Magnesia Based Dry Vibrating Mix for Tundish

摘要

Influence of binders, particle size distributions and mineralogical compositions on physical properties at room temperature and slag resistance of magnesia based vibrating mix were investigated in this paper. The results showed that Na_2SiO_3.5H_2O was an environment-friendly binder though magnesia based vibrating mix had higher cold crushing strength after heat-treated at 250℃×24h,1100℃×3h and 1500℃×3h separately when phenolic resin and boric acid used as binder. The packing density of dry mix reached the maximum when the particle size distribution of magnesia was: 3-1mm 30%, 1-0mm 40%, ＜0.088mm 30%. And it dropped gradually with the addition of magnesia micropowder. The slag resistance of dry mix wasn't remarkably improved as adding corundum fine powder. However it was improved by adding dolomite owing to the formed free lime though its bulk density decreased obviously. In contrast the penetration of molten slag was prevented whereas the corrosion resistance became worse when quartz fine powder was added.