球团链箅机回转窑工艺中氯和硫元素迁移规律

摘要：对链箅机回转窑工艺中各段球团样品进行实验分析，研究了氯元素和硫元素在链箅机回转窑工艺中的迁移规律，明晰了烟气中HCl的生成机制。结果表明，球团原料中的氯元素主要是以NaCl的形式存在，氯元素有一部分在链箅机抽风干燥段会转变成HCl气体并进入烟气，一部分在链箅机预热Ⅱ段之后以NaCl的形式汽化进入烟气，剩余的氯元素仍以NaCl的形式存在于成品球团矿中。烟气中的HCl气体是在抽风干燥段，由富含SO2的烟气与含水球团料层中的NaCl发生反应生成的，烟气中SO2转变成Na2SO4重新固定于料层中。在预热Ⅰ段和预热Ⅱ段，烟气中的SO2与原料中碳酸钙分解生成的游离CaO反应生成CaSO4，也会重新固定烟气中的SO2。

Migration rule of chlorine and sulfur in grate-kiln process of pellet production

The pellet samples of each section in the grate rotary kiln process were experimentally analyzed, the migration law of chlorine and sulfur in the grate rotary kiln process was studied, and the formation mechanism of HCl in flue gas was clarified.The results show that the chlorine element in the pellet raw material mainly exists in the form of NaCl. Part of the chlorine element will be transformed into HCl gas and enter the flue gas in the exhaust and drying section of the grate, and part will vaporize into the flue gas in the form of NaCl after preheating section II of the grate. The remaining chlorine element still exists in the finished pellet in the form of NaCl. The HCl gas in the flue gas is generated by the reaction between the flue gas rich in SO2 and NaCl in the water containing pellet material layer in the exhaust drying section. The SO2 in the flue gas is transformed into Na2SO4 and refixed in the material layer. In preheating section I and preheating section II, the SO2 in the flue gas reacts with the free CaO generated by the decomposition of calcium carbonate in the raw material to generate CaSO4, which will also refix the SO2 in the flue gas.