混酸法硝酸磷肥酸解尾气及浓缩蒸汽冷凝液的综合利用

混酸法硝酸磷肥酸解尾气的主要成分是氮氧化物,其浓缩过程产生的蒸汽冷凝液含有氨。本文提出用蒸汽冷凝液洗涤酸解尾气,然后用于洗涤磷石膏的洗水,返回结晶槽,并对系统的水平衡进行计算,可以实现硝酸磷肥生产的废水和废气的达标排放。同时,尾气吸收液返回结晶槽一方面可以调节液固比,另一方面带入的铵根离子可以改善磷石膏的结晶,既回收了有效成分,又实现了清洁生产与经济效益双丰收。

Comperhensive Utilization of Acidulation Tail Gas and Condensate of Steam for Evaporation from Nitrophosphates Production by Mixed Acid Process

In the production of nitrophosphates by the mixed acid process the main components of the acidulation tail gas are nitrogen oxides,and the steam condensate from evaporation contains ammonia.This paper proposes the use of steam condensate to wash the acidulation tail gas,then to be used as wash water for washing phosphogypsum,to be returned to the crystallizer,and a calculation is made of water balance in the system,so that the discharge of wastewater and waste gas is up to standard.The tail gas absorption solution is returned to the crystallizer,thereby adjusting the liquid-solid ratio,and improving the phosphogypsum crystals with the entrained ammonium ions,with the result that the available components are recovered,and clean production and economic benefit are realized.