分散剂对刚玉-氮化硅浆体流变性能的影响

Effect of dispersant on rheology properties of corundum-silicon nitride suspension

为优化刚玉-氮化硅透气砖用浇注料的性能,研究了刚玉水基浆体和氮化硅水基浆体的流变性能,并在此基础上研究了4种分散剂(分别为聚丙烯酸钠、高分子多元醇、木质素磺酸钙和六偏磷酸钠)对刚玉-氮化硅悬浮液流变性能的影响。结果表明:随着氮化硅悬浮液pH值的增大,其ζ电位的绝对值也增大,碱性条件有利于氮化硅悬浮液的稳定;当刚玉-氮化硅悬浮液的pH值=10时,其ζ电位的绝对值最大,悬浮液最稳定,分散性也最好;聚丙烯酸钠使刚玉-氮化硅悬浮液的ζ电位的绝对值明显增加,提高了悬浮液的稳定性,但其加入量不宜超过0.5%。将其结果应用在制备刚玉-氮化硅透气砖用浇注料上,使透气砖的性能得到了改善。

The rheology properties of corundum slurry and β-silicon-nitride slurry were studied to optimize the performance of corundum-β-silicon nitride castable for making purging plugs. The effects of four dispersants (polyacrylate sodium, polyvinyl ether, calcium oxide ligno surfnate, hexameta phosphate) on the rheology of corundum-silicon nitride suspension were studied by using ζ potential and rheology curve testing method. The study results show that: (1) The absolute value of ζ potential of silicon nitride suspension increases with the increasing of its pH value, and the basic condition is beneficial for the stability of silicon nitride suspension; (2) The absolute value of ζ potential of corundum-silicon nitride suspension is maximum when its pH value is 10, and its stability and dispersing effect is optimal; (3) When polypropylene sodium is added into corundum-silicon nitride suspension with the addition less than 0.5%, the absolute value of ζ potential of the suspension has an obvious increase, and the stability of the suspension is improved, the water demand of castable is decreased. The study results were used to prepare the corundum-silicon nitride castable for preparing purging plug, and the properties of the purging plug were improved.