| 摘要 |
A process and a device for recycling waste acid produced in the process of producing Zoalene. The process comprises steps: heating, depressurizing and distilling the waste acid recycled after nitration reaction; collecting acid liquid A and distilled water A; mixing the acid liquid A with new concentrated sulfuric acid in proportion, and putting the mixture to a new Zoalene nitration reaction process; and putting the distilled water A into a diluting pot for diluting the liquid produced in the nitration reaction. The waste acid produced in the process of producing Zoalene is recycled and not directly discharged; water resources are recycled, waste of the water resources is reduced, and discharge of waste water produced in the process of producing Zoalene is greatly reduced, so that not only production cost is saved, but also environment pressure is reduced. |
| 主权项 |
1. A process for recycling waste acid produced in the process of producing Zoalene, comprising a nitration process, a chlorination process and an ammonization process, wherein the nitration process comprises the following steps: putting concentrated sulfuric acid into an enamel reactor (12), starting a mixer (18), putting in ortho-toluic acid and mixing it until completely dissolved, adding nitric acid to the system, controlling the system temperature at 90-100 DEG. C, continuously mixing to react for 0.5-1.5 h after added, and then cooling; diluting the liquid with distilled water, then filtering, and then washing and drying the solid to obtain a nitration product 3,5-dinitro-2-methylbenzoic acid; putting the waste acid which is diluted and washed in the nitration process into a distillation tower (1), later heating, depressurizing and distilling; setting the vacuum degree for depressurizing and distilling the water acid at 0.07-0.1 MPa, putting the acid liquid A obtained by distillation and concentration into a mixing tank (8), and adding new concentrated sulfuric acid to the mixing tank (8), wherein the mass ratio of the acid liquid A to the new concentrated sulfuric acid mixed above is 1-5:1; after mixing, putting the mixed sulfuric acid to a reactor to carry out a new nitration reaction; recycling and putting the distilled water A which is obtained by heating, depressurizing and distilling into a condenser (15) for cooling, storing the cooled distilled water A in a recycled water storage tank (17), and putting the distilled water A to a diluting pot (13) to dilute the 3,5-dinitro-2-methylbenzoic acid produced in the new nitration process. |
