化工冶金中反应与传质耦合过程的研究——硫化锌精矿直接浸出与萃合物水热反萃新工艺及机理
文献类型：学位论文
| 作者 | 康晓红 |
| 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 | 卢立柱 |
| 关键词 | 耦合过程 浸出 溶剂萃取 水热反萃 硫化锌精矿 |
| 其他题名 | Coupling Process of Chemical Reaction and Mass Transfer in Chemical Metallurgy |
| 学位专业 | 化学工艺 |
| 中文摘要 | 传统的湿法炼锌过程中,一般需要焙烧、烟气制酸等步骤,易造成环境污染;同时,目前的湿法除铁工艺包括黄钾铁矾法、针铁矿法、赤铁矿法,但这些沉淀方法仍然存在着如下问题,如沉淀的铁渣由于杂质含量高而难以合理利用,带走有用金属以及铁渣堆积造成的环境污染等等.该文提出耦合操作新工艺,即在硫化锌精矿不经焙烧直接进行浸出的同时完成硫磺和铁萃取,然后分别通过低温反萃和高温水热反萃,将负载在有机相中的硫以高品质硫磺粉的形式产出,铁以超细氧化铁粉末形式回收.这样可以极大地简化流程,减少对环境的污染,充分利用矿产资源。 |
| 英文摘要 | In the traditional metallurgy of nonferrous metal, roasting is usually used first to desulfurize the ore or concentrate. But it produces SO2-rich gas which must be collected, otherwise it will cause serious environmental pollution. Meanwhile, a controlled hydrolytic precipitation process (jarosite, goethite or hematite) to remove iron from the leaching solution must be used. But these precipitation methods are associated with a number of processing and environmental problems, such as the loss of valuable metals, the poor quality (low grade and high impurity content) of iron residue which makes the residue an unsuitable source of iron for other uses. In this work, a coupling process of leaching with solvent extraction was proposed. The application of the solvent extraction to the leaching pulp not only recovered highly pure sulfur by cooling and iron oxide powder by the hydrothermal stripping, but also enhanced the leaching rate significantly. Meanwhile, coupling process of zinc sulfide concentrate leaching with solvent extraction had the advantage of simplifying the process flow-sheet, decreasing the investment cost, and reducing the environmental contaminant. The following topics are covered in this dissertation: 1. It was established the common mathematical model for the coupling process of zinc sulfide concentrate leaching with solvent extraction. Meanwhile, it was analyzed and predicted the effects of different factors on the coupling process. 2.The novel coupling process of zinc sulfide concentrate leaching with solvent extraction of sulfur in pulp. Tetrachloroethylene was the effective organic solvent for sulfur in improving the zinc recovery from zinc sulfide concentrate in the FeCl3-HCl-tetrachloroethylene system. Meanwhile, the satisfactory recycling of the solvent and a good recovery of sulfur in elemental form were obtained. The apparent activation energy of the common leaching calculated by the initial rate method was 32.2kJ/mol. When the O/A (organic phase/aqueous phase) was less than 1/50, zinc recovery increased with the increase of O/A, and the rate-controlling step of the leaching was the diffusion through the sulfur layer. The case was the same as the common leaching. After that point, the O/A had little effect on zinc recovery, which was as high as 95%. When the O/A was higher than 1/5, the combined diffusion through the outer layer and sulfur layer became the rate-controlling step of the leaching, and the apparent activation energy was 12.1kJ/mol. 3. The effects of surfactant on the coupling process of zinc sulfide concentrate leaching with solvent extraction When sodium dodecylsulfonate concentration in the range of 0.5 to 2g/L was lower than the critical micelle concentration, the aggregation of ore particles could be prevented, and the very high recovery of zinc and less organic loss could be obtained To reduce the loss of the organic further, the following methods were effective such as enhancing the ionic strength, introducing some non-ionic surfactant, and increasing the concentration of HC1. 4. The hydro thermal stripping from iron-loaded organic phase By hydrothermal stripping which involved the hydrolysis of metal organic compounds with pure water at elevated temperature, the desired oxide powder was precipitated from the organic solvent, while the organic solvent itself was regenerated. By the coupling of stripping process with precipitation process, the process flow-sheet was simplified and the environmental contaminant was reduced. (1) Homogeneous and heterogeneous hydrothermal stripping of iron from naphthenic acid-isooctylalcohol-kerosene system. Through comparing the infrared spectra of naphthenic acid and the whole extraction system (naphthenic acid-isooctylalcohol-kerosene) at different temperature, it was found that the composition of the extraction system was chemical-stable and thermostable under the conditions of the present work. Factors affecting the stripping process, such as the initial iron concentration, the initial free naphthenic acid concentration, the seed, and the temperature, were investigated. The final expressions of the stripping rate were: For homogeneous hydrothermal stripping: The rate-determining step was hydrolysis for both the homogeneous and heterogeneous hydrothermal stripping. Meanwhile, the relationship between the stripping and time was established for both cases separately, which was fitted to the experiment data well. (2) Preparation of iron oxide powder by hydrothermal stripping The effects of the stripping temperature, the initial iron concentration in the organic phase and the initial pH of the aqueous phase on the nanoparticle were investigated by means of XRD and TEM. The particle size would become larger by enhancing the temperature, increasing the initial iron concentration in the organic phase and decreasing the initial pH of the aqueous phase. Adding H2PO4" into the hydrothermal stripping system could decrease the size of hematite powder. The powder obtained by using hydrothermal stripping directly was well crystallized and mainly composed of a -I 5. The novel coupling process of zinc sulfide concentrate leaching with solvent extraction of both sulfur and iron in the H2SO4-HNO3 system. It was found that the coupling process was affected by the following factors such as the concentration of HNO3, oxygen pressure, the temperature, the sodium dodecylsulfonate concentration, the O/A, as well as the composition of the organic phase. To get the satisfactory zinc recovery, the HNO3 concentration within 0.2-0.5mol/L, oxygen pressure higher than O.lMPa, and the higher temperature were better. In addition, it was necessary to control O/A less than 1/2, sodium dodecylsulfonate in the concentration range of 0.5 to 2g/L, and the lower percentage of P204 in the organic phase. It was required to make up the missed tetrachloroethylene for better coupling leaching. The purity and the size of the iron oxide powder were investigated by X-Ray Fluorescence Spectroscopy (XRF) and TEM. It was concluded that the nanometer iron oxide powder could be obtained, which consisted of 97.36% Fe2C>3. In addition, Crystal morphology of the iron oxide powder was changed by the sulfur disproportionation reaction. |
| 语种 | 中文 |
| 公开日期 | 2013-09-16 |
| 页码 | 167 |
| 源URL | [http://ir.ipe.ac.cn/handle/122111/1371]  |
| 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 | 康晓红. 化工冶金中反应与传质耦合过程的研究——硫化锌精矿直接浸出与萃合物水热反萃新工艺及机理[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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