氯元素在高炉中的热力学行为

Thermodynamic behavior of chlorine in blast furnace

为了探究高炉中氯元素的行为规律,以国丰1号1 780m3高炉为研究对象,采用FactSage 6.4软件通过热力学计算系统分析高炉实际冶炼条件下的氯元素行为。结果表明,高炉入炉料中的氯化物与高炉中的P2O5、SiO2、H2O、CO2、H2等均会发生反应,且炉料在下降过程中在高炉不同区域会与不同的物质发生反应。入炉料中的氯元素主要以气体HCl的形式释放,被释放的HCl会随着煤气流的上升黏附在炉料和炉壁上,从而与炉料炉壁中的物质发生一系列复杂的物理化学反应,从而生成NaCl、KCl、MgCl2和CaCl2等氯化物,随着炉料继续下降氯化物又会以HCl的形式逸出,因而形成氯化物在高炉内的循环富集。未参加反应的HCl随着炉顶煤气逸出,对后续的除尘设备、发电装置、煤气管道等均会产生一定的影响。通过氯元素在高炉内的热力学行为分析,可以更好地掌握氯元素在高炉中的演变规律,为降低氯元素对高炉干法除尘工艺的危害提供充分的依据。

In order to study the behavior evolution law of chlorine in the blast furnace（BF）,Guofeng No.1 1 780m3 BF was selected as a case to systemically analyze the thermodynamic behavior of chlorine under actual smelting conditions by means of calculation method using FactSage 6.4software.The results indicated that the chlorides in furnace burden reacted with P2O5,SiO2,H2 O,CO2and H2 in BF,and the corresponding different reactions occurred in different areas of BF in the burden descending process.The chlorine in furnace burden was predominantly released in the form of HCl.The released HCl rose along with the gas flow and adhered to the furnace burden and inner walls,where a series of complex physiochemical reactions took place,generating chlorides such as NaCl,KCl,MgCl2 and CaCl2.Along with the decline of furnace burden,these chlorides were released again in the form of HCl,thus forming the circulating enrichment of chlorides in the BF.The unreacted HCl escaped with top gas,which would affect the subsequent dust removal equipments,power generation equipments and gas pipes.Herewith through the thermodynamic analysis of chlorine in BF,its evolution law could be better mastered to provide a sufficient basis for reducing the harm of chlorine to the dry dedusting technology BF.