钛白粉生产废酸资源化循环利用技术研究（Research on Resource Recycling and Utilization Technology of Waste Acid from Titanium Dioxide Production）

Abstract： During the production of titanium dioxide via the sulfuric acid process, a significant amount of waste acid is generat-ed. The high-concentration sulfuric acid and various impurities in the waste acid pose a considerable burden on the environment.Traditional neutralization treatment methods not only waste resources but may also cause secondary pollution. To efficiently con-vert this waste acid into usable resources, this paper focuses on the production process of titanium dioxide via the sulfuric acid process, exploring how to recover the remaining sulfuric acid in the waste acid and extract valuable metal impurities from it. Initially, this paper conducts a systematic analysis of the specific components of the waste acid. Subsequently, it develops an in-tegrated treatment scheme centered around diffusion dialysis, combined with concentration crystallization and neutralization pre-cipitation processes. Laboratory data indicates that using selective ion exchange membranes for diffusion dialysis can separate and recover free sulfuric acid from the waste acid. The recovered acid can be directly sent back to the acidolysis or concentration process for reuse. The residual liquid after dialysis can be further processed to precipitate and separate out metal impurities such as iron and manganese, which can be enriched. The resulting metal slag can also be utilized as a by-product for further develop-ment and utilization. In laboratory tests, this integrated process achieved a sulfuric acid recovery rate exceeding 75%, while also reducing the workload and solid waste output in subsequent neutralization treatment.