目的 研究超导材料清洗过程中产生的废酸的处理和回收技术,实现废酸提纯回用,达到废酸液零排放的目标。 方法 向废酸液中配入工业浓硫酸,以提供适量浓度的环境,然后在 25 kPa 真空环境下进行蒸发,酸蒸气通过换热器冷凝再生,浓缩后获得的金属硫酸盐溶液进行常温下冷却结晶回收。 按照配酸、蒸发、冷凝、结晶等工艺要求,设计、制作废酸再生回用的耐腐蚀过程设备,调试组成废酸再生系统,验证并优化工艺细节。 结果 研制的负压蒸发再生系统日处理废酸量达到 9 ~ 15 t,再生酸经浓度调整后直接回用,从浓缩液中得到的硫酸盐结晶物可作为其它化工原料。 结论 成功实现了清洗超导材料用硝酸和氢氟酸的再生,整个环节没有污染物排放,同时设备具备造价低、运行稳定可靠、维护量小等优点。

Objective To study the treatment and recycle technology of waste acid generated during the cleaning process of superconducting material, in order to realize the purification and reuse of waste acid, reaching the goal of zero release of waste acid.Methods Concentrated sulfuric acid was mixed with the waste acid liquid to provide the suitable concentration, then the mixture was evaporated in a vacuum environment under 25 kPa, where the acid evaporator was condensed and regenerated,and metal crystals were obtained from the enriched melt sulfate solution after cooling at room temperature. A whole set of corrosion resistant equipment were designed and developed according to the requirements of mixing acid, evaporation, condensation and crystallization.The process details were validated and optimized with commissioning. Results Totally 9 ~ 15 tons of waste acid was treated daily with the system. The regenerated acid could be reused after concentration adjustment, and the sulfate crystals from the concentrated liquid could be used raw materials for other chemicals. Conclusion Nitric acid and hydrofluoric acid for cleaning of superconducting material were successfully regenerated and reused. No pollutant was discharged in the whole process. Meanwhile, the equipment had a number of advantages, such as stability, reliability, low cost and low maintenance.