钢渣中游离氧化镁的测定和提高钢渣水泥复合胶凝材料水化性能的研究

发布时间：2018-01-03 06:35

本文关键词：钢渣中游离氧化镁的测定和提高钢渣水泥复合胶凝材料水化性能的研究　出处：《北京化工大学》2013年硕士论文　论文类型：学位论文

【摘要】：我国是钢铁大国，每年因炼钢产生大量的钢渣。目前累计堆放尚未利用的钢渣达3亿吨。这些钢渣不综合利用，就会占用土地，既污染环境，又浪费资源。钢渣具有和硅酸盐水泥熟料相似的化学组成和矿物组成，因此，用作水泥和混凝土掺合料有很大发展空间。但钢渣中含有较高含量的游离氧化钙和游离氧化镁，影响了钢渣体积安定性，并且由于钢渣形成条件的原因，，钢渣早期活性低。如果将钢渣应用于建筑行业中，则会引起建筑材料早期强度低和后期体积安定性不良问题，影响了钢渣的利用。本文主要研究了三方面内容：一是钢渣中游离氧化镁含量测定方法的研究；二是钢渣颗粒粒径分布对钢渣水泥复合胶凝材料水化性能的影响；三是早强剂对钢渣水泥复合胶凝材料水化性能的影响。以乙二醇-乙醇溶液为溶剂，氯化铵为催化剂，利用氯化铵-乙二醇-乙醇法测定钢渣中游离氧化镁含量。采用正交试验及方差分析，研究了钢渣试样量、氯化氨添加量、溶剂用量、加热时间4个主要因素对测定结果的影响。结果表明：氯化氨添加量对测定结果有显著性影响，其它因素均无显著性影响。并通过单因素分析方法确定了氯化铵最佳添量。采用获得的优化参数分别对不同钢厂钢渣进行检测，平行测定的相对标准偏差小于3%，加标回收率为95.98%~98.05%，表明该方法具有较高的精密度和准确度，能够快速准确测定钢渣中游离氧化镁含量。采用灰色关联分析方法研究钢渣颗粒粒径分布对钢渣水泥复合胶凝材料水化性能的影响，结果表明：不同粒径的钢渣颗粒与不同龄期复合胶凝材料的水化性能有不同的关联极性及关联度。最终确定钢渣较佳比表面积为453m~2·kg~（-1），同时，应尽量增加4.62~31.39μm范围的钢渣颗粒含量，以此来优化钢渣颗粒粒径分布，提高复合胶凝材料水化性能。 NaOH和Na_2SO_4均可以提高钢渣水泥复合胶凝材料的早期强度，但对28d之后的强度产生不利的影响；CaSO_4·1/2H_2O可以提高钢渣水泥复合胶凝材料28d之内的强度，而Ca(OH)_2不利于钢渣水泥复合胶凝材料早期强度的提高。NaOH、Na_2SO_4和CaSO_4·1/2H_2O均可以增加钢渣水泥复合胶凝材料3d之内的化学结合水含量。而Ca(OH)_2对钢渣水泥复合胶凝材料化学结合水含量影响不大。
[Abstract]:China is a big country of iron and steel, which produces a large amount of steel slag every year. At present, the accumulated amount of steel slag is 300 million tons. If the slag is not used comprehensively, it will occupy the land and pollute the environment. Steel slag has chemical and mineral composition similar to Portland cement clinker, therefore. There is great room for development as cement and concrete admixture, but the steel slag contains high content of free calcium oxide and free magnesium oxide, which affects the volume stability of steel slag, and because of the formation condition of steel slag. If the steel slag is used in the construction industry, it will lead to low early strength of building materials and poor volume stability in the later stage, which will affect the utilization of steel slag. This paper mainly studies three aspects: first, the determination method of free magnesium oxide in steel slag; Second, the influence of the particle size distribution of steel slag on the hydration performance of steel slag cement composite cementing material; Third, the effect of early strength agent on the hydration performance of steel slag cement composite cementing material. The content of free magnesium oxide in steel slag was determined by ammonium chloride ethanol-ethanol method using ethyleneglycol solution as solvent and ammonium chloride as catalyst. The content of steel slag sample was studied by orthogonal test and variance analysis. The results showed that the amount of ammonia chloride had a significant effect on the determination results. 4 main factors, such as the amount of ammonia chloride, the amount of solvent and the heating time, had a significant effect on the determination results. All other factors have no significant influence. The optimum amount of ammonium chloride is determined by single factor analysis method. The optimized parameters are used to detect steel slag in different steel plants. The relative standard deviation of parallel determination is less than 3 and the recovery rate is 95.98% 98.05, which indicates that the method has higher precision and accuracy. The content of free magnesium oxide in steel slag can be determined quickly and accurately. The influence of particle size distribution of steel slag on the hydration performance of steel slag cement composite cementing material was studied by grey correlation analysis. The results show that the hydration properties of steel slag particles with different particle sizes and different ages have different correlation polarity and correlation degree. Finally, the optimum specific surface area of steel slag is 453 m ~ (2) 路kg ~ (-1). . At the same time, the content of steel slag particles in the range of 4.62 ~ 31.39 渭 m should be increased as much as possible in order to optimize the particle size distribution of steel slag and improve the hydration performance of composite cementing materials. Both NaOH and Na_2SO_4 can improve the early strength of steel slag cement composite cementing material, but have a negative effect on the strength after 28 days. CaSO_4 路1 / 2 H _ 2O can improve the strength of steel slag cement composite cementing material within 28 days. However, Ca(OH)_2 is not conducive to the improvement of the early strength of steel slag cement composite cementing material. NaOH. Both Na_2SO_4 and CaSO_4 路1 / 2 H _ 2O could increase the chemically bound water content of steel slag and cement composite cementitious materials within 3 days. The content of chemically bound water of steel slag cement composite cementing material is not affected much by S 2.
【学位授予单位】：北京化工大学
【学位级别】：硕士
【学位授予年份】：2013
【分类号】：TQ172.781

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