| 题名 | 碱熔盐法处理熔分钛渣制备钛白新工艺研究 |
| 作者 | 王淑奕 |
| 学位类别 | 硕士 |
| 答辩日期 | 2013-05-01 |
| 授予单位 | 中国科学院研究生院 |
| 导师 | 齐涛 ; 初景龙 |
| 关键词 | 钛渣 熔盐反应 预处理 钛液 粒度分布 |
| 其他题名 | Preparation of Titanium Dioxide Pigment from Titanium Slag by Alkaline Molten Salt Method |
| 学位专业 | 化学工程 |
| 中文摘要 | 碱熔盐法钛白清洁生产新工艺克服了传统硫酸法和氯化法制备钛白过程中的污染和对原料要求苛刻的问题，以钛渣为原料，以氢氧化钠熔盐为反应介质，从生产源头上消除环境污染，实现钛资源的高效-清洁-综合利用。本文实验原料为直接还原含钛炉渣，是由钒钛磁铁矿经转底炉煤基直接还原-电炉熔分技术得到的熔分渣，二氧化钛含量仅为45%，利用碱熔盐法钛白生产技术实现熔分渣中的钛回收利用，是对钒钛磁铁矿钛资源综合利用的重大突破。主要研究内容和成果如下：（1）采用预处理的方法，解决钛渣熔盐反应的结块问题，将原料和NaOH低温低碱渣比下进行预反应和水洗，破坏原料的矿相结构和降低杂质含量；通过XRD、红外、能谱、BET等手段对预处理过程中硅元素的走向和赋存状态改变；确定预处理工艺条件。（2）对NaOH熔盐反应进行热力学分析；通过单因素实验考察反应温度、反应时间、碱渣质量比及钛渣粒径对钛转化率的影响，结果表明，在优化的分解条件下钛转化率能达到98%以上；研究熔盐反应过程中的宏观动力学，表明分解过程属于为反应收缩核模型，过程速度收界面化学反应控制，其表观活化能为77.45kJ/mol；对熔盐产物进行XRD表征，分析产物中Na2TiO3随着碱渣比、温度、时间等变化时其晶型的变化。（3）改进洗涤工艺；研究洗涤工艺中杂质的浸出率；研究酸溶过程中初始酸浓度、固液比等因素对钛液浓度和F值的影响，得到钛液浓度180g/L，F值=1.85，成功水解得到粒度合格的偏钛酸，经煅烧得到白度为96、纯度为98%的二氧化钛初品；详细研究了杂质离子对钛液水解制备偏钛酸粒度的影响，结果表明：适量的添加Mg2+、Al3+离子有助于抑制偏钛酸颗粒的长大，降低偏钛酸粒度。 |
| 英文摘要 | Industrial production methods of titanium dioxide pigments include the sulfate process and the chloride process, which discharge a large amount of toxic waste, resulting in serious environmental problems, also, requirement of raw material is harsh. A novel metallurgical clean process for production of titanium dioxide by decomposing titanium slag with NaOH molten salt was proposed. The aim of this process is to eliminate the pollution at the source and to fully utilize valuable compounds in titanium slag. The raw material in this paper furnace slag which contains TiO2 of 45% percent. it was produced by rotary furnace directed reduction circuit melting process via vanadium-bearing titanomagnetite, Making use of this slag through NaOH molten salt clean process is a huge breakthrough for comprehensive utilizationof vanadium-bearing titanomagnetite .The main points are as follows: (1) Solve the problem of the caking and adhesion of intermediate prduct via NaOH Molten Salt by using pretreatment method., Raw material and NaOH molten salt reacted at low temperature and low NaOH-to-slag mass ratio, and made a washing , thus changed the mineralogical structure and reduced the impurity content; Changes on occurrence of silicon elements in raw materials was studied by XRD, IR,EDS spectrum, BET and other means. Experimental conditions of the pretreatment was investigated.(2) A novel reaction system of molten NaOH and titanium slag was established. By thermodynamic calculation. Effects of reaction temperature, time, NaOH-to-slag mass ratio and particle size on titanium fractional conversion were studied. Approximately 98% of titanium in the slag could be converted under the optimal reaction conditions, and the product was characterized to be Na2TiO3 by XRD. The decomposition kinetics of titanium slag with molten NaOH under optimal reaction conditions indicates that the shrinking core model with chemical reaction controlled process is most applicable for the decomposition of titanium slag, with the apparent activation energy of 77.45kJ mol-1. (3) Improve the multi-stage countercurrent wash of molten reaction product. The leaching rate of each elements was studied. The effect of H2SO4 concentration silod-liquid-radio on titanium solution concentration and value of F was studied.we got a titanium solution of 180g/L ,F=1.85 and made the qualified particle size distribution of hydrous titanium oxides sucessfully. The chemical composition of the product is TiO2 98%,with Hunter white (Wh) 96. Influence of Mg2+、Al3+ on particle size distribution of hydrous titanium oxides was investigated. The result was: adding a certain concentration of Mg2+、Al3+ was helpful to inhibitiing the growing of hydrous titanium oxides, which lower the particle size. |
| 语种 | 中文 |
| 公开日期 | 2014-06-26 |
| 页码 | 96 |
| 内容类型 | 学位论文 |
| 源URL | [http://ir.ipe.ac.cn/handle/122111/8351]  |
| 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 | 王淑奕. 碱熔盐法处理熔分钛渣制备钛白新工艺研究[D]. 中国科学院研究生院. 2013. |
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