Processing process for production waste water of tetrabutyltin

The invention relates to a process for processing wastewater discharged during the production process of tetrabutyl tin. The specific process is as follows: pretreatment; photocatalysis/chemical oxidation; distillation and crystallization; photocatalysis/chemical oxidation; and acid-alkali neutralization. Not only the process and the fabrication are simple, and effluent water quality can achieve the secondary discharge standard of metallurgy class in the 'Integrated Wastewater Discharge Standard' (GB1978-1996), but also a MgCl2 6H2O solid with large practical value can also be obtained from the wastewater, and the content of the MgCl2 6H2O solid is 25 to 35 percent of the wastewater. The process has the advantages of high efficiency, low cost and convenient operation; furthermore, the process is suitable for processing the wastewater discharged during the production process of the tetrabutyl tin by adopting an alkane halogenation process.