高离子强度下钾盐浮选捕收剂吸附性能研究

发布时间：2018-04-23 13:25

本文选题：低温 + 氯化钾　；参考：《山西大学》2016年硕士论文

【摘要】：氯化钾是农业生产中的一种重要的钾肥来源,以泡沫正浮选法生产为主,盐酸十八胺是常用的浮选捕收剂。但是,在低温下浮选效率低,药剂消耗量大,大量氯化钾损失在浮选尾矿中,严重影响了钾肥的年产量和供给。同时,氯化钾作为一种可溶性盐,其浮选是在饱和溶液中进行的,溶液体系的离子种类和高离子强度都使得氯化钾浮选具有一定的特殊性。为了揭示低温下氯化钾正浮选回收率低的问题,本论文结合我国钾盐浮选体系中存在大量复杂盐离子的情况,在优化捕收剂浓度测定方法的基础上,研究胺类捕收剂在氯化钾晶体表面吸附行为、吸附机理以及无机盐对氯化钾浮选行为的影响。主要研究内容和结果如下:(1)利用气相色谱法和金橙-2分光光度法研究了盐酸十八胺在高离子强度饱和盐溶液体系中的浓度测定方法,结果表明当盐酸十八胺的浓度范围分别为2×10~(-5)～1×10~(-4)mol/L和1×10~(-6)～2×10~(-5)mol/L时,两种方法所测盐酸十八胺的浓度与吸光度线性关系良好。综合比较,金橙-2分光光度法测定盐酸十八胺的浓度更低,操作方便,仪器简单,适合用来测定KCl饱和溶液中盐酸十八胺的浓度。(2)通过恒温静态吸附实验研究了胺类捕收剂在氯化钾晶体颗粒表面的吸附。实验结果表明,胺类捕收剂在氯化钾晶体颗粒表面吸附的平衡时间为4 h,吸附实验实验选择5h,饱和吸附量都随着温度的升高而增大。而且饱和溶液体系也对吸附有较大的影响,与KCl饱和体系相比,KCl-MgCl_饱和体系中的平衡吸附量明显减少,并且低温时减少较多。(3)采用动力学方程和吸附等温方程对盐酸十八胺捕收剂在氯化钾晶体颗粒表面的吸附数据进行了拟合,表明盐酸十八胺在氯化钾晶体颗粒表面的吸附行为符合一级动力学模型,吸附等温线拟合符合Langmuir吸附等温线模型,分子之间作用力比较弱,属于单层吸附,吸附量很少。通过被俘气泡法对各种饱和盐溶液中KCl晶体颗粒表面接触角进行测定,KCl晶体颗粒的接触角随着盐酸十八胺浓度升高先增大后平稳,随着温度升高增大;KCl饱和体系中比KCl-MgCl_饱和体系中的接触角大。FT-IR红外光谱的分析结果表明,盐酸十八胺在氯化钾晶体颗粒表面有选择性的吸附,而在同样条件下氯化钠晶体颗粒表面并没有出现盐酸十八胺的特征吸收峰。(4)通过微浮选实验考察了温度和饱和盐溶液体系对盐酸十八胺浮选回收率的影响。实验结果表明,温度的降低显著降低了盐酸十八胺在氯化钾晶体颗粒表面的吸附,浮选回收率明显降低,尤其是在0℃下捕收剂浓度较高的时候浮选回收率急剧降低,降低了40%多。与KCl饱和体系相比,在KCl-MgCl_饱和体系中盐酸十八胺在氯化钾晶体颗粒表面的吸附量减少,浮选回收率降低。本研究工作拓展了氯化钾浮选研究的手段,丰富了氯化钾浮选机理,为提高低温高离子强度氯化钾浮选回收率以及制定合理的盐湖化工生产工艺提供科学依据和理论支撑,对解决我国钾肥资源缺乏的困境具有科学意义。
[Abstract]:Potassium chloride is an important source of potassium fertilizer in agricultural production, mainly in the foam positive flotation process, and eighteen amine hydrochloride is a commonly used flotation collector. However, the flotation efficiency is low at low temperature, the consumption of chemicals is large, and a large amount of potassium chloride is lost in the flotation tailings, which seriously affects the annual production and supply of potash fertilizer. The flotation of the soluble salts is carried out in the saturated solution. The type of ion and the high ionic strength of the solution system make the flotation of potassium chloride a certain particularity. In order to reveal the low recovery rate of the positive flotation of potassium chloride at low temperature, this paper combines the situation of a large number of complex salt ions in the potash floatation body in our country, and is optimized in this paper. On the basis of the determination of collector concentration, the adsorption behavior of amine collectors on the surface of potassium chloride crystals, the mechanism of adsorption and the effect of inorganic salts on the flotation behavior of potassium chloride are studied. The main contents and results are as follows: (1) the high ionic strength saturated salt solution of eighteen amine hydrochloride was studied by gas chromatography and gold orange -2 spectrophotometric method. The results show that when the concentration range of eighteen amine hydrochloride is 2 * 10~ (-5) ~ 1 * 10~ (-4) mol/L and 1 x 10~ (-6) to 2 x 10~ (-5) mol/L respectively, the concentration of eighteen amine hydrochloride has a good linear relationship with the absorbance, and the concentration is lower than the gold orange -2 spectrophotometric method for the determination of the concentration of eighteen amine hydrochloride. The operation is convenient and the instrument is simple. It is suitable for the determination of the concentration of eighteen amine hydrochloride in KCl saturated solution. (2) the adsorption of amine collectors on the surface of potassium chloride crystal particles is studied by static adsorption experiments at constant temperature. The experimental results show that the equilibrium time for the adsorption of amine collectors on the surface of potassium chloride crystals is 4 h, and the adsorption experiment is selected. 5h, the saturated adsorption capacity increases with the increase of temperature. Moreover, the saturated solution system also has a great influence on the adsorption. Compared with the KCl saturation system, the equilibrium adsorption amount in the KCl-MgCl_ saturation system is obviously reduced and the low temperature decreases more. (3) the kinetic equation and the adsorption isotherm equation are used for the chlorination of the eighteen amine hydrochloric acid collector. The adsorption data on the surface of potassium crystal particles have been fitted. It is shown that the adsorption behavior of eighteen amine hydrochloride on the surface of potassium chloride crystal conforms to the first order kinetic model. The adsorption isotherm fits the model of Langmuir adsorption isotherm, and the interaction between molecules is weak, which belongs to single layer adsorption, and the adsorption amount is very few. The contact angle of the KCl crystal particles in the saturated salt solution is measured. The contact angle of the KCl crystal particles increases first and then becomes stable with the increase of the concentration of eighteen amine hydrochloride, and increases with the temperature. The analysis of the.FT-IR infrared spectra of the contact angle of the KCl saturation system compared with the KCl-MgCl_ saturation system shows that the eighteen amine hydrochloride is in the potassium chloride crystal. The surface of the particles was selectively adsorbed, and the characteristic absorption peak of eighteen amine hydrochloride was not found on the surface of the sodium chloride crystal particles under the same conditions. (4) the effect of temperature and saturated salt solution system on the flotation recovery of eighteen amine hydrochloride was investigated by micro flotation. The experimental results showed that the decrease of temperature was significantly reduced by eighteen hydrochloric acid. The flotation recovery rate of amine on the surface of potassium chloride crystal particles is obviously reduced, especially when the collector concentration is high at 0 C, and the flotation recovery rate decreases rapidly and reduces by more than 40%. Compared with the KCl saturation system, the adsorption of eighteen amine hydrochloride on the surface of potassium chloride particles in the KCl-MgCl_ saturation system is reduced, and the flotation recovery rate is reduced. The research work extends the study of potassium chloride flotation, enriches the mechanism of the flotation of potassium chloride, provides scientific basis and theoretical support for improving the recovery rate of potassium chloride flotation at low temperature and high ionic strength, and formulating a reasonable production technology of Saline Lake chemical industry. It is of scientific significance to solve the plight of the lack of potash resources in China.

【学位授予单位】：山西大学
【学位级别】：硕士
【学位授予年份】：2016
【分类号】：TD923.13

【参考文献】