铬盐清洁生产工艺的铬渣综合利用及零排放
文献类型：学位论文
| 作者 | 王万平 |
| 学位类别 | 博士 |
| 答辩日期 | 2003 |
| 授予单位 | 中国科学院过程工程研究所 |
| 授予地点 | 中国科学院过程工程研究所 |
| 导师 | 张懿 |
| 关键词 | 铬渣 零排放 动力学 反应结晶 碳酸镁晶须 铬盐生产 |
| 其他题名 | Comprehensive Utilization and Zero Emission of the ChromiumContaining Residue in the Cleaner Production of Chromates |
| 学位专业 | 化学工艺 |
| 中文摘要 | 中国科学院过程工程研究所开拓的亚熔盐铬化工清洁生产新工艺,大幅度降低了反应温度和能耗,提高了铬资源利用率,从生产源头使铬渣削减了80%.铬铁矿资源全组分深度利用和铬渣零排放是铬盐清洁生产后续工艺的主要组成部分.该文针对新工艺减量后铬渣的镁回收、铬渣零排放的工艺与工程问题进行了相关基础研究,为产业化实施提供依据.该文提出了铬渣的碳酸化提镁,得到轻质碳酸镁产品;提镁后的铬渣成为水泥生产的合格原料,实现了铬铁矿资源的综合利用和铬渣的零排放.该文还提出了碳酸氢镁反应结晶和碳酸镁晶须及纤维状氧化镁制备新工艺,反应结晶可大幅度降低碳酸镁生产能耗,碳酸镁晶须及纤维状氧化镁产品提高了产品的附加值,对实现零排放和产品的高值化有指导意义. |
| 英文摘要 | The cleaner production technology of chromates (CPTC) developed by the Institute of Process Engineering, Chinese Academy of Sciences, is based on the original kernel technology of the sub-molten liquid oxidation in an alkaline medium. It significantly decreases the reaction temperature and the energy consumption, greatly improves the conversion of chromium in chromite ores, and reduces the amount of chromium containing residue (CCR) by 80%. The comprehensive utilization of all valuable components in the chromite ore, as well as the final zero emission of the CCR, is among the most important targets in the CPTC process. In this thesis, fundamental research was carried out on the extraction and recovery of magnesium from the CCR in the CPTC process by carbonation, and the technological and engineering issues regarding the zero emission of the CCR were also discussed. Both provided the basis for the industrialization of the CPTC. In this work, a novel method of extracting agnesium from the CCR and producing magnesium carbonate light was proposed. The treated CCR becomes the eligible raw material in cement industry, which achieves the comprehensive utilization of all valuable components in the chromite ore and the zero emission of the CCR in the CPTC process. Furthermore, a new process was developed on the reactive crystallization of magnesium carbonate for preparation of magnesium carbonate whisker. Compared to the conventional pyrogenation by steam, the reactive crystallization process decreases the energy consumption significantly. Advanced products of magnesium carbonate whisker and fibrous magnesium oxide are of higher performance and lower cost than ordinary magnesium carbonate light. The new process is important in achieving the zero emission of CCR and improving magnesium products. The main contents of this thesis are as follows: (1) Fundamental research work was systematically carried out on the carbonation of CCR from the CPTC process to prepare light magnesium carbonate. The kinetic effects of the reaction temperature, the partial pressure of CO2, the volume ratio of liquid to solid (L:S), the particle size of the residue, the stirring speed and the additives on the carbonation of CCR and the extraction of magnesium were specifically investigated. The macro-reaction-kinetics analysis of the carbonation process indicates that, at 20-40 °C, the reaction is of mixed control by the chemical reaction and the mass transfer, and the apparent activation energy of the reaction is 25.0 kJ/mol. The yield of magnesium can reach as high as 90% under operable conditions. Light magnesium carbonate was prepared through a series of processes including pyrogenation, washing and drying of the Mg(HCO3)2 solution obtained after carbonation and separation of the CCR in the CPTC process. The products are of the high quality. The replacement of K+ in the residue by Ca2+ was examined. The results indicate that, the temperature and the amount of CaO show a great effect on the reaction process; when the amount of CaO is as much as 1.5 times the amount of K+ in the residue, the reaction temperature is 160°C, and the reaction time is 60 minutes, the K content in the residue can be reduced to lower than 1%. The enhancement of the carbonation process of the CCR by adding CaCl2 was investigated. It is indicated that, the content of Mg and K in the residue can be decreased to a certain level simultaneously at a lower L:S and a higher temperature, when CaCb is present. The industrialization related issues for the carbonation extraction of magnesium from the CCR were discussed. It is shown that, extracting magnesium by carbonation of the CCR from the CPTC process is not only feasible at both technological level and engineering sense, but also of both social and economic advantages over the traditional process. A. new approach to the reactive crystallization of Mg(HCO3)2 by adding MgO was explored. The effects of temperature, amount of MgO, activity of MgO and stirring speed were studied. It is shown that, crystal of magnesium carbonate light can be obtained at a relatively low temperature by adding MgO to the Mg(HCO3)2 aqueous solution, the amount of MgO and the activity of MgO play an important role in the reactive crystallization of Mg(HCO3)2 in the presence of MgO, and however, the reaction temperature and the stirring speed are of minor influence. The optimum reaction conditions were obtained. The MgCO3-3H2O whisker was prepared by controlling the conditions of the reactive crystallization of the Mg(HCO3)2 solution in the absence of MgO. The results show that the reaction temperature, the stirring speed and the additives exhibit strong effect on the content and shape of the MgCCVSBbO whisker. The optimum conditions were obtained. Fibrous MgO with the shape of the MgCO3-3H2O whisker was prepared by controlling the sintering process of the MgCO3-3H2O whisker. The mechanism of the reaction was discussed and the optimum conditions were acquired. |
| 语种 | 中文 |
| 公开日期 | 2013-09-16 |
| 页码 | 108 |
| 源URL | [http://ir.ipe.ac.cn/handle/122111/1383]  |
| 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 | 王万平. 铬盐清洁生产工艺的铬渣综合利用及零排放[D]. 中国科学院过程工程研究所. 中国科学院过程工程研究所. 2003. |
入库方式： OAI收割
来源：过程工程研究所
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