微波均相沉淀法制备超细碳酸钡粉体的研究

发布时间：2018-06-02 01:09

  本文选题：超细碳酸钡 + 均相沉淀法　； 参考：《昆明理工大学》2011年硕士论文

【摘要】：碳酸钡是一种重要的基础无机化工原料,也是最为重要的钡盐之一,广泛应用于钡盐、显像管玻壳(CRT)、磁性材料、光学玻璃、颜料等产品的制造以及陶瓷、搪瓷、油漆、钢铁渗碳、冶金、橡胶等领域。随着科学技术快速发展,电子化工等领域对碳酸钡的要求越来越高,普通工业碳酸钡难以满足其要求,而超细碳酸钡具有高的介电系数、低损耗、高磁导率、饱和磁化强度等优点,应用前景广阔,成为研究的热点。 本论文结合微波加热与均相沉淀法的优点提出采用微波均相沉淀法制备超细碳酸钡粉体的新工艺,以廉价的氯化钡(BaCl2)和氢氧化钠(NaOH)为原料,尿素(CO(NH2)2)为均相沉淀剂,分别采用常规和微波均相沉淀法来制备超细碳酸钡粉体,研究了Ba2+浓度、尿素含量、氢氧化钠含量、反应温度和反应时间等因素对产品粒度及产率的影响规律；并通过添加不同的晶形控制剂合成出不同形貌的超细碳酸钡粒子；同时对常规和微波均相沉淀法制备超细碳酸钡粉体实验的动力学进行研究,并获得了相关动力学参数;利用XRD、SEM、激光粒度分析仪、差热差重分析和BET比表面积测试等对样品进行了分析与表征。 结果表明：微波均相沉淀法制备超细碳酸钡粉体的最佳的工艺条件为：反应温度：85℃；反应时间：2h；Ba2+浓度：0.8mol/L; n(NaOH)=2.5n (BaCl2·2H2O); n ((NH2)2CO:n (BaCl2·2H2O)=6；得到的碳酸钡粉体粒度分布均匀,平均粒度1.61μm,比表面积可达16.88 m2/g；柠檬酸、多聚磷酸钠和乙二胺四乙酸的作用下,成功制备出了针状、柱状、花朵状和鸟巢状的超细碳酸钡粉体；常规与微波均相沉淀法制备超细碳酸钡粉体的反应的表观活化能分别约为98.38 KJ/mol和88.40 KJ/mol. 通过本论文的研究可知：微波均相沉淀法具有诸多优势,如升温速率快,反应速率快,产品质量高等,微波均相沉淀制备超细碳酸钡粉体的新工艺具有工艺流程简单、成本低、生产周期短、清洁无污染、安全性好、产品质量高等优点,如若将其应用于改造传统碳酸钡生产工业中,对节能降耗,提高生产效率及产品价值将具有重大意义。
[Abstract]:Barium carbonate is an important basic inorganic chemical raw material and one of the most important barium salts. It is widely used in the manufacture of barium salt, CRT, magnetic material, optical glass, pigment and other products, as well as ceramics, enamel, paint, etc. Steel Carburizing, Metallurgy, Rubber and other fields. With the rapid development of science and technology, the requirements of barium carbonate are more and more high in the fields of electronics and chemical engineering, and it is difficult to meet the requirements of ordinary industrial barium carbonate, while ultrafine barium carbonate has high dielectric coefficient, low loss and high permeability. Saturation magnetization has a wide application prospect and has become a hot research topic. Combining the advantages of microwave heating and homogeneous precipitation method, a new technology of preparing ultrafine barium carbonate powder by microwave homogeneous precipitation method was proposed in this paper. The raw materials were cheap barium chloride (BaCl2) and sodium hydroxide (NaOH), and urea (COC) NH2 (2) was used as homogeneous precipitating agent. Ultrafine barium carbonate powders were prepared by conventional and microwave homogeneous precipitation methods. The effects of Ba2 concentration, urea content, sodium hydroxide content, reaction temperature and reaction time on product size and yield were studied. The ultrafine barium carbonate particles with different morphology were synthesized by adding different crystal shape control agents, and the kinetics of preparing ultrafine barium carbonate powder by conventional and microwave homogeneous precipitation method was studied, and the relevant kinetic parameters were obtained. The samples were analyzed and characterized by XRD-SEM, laser particle size analyzer, differential thermogravimetric analysis and BET specific surface area measurement. The results show that the optimum conditions for the preparation of ultrafine barium carbonate powder by microwave homogeneous precipitation are as follows: reaction temperature: 85 鈩，

本文编号：1966599