焦化硫泡沫制酸的品质优化研究及工业应用

Study on Quality Optimization and Industrial Application of Acid Production from Coking Sulfur Foam

摘要: 硫酸作为化工行业核心基础原料，其品质直接影响产品售价、储运成本及下游硫酸铵的产品质量。采用“湿法–直接焚烧”工艺制备98%工业浓硫酸，虽具备流程短、处理彻底、资源回收率高的优势，但工艺中易生成氮氧化物(NO_x)，不仅会强烈腐蚀设备，还会影响硫酸铵的结晶质量。本研究系统分析了工艺中NO_x的三大生成机制：热力型、燃料型、快速型，并深入探究了硫酸色泽异常的成因。通过不同温度下的碳钢腐蚀试验与工业工况验证，证实硫酸肼对NO_x具有高效脱除作用，可显著抑制浓硫酸对碳钢的腐蚀，且在一吸槽85℃左右的工业工况下处理效果最优。微量硫酸肼即可使异常硫酸恢复正常色泽，该方法为“湿法–直接焚烧”制酸工艺的品质升级提供了经济可行的技术方案。

Abstract: As a core basic raw material in the chemical industry, the quality of sulfuric acid directly affects the product price, storage and transportation costs, and the quality of downstream ammonium sulfate products. The preparation of 98% industrial concentrated sulfuric acid by the wet-process direct incineration technology has the advantages of short process flow, thorough treatment and high resource recovery rate. However, nitrogen oxides (NO_x) are easily generated in the process, which not only cause severe corrosion to equipment but also deteriorate the crystallization quality of ammonium sulfate. This study systematically analyzed the three major formation mechanisms of NO_x in the process: thermal NO_x, fuel NOₓ and prompt NO_x, and deeply investigated the causes of abnormal color of sulfuric acid. Corrosion experiments of carbon steel at different temperatures and verification under industrial operating conditions demonstrated that hydrazine sulfate has a high-efficiency removal effect on NO_x, can significantly inhibit the corrosion of concentrated sulfuric acid on carbon steel, and achieves the optimal treatment effect at approximately 85˚C in the first absorption tank under industrial operating conditions. A small amount of hydrazine sulfate can restore the normal color of abnormal sulfuric acid, which provides an economically viable technical solution for the quality upgrading of the wet-process direct incineration acid production technology.