富氧熔炼烟气中三氧化硫的形成与抑制

Tormation and inhibition of SO_3 in oxygen-enriched smelting flue gas

富氧熔炼过程中SO_3(g)的形成是设备腐蚀及污酸形成的主要原因。通过模拟计算,研究温度、O_2(g)和H_2O(g)含量以及硫酸盐的存在这4种因素对烟气中SO_3(g)、H_2SO_4(l)等含硫组分形成的影响。结果表明:温度越高,越不利于SO_3(g)、H_2SO_4(l)的形成;烟气中O_2(g)和H_2O(g)的量越低,SO_3(g)和H_2SO_4(l)含量也越低,这是控制烟气酸性物质生成的决定性因素;物料中硫酸盐属于不利因素,在一定温度范围内分解生成SO_3(g)和O_2(g),导致SO_3(g)发生率增大。分析认为,精确控制烟道漏风量,尽可能减少物料水分和硫酸盐含量,并延长物料在炉内停留时间,可抑制烟气中SO_3(g)、H_2SO_4(l)的形成,对解决熔炼过程设备腐蚀及污酸问题有一定意义。

In oxygen-enriched smelting process,the problems of equipment corrosion and waste acid formation are closely related to the formation of SO3(g).By simulating calculation,the influences of temperature,the amount of O2(g)and H2O(g),sulphates existing on the component content of SO3(g),SO2(g)and H2SO4(l)of flue gas were studied.The results show that,the high temperature goes against the formation of SO3(g)and H2SO4(l).The higher the temperature,the less the content of SO3(g)and H2SO4(l).The less the amount of O2(g)and H2O(g),the less the content of SO3(g)and H2SO4(l).The amount of O2(g)and H2O(g)are the decisive factor to generate SO3(g)and H2SO4(l).Sulphates existing is an unfavorable factor for equipment corrosion and waste acid formation.The sulphates decompose and lead to the content of SO3(g)and O2(g)increasing at some temperature.The analysis results suggest that accuracy control of the air-leakage rates of feed opening and flue,reducing the water and sulphates content as much as possible,and prolonging the residence time in the furnace of raw materials can all inhibit the formation of SO3(g)and H2SO4(l),and has certain significance on solving the problems of equipment corrosion and waste acid formation.