of producing a
perylene-3,4,9,10-tetracarboxylic dianhydride
pigment, mainly solving the problem that the waste
sulfuric acid generated when
perylene series pigments are produced can not be recovered. The device comprises a concentrating pan, a fractionating
tower, a dilute sulfuric acid preheater, a concentrated sulfuric acid cooler, a concentrated sulfuric acid
buffer tank, a concentrated sulfuric acid head tank, a waste sulfuric acid head tank, a medicament head tank and the like. The method is characterized in that concentrated sulfuric acid in the concentrated sulfuric acid
buffer tank is circularly preheated in the concentrated sulfuric acid head tank, the preheater, the fractionating
tower, the concentrating pan and the concentrated sulfuric acid cooler; the sulfuric acid enters the fractionating
tower after being evaporated, and the waste sulfuric acid in the concentrating pan is sent to the waste sulfuric acid head tank and then enters the preheater; the waste sulfuric acid enters the fractionating tower; the waste sulfuric acid enters the concentrating pan after being concentrated, and a medicament is added to the concentrating pan; and the hot sulfuric acid enters the cooler after being cooled and then enters the concentrated sulfuric acid
buffer tank, and part of the sulfuric acid is sent to the head tanks and part of the sulfuric acid is sent to a product
storage tank by a pump. The device and the method have the
advantage that the sulfuric acid in the waste sulfuric acid can be effectively recovered.