| With the crude oil being heavier and the development of residual oil catalytic cracking (RFCC) technology, the demand of superstable molecular sieve in market grows increasingly. During the production of superstable molecular sieve, a great deal of ammonium salt is consumed to exchange sodium ion absorbed on the framework structure of molecular sieve. According to the process for the production of superstable molecular sieve in Catalyst Plant of Lanzhou Petrochemical Company, most of ammonium salt added in the production is finally discharged into the waste water as the form of N-NH3. The amount of N-NH3 in waste water amounts to 6,000mg/L. Our company lies in the upper reaches of Yellow River. To meet the high requirement of the national environmental protection regulation, the amount of N-NH3 in waste water must be reduced to below 15mg/L before discharging. So, a comprehensive treating plan is proposed, which combines with the technologies of the source treatment, the recycling of N-NH3 and the bio-treatment. Through continuous tests and modification, the waste water containing high N-NH3 in Catalyst Plant reaches a set standard and can be discharged stably.In the source treating of waste water containing N-NH3, several industrial tests were performed on the modification of ammonium salt, the improvement of exchanging technology, the optimization of calcination technology and the reforming for the filtering slurry of the molecular sieve on the basis of bench scale. During the production of superstable molecular sieve, the feed ratio of ammonium salt was decreased from 1.8 to 0.8. At the same time, through the process analysis and industrial tests, the secondly exchanged waste liquid successfully replaces the fresh liquid for the first exchanging, which decreases the amount of discharged waste water containing N-NH3. Though source treatment on waste water containing N-NH3, the total amount of waste water continuously decreases, and the amount of...
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