| This paper relies on the 16Wt per year concentrated nitric acid plant using magnesium nitrate method which went into operation in 2013.And the paper discusses the high consumption of dilute nitric acid,magnesium nitrate,steam and circulating water,the treatment of acidic waste water and waste gas,the condensation of concentrated nitric acid pipeline,the obvious corrosion of some acid-resistant pipes and equipment,the poor running effect of concentrating tower,and one by one analyzes these issues combining with the experiment results,then makes the appropriate transformation measures.This paper focuses on the core equipment of concentrated nitric acid nitric acid enrichment tower operating poor results,easy to corrode magnesium nitrate leak leakage through the existing rectification tower retrofit experience,combined with the tower outside the experiment,analysis of the device was concentrated The tower operation is mainly affected by poor distribution of liquid distributor in the top of the condensing tower,unreasonable filling of the structured packing,and gaps between the packing and the tower wall,causing the wall flow and channeling in the tower to be affected by unreasonable flow conditions.After the implementation of the corresponding transformation,the operating efficiency of the nitric acid enrichment tower has been significantly improved.The acid output and the quality index of the finished products have also been greatly improved.The operation period has been extended from two months to four months.The average steam consumption has been significantly reduced and a good transformation has been achieved effect.In this paper,the acid gas is absorbed by the jet pump,and then the acid water is delivered to the dilute nitric acid synthesis unit as the absorption liquid.After being reformed,the acid gas and the acid water are effectively recovered.In this paper,the operation conditions of the device before and after the transformation are compared.The results show that the device after modification of 63.5%dilute nitric acid consumption by 1.60 t/t nitrate(pure)reduced to 1.57 t/t,1.12 kg/t nitrate consumed by nitrate(pure)reduced to 0.96 kg/t,the steam consumption by 2.09 t/t nitrate(pure)reduced to 1.87t/t,cooling water consumption reduced from 208 m3/t concentrated nitric acid to 202 m3/t.Operation time of the device is extended from one month to more than four months.In the period,concentrated magnesium nitrate pipeline and magnesium nitrate evaporator do not appear blocking phenomenon,acid resistant pipeline and magnesium nitrate heater and other equipment do not appear a new leak. |
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