Locke Lord LLP
Method for treating waste saline water produced in production process of diphenylmethane diisocyanate (MDI)
The invention relates to a method of circular use of waste brine produced in the manufacture process of MDI, comprising the following steps: (1) the waste brine produced in the manufacture process of MDI is subjected to a high-gravity extraction and then to a column extraction, wherein said waste brine contains aniline, diaminodiphenylmethane and polyamine; (2) the waste brine from step (1) is transmitted to a stripping tower for steam stripping; (3) the waste brine from the stripping tower of step (2) and a chemical oxidant are transmitted to an oxidation reactor to which air is blown for aeration; (4) the waste brine after the treatment of step (3) is transmitted to an absorption tower for absorption. The invention makes the salt water have TOC of less than 8 ppm and TN of less than 2.5 ppm and achieves regeneration of resources in the waste brine such as sodium chloride and water and the like for circular use.
WANHUA CHEMICAL (NINGBO) CO., LTD.
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Haikui Xiaogao Jianfeng Guangwen Hongke Zhenhua Shuchang Weiqi Jiansheng Limin Pengyuan
Zou Liu Chen Chu Zhang Zhao Sun Hua Ding Xu Zhang