材料期刊网

为了解采用可燃性废弃物作为替代燃料煅烧水泥熟料时产生的气氛对水泥窑烧成带用方镁石－复合尖晶石砖的侵蚀情况，首先进行了化学试剂 V2 O5分别与高纯镁砂和镁铝尖晶石砂在1500℃下的反应试验；然后以高纯镁砂、高铁镁砂、铁铝尖晶石砂为原料，于1600℃烧成制备了方镁石－复合尖晶石坩埚试样，按水泥熟料、橡胶轮胎、石油焦的质量分数分别为50％、25％、25％配成侵蚀介质，采用静态坩埚法进行了替代燃料对方镁石－复合尖晶石材料的侵蚀试验（1450℃保温3 h）。利用 XRD 检测了试样的物相组成，采用 SEM观察和分析了气氛侵蚀后试样的显微形貌。结果表明：1）V2 O5与 MA 中的 MgO 反应产生刚玉相和钒酸镁，破坏了尖晶石结构，并伴随较大的体积膨胀而破坏了砖的结构。因此，在水泥窑使用替代燃料的情况下，方镁石－复合尖晶石砖中不适合加入镁铝尖晶石。2）替代燃料燃烧产生的 SO3、V2 O5等酸性气体沿着气孔和晶界向砖内扩散，在气孔和晶界处聚集，与方镁石－复合尖晶石材料中的 CaO、MgO 反应生成 Ca3（VO4）2、Mg3（VO4）2、CaSO4、MgSO4，产生体积效应，不利于材料的稳定；另外还与水泥熟料中的 C2 S 反应生成 CaSO4和低熔点相，不利于窑皮的稳定。

This paper aims at researching the produced atmosphere corrosion during the calcination of ce-ment clinker using combustible wastes as substitute fuels to periclase-compound spinel bricks for burning zone of cement kilns.Firstly,chemical reactions between V2 O5 and high purity magnesia or magnesium alu-minate spinel at 1 500 ℃ were researched.Secondly,periclase-compound spinel crucible specimens were prepared at 1 600 ℃ using high purity magnesia,ferruginous magnesia,and hercynite as raw materials;the corrosion medium was prepared using 50% cement clinker,25% rubber tyre and 25% petroleum coke;the static crucible corrosion tests were carried out at 1 450 ℃ for 3 h.The microstructure and phase composition of the corroded specimens were analyzed by SEMand XRD,respectively.It is found that (1)V2 O5 reacts with MgO from spinel forming corundum and magnesium vanadate accompanied by a large volume expansion, deteriorating the spinel structure,thus damaging the brick structure,so when the substitute fuels are used for cement kilns,magnesium aluminate spinel is not a suitable raw material for periclase-compound spinel bricks;(2)the produced acid gases such as SO3 and V2 O5 during the combustion of alternative fuels pene-trate into the bricks along pores and crystal interfaces,gather in pores and crystal interfaces,react with CaO and MgO from periclase-compound spinel bricks forming Ca3 (VO4 )2 ,Mg3 (VO4 )2 ,CaSO4 and MgSO4 ac-companied by volume effect,which is disadvantage to the brick stability;additionally,the acid gases react with C2 S forming low melting phases and CaSO4 ,which goes against the stability of kiln coating.