氯化钠增白煅烧高岭土的反应热力学  

Thermodynamics of Reaction of Whitening Calcined Kaolin by Sodium Chloride

作　　者：张锦化[1,2] 吴红丹[1,2] 雷新荣[1,2] 于吉顺[3] 裴大婷[2] 李启超[2] 

机构地区：[1]中国地质大学(武汉)教育部纳米矿物材料及应用工程研究中心,武汉430074 [2]中国地质大学(武汉)材料科学与化学工程学院,武汉430074 [3]中国地质大学(武汉)地质过程与矿产资源国家重点实验室,武汉430074

出　　处：《武汉理工大学学报》2011年第10期104-107,共4页Journal of Wuhan University of Technology

基　　金：国家自然科学基金(40972003);国家自然科学基金重点项目(90714010)

摘　　要：采用氯化钠作为氯化剂氯化增白煅烧高岭土,并对相关反应进行化学热力学计算。结果表明,当氯化钠的添加量为6%,煅烧温度为900℃,煅烧时间为2h时,产品白度提高到92.3%,Fe2O3的去除率达到16.9%。其反应机理:在Al2O3参与的情况下,Fe2O3被氯化生成气态的FeCl3,900℃时,该反应的吉布斯自由能ΔrGΘm约为-350kJ/mol,且随着反应温度的提高,ΔrGΘm减小,有利于反应的进行。The calcined kaolin was whitened with sodium chloride as chloridizing agent, and thermodynamics calculations of the relative reactions were performed for the Gibbs free energy. The results showed that the whiteness of the eal eined kaolin was increased to 92.3 % and the leaching rate of Fe2O3 reached 16.9 % at 900 ℃ for 2 h with sodium chloride added at 6 %. The reaction mechanism was that Fe2O3 was chlorinated and formed gaseous FeCla with the participation of alumina. The Gibbs free energy of the reaction was about - 350 kJ/mol. With increase in reaction temperature, the Gibbs free energy decreased, which was suitable to the synthesis reaction.

关 键 词：煅烧高岭土 增白 热力学分析 吉布斯自由能 

分 类 号：O624.1[理学—有机化学] TD985[理学—化学]