Alkali-alkali waste water
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I would like to ask everyone: The main production process is coal-to-gas – ammonia synthesis – vacuum salt production – caustic soda production. What is the situation regarding pollutant emissions from the vacuum salt production and caustic soda production units?
With comprehensive utilization, there should be no wastewater!
The problem with caustic soda wastewater is mainly the excessive ammonia nitrogen level; a ammonia evaporation unit can be used to treat it so that the emissions meet the standards.
It’s not that simple, right? In the caustic soda industry that uses coal as a raw material, what is known about the volume and quality of the wastewater generated from coal gas production, ammonia synthesis, vacuum salt production, and caustic soda production? If you know, please share. Thanks
Coal-to-gas processes have relatively high water pollution indicators, but this also depends on the type of gasifier used. The wastewater from other process sections should have low pollutant levels.
The dilute solution from the caustic soda plant consists of the condensate from calcination and the dilute ammonia water from the comprehensive recovery tower. The main components of this dilute solution are as follows: the NH3 concentration is 33.57, with a value of Ti=1.67857 mol/L, which corresponds to 28.5357 g/L or 2.85%; the Na2CO3 concentration is 3.57, with a value of Ti=0.17857 mol/L, corresponding to 18.93 g/L or 1.89%; the Cl- concentration is 0.14, with a value of Ti=0.007 mol/L, corresponding to 0.2485 g/L or 0.02485%; and the CO2 concentration is 17.77, with a value of Ti=0.8886 mol/L, corresponding to 39.097 g/L or 3.9%. The dilute ammonia solution enters a packed distillation tower; under normal design conditions, the ammonia content in the treated waste dilute solution should be ≤25 mg/L, and in optimal operating conditions, it should be ≤10 mg/L. Currently, this technology is mature and reliable, and we can provide the complete set of technologies. Relevant engineering experience: 1. Shijiazhuang Union Alkali Plant (two light liquid distillation units), with over 5 years of operation experience. 2. Glantai Salt Industry Co., Ltd.’s φ4000 light ammonia liquid distillation tower, with over 3 years of operational experience. 3. Light liquid distillation at Hubei Yingcheng United Alkali Factory. 4. Light liquid distillation in the United Alkali project at Fujian Yaolong Chemical. 5. Light liquid distillation in the integrated magnesium production project from salt lakes in Qinghai