Research On Properties Of SO₂ Exhaustion Reduction By Preheater-Precalciner Technology With High Ratio Of Solid To Gas

The sulfur dioxide(SO₂)is one of the main harmful gases to ecological environment of the mankind and the SO₂ exhaustion reduction in the cement industry can not be neglectful.The cement clinker calcination technology of new dry process has the function of sulfur fixation,and the preheater-precalciner technology with high ratio of solid to gas in the application of cement industry shows the better effect for energy-saving and exhaustion reduction.The study on SO₂ exhaustion reduction was done for the purpose of proving the practical theoretical basis for preheater-precalciner technology with high ratio of solid to gas of having the obvious effect of the SO₂ exhaustion reduction.The cement raw meal contain a large number of CaCO₃ and small amount of SiO₂,Fe₂O₃,Al₂O₃ and MgO etc.,and has the function of reliable sulfur fixation.The cement raw meal of cement factory was adopted and the test for sulfur fixation of the raw meal was done in the suspension resistance furnace.The influences of solid-gas ratio,temperature,Flow velocity,concentration of sulfur dioxide and specific surface of raw meal on sulfur fixation effect were investigated.The sulfur fixation products after reaction were analyzed by using the XRD and SEM,and the shape and appearance of the raw meal in different temperature conditions are investigated.The results of experiments show that the influence of the temperature and solid-gas ratio on the sulfur fixation efficiency is more obvious.The material adopted from the industrial site were analyzed by means of the XRD and SEM.Comparing the effect of sulfur fixation of preheater and precalciner system, it shows that the sulfur content of the thermal material into kiln and clinker of the high solid-gas ratio preheater exceeds 50%of those for common model.The content of five stage cyclone meal exceeds 100%of those for four stage cyclone meal.Applying the high solid-gas ratio preheater and precalciner system and common model preheater and precalciner system for detecting the practical site gas respectively,the each index of the former is all better than the latter.Especially,the exhaustion of the harmful gas SO₂ decreases 80%.The reason for exhaustion reduction was synthetically analyzed.The results show that the use of high solid-gas and out-cycle precalciner strengthen the sulfur fixation reaction effect of the cement raw meal of the preheater-precalciner technology with high ratio of solid to gas.From the aspects of the use of energy resource,environment pressure reduction, technique economy and so on,the benefit of exhaustion reduction of the preheater-precalciner technology with high ratio of solid to gas were analyzed,and the application prospects were evaluated as well.The preheater-precalciner system with high ratio of solid to gas have a wide developing prospects both of the effect of economy and society.