高性能无机-有机复合注浆材料研究

Research of high performance inorganic-organic composite grouting materials

针对千米深井巷道围岩大变形控制难题,提出了支护-改性-卸压“三位一体”协同控制技术,其中要求注浆改性材料具有“高渗透、高强度、高黏结”性能。“高渗透”可以通过减小粒度、增加界面润湿性来实现;“高强度”可以通过优选快速水化矿物,添加纳米增强材料来实现;“高黏结”可以通过添加有机调节剂,增加界面润湿并形成强化学键来实现。本文以超细化的硫铝酸盐水泥熟料、石膏、石灰为主要原料,通过优化配比研发了无机注浆材料,材料粒径D 95<7.0μm,最佳配比为硫铝酸盐水泥熟料、石膏、石灰质量比5∶4∶1;合成了纳米锂铝类水滑石增强材料,具有锂离子增强和纳米晶核诱导结晶双重协同增强作用,当掺量为无机注浆材料质量的2%时,抗压强度提高145%,达到12.3 MPa;采用“一锅法”合成了两亲性有机调节剂,掺量为无机注浆材料质量的3%时,可以将水与煤表面接触角从72.80°减小到19.23°,并在注浆材料与裂隙表面间形成氢键作用,显著改善界面润湿性,增加界面黏接强度。以无机注浆材料、纳米锂铝类水滑石、有机调节剂按95%,2%,3%的质量百分比混合制备了微纳米注浆材料,材料初、终凝时间分别为8.0,13.0 min,2 h抗压强度为10.2 MPa,煤的黏结强度大于煤自身拉伸断裂强度。微纳米注浆材料在口孜东矿进行了超前注浆应用,可以良好注入10μm开度的裂隙,与裂隙表面结合紧密,锚杆拉拔力由注浆加固前的37 kN提高到注浆后的145 kN。

To address the issue of controlling the large deformation of surrounding rock in the roadway with more than 1000 m depth,the project“strata control and intelligent mining technology in coal mines at 1000 m depth”sponsored by National Key Research and Invention Program,proposes the“three-in-one”cooperative control technology,which is for bolting-grouting-destressing of coal mine roadways.The properties of“high permeability,high strength and high bonding”are required for grouting materials.“High permeability”can be achieved by reducing particle size and increasing interface wettability,“High strength”can be achieved by selecting minerals which hydrate rapidly and“High bonding”can be achieved by adding organic modifier which can improve wettability and bonding strength by mechanical bonding.In this study,the superfine sulphoaluminate cement clinker,anhydrite and lime were selected to make inorganic grouting material by optimizing their ratio.The particle size D 95 of the materials was less than 7.0μm,the optional ratio of sulphoaluminate cement clinker,anhydrite and lime was 5∶4∶1.Nano lithium aluminum hydrotalcite(LiAl-LDH),which had the synergistic effect of lithium ion enhancement and nano-crystalline inducing crystallization,was synthesized to accelerate the hydration of inorganic grouting material.When the content of LiAl-LDH was 2%of inorganic grouting material,the compressive strength was increased by 145%and reached 12.3 MPa.The amphiphilic organic modifier was synthesized by“one-pot method”,when its content was 3%of inorganic grouting material,the contact angle between water and coal surface could be reduced from 72.80°to 19.23°.Hydrogen bonding was formed between the grouting material and the crevice surface,significantly improving the wettability of the interface and increasing the bonding strength of the interface.The micro-nano grouting materials were prepared by mixing inorganic grouting materials,nano-LiAl-LDH and organic modifier with 95%,2%and 3%mass percentages,respectively.The initial and final setting time of the material was 8.0 and 13.0 min,respectively,and the compressive strength was 10.2 MPa in 2 h.The bonding strength towards coal was greater than the tensile fracture strength of coal itself.The micro-nano grouting material was applied to advanced grouting at Kouzidong mine.SEM observation showed that the slurry could pass through the 10μm crevices and the cement stone had good bonding with crevice surface.After grouting,the pull-out force of anchor bolts was increased from 37 to 145 kN.