高分子聚合物对蒙脱石剥层的抑制及其机理研究毕业论文
2021-03-16 22:54:01
摘 要
蒙脱石在水溶液中具有良好的膨胀性,水分子吸附在层与层之间,使得蒙脱石在剪切力作用下容易发生剥离,产生二维层状的小颗粒,造成矿浆泥化和浮选机械夹带等问题,影响浮选精矿的回收率和品位,导致尾矿难脱水。本研究针对上述问题,通过探究高分子聚合物与蒙脱石端面发生反应对蒙脱石膨胀性质的影响,为解决矿浆泥化和浮选机械夹带等问题提供新思路。
本研究以钠化制得的钠基蒙脱石为原料,主要分析高分子聚合物羧甲基纤维素钠(CMC)对钠基蒙脱石膨胀性质的影响,通过吸附动力学实验及红外测试来确定CMC与钠基蒙脱石的反应情况,通过粒度分析,膨胀容表征CMC对钠基蒙脱石膨胀性质的影响,通过XRD及红外测试来探究高分子聚合物CMC对钠基蒙脱石膨胀性质的影响机理。
本研究对蒙脱石进行钠化,制得的样品进行XRD测试及粒度分析,研究结果显示样品为钠基蒙脱石,粒度适合进行钠基蒙脱石膨胀性研究;吸附动力学实验和红外测试结果表明CMC与钠基蒙脱石发生反应,在端面与钠基蒙脱石的Al-OH形成氢键;粒度分析和膨胀容实验表明CMC与钠基蒙脱石反应后对钠基蒙脱石的膨胀性能没有太大影响;最后CMC对钠基蒙脱石膨胀性质的影响机理探究实验则说明了CMC与钠基蒙脱石反应会对钠基蒙脱石的膨胀性能有影响,但作用力很弱,继续加水膨胀,CMC会发生部分脱落,无法影响钠基蒙脱石的膨胀性能。综上所述:钠基蒙脱石与CMC在水溶液中会发生吸附反应,在端面生成氢键,但结合力比较弱,结合力小于钠基蒙脱石水化膨胀力,继续加水膨胀时,CMC会发生部分脱落,对钠基蒙脱石膨胀性没有影响。
关键词:钠基蒙脱石;羧甲基纤维素钠(CMC);膨胀性
Abstract
Montmorillonite have a good property of dispersion in an aqueous solution, water molecules adsorbed between the layers and layers, making the montmorillonite easy to peel off under shearing force, producing two-dimensional layered small particles, resulting in pulp sludge and flotation mechanical entrainment or other issues, affecting the recovery rate and grade of flotation concentrate, resulting in tailings difficult to dehydration. In this study, the effect of the reaction of polymer and montmorillonite on the swelling properties of montmorillonite was investigated, which provided new ideas for solving the problem of pulp sludge and flotation mechanical entrainment.
In this study, Na-montmorillonite prepared by sodium was used as the raw material to analyze the effect of high molecular polymer sodium carboxymethyl cellulose (CMC) on the swelling properties of Na-montmorillonite through the adsorption kinetics experiment and IR test to determine the reaction of CMC and Na-montmorillonite, the effect of CMC on the swelling properties of Na-montmorillonite was characterized by particle size analysis and expansion capacity, and the influence mechanism of polymer CMC on the swelling properties of Na-montmorillonite was investigated by XRD and IR test.
The results show that the sample is Na-montmorillonite and the granularity is suitable for the study of Na-montmorillonite swelling by the method of XRD and particle size analysis of Na-montmorillonite ores. The experimental results of adsorption kinetics and IR test show that CMC reacts with Na-montmorillonite, forming hydrogen bond at the Al-OH of the end face and Na-montmorillonite; the particle size analysis and swelling capacity experiment showed that the swelling property of Na-montmorillonite was not affected by the reaction of CMC and Na-montmorillonite Finally, The influence mechanism experiment of CMC on the swelling properties of Na-montmorillonite shows that the reaction of CMC and Na-montmorillonite has an effect on the swelling property of Na-montmorillonite, but the force is very weak, continue to add water to expansion, the CMC will occur partial shedding, can not affect the expansion of Na-montmorillonite properties. To sum up: Na-montmorillonite and CMC in aqueous solution will occur adsorption reaction, forming a hydrogen bond at the end face, but the binding force is weak, the binding force is weaker than the Na-montmorillonite swelling force, continue to add water to expansion, CMC will occur part of the fall off, no effect on Na-montmorillonite swelling.
Keywords: Na-montmorillonite; sodium carboxymethyl cellulose (CMC); swelling
目 录
第1章 绪论 1
1.1 蒙脱石概述 1
1.1.1 蒙脱石的矿物学特征 1
1.1.2 蒙脱石资源概况 3
1.2 蒙脱石的膨胀 5
1.2.1 膨胀机理 5
1.2.2 蒙脱石膨胀性在选矿中的危害 5
1.2.3 蒙脱石膨胀性影响方法研究 6
1.3 研究的目的及意义 7
1.4 研究内容 7
第2章 实验原料及研究方法 8
2.1 实验试剂与设备 8
2.1.1 实验试剂 8
2.1.2 实验设备 8
2.2 实验原矿 9
2.3 研究方法 9
2.3.1 CMC检测方法 9
2.3.2 吸附动力学实验 10
2.3.3 傅里叶变换红外光谱分析 10
2.3.4 粒度分析 10
2.3.5 膨胀容实验 11
2.3.6 X射线衍射分析 11
第3章 实验结果分析 12
3.1 钠基蒙脱石表征 12
3.2 吸附动力学实验 13
3.3 傅里叶变换红外光谱分析 14
3.4 粒度分析 14
3.5 膨胀容实验 15
3.6 CMC对钠基蒙脱石膨胀性影响机理分析 17
3.6.1 傅里叶变换红外光谱分析 17
3.6.2 X射线衍射分析 18
第4章 结论 19
4.1 结论 19
4.2 展望 19
参考文献 20
致 谢 22
第1章 绪论
1.1 蒙脱石概述
1.1.1 蒙脱石的矿物学特征
1847年,Salvetet和Damur在研究法国所产粘土时,发现一种含水铝硅酸盐粘土矿物,它含有少量碱和碱土金属,他们将其命名为蒙脱石(Montmorillonite)。1926年和1954年Ross等经进一步研究,明确了蒙脱石的矿物性质。以后又发现蒙脱石是化学成分非常复杂的一大族矿物,国际粘土研究协会决定其族名为Smectite,我国学者翻译成蒙皂石族(亦称蒙脱石族)[1]。蒙脱石通常都呈块状或土状集合体产出,颗粒非常细小,大小约0.2~1μm,具胶体分散特性。蒙脱石颜色多为白色,除此以外还有浅绿色、粉红、浅灰。蒙脱石晶体属单斜晶系,鳞片状者解理完全,硬度2~2.5,相对密度2~2.7,非常柔软,有滑感[2]。
(1)蒙脱石的晶体结构
蒙脱石是典型的层状粘土矿物,由2:1型层状硅酸盐组成。分子式为(Na,Ca)0.33(Al,Mg)2[Si4O10](OH)2·nH2O。一层铝氧八面体(O)被两层硅氧四面体(T)夹着组成了蒙脱石的一个单层,硅氧四面体(T)与铝氧八面体(O)通过共用氧原子连接在一起[3],如图1.1所示。蒙脱石容易发生同晶置换,即蒙脱石结构中硅氧四面体(T)的中心原子Si4 容易被低价态的Fe3 、Al3 等取代,铝氧八面体(O)的中心原子Al3 容易被低价态的Mg2 、Fe2 等取代。因此蒙脱石晶层带负电,蒙脱石会通过在晶层外表和晶层间吸附金属阳离子的方法来中和和平衡电荷[4],如图1.2所示多层结构就是蒙脱石的晶体结构。