摘要
为提高粉煤灰在矿山膏体充填中的利用率,采用控制变量法及力学分析法,分别研究了掺量为2%、4%和6%的硫酸钠和硅酸钠对水泥-粉煤灰基充填膏体的标准稠度用水量、初终凝时间以及各龄期单轴抗压强度的影响效果,使用扫描电镜分析激发后胶结体的微观结构。结果表明,两种激发剂都能增加胶凝体系的标准稠度用水量;硫酸钠可促进胶结体的早凝,且其后期强度提升显著,掺量为4%时效果最佳;硅酸钠的早凝作用优于硫酸钠,其对胶结体强度的提升主要表现在早期,最佳掺量为2%。扫描电镜结果显示,掺硫酸钠的胶结体反应前期水化产物以水化硅酸钙为主,后期针状钙矾石产量增多,充填在胶结体孔隙中;掺硅酸钠的胶结体水化前期生成大量絮状水化硅酸钙,后期基本没有新的物质产生。
In order to improve the utilization rate of fly ash in paste filling of mine, the control variable method and the mechan- ics analysis method were applied to study the effect of sodium sulfate with dosage of 2%, 4% and 6%, as well as sodium sili- cate on three indexes of cement and fly ash paste, including the water consumption with standard consistency, the initial finish time and the uniaxial compressive strength at each age. And the microstructures of the cemented bodies after excitation were analyzed by scanning electron microscopy. The results showed that both activators could increase the water consumption with standard consistency of the gel system. Sodium sulfat）e could promote the early coagulation of cement, and its late strength was enhanced significantly, especially its dosage of 4% had the best effect. The effect of sodium silicate on the early agglutination was better than that of sodium sulfate. The improvement of the cement strength was mainly at the early stage, and the best dosage was 2 %. The results of scanning electron microscopy indicated that the hydration products of cement with sodium sul- fate were mainly hydrated calcium silicate at first, and the production of acicular ettringite was increased later and filled in the pores of adhesive; the cement with sodium silicate generated a large number of flocculent hydrated calcium silicate at the early hydration, and no new substance was produced in the later stage.
出处
《矿业研究与开发》
CAS
北大核心
2018年第3期127-131,共5页
Mining Research and Development
基金
山东省重点研发计划项目(2016GGB01176)
河南省矿产资源绿色高效开采与综合利用重点实验室项目(S201609)
关键词
化学激发
充填膏体
硫酸钠
硅酸钠
胶凝活性
Chemical excitation, Filling paste, Sodium sulfate, Sodium silicate, Gel activity
