碱性谷氨酸钠体系处理低品位氧化铜矿的研究

【作者】 刘珍珍；

【导师】 杨天足；

【作者基本信息】 中南大学 ， 材料冶金， 2010， 硕士

【摘要】 本文针对我国氧化铜矿资源的现状,提出了碱性谷氨酸钠体系浸出的新方法,为冶金工作者提供了新思路。以谷氨酸钠作为浸出剂浸出碱式碳酸铜,根据配位化学理论,研究了体系中Cu(Ⅱ)的配合平衡热力学,并绘制了谷氨酸钠浓度0-3mol/L和pH 5-14内的热力学平衡图,研究了谷氨酸钠浓度、pH和游离碳酸根离子浓度对浸出碱式碳酸铜的影响,并对热力学计算结果进行了实验验证。结果表明,铜离子浓度理论计算值与实验值之间相对误差的绝对平均值为5.32%,从理论上用谷氨酸钠浸出低品位氧化铜矿是可行的。对汤丹低品位氧化铜矿进行实验,证明了碱性谷氨酸钠体系处理低品位高碱性脉石型氧化铜矿完全可行。确定实验最佳条件：浸出剂谷氨酸钠浓度2mol/L、浸出液pH为9、温度为80℃、反应时间6 h、液固比6：1,最佳浸出率为58.33%。浸出后液铜离子浓度为0.955g/L。用循环浸出的方法提高浸出后液中铜离子的浓度,循环浸出10次之后浸出后液的浓度也只能达到5.63 g/L。为了提高浸出后液中铜离子的浓度,考察了D850螯合树脂对Cu2+的吸附性能,进行了吸附动力学和热力学研究。由不同温度时D850吸附交换铜离子的热力学函数△G、△H和△S计算结果可知,铜离子在D850树脂上的吸附过程是自发过程(△G<0),伴随吸热(△H＞0),熵变为正值(△S＞0)。由此从理论上证明了该过程是吸热过程,以化学吸附为主,并且较好的符合Langmnir等温吸附方程,表明自由能的减小和熵值的增大是D850树脂吸附铜离子的推动力。对动力学数据进行拟合,表明吸附交换过程为液膜扩散和颗粒扩散共同控制。随着溶液pH的升高,螯合树脂的Cu2+吸附量呈下降趋势。在pH为9的溶液中,当吸附剂浓度为14.45 mmol/L时,树脂的静态吸附量为0.35 mmol/g。动态解析实验研究表明,2 mol/L的稀硫酸是螯合树脂D850良好的解析剂,铜解析高峰液浓度达25 g/L左右。更多还原

【Abstract】 A new process of leaching copper oxide ore in the alkaline solution of sodium hydroxide containing monosodium glutamate has been investigated in view of the present situation of copper oxide ore in our country, which may supply a new method for metallurgistLeaching behaviors of basic cupric carbonate with monosodium glutamate were studied, and thermodynamics of Cu(Ⅱ) complex equilibrium in this system was studied by coordination chemistry fundamental. Varying the concentration of monosodium glutamate and pH value in the ranges of 0-3 mol/L and 5-14 respectively, the equilibrium thermodynamic diagrams were drawn, and the effects of monosodium glutamate concentration, pH value and free carbonate ion concentration on leaching of basic cupric carbonate were also studied. The comparison of theoretical calculation with experimental result shows that the absolute average value of relative error between them is 5.32%. From the results it is indicated that it is feasible to leach low grade cupric oxide ore with monosodium glutamate.The results of experiments about leaching the low grade cupric oxide ore from TangDan indicate that monosodium glutamate is a kind of feasible leaching reagents. The optimum conditions are as follows: concentration of monosodium glutamate 2mol/L, pH 9, temperature 80℃, reacting time 6 hours, ratio of liquid to solid 6:1. In the condition, the leaching rate of copper is 58.33%, while [Cu2+]T is 0.955g/L. Recycle leaching was carried out to increase the concentration of copper ion, which can only reach to 5.63 g/L after 10 times of being cycled.Adsorption thermodynamics and kinetics of copper(Ⅱ) on chelating resin D850 were studied to increase the concentration of copper ion in the leach liquor. The thermodynamic equilibrium functions of copper(Ⅱ) on chelating resin D850 in different temperatures determine AG<0, AH>0,△S>0, so the adsorption is spontaneous, endothermic and entropy increasing, which also indicates that chemisorption is the main process. Experimental data fitted well to the Langmuir model at all temperatures studied. And the decrease of free-energy and the increase of entropy are the driving force of copper(Ⅱ) on chelating resin D850. The kinetics results showed the process of ion adsorption is controlled by liquid film diffusion and particle diffusion. With the rising of concentration of OH-, adsorptive capacity of copper(II) on chelating resin D850 fell. When pH was 9 and concentration of copper(II) in solution was 14.45mmol/L, static adsorptive capacity of copper(II) on resin was 0.35mmol/g. Dynamic desorption results shows that 2 mol/L dilute sulphuric acid is a kind of good stripping agent of the loaded resin D850, and concentration of copper(II) in stripping solution can reach to 25g/L.更多还原