Design Of Soda Ash Tail Gas Purification And Recovery System

This article introduced the type, main contents and influencing factors to consumption of soda ash tail gas by Hou's process, analyzed the problems of purification and recovery unit and provided production process for the recovery and utilization of soda ash tail gas in such small enterprises by Hou's process.The subject has completed existing tail gas purification and recovery system from four aspects: (1) carbonation tail gas purification;(2) ammonia cleaning of soda ash filtering machine filtered tail gas; (3) NH3 and CO2 recovery and utilization of sodium carbonate producing tank; (4) distillation and recovery of furnace gas condensate.In this new process, the soft water was wholly introduced into filtered tail gas ammonia cleaning section of filtering machine, it has increased the efficiency of ammonia cleaning to 97.4%; as carbonation tail gas ammonia cleaning and furnace gas washing, the water of ammonia cleaning of filtering machine do not effect the efficiency of ammonia cleaning and the total efficiency of carbonation ammonia cleaning reached to 98.7%; the recycle alkalinity of weak alkali liquid did not accumulate and cannot effect the quality of soda ash and alkali substance of ammonium chloride.The distillated condensate of furnace gas showed that NH3 cleaning efficiency will reach to 98% and the recovery rate of CO2 reach to 30% while adoptingMl asabsorber, CO2 in tail gas recovered for carbonation-soda ash production, then ammonia and CO2 are recovered; the condensation of ammonia in waste water is lower than 0.5tt, CO2 is below 0.03tt, so it can be used directly as soft water, then it has decreased the total quantity of various water containing ammonia in soda ash making system and improved environment.It has adopted sealed cap for sodium carbonate producing tank to recover about CO2 13Nm3~15Nm3 per ton of soda ash.Consumption was obviously decreased, ammonia consumption was decreased from 380kg to 352kg perton of soda ash and salt from 1160kg to 1146kg.The subject has dissolved the problem of mother liquid balance which had been troubling Hou's process enterprises and realized complex recovery and utilization of various water containing ammonia, achieved favourable benefits both in society and economy, it has a practical significance for China's Hou's process enterprises especially for those medium and small - sized enterprises to realize complex purification and utilization of soda ash tail gas at present.