硫精砂制酸尾气达标排放及资源化回收利用

硫精砂制酸排出的尾气中SO2含量一般为0.2%~0.5%(体积分数,下同),目前国内普遍采用一转一吸或两转两吸流程来吸收硫酸尾气,使SO2质量浓度达到低于860 mg/m3的国家二级排放标准。但随着国家颁布新的《硫酸工业污染物排放标准》,要求现有硫酸企业SO2排放质量浓度必须于2013年10月1日前全部低于400mg/m3,因此必须对尾气进行进一步的处理。本文结合湖北新洋丰肥业股份有限公司和武汉中东化工有限公司硫酸生产的实际情况,总结了采取三段氨吸法处理硫酸尾气的技术改造和资源化回收利用。

Qualified Exhaust Emission and Resources Recovery in Acid Preparation from Pyrite Concentrate

The exhaust emitted during acid preparation from pyrite concentrate contains generally 0.2%~0.5%(in volume,the same below) of SO2.In our country,nowadays,a one-conversion-one-absorption process or a two-conversions-two-absorptions process is widely used to absorb sulphuric acid exhaust so that the content of SO2 therein is decreased to as low as 860 mg/m3.However,the newly issued Standards on Pollutants Emissions for Sulphuric Acid Industry requires all the sulphuric acid manufactures to control the SO2 content in the exhaust to be less than 400 mg/m3 prior to october 1,2013.Accordingly,the exhaust shall be further treated before emission.In this paper,novel 3-stage ammonia absorption techniques for treating sulphuric acid exhaust as well as its resources recovery yield are introduced,based on the actual manufacturing status in Xinyangfeng Fertilizer Co.,Ltd.of Hubei and Middle East Chemical Engineering Corporation,Ltd.of Wuhan.