水泥生料高温双固硫体系与SO_2释放

The Double System of Raw Cement Sulfur-capturing in High Temperature and the Release of SO_2

水泥生料含有大量CaCO3和SiO2、Al2O3、Fe2O3、MgO等矿物,理论上是性能优良的复合固硫剂。利用"反相萃取分离法"分离硅酸盐矿物相,借助XRD和TG-FTIR对不同硫含量生料在煅烧过程中复合高温固硫体系作用机理和升温过程中SO2释放情况进行了探讨。结果表明,水泥生料高温固硫分为两个体系:1150～1400℃温度区间CaO-Al2O3-CaSO4铝相固硫体系起主导作用;1400～1450℃区间CaO-Al2O3-Fe2O3-CaSO4铁铝酸盐相固硫体系起主导作用;两者的固硫效果不尽相同,前者是非稳态固硫在温度升高至1400℃左右会再次释放出大量SO2,后者属于稳态固硫,最终将硫固化在熟料当中。

There are a large number of CaCO3 and SiO2、Al2O3、Fe2O3、MgO etc.minerals in raw cement.In theory,this element is the excellent performance composite sulfur-capturing agent.Through using ＂Anti-Extraction-Determination methods＂separated Silicate phase,and Using XRD and TG-FTIR means to discuss mechanism of the compound sulfur-capturing system in high temperature and SO2 releasing in the process of raw cement heating.The result show that the sulfur-capturing in high temperature of raw cement can be separated into double system：temperature range 1150-1400 ℃ the Aluminum phase CaO-Al2O3-CaSO4 plays a leading role in raw cement sulfur-capturing system;In the temperature range 1400-1450 ℃ aluminate-ferrite phase CaO-Al2O3-Fe2O3-CaSO4 plays a leading role in raw cement sulfur-capturing system.The effection of sulfur-capturing is very different in this two system,The first one is nonsteadystate sulfur-capturing,When the temperature rise to about 1400 ℃ will release a large amount of SO2;But the second one is steadystate sulfur-capturing,it will put sulfur curing in the cement clinker.