东北大学毕业设计(论文) 中文摘要
赤峰沸石改性药剂研究
中文摘要
沸石是一种主要的非金属矿产资源，在石油化工、日用化工、建筑行业、国防工业、农林牧等多个领域有着广泛的应用。本文以产于内蒙古赤峰的天然沸石为实验原料，开发深加工产品。在了解沸石的结构特点和基本特性后，系统研究了沸石的改性方法和改性药剂。
本文对原矿的特性进行了检测和分析，由性质分析结果可知：该沸石为片沸石，孔道中平衡电荷的金属阳离子主要为K+和Ca2+，其次为Mg2+和Na+，耐热性较一般片沸石高，在450℃左右结构骨架开始破坏，具有较好的耐酸性和一定的耐碱性，其CEC为48.7mmol/100g，粒度为0.0500~0.075mm的样品比表面积为18.601m2/g，孔径主要在0.6~1.26nm之间，对Zn2+、Ni2+和Pb2+的去除能力较低。因此有必要对该沸石进行改性，以克服其作为吸附材料在废水处理应用中的不足。
本文首先选取HCl、NaOH、NaCl和NH4Cl四种典型的无机酸、碱和盐对沸石进行内孔结构改性。结果表明，NaOH改性沸石的吸附性能相对较好。对Pb2+的去除率高达99.95%，但对Zn2+和Ni2+的去除率只有44.83%和21.12%。为了进一步改善改性效果，进行了组合药剂研究。结果发现，与单一药剂相比，经C2H2O4—NaOH改性后的沸石性能有了很大提高。对Pb2+、Zn2+和Ni2+的去除率分别为99.08%、90.33%和55.98%。随后又对C2H2O4—NaOH药剂组合进行条件试验。结果表明，在改性温度为60℃，改性时间为6小时，吸附时间为4小时的最佳条件下，改性沸石对Pb2+、Zn2+和Ni2+的去除率分别达到99.98%、99.96%和94.45%的理想效果。
本文还对沸石改性和吸附的机理进行了研究。结果表明，沸石的改性和吸附过程主要以离子交换作用为主。改性沸石与重金属离子进行离子交换的速率主要受粒扩散速率的控制。
上述研究成果对促进赤峰沸石的高效开发及其在废水处理中的实际应用具有一定的指导意义。
关键词：沸石，改性，离子交换，吸附
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东北大学毕业设计(论文) Abstract
Research on modified reagent of Chifeng zeolite
Abstract
The zeolite is a kind of non-metal mineral resources which is widely used and has a great amount dosage in the national economy. At present, many kinds of deeply processing products made of zeolite have been extensively applying in the petroleum artesian well, petrochemical engineering, metallurgy, foundry, medicine and hygiene, agriculture, environmental protection and cosmetics industry etc. In this paper, fine processing products of zeolite were developed, by using the natural zeolite mineral of Chifeng in Inner Mongolia Autonomous Region. After the structure feature and basic characteristic of zeolite were described ，the methods and reagent of the zeolite modification were discussed.
In this paper, the characteristic of raw ore was analysed. The results provided the basis for the next stage processing treatment. It was found that the raw ore was Ca-heulandite and the metal cations which counterpoise electric charge are K+ ,Ca2+，Mg2+ and Na+. It has good heat resistance and acid resistance, also has a certain alkali resistance. The crystal structure is destroyed when the temperature is higher than 450℃. The CEC result expresses that the cation (NH4+) exchange capacity is 48.7mmol/100g. The specific surface area is 18.601m2/g and the pore radius is 0.6~1.26nm when the zeolite granularity is 0.0500~0.075mm. The capacity of adsorb Zn2+, Ni2+ and Pb2+ is low. It is necessary to modify the zeolite to overcome the disadvantages as adsorbent used in wastewater treatment.
HCl, NaOH, NaCl and NH4Cl were selected to modify the zeolite. The result showed that, After NaOH modification, the zeolite adsorption performance is relatively good. The elimination rate of Pb2+ reaches as high as 99.95 %, but the elimination rate of Zn2+ and Ni2+ only has 44.83% and 21.12%. To further improve the modified effect, the combined reagent also has been researched. The result showed that, compares with the sole reagent, the zeolite moditied by C2H2O4 and
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东北大学毕业设计(论文) Abstract
NaOH has the very big enhancement in Adsorption performance. The elimination rate of Pb2+, Zn2+ and Ni2+ reaches99.08%, 90.33% and 55.98%.Then has carried on the zeolite modification and the adsorption condition experiment. The result indicated that when the modified temperature at 60℃, the modified time is 6 hours and the adsorption time is 4 hours, The elimination rate of Pb2+, Zn2+ and Ni2+ achieves 99.98%, 99.96% and 94.45%.
This article also has conducted the research to the zeolite modification and the adsorption mechanism. The result indicated that the process of modification and adsorption is mainly determined by ionic exchange function. The speed of ionic exchange between modified zeolite and heavy metal ion is controled mainly by particle diffusion speed.
These results are of significance on facilitating the exploitation of zeolite and its practicality in wastewater treatment.
Key words：zeolite, modification, ion exchange, adsorption
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