白钨矿碱分解过程的热力学和动力学研究
来源期刊：中南大学学报(自然科学版)1990年第1期
论文作者：李运姣 李洪桂 刘茂盛
文章页码：39 - 45
关键词：钨； 白钨矿； 浸出； 热力学； 动力学
Key words：tungsten； scheelite； leaching； thermodynamics； dynamics
摘 要：研究了白钨矿碱分解过程的热力学和动力学。测定了70℃,90℃及105℃下氢氧化钠溶液与人造白钨反应的平衡浓度商Kc。研究结果表明,该反应的Kc随温度的升高而增大,随碱浓度的升高而明显地增大;105℃下,NaOH浓度为5.68mol/L时,平衡浓度商Kc为0.0259;在70～90℃之间,其反应热为25.80kJ/mol,是一个吸热反应。动力学研究结果证明,反应过程受化学反应控制,反应的表观活化能为58.83kJ/mol,表观反应级数为1.73。升高温度和增大碱浓度都可加快反应速度,强化浸出过程。
Abstract: The thermodynamics and kinetics of alkaline decomposition of scheelite werestudied. The equilibrium concentration quotients Kc of the reaction of NaOH with synthetic scheelite at different temperatures were determined. Experimentalresult showed that Kc increases significantly with the elevation of temperatureand the concentration of NaOH. When the concentration of NaOH is 5.68mol/L, Kc is equal to 0.0259 at 105℃. The reaction of scheelite with causticsoda is endothermic, the heat of the reaction being 25.80 kJ/mol in the temperaturerange of 70～90℃. Kinetic study indicated that the caustic alkaline-leaching ofscheelite concentrate is controlled by chemical reaction under the experimentalconditions. The apparent activation energy of the reaction is about 58.83 kJ/mol,and the apparent order of the reaction is about 1.73. Temperature and the con-centration of NaOH have greater influences on the leaching velocity. The increaseof temperature and NaOH concentration will effectively accelerate the rate of theleaching process.
