煤矸石复合材料制备及其吸附性能的研究

发布时间：2018-08-19 19:23

【摘要】：煤矸石是洗煤和采煤过程产生的固体废物，是我国堆放累积量最大的工业废渣，其主要成分是SiO2和Al2O3，因其矿物特性和化学特性使它经过合适的工艺能够提高活性，适合作为污水处理药剂的原料。本文以煤矸石、石灰石和氯化铝为原料，探究了制备吸附剂的最佳工艺条件，并对吸附剂进行结构性能表征，确定了吸附剂处理铬、铅、锌废水的最佳条件，并探讨了吸附机理。制备吸附剂的最佳条件为：当煤矸石粒径为200目，以2：3的比例与石灰石混合，加入质量百分含量10%的氯化铝，混合在马弗炉内从室温缓慢升温至800oC，保温90min，取出自然冷却，得到呈碱性的复合型吸附剂。复合型吸附剂的SEM图谱表明其表面凹凸不平，孔径数量多，孔径直径大，这有利于吸附过程的进行。由XRD图谱可见三种物质反应生成具有活性的不稳定的物质：Mg2Al4Si5O18（堇青石）、Al2Si2O5(OH)4（高岭石）、C2CaO4（草酸钙）、CaSiO3（硅酸钙）等。经Boehm检测其中Al—O基团、Ca含量增大，其零点电荷高，吸附重金属离子效果好。复合吸附剂吸附铬模拟废水去除率为94.79%，低浓度符合Langmuir拟合，高浓度符合Freundlich拟合，主要以单分子层物理吸附为主。复合吸附剂吸附铅模拟废水去除率为96.68%，低浓度和高浓度均符合Freundlich拟合，主要以单分子层物理吸附为主。复合吸附剂吸附锌模拟废水去除率为96.28%，低浓度符合Freundlich拟合，高浓度符合Langmuir拟合，主要以化学吸附为主，同时存在单分子层物理吸附。准二级动力学方程能更好的描述三种重金属离子整个吸附过程。利用煤矸石制备吸附剂不仅节约了资源，降低成本的同时也缓解了固体废弃物对于环境的污染程度，，达到以废治废的目的。
[Abstract]:Coal gangue is the solid waste produced in coal washing and coal mining process, and it is the largest accumulated industrial waste residue in China. Its main composition is SiO2 and Al _ 2O _ 3. Because of its mineral and chemical characteristics, coal gangue can improve its activity through proper process. Suitable as raw material for wastewater treatment agent. In this paper, using coal gangue, limestone and aluminum chloride as raw materials, the optimum conditions of preparation of adsorbent were studied, and the structure and properties of adsorbent were characterized, and the optimum conditions for treating chromium, lead and zinc wastewater by adsorbent were determined. The adsorption mechanism was also discussed. The optimum conditions for the preparation of adsorbents are as follows: when the coal gangue particle size is 200 meshes, when the coal gangue is mixed with limestone at 2:3 ratio, and 10% aluminum chloride is added, the mixture slowly heats up from room temperature to 800oC in a muffle furnace for 90 minutes, and the natural cooling is taken out. The composite adsorbent was obtained. The SEM spectra of the composite adsorbent show that the surface is uneven, the pore size is large and the pore diameter is large, which is beneficial to the adsorption process. It can be seen from the XRD spectra that three kinds of substances have been reacted to form the active unstable substance: Mg2Al4Si5O18 (cordierite), Al2Si2O5 (OH) 4 (kaolinite), C2CaO4 (calcium oxalate), CaSiO3 (calcium silicate) and so on. The content of Ca in Al-O group was increased by Boehm, and its zero charge was high, and the adsorption effect of heavy metal ions was good. The removal rate of simulated wastewater adsorbed by composite adsorbent is 94.79. The low concentration accords with Langmuir fitting and the high concentration accords with Freundlich fitting. The main adsorption is single molecular layer physical adsorption. The removal rate of simulated waste water adsorbed by complex adsorbent was 96.68. The low concentration and high concentration accorded with Freundlich fit, and the main adsorption was single molecular layer physical adsorption. The removal rate of simulated wastewater adsorbed by complex adsorbent is 96.28, the low concentration accords with Freundlich fitting, the high concentration accords with Langmuir fitting, and the chemical adsorption is the main one, and the physical adsorption of single molecular layer exists at the same time. The quasi-second-order kinetic equation can better describe the whole adsorption process of the three heavy metal ions. The preparation of adsorbents from coal gangue not only saves resources and reduces the cost, but also alleviates the environmental pollution caused by solid waste, and achieves the purpose of waste treatment.
【学位授予单位】：内蒙古科技大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：X752;X703

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