文章摘要
钢渣中游离氧化钙和氧化镁碳酸化消解
Carbonation reaction of free CaO and MgO in steel slag
投稿时间:2018-04-04  修订日期:2018-05-08
DOI:
中文关键词: 钢渣,碳酸化,体积安定性,Rietveld定量方法
英文关键词: steel slag  carbonation  volume stability  Rietveld quantitative phase analysis
基金项目:国家自然科学基金项目(面上项目51172096)
作者单位E-mail
张妍 大连理工大学 zhangyan_job0@163.com 
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中文摘要:
      在CO2浓度为99.9%,压力为0.2MPa条件下,对钢渣粉进行碳酸化处理,并作为水泥混合材制成净浆试件,研究碳酸化反应程度对试件安定性的影响。结果表明,掺加未经碳酸化处理的钢渣的试件,压蒸后破坏严重;掺加碳酸化反应10 min钢渣的试件膨胀率1.03%,试件有明显裂纹;掺加碳酸化反应20 min钢渣的试件的膨胀率为0.29%,符合国家标准,安定性合格。随着碳酸化反应时间的延长,钢渣中的硅酸盐相、氢氧化钙(CH)、游离氧化钙(f-CaO)和游离氧化镁(f-MgO)等物质与CO2进行反应,生成碳酸钙(CaxMg1-xCO3)。碳酸化处理20 min后,钢渣中f-CaO含量由2.54%降至0.84%, f-MgO含量由3.8%降至2.4%,试块压蒸后未出现氢氧化镁(MH),镁离子以水化硅酸镁(M-S-H)形式存在于无定型物中。
英文摘要:
      In this study, samples were prepared by using steel slag powders carbonated at different times as partial replacements of Portland cement. The samples were then autoclaved to investigate the influence of carbonation time on the volume stability of the samples. The results show that the carbonation time facilitated the carbonation reaction, the dicalcium silicate (C2S), tricalcium silicate (C3S), free lime (f-CaO), calcium hydroxide (CH) and periclase (f-MgO) in the steel slag can be reacted with CO2 gas, and the products of carbonation are mainly calcite (CaxMg1-xCO3). The volume stability of samples improved significantly after carbonation. After autoclaved, the sample with steel slag uncarbonated were broken completely. The sample with steel slag carbonated for 10 minutes was cracked and the expansion degree was 1.03%. However, the expansion degree of the sample with steel slag carbonated 20 minutes was 0.29%, the stability of volume was qualified, and the contents of f-CaO decreased from 2.54% to 0.84%, f-MgO decreased from 3.8% to 2.4%. Magnesium hydroxide (MH) was not found in the autoclave samples, because Mg2+ exists in the amorphous in the form of hydrated magnesium silicate (M-S-H).
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