铬酸钠碳化生产重铬酸钠的基础研究
文献类型：学位论文
| 作者 | 韩晓英 |
| 学位类别 | 硕士 |
| 答辩日期 | 2011-05-25 |
| 授予单位 | 中国科学院研究生院 |
| 导师 | 齐涛 ; 曲景奎 |
| 关键词 | 重铬酸钠 二氧化碳 溶解度 相平衡 热力学 |
| 其他题名 | Fundamental Research on the Manufacture of Sodium Dichromate by Carbonization of Sodium Chromate Aqueous |
| 学位专业 | 化学工艺 |
| 中文摘要 | 传统硫酸法生产重铬酸盐存在资源利用率低、环境污染严重的重大难题。碳化法作为一种新型的技术，实现了铬资源和二氧化碳的高效-清洁-综合利用和零排放生产。本文以优化碳化工艺为切入点，从实验、模型计算以及计算机模拟三个方面研究了碳化法工艺的热力学特征，从而获取过程机理信息及调控规律，为工业应用提供可靠的理论依据。论文主要取得以下进展： 1) 建立了气体高压溶解度测定装置，并通过此装置测定了在40~60 ℃，压力为0.3~2 MPa时，二氧化碳在碳酸氢钠水溶液中的溶解度。 2) 通过半经验方法以及活度系数法分别建立了两套碳酸氢钠对二氧化碳吸收的热力学模型，拟合结果与实验数据相比误差较小，拟合效果较好。在此基础上通过化学平衡原理建立了碳化工艺的碳化率模型，计算了在给定外界条件时体系的平衡碳化率。 3) 通过等温法测定了在40~60 ℃时，铬酸钠-碳酸钠-碳酸氢钠-水四元水盐体系相平衡，为进一步研究碳化液中所有成分的固液相平衡，即重铬酸钠-铬酸钠-碳酸钠-碳酸氢钠-水五元水盐体系提供可参照性的数据及实际的测定提供指导意义，从而为重铬酸钠的结晶分离工艺设计提供了理论基础。 4) 通过OLI热力学软件模拟了碳化工艺全流程的各个平衡过程的热力学性质，包括一次碳化、二次碳化工艺、常压时碳酸氢钠受重铬酸钠同离子效应影响的溶解度、加压下碳化液中碳酸氢钠含量、碳酸氢钠湿法分解、产品重铬酸钠蒸发等过程，详细探讨了上述各个平衡过程的最优条件，为碳化工艺提供了可靠的理论依据。 |
| 英文摘要 | Sulphate route for the manufacture of sodium dichromate is a conventional method which is inefficient and serisely contaminative. On the contray, the carbonation route is an attractive alternative to the conventional acidification route, because it is efficient, clean, high untilization and zero pollution. In this thesis, for acquiring optimized conditions, thermodynamic properties were studied by means of experiments, models and OLI-system simulation. The following achievements and progress were exhibited: 1) The solubility of CO2 in NaHCO3 aqueous solutions (0, 0.05, 0.1, 0.5, 1.0 mol·kg-1) were measured in the temperature range from 40 to 60 ℃ with pressure range from 0.3 to 2.0 MPa by employing a new designed batch apparatus. 2) Two thermodynamic models were proposed for correlating the experimental data, that is, modified Setschenow and PR-Duan equations. It was proved that the models fitted well in with the experimental data, and the average relative deviations were 4.06 and 3.90 %, respectively. Additionally the model of the ratio of carbonization is established by principles of chemical equilibrium and the CO2 solubility model as before. 3) The phase equlibria of the Na2CrO4-NaHCO3- Na2CO3-H2O system at 40, 50, 60 ℃were studied. It provided a guide for determinating a more complex system, that is, Na2CrO4- Na2Cr2O7-NaHCO3- Na2CO3-H2O. Further, it can provide the theoretical basis for the production of sodium dichromate. The thermodynamic properties of carbonization process was simulated by OLI-system, i.e. the process of first and second carbonization, the solubility of sodium bicarbonate in aqueous solutions of sodium dichromate at pressure of 1 atm, the separation of sodium bicarbonate from carbonization liquid, the wet decomposition of sodium bicarbonate and the evaporation of sodium dichromate aqueous solutions, etc. The trend of each thermodynamic property which is involved in the process of carbonization is investgated by OLI and the optimized conditions were selected. |
| 语种 | 中文 |
| 公开日期 | 2013-09-24 |
| 页码 | 69 |
| 源URL | [http://ir.ipe.ac.cn/handle/122111/1717]  |
| 专题 | 过程工程研究所_研究所（批量导入） |
| 推荐引用方式 GB/T 7714 | 韩晓英. 铬酸钠碳化生产重铬酸钠的基础研究[D]. 中国科学院研究生院. 2011. |
入库方式： OAI收割
来源：过程工程研究所
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