新疆尉犁蛭石膨胀动力学研究毕业论文
2021-03-19 22:07:36
摘 要
蛭石是一种具有优异物理化学性质层状硅酸盐矿物,广泛应用于各行各业,对蛭石膨胀动力学展开研究,将为制备高膨胀率、高质量和高附加值的蛭石材料提供有效的理论支撑,并对扩大其在催化剂载体和高分子复合材料等领域应用具有重要意义。
论文采用物理法和化学法研究不同粒度蛭石的膨胀过程,并对其进行机理分析,相关研究结果表明:
(1)微波膨胀蛭石主要利用微波对蛭石层间水的加热作用使其发生膨胀,粗粒级蛭石的膨胀率高于细粒级蛭石,微波功率能显著提高蛭石膨胀速率,当微波功率为800w时,作用时间为30s时,蛭石膨胀率可达7.3。微波膨胀蛭石层片径边缘没有出现焦化。XRD分析说明,微波法膨胀蛭石过程中,微波与蛭石层间极性水分子直接作用,不会破坏蛭石的结构水。
(2)高温膨胀蛭过程微波膨胀蛭石类似,随着温度升高,蛭石膨胀速率逐渐增大,当温度达到900℃时,蛭石膨胀率可达7.62,此时蛭石层间结构水失去,蛭石边缘发生焦化,XRD物相分析结果说明,较高的膨胀温度会使得蛭石发生结构变化,向镁橄榄石转变。
(3)化学法利用双氧水浸入蛭石层间分解反应放出氧气使其膨胀,1.44-4mm粒级蛭石在相同浸泡时间下膨胀率大于0.3-1mm粒级蛭石,这是由于粗粒蛭石孔隙较大,有更多双氧水渗透进入蛭石且渗透速率较快,使蛭石迅速膨胀,且高浓度双氧水分解速率较快,蛭石膨胀速率亦较快,pH值分析可知,随着蛭石膨胀的进行,浸出液中pH值不断增大,在0-10h过程中,各离子浓度增长迅速,10-25h离子浓度增长变缓,结合化学膨胀过程可知,在0-10h双氧水进入蛭石分解速率迅速,交换出阳离子速度也变快,10h以后反应速率明显变缓慢。NA 、K 的浓度是一直在增大的,是由于K 、Na 被交换出后促进的反应的进行。浸出液中存在Si4 ,可见蛭石可能不仅是层间域中离子被交换出,结构单元中的离子也被交换出。
关键词:膨胀蛭石,物理法,化学法,浸出液分析
Abstract
Vermiculite is a kind of excellent physical and chemical properties of layered silicate minerals, widely used in all walks of life, vermiculite expansion kinetics of the study, will be prepared for the high expansion rate, high quality and high value-added vermiculite materials To provide effective theoretical support, and to expand its catalyst carrier and polymer composites in areas such as the application of great significance.
In this paper, the swelling process of vermiculite with different grain size was studied by physical method and chemical method, and the mechanism was analyzed. The results showed that:
(1) microwave expansion of vermiculite mainly using microwave on the vermiculite interlayer water heating to expand, coarse-grained vermiculite expansion rate is higher than the fine-grained vermiculite, microwave power can significantly improve the vermiculite expansion rate, When the microwave power of 800w, the role of time for 30s, vermiculite expansion rate of up to 7.3. There is no coking in the edge of the microwave expanded vermiculite slice. XRD analysis shows that the microwave and vermiculite layers of polar water molecules directly under the action of microwave expansion of vermiculite can not destroy the structural water of vermiculite.
(2) high temperature expansion of leech process microwave expansion of vermiculite similar to the temperature, vermiculite expansion rate gradually increased, when the temperature reaches 900℃, vermiculite expansion rate of up to 7.62, then vermiculite interlayer structure of water The results show that the higher expansion temperature will cause the structural changes of vermiculite to change to forsterite.
(3) Chemical method The use of hydrogen peroxide immersed in vermiculite decomposition reaction to release oxygen to expand, 1.44-4mm granular vermiculite in the same soaking time expansion rate of more than 0.3-1mm grain grade vermiculite, which is due to coarse coarse vermiculite porosity larger , There are more hydrogen peroxide infiltration into the vermiculite and the infiltration rate is faster, so that vermiculite rapid expansion, and high concentrations of hydrogen peroxide decomposition rate faster, vermiculite expansion rate is also faster, pH analysis shows that with the vermiculite expansion , The pH value of the leaching solution increased continuously. In the process of 0-10h, the ion concentration increased rapidly, and the concentration of 10-25h was slowed down. After the chemical expansion process, it was found that the decomposition rate of vermiculite was rapid and exchanged at 0-10h The cationic speed is also faster, 10h after the reaction rate significantly slow down. The concentration of NA , K is always increasing, due to the progress of K , Na being exchanged after the reaction is promoted. There is Si4 present in the leaching solution. It can be seen that the vermiculite may not only be the exchange of ions in the interlayer, but also the ions in the structural unit
Key words:Expanded vermiculite, physical method, chemical method, leaching solution analysis
目录
摘要 I
目录 1
第一章 绪论 1
1.1蛭石的概况 1
1.1.1蛭石的结构及组成 1
1.1.2 蛭石的物化性能 1
1.1.3 蛭石的应用 2
1.2蛭石的改性 3
1.2.1 热处理改性 3
1.2.2 酸处理改性 3
1.2.3 蛭石有机化改性方法 4
1.3蛭石的研究现状 4
1.4研究的目的及意义 5
2.1 试验原料 6
2.2 蛭石原料测试及分析 6
2.2.1 蛭石的化学成分分析 6
2.2.2 蛭石的x射线衍射分析 6
2.2.3 蛭石的热分析 7
2.3 试验设备及药剂 8
2.4 研究方法 9
2.4.1 膨胀率的测试 10
2.4.2 膨胀蛭石结构分析 10
2.4.2 浸出液分析测试 10
第三章 物理法膨胀蛭石过程研究 11
3.1微波膨胀蛭石过程研究 11
3.1.1 蛭石粒度对蛭石微波膨胀过程的影响 11
3.1.2 微波功率对蛭石膨胀过程的影响 11
3.2高温膨胀蛭石过程研究 12
3.2.1 蛭石粒度对蛭石高温膨胀过程的影响 12
3.2.2 温度对蛭石高温膨胀过程的影响 13
3.3物理法膨胀蛭石结构观察 14
3.3.1 膨胀蛭石形貌特征 14
3.3.2 蛭石膨胀物相变化 15
3.4本章小节 16
第四章 化学法膨胀蛭石过程研究 18
4.1双氧水膨胀蛭石过程研究 18
4.1.1 粒度对蛭石膨胀过程的影响 18
4.1.2 双氧水浓度对蛭石膨胀过程的影响 18
4.2 蛭石浸出液分析 19
4.2.1浸出液pH变化 19
4.2.2浸出液ICP分析 20
4.3本章小结 22
第五章 结论 23
参考文献 24
致谢 26
第一章 绪论
1.1蛭石的概况
蛭石是一种在工业、环保业等众多领域中有广泛应用的非金属矿物。世界蛭石的主要产地有美国、南非、中国和俄罗斯。在我国内,蛭石产地分布也很广泛,主要有新疆和内蒙,其中新疆尉犁县且干布拉克蛭石矿是最具代表性的,其储量占全国总储量的90%以上,在世界上储量占第二位,仅次于南非,是世界上罕见的超大矿床,新疆尉犁蛭石是一种优质的矿产资源,具有杂质少,膨胀倍数高等优良特点。
1.1.1蛭石的结构及组成
(1)蛭石的组成
蛭石是一种天然、无毒的粘土矿物,与蒙脱石较为相似,受热易于膨胀,是一种层状结构的硅酸盐。通常情况下,黑云母经过风化作用和热液侵蚀形成蛭石。