Effect of TiO2 on the crystallization and properties of MgO-Al2O3-SiO2 glass-ceramics prepared by an "one-step" method from laterite ore
Effect of TiO2 on the crystallization and properties of MgO-Al2O3-SiO2 glass-ceramics prepared by an "one-step" method from laterite ore
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DOI：
10.1016/j.ceramint.2018.10.051
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发表时间：
2019-03
影响因子：
5.2
通讯作者：
Chengyun Wang;H. Jia;Aiping Wang;Xin Wang;Yanling Guo;Jieyu Zhang
中科院分区：
文献类型：
--
作者：
Chengyun Wang;H. Jia;Aiping Wang;Xin Wang;Yanling Guo;Jieyu Zhang
本文提出了一种“一步法”从红土矿中同时制备MgO-Al_2O_3-SiO_2微晶玻璃和Ni-Fe合金的方法。“一步法”充分利用了熔渣的热能，生产微晶玻璃的能耗比传统方法低得多。炉渣利用率可达100%。在红土矿中加入0~4 g的二氧化钛作为晶核剂，控制微晶玻璃的物相组成和显微结构。利用X射线衍射仪、扫描电子显微镜、能谱仪和维氏硬度计研究了不同掺杂量的二氧化钛对微晶玻璃的析晶行为、主晶相、显微结构和各项性能的影响。结果表明，随着二氧化钛加入量的增加(0~3 g)，μ-堇青石逐渐析出，并成为微晶玻璃的主晶相。同时，随着二氧化钛加入量的增加，催化剂的结晶度、晶粒度和耐酸碱性能都有所提高。显微硬度从6.699 Gpa提高到9.156 Gpa。当二氧化钛加入量增加到4 g时，在微晶玻璃中析出大量蓝宝石((Mg_4Al_4)(Al_4Si_2)O_20)。微晶玻璃的主晶相开始由μ-堇青石转变为蓝宝石，其密度、耐酸碱性和显微硬度都有所下降。这项研究有助于将微晶玻璃和金属同时制备的“一步法”推广到其他低品位矿石，而不仅仅是红土矿。
In the current paper, we proposed a novel, "one-step" method to simultaneously prepare MgO-Al2O3-SiO2glass-ceramics and Ni-Fe alloy from laterite ore with the addition of TiO2. The "one-step" method makes full use of the thermal energy of the molten slag so that the energy consumption for the production of the glass-ceramics is much lower than that in a more conventional method. Moreover, the slag utilization rate can reach 100%. In this method, 0–4 g of TiO2as a nucleating agent was added into laterite ore to control the phase composition and microstructure of glass-ceramics. The effects of the addition of different amounts of TiO2on the crystallization behaviour, major crystalline phase, microstructure and various properties of glass-ceramics were investigated by XRD, SEM, EDS and a Vickers hardness tester. The results show that with an increase in the amount of TiO2added (0–3 g), the μ-cordierite gradually precipitated and became the main crystalline phase of the glass-ceramics. Meanwhile, the crystallinity, grain size and acid/alkali resistance were all enhanced with increased TiO2addition. The micro-hardness increased from 6.699 GPa to 9.156 GPa. However, as the amount of TiO2added increased up to 4 g, a large amount of sapphirine ((Mg4Al4)(Al4Si2)O20) precipitated in the glass-ceramics. The major crystalline phase of the glass-ceramics begins to change from μ-cordierite to sapphirine, accompanied by a decrease of its density, acid/alkali resistance and micro-hardness. This study is helpful for extending the "one-step" method of simultaneously preparing glass-ceramics and metals to other low-grade ores and not just laterite ore.