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采用盐酸和磷酸络合浸出白钨矿,用原子吸收分光光度法(AAS)测定溶液中钨的含量,研究了盐酸初始浓度、W/PO2-4重量比、反应温度对浸出动力学的影响,并通过二次回归的方法处理这些结果,建立了宏观的动力学方程。另外,考察了粒度、盐酸初始浓度、温度、W/PO2-4重量比、液固比和浸出时间对白钨矿浸出率的影响,分析了实验结果并利用单因素法对影响反应体系的各个影响因子进行优化。结果表明,白钨矿络合浸出反应属液-固相非催化收缩核模型,整个反应过程属于界面化学反应控制,计算得出该络合反应的表观活化能为59.8kJ·mol-1,其反应动力学方程为:K=4.85×108C0.585HClC0.504PO3-4exp(-59910/RT);最佳工艺参数为:温度90℃、搅拌速度900 r·min-1、粒度48~58μm、盐酸初始浓度2 mol·L-1、W/PO3-4质量比mw/mPO3-4=3∶1、液固比8∶1和浸出时间2.5 h。在此工艺参数下,白钨矿的浸出率为99.6%。
The scheelite was obtained by the complexation of hydrochloric acid and phosphoric acid, and the content of tungsten in the solution was determined by atomic absorption spectrophotometry (AAS). The effects of initial concentration of hydrochloric acid, W / PO2-4 weight ratio and reaction temperature on leaching kinetics were studied. And through the second regression method to deal with these results, the establishment of a macroscopic kinetic equation. In addition, the effects of particle size, initial concentration of hydrochloric acid, temperature, W / PO2-4 weight ratio, liquid-solid ratio and leaching time on the leaching rate of scheelite were investigated. The experimental results were analyzed and the influence of single factor method Factor optimization. The results show that the leaching reaction of scheelite is a liquid-solid non-catalytic shrinking nuclear model, and the reaction process belongs to the interface chemical reaction control. The apparent activation energy of the complex reaction is 59.8 kJ · mol -1, The reaction kinetic equation was: K = 4.85 × 108C0.585HClC0.504PO3-4exp (-59910 / RT). The optimum technological parameters were temperature 90 ℃, stirring speed 900 r · min-1, particle size 48 ~ 58μm, The initial concentration of 2 mol·L-1, W / PO3-4 mass ratio mw / mPO3-4 = 3:1, liquid-solid ratio of 8:1 and leaching time of 2.5 h. In this process parameters, scheelite leaching rate of 99.6%.