微波场中铝土矿-氢氧化钠体系的加热性能和相变规律研究.doc

一水硬铝石矿—氢氧化钠体系加热过程中的相变规律 黎氏琼春1,2,3，巨少华1,2,3，彭金辉1,2，王仕兴1,2,3，周烈兴1,2 （1.微波能工程应用及装备技术国家地方联合工程实验室，昆明 650093；2.云南省特种冶金重点实验室，昆明 650093；3.昆明理工大学 冶金与能源工程学院，昆明 650093） 摘要：研究了焙烧温度和氢氧化钠添加量对一水硬铝石矿—氢氧化钠体系相变规律的影响。利用DTA-TG、XRD和SEM技术对焙烧产物的加热性能、物相转变和微观形貌进行了分析。结果表明，当焙烧温度较低、氢氧化钠添加量较少时，大量AlOOH没有转变，主要反应是高岭石白云母与氢氧化钠反应生成沸石、方钠石、霞石等不同物相。温度升高利于沸石和方钠石换成钙霞石。氢氧化钠添加量增多利于AlOOH与NaOH反应生成铝酸钠物相。当温度升高到500 ℃以上时，主要反应是AlOOH脱水形成Al2O3。 关键词：一水硬铝石矿；饱和氢氧化钠溶液；焙烧；相变 中图分类号：TF821 文献标志码：A 文章编号：1007-7545（2016）03-0000-00 Phase Transformation f Diasporic Bauxite-Sodium Hydroxide System during Heating Process LE Thi-quynh-xuan1,2,3, JU Shao-hua1,2,3, PENG Jin-hui1,2, WANG Shi-xing1,2,3, ZHOU Lie-xing1,2 (1. National Local Joint Laboratory of Engineering Application of Microwave Energy and Equipment Technology, Kunming 650093, China; 2. Yunnan Provincial Key Laboratory of Intensification Metallurgy, Kunming 650093, China; 3. Faculty of Metallurgical and Energy Engineering, Kunming University of Science and Technology, Kunming 650093, China) Abstract: Effects of roasting temperature and NaOH addition on phase transformation of diaspore-sodium hydroxide system were investigated. Heating performance, phase transformation, and microstructure of roasting ore were comparatively analyzed with DTA-TG XRD and SEM. The results show that AlOOH is not changed to a large extent with low roasting temperature and a small amount of NaOH dosage, and kaolinite and muscovite reacts with NaOH to form zeolites, sodalite, and cancrinite respectively. Raising temperature facilitates conversion of zeolite and sodalite into cancrinite. Increasing NaOH dosage promotes reaction of AlOOH with NaOH to form sodium aluminate phases. When temperature rises to 500 ℃ above, AlOOH is decomposed into Al2O3. Key words: diaspore bauxite; saturated NaOH solution; roasting; phase transformation 我国绝大多数铝土矿（约95%）都是一水硬铝石型铝土矿[12]，而且中低品位居多[3]，矿石结晶状态好必须采用苛刻的溶出条件或者高温烧结技术，才能得到可接受的溶出效果[4-6]。因此，通过预处理来改善一水硬铝石的微观结构，从根本上改变矿石性质，提高其中氧化铝的化学活性，从而提高铝土矿的溶出性能。 目前，利用焙烧加热方式预处理一水硬