TiO_2和Cr_2O_3作晶核剂对金矿尾砂微晶玻璃结晶性能的影响

Effect of TiO_2 and Cr_2O_3 as Crystal Nucleus on Crystallization of Glass-ceramics from Gold Tailings

以金矿尾砂为主要原料,方解石、硼砂等为添加原料,采用熔融法制备Ca O-Al2O3-Si O2系微晶玻璃。采用X射线衍射分析(XRD)、差热分析(DSC)、扫描电镜(SEM)等分析手段对所制备样品进行性能测试与结构表征,研究了Ti O2和Cr2O3对金矿尾砂微晶玻璃结晶性能的影响。结果表明,以2%Ti O2为晶核剂,金矿尾砂微晶玻璃只有表面析晶,晶相从表面向内部生长;以4%Ti O2为晶核剂,样品内部析出少量团聚晶体;以2%Cr2O3为晶核剂,样品内部析出少量团聚粒状晶体;以2%Ti O2和2%Cr2O3为复合晶核剂,样品内部析出大量均匀分布的颗粒状晶体,极大地提高了金矿尾砂微晶玻璃的整体析晶能力,主晶相为透辉石(Ca Mg Si2O6),次晶相为钙长石(Ca Al2Si2O8)。

Ca O-Al2O3-Si O2glass-ceramics were prepared by melting method using gold tailings as the main raw materials,and calcite,borax as auxiliary materials. The phases,thermal properties and microstructures of the as-prepared samples were characterized by XRD,DSC and SEM. The effects of Ti O2 and Cr2O3as crystal nucleus on crystallization of glass-ceramics samples from gold tailings were investigated,respectively. The results show that only the surface of the samples crystallize a lot of crystal,and it crystallized from surface to the inside when using 2% Ti O2 as crystal nucleus. The inside of the samples crystallized a little crystal when uisng 4% Ti O2 as crystal nucleus. The inside of the samples crystallizes a little reunion crystals when using the 2% Cr2O3 as crystal nucleus. The inside of the samples crystallizes a lot of particle crystals when using 2% Ti O2 and 2% Cr2O3 as composite crystal nucleus,and it is greatly improved the overall crystallization ability of the glass-ceramics. The main crystalline phase is diopside（ Ca Mg Si2O3）, and the secondary crystalline phase is Anorthite（ Ca Al2Si2O8）.