高浓介质强化处理一水硬铝石矿新工艺的基础研究
文献类型：学位论文
| 作者 | 元炯亮 |
| 学位类别 | 博士 |
| 答辩日期 | 1999-12-24 |
| 授予单位 | 中国科学院研究生院 |
| 导师 | 张懿 |
| 关键词 | 高浓碱性介质法 一水硬铝石矿 氧化铝溶出率 赤泥分离 脱硅 铝酸钠结晶 |
| 其他题名 | A New Process to Leach Diasporic Bauxite Reinforced by High Concentration Medium of Caustic Soda |
| 中文摘要 | 本文首次提出了高浓介质强化处理一水硬铝石矿的新过程。该过程具有氧化铝回收率高、常压操作等优点。在常压260～280 ℃的高碱性介质中氧化铝溶出率较传统拜耳法提高约20%，达97%以上。赤泥中氧化铝含量仅为拜耳法中的1/4。淀粉和A1000絮凝剂均可加速赤泥浆液的沉降速度，A1000絮凝剂效果更好。而采用高梯度强磁场分离赤泥浆液，分离效果优于絮凝沉降。用合成的铝酸钙对高碱度高苛性化系数铝酸钠溶液进行一步脱硅，精制液硅量指数可达2000以上，脱硅产物中二氧化硅饱和系数可达0.4以上。在90～120 ℃的温度区间内，脱硅反应对铝酸根为一级反应，活化能为106kJ/mol。对铝酸钠溶液结晶的研究表明，初始硅量指数越小，初始结晶速度越慢，进入结晶体的二氧化硅越多。 |
| 英文摘要 | A new process has been suggested to digest diasporic bauxite in high concentration medium of caustic soda in this paper. It is composed of the following processes: digestion of diasporic bauxite in atmospheric pressure, dilution of digestion material and separation of red mud, desilication in aluminate solution of high sodium oxide concentration and high caustic modulus, crystallization and seeding decomposition of sodium aluminate solution. It has some advantages such as higher recovery of alumina, lower pressure, shorter flow sheet and less critical need of equipment materials. Recovery of alumina is more than 97% at temperature above 260 ℃ in high concentration medium of caustic soda, which is 20% more than that in Bayer process. Alumina content in red mud is only 1/4 of that in Bayer method, and sodium oxide content is 1/4 of that in Bayer method. It can be concluded from flocculation settlement experiments that starch or A1000 can accelerate the settling process of red mud slurry, and A1000 is more effective. The separation of red mud slurry in high gradient and strong magnetic field is more effective than flocculation separation in separation velocity and transmittance of settling solution. One-step desilication process using compounded tricalcium hydroaluminate can obtain higher desilication index (>2000) in aluminate solution with high sodium oxide concentration and high caustic modulus. Saturation coefficient of silicon dioxide in desilication product (DSP) is over 0.4. The distribution of silicon dioxide in DSP of adding tricalcium hydroaluminate, is more uniform than that of adding CaO which is higher outside and lower inside. The reaction adding tricalcium hydroaluminate is first order to silicate, and its activation energy is 106 kJ/mol. The results of crystallization of sodium aluminate shows that with the decreasing of initial desilication index, initial crystallization rate decreases and the amount of silicon dioxide in crystal increases because aluminate and silicate polymerize at the surface of seeds. |
| 语种 | 中文 |
| 公开日期 | 2013-09-27 |
| 页码 | 116 |
| 源URL | [http://ir.ipe.ac.cn/handle/122111/1995]  |
| 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 | 元炯亮. 高浓介质强化处理一水硬铝石矿新工艺的基础研究[D]. 中国科学院研究生院. 1999. |
入库方式： OAI收割
来源：过程工程研究所
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