南方稀土尾砂制备低温烧结玻化砖变形缺陷的研究

Deformation Defect of Low Temperature Vitrified Tile Prepared with Southern Rare Earth Tailings

本实验通过矿物MLA分析发现:稀土尾砂中长石含量较高,而且稀土尾砂样品中高岭土和石英矿物都包含云母和磁铁矿,大量的稀土尾砂单独引入配方中易造成坯体烧成过程中液相集中在较小的温度段内大量出现。实验利用南方稀土尾砂为主要原料,并辅以多种熔剂型原料,成功制备出了稀土尾砂用量大于40wt.%、能在1100℃以下烧结、且性能符合并部分高于国家玻化砖标准的样品。实验结果表明:选择合适的多元复合熔剂系统,可以明显降低瓷坯中出现液相的始熔温度,使坯体提前进入烧结阶段,并且液相梯度缓慢出现在坯体中,能有效解决单独使用稀土尾砂造成产品变形大、烧成温度范围窄等关键技术难题。

MLA analysis has found： due to the high content of feldspar in rare earth tailings and the existence of mica and magnetite in kaolin and quartz in rare earth tailings,introducing abundant rare earth tailings alone can easily cause the appearance of a large amount of liquid phase in the low temperature range. In this study,vitrified tile that could be sintered below 1100°C was successfully prepared using more than 40wt% of southern rare earth tailings as the main raw material and some fluxes as the auxiliary aids. The results showed that choosing an appropriate multiple flux system could effectively reduce the initial melting temperature of the liquid phase and make the body sintered sooner. In addition,the slow appearance of the liquid phase in the body may effectively solve the key technical problems of narrow sintering temperature range and easy-deformation due to the use of rare earth tailings alone.