铬铁渣活化制备低温陶瓷胶凝材料

发布时间：2018-05-14 12:17

本文选题：铬铁渣 + 胶凝材料　；参考：《昆明理工大学》2016年硕士论文

【摘要】：铬铁渣是冶炼铬铁合金时所排放的含铬工业废渣,随着对铬铁合金需求量的增加,我国每年排放铬铁渣超过500万吨。铬铁渣导致的环境问题引起了国内外众多学者的关注,并就其无害化治理进行了大量研究,其中利用铬铁渣制备胶凝材料是一种行之有效的途径。本论文研究了铬铁渣、矿渣等废渣的胶凝性能,通过物理、化学活化制备了性能优良的铬铁渣基低温陶瓷胶凝材料。通过研究铬铁渣、矿渣和粉煤灰的粉磨特性及活性发展,制备高活性的铬铁渣、矿渣和粉煤灰微粉。结果表明：铬铁渣比矿渣和粉煤灰易粉磨,矿渣在粉磨过程中易发生团聚,需要添加少量的助磨剂。铬铁渣最佳粉磨时间为1h,矿渣和粉煤灰为2h,此时铬铁渣、矿渣、粉煤灰28 d活性分别为0.71、0.89、0.79,矿渣和粉煤灰28 d活性高于铬铁渣。粉磨1h的铬铁渣颗粒粒径主要集中在0-10μm和10～33μm。通过单因素考察不同矿物掺合料掺量对铬铁渣基胶凝材料性能的影响,得出胶凝材料制备的最佳基础配方：铬铁渣40%,矿渣20%,矿物激发剂24%,粉煤灰7%,石灰5%和脱硫石膏4%,可以达到普通硅酸盐水泥52.5强度等级。通过XRD、SEM和TG-DSC等手段对材料物相组成及微观结构进行表征,其水化产物主要有C-S-H凝胶、AFt晶体和Ca(OH)2。研究了不同化学外加剂对铬铁渣基胶凝材料性能的影响。采用正交试验方法探讨了四种外加剂的复配效果。通XRD、SEM、TG-DSC对铬铁渣基胶凝材料水化机理和复合外加剂作用机理进行了分析探讨。基于胶凝材料的最佳基础配方制备了复合外加剂,确定了最佳掺量配比：氯化钠0.6%,硫酸钠1.2%,氟化钠0.6%,硫酸铝0.7%。掺复合外加剂后,对铬铁渣基胶凝材料水化过程有明显的改善作用,充分激发了铬铁渣、矿渣和粉煤灰的活性,促进C-S-H凝胶和AFt更多更快的形成是胶凝材料性能提高的原因。通过技术经济分析,铬铁渣基胶凝材料项目具有较强的抗风险能力,预期的社会、经济和环境效益十分显著。铬铁渣基胶凝材料制备的复合材料具有优良的物理性能和耐久性能,可替代水泥基材料广泛用于道路工程,前景广阔。
[Abstract]:Ferrochrome slag is a kind of chromium-bearing industrial waste slag discharged from smelting ferrochrome alloy. With the increasing demand for ferrochromium alloy, more than 5 million tons of ferrochrome slag is discharged in China every year. The environmental problems caused by ferrochrome slag have attracted the attention of many scholars at home and abroad, and a great deal of research has been done on its harmless treatment, among which the preparation of cementitious material with ferrochrome slag is an effective way. In this paper, the cementitious properties of ferrochrome slag and slag were studied. The excellent low temperature ceramic cementitious material based on ferrochrome slag was prepared by physical and chemical activation. High active ferrochrome slag, slag and fly ash powder were prepared by studying the grinding characteristics and activity development of ferrochrome slag, slag and fly ash. The results show that ferrochrome slag is easier to be ground than slag and fly ash, and the slag is easy to be agglomerated in the grinding process, and a small amount of grinding aids are needed. The optimum grinding time of ferrochrome slag is 1 h, and the activity of slag and fly ash is 2 h. The activity of ferrochrome slag, slag and fly ash in 28 days is 0.71-0.89 ~ 0.79, respectively. The activity of slag and fly ash in 28 days is higher than that in ferrochrome slag. The particle size of ferrochrome slag is mainly 0-10 渭 m and 10 ~ 33 渭 m after grinding for 1 h. The effects of different mineral admixtures on the properties of ferrochrome based cementitious materials were investigated by single factor. The optimum basic formula for the preparation of cementitious material is: ferrochrome slag 40, slag 20, mineral activator 24, fly ash 7, lime 5% and desulphurized gypsum 4. The strength grade of ordinary Portland cement is 52.5. The phase composition and microstructure of the material were characterized by means of TG-DSC and SEM. The hydration products were mainly C-S-H gel, AFT crystal and CaOH _ (2). The effects of different chemical admixtures on the properties of ferrochrome based cementitious materials were studied. The compound effect of four admixtures was studied by orthogonal test. The hydration mechanism of ferrochrome based cementitious material and the action mechanism of composite admixture were analyzed and discussed by XRDX SEMG-DSC. Based on the optimum formula of cementitious material, the compound admixture was prepared, and the optimum proportion was determined: sodium chloride 0.6, sodium sulfate 1.2, sodium fluoride 0.6, aluminum sulfate 0.7. The hydration process of ferrochrome based cementitious material was improved obviously by adding compound admixture, and the activity of ferrochrome slag, slag and fly ash was fully stimulated, and the more and faster formation of C-S-H gel and AFt were the reasons for improving the properties of cementitious material. Through technical and economic analysis, the project of ferrochrome slag based cementitious material has strong ability to resist risks, and the expected social, economic and environmental benefits are very significant. The composite made of ferrochrome slag cementitious material has excellent physical properties and durability. It can be used as a substitute for cement-based materials for road engineering and has a broad prospect.
【学位授予单位】：昆明理工大学
【学位级别】：硕士
【学位授予年份】：2016
【分类号】：X757;TQ177

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