抑杂剂与离子型稀土矿中铝杂质相互作用的分子动力学模拟分析

发布时间：2019-06-12 08:56

【摘要】：稀土是我国的战略储备资源,其优异的物理化学性能使其用途非常广泛。南方风化壳淋积型稀土矿自二十世纪七十年代被发现以后,人们对它的开采和研究一直不断。目前采用化学浸出方式提取稀土,浸出母液中含有杂质离子对稀土提炼影响较大,每年由于杂质对萃取剂乳化造成的损失达几千万,而且影响稀土产品质量。本文主要对如何降低浸出母液中铝离子的含量进行探索试验,并对抑杂剂与稀土离子进行分子动力学模拟研究。对磺基水杨酸抑制铝离子的行为进行分子动力学模拟。比较发现铝离子与磺基水杨酸之间的径向分布函数图中出现的峰值最大,即磺基水杨酸附近出现铝离子的概率最高,稀土镧,钇离子出现的概率较低。磺基水杨酸对铝离子的作用能是-2502 kcal/mol,与镧离子的作用能是-302 kcal/mol,与稀土钇离子的作用能是-570 kcal/mol。从能量的角度可以得出磺基水杨酸与铝离子的作用强度明显比它与稀土离子的作用强度大。分子动力学计算高岭石(1 0 0)面与磺基水杨酸的吸附能为-3251 kal/mol,可见它们之间发生了较强的吸附作用。从它们之间的径向分布函数可以看出,磺基水杨酸与高岭石表面的铝离子发生作用。同时表明磺基水杨酸是通过与高岭石表面的铝离子发生作用而吸附在矿物表面。在南方风化壳淋积型稀土矿的矿石性质研究基础上,确定稀土常规浸出最佳条件:试样质量200 g,浸出方式为柱状淋浸,浸出剂为硫酸铵,浸出剂浓度3%,液固比0.8:1,浸出剂流速1.7 ml/min,矿石高度150 mm,常温常压。此时稀土浸出率为95%,浸出液中稀土离子含量为0.45 g/L,铝离子含量为390 mg/L。通过多种抑制剂的试验对比,发现磺基水杨酸,乙酰丙酮,酒石酸对铝的抑制效果较好,而且对稀土的浸出率影响不大。
[Abstract]:Rare earth is a strategic reserve resource in China, and its excellent physical and chemical properties make it widely used. Since the discovery of leachate rare earth deposits in the seventies of the 20th century, the mining and research of leachate rare earth deposits in southern China have been continuous. At present, the chemical leaching method is used to extract rare earth. The impurity ions in the leaching mother liquor have a great influence on the extraction of rare earth. The annual loss caused by impurities to the emulsification of extractant is tens of millions, and the quality of rare earth products is affected. In this paper, how to reduce the content of aluminum ion in leaching mother liquor was studied, and the molecular dynamics simulation of impurity inhibitor and rare earth ion was carried out. The inhibition of aluminum ion by sulfosalicylic acid was simulated by molecular dynamics. It is found that the peak value of the radial distribution function between aluminum ion and sulfosalicylic acid is the highest, that is, the probability of aluminum ion near sulfosalicylic acid is the highest, and the probability of rare earth lanthanum and yttrium ions is low. The interaction energy of sulfosalicylic acid on aluminum ion is-2502 kcal/mol, with lanthanum ion. The interaction energy between-2502 kcal/mol, and rare earth yttrium ion is-570 kcal/mol.. From the point of view of energy, it can be concluded that the interaction strength between sulfosalicylic acid and aluminum ion is obviously higher than that between sulfosalicylic acid and rare earth ion. The adsorption energy of kaolinite (100) surface and sulfosalicylic acid was calculated by molecular dynamics to be-3251 kal/mol,. It can be seen that there is a strong adsorption between kaolinite (100) surface and sulfosalicylic acid. From the radial distribution function between them, it can be seen that sulfosalicylic acid interacts with aluminum ions on the surface of kaolinite. It is also shown that sulfosalicylic acid is adsorbed on the surface of minerals by interacting with aluminum ions on the surface of kaolinite. Based on the study of ore properties of leachate rare earth ore in southern weathered crust, the optimum conditions of conventional rare earth leaching are determined as follows: sample mass 200g, leaching mode is columnar leaching, leaching agent is ammonium sulfate, leaching agent concentration is 3%, liquid-solid ratio is 0.8 ml/min, leaching agent flow rate is 1.7 mm, at room temperature and atmospheric pressure. At this time, the leaching rate of rare earth is 95%, the content of rare earth ion in the leaching solution is 0.45 g 路L, and the content of aluminum ion is 390 mg/L.. Through the comparison of various inhibitors, it was found that sulfosalicylic acid, acetylacetone and tartaric acid had better inhibitory effect on aluminum, and had little effect on the leaching rate of rare earth.
【学位授予单位】：江西理工大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：TD955

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