氰尿酸合成工艺研究进展

从直接热解法、熔盐热解法、溶剂热解法三个方面对以尿素为原料热解制备氰尿酸的生产工艺和研究进展进行了综述,分析了各种工艺技术的优势与不足,提出了今后的研发重点和改进方向。重点介绍了氰尿酸生产工艺所取得的技术进步,对今后氰尿酸合成工艺的发展前景进行了展望。

氰尿酸的合成与应用

氰尿酸（Cyanuric acid,简称CA）亦称三聚氰酸，异氰尿酸，学名为2，4，6－三羟基－1，3，5－三嗪。它具有两种互变的异构体。

氯化钙对棉秆炭理化性质的影响

以棉花秸秆(棉秆)为原料,研究了不同温度下添加无水氯化钙对热解产物棉秆炭理化特性的影响。通过同步热分析(TG/DSC)、X射线衍射(XRD)、拉曼光谱(Raman)、扫描电子显微镜(SEM)、透射电子显微镜(TEM)和N2吸附-脱附分析表征了其微观形貌和结构。TG分析显示热解温度达到500℃后,样品失重较少,故选择550~750℃为热解温度范围;试验结果表明直接热解和氯化钙活化这两种热解法制备的样品均是无定形炭结构,在550~750℃时,直接热解法制备的样品拉曼分析参数I_(D)/I_(G)约为0.93,最大比表面积2.09 m^(2)/g,最大平均孔径为7.21 nm,氯化钙活化法制备样品I_(D)/I_(G)约为0.85,最大比表面积487.68 m^(2)/g,最大平均孔径为5.97 nm。活化法制备的样品在石墨化程度、比表面积大小、孔径数量等方面优于直接热解法制得的样品,而直接热解法制得的样品孔径较大、无序化程度高、稳定性较好。

多孔炭材料的前驱体选择研究

介绍了直接热解法制备多孔炭材料的炭前驱体,包括聚合物、金属有机骨架、共价有机骨架和生物质,并展望了制备多孔炭材料的发展方向。

Thermodynamic analysis on the direct preparation of metallic vanadium from NaVO_3 by molten salt electrolysis

A novel and environmentally friendly route to directly prepare metallic vanadium from NaV03 by molten salt electrolysis is proposed. The feasibility about the direct electro-reduction of NaV03 to metallic vanadi- um is analyzed based on the thermodynamic calculations and experimental verifications. The theoretical decomposition voltage of NaV03 to metallic vanadium is only 0.47 V at 800 ℃ and much lower than that of the alkali and alkali earth metal chloride salts. The value is slightly higher than that of low-valence vanadium oxides such as V203, V305 and VO. However, the low-valence vanadium oxides can he further electro-reduced to metallic vanadium thermodynamically. The thermodynamic analysis is verified by the experimental results. The direct preparation of metallic vanadium from NaV03 by molten salt electrolysis is feasible.