Ausmelt炼锡炉炉渣对镁铬耐火材料的侵蚀

Corrosion Mechansim of Magnesite-chrome Bricks by Slag of Ausmelt for Tin Smelting

采用静态坩埚法对镁铬砖抗Ausmelt炼锡炉炉渣侵蚀性进行了研究,并用扫描电镜和能谱分析等手段对抗渣前后试样的显微结构进行了分析。研究结果表明:随着Cr2O3含量的增加,镁铬砖的抗渣性能提高。炉渣对镁铬砖的侵蚀机理主要表现为:炉渣中的FeO、SiO2与镁铬砖中的MgO发生反应生成低熔点的镁铁橄榄石(MFS),导致镁铬砖的直接结合结构被破坏;炉渣中的SnO不与耐火材料各成分发生反应,对镁铬砖的侵蚀以渗透为主;镁铬砖中的铬矿不与炉渣发生反应,表现出良好的抗渣性能。

The corrosion resistance to slag of magnesite-chrome bricks with different Cr2O3 content was studied by the method of static crucible slag test. The microstructures of the as-delivered and tested refractories were analyzed by means of SEM and EDS. The results showed that： the more Cr2O3 content of magnesite-chrome bricks the better its slag resistance. The corrosion mechanisms of magnesite-chrome refractory can be described as follows： SiO2 and FeO in slag react with MgO in magnesite-chrome bricks, which results in the formation of lowmelting compounds of olivine （MFS）, and then the direct-bonded microstructure of brick is destroyed. SnO in acidic slag does not react with the components of refractory, and the infiltration is its main corrosion form. There is no reaction between chrome in magnesite-chrome brick and slag, which demonstrates that the chrome has better slag resistance.