铁矿矿山充填采矿用胶结充填料研究

发布时间：2018-11-11 09:39

【摘要】：本文针对地下胶结充填采矿所面临的需要积极寻求价格低廉、来源广泛、性能优良的充填材料作为水泥的替代品,降低胶结剂成本的难题,以铁矿矿山地下充填料为研究对象,全固废胶结充填料采取就近取材的原则,根据不同矿区尾矿及原材料的特点设计了粉煤灰体系胶结充填料和钢渣-矿渣体系胶结充填料两种方案。并以矿渣-钢渣-脱硫石膏胶结剂为基础,探讨了矿渣在硫酸盐激发下的水化机理和矿渣-钢渣体系胶结剂固化重金属的原理及效果。通过对矿渣-钢渣-脱硫石膏胶凝体系和普通硅酸盐水泥固化铅进行对比研究,揭示其固化机理,特别是铅在固化体中的赋存状态对固化效果的影响,以及铅离子的介入对C-S-H凝胶和钙矾石晶体结构产生的影响。为利用矿渣-钢渣体系充填用胶结剂对危险固体废弃物进行地下安全充填填埋提供基础研究和理论支撑。其中粉煤灰体系充填料按粉煤灰75%、脱硫石膏10%、石灰15%,胶凝材料：尾矿为1：4,所制备的料浆流动性良好,养护90天后抗压强度最高为11.35MPa,固体废弃物利用率达到97%。以钢渣和尾砂为主要原料的胶结充填材料,当钢渣掺量为60%、矿渣掺量28%、脱硫石膏掺量12%时,料浆流动性能满足自流型胶结充填的流动性要求,充填体28d抗压强度为4.09MPa,满足矿山充填强度要求。按胶砂比1：4制备的充填体自由膨胀率为0.27%,后期趋于稳定,有利于提高充填接顶率,28d抗压强度为5.98MPa,满足充填接顶强度要求。论文综合采用XRD、SEM、TG/DSC、IR、NMR等方法分析了在硫酸盐的激发下矿渣的水化产物和水化机理,提出了矿渣水化的四个阶段。铅离子浸出试验结果表明矿渣钢渣胶凝材料对铅离子有较普通硅酸盐水泥更为良好的固化效果。研究发现矿渣-钢渣胶凝体系更能激发Pb离子与Ca离子的置换作用,使铅离子更容易被捕获进入C-S-H凝胶及钙矾石的硅氧四面体网络体中平衡电荷,或替换其晶格中的被捕获的Ca离子,形成大量的含铅钙矾石、含铅类沸石相、含铅C-S-H和铅铁矾类((Pb,H+)(Al3+,Fe3+,Fe2+)3(SO42-, AsO43-)2(OH)6)等大分子复盐沉淀从而固化铅离子阻止其浸出。
[Abstract]:In view of the need of underground cemented filling mining, this paper actively seeks for the filling material with low price, wide source and excellent performance as a substitute for cement and reduces the cost of cementing agent. The underground filling material of iron mine is taken as the research object. According to the characteristics of tailings and raw materials of different mining areas, two schemes of fly ash system cemented filling material and steel slag system cemented filling material are designed. Based on slag, steel slag and desulphurization gypsum cementing agent, the hydration mechanism of slag under sulfate excitation and the principle and effect of solidifying heavy metal with slag steel slag system cementing agent were discussed. The solidification mechanism of slag, steel slag and desulphurized gypsum cementitious system and common Portland cement was studied, and the effect of the occurrence of lead in solidified body on the curing effect was revealed. And the influence of lead ion on the crystal structure of C-S-H gel and ettringite. It provides basic research and theoretical support for underground safe filling and landfill of hazardous solid waste by using cementing agent of slag and steel slag system. The filling material of fly ash system is 75% fly ash, 10% gypsum desulphurization, 15 lime, 15 cement material: 1: 4 tailings, the fluidity of the slurry prepared is good, the compressive strength is 11.35 MPA after 90 days of curing. The utilization rate of solid waste reached 97%. When steel slag and tailings are the main raw materials of cemented filling material, when the content of steel slag is 60, slag is 28m and desulphurization gypsum is 12, the fluidity of slurry can meet the fluidity requirement of self-flowing cemented filling. The compressive strength of the filling body is 4.09 MPA in 28 days, which meets the requirement of the filling strength in the mine. The free expansion rate of the filling body prepared at 1:4 is 0.27, which tends to be stable in the later stage, which is beneficial to the improvement of the filling rate, and the compressive strength of the filling body is 5.98 MPA in 28 days, which meets the requirement of the filling roof joint strength. In this paper, the hydration products and hydration mechanism of slag under sulfate excitation were analyzed synthetically by XRD,SEM,TG/DSC,IR,NMR method, and four stages of slag hydration were put forward. The results of lead ion leaching test show that slag steel slag cementitious material has better curing effect than common Portland cement. It is found that the slag / steel slag cementitious system can excite the substitution of Pb ion with Ca ion, and lead ion can be easily captured in the SiO2 tetrahedron network of C-S-H gel and ettringite. Or replace the trapped Ca ions in their lattice to form a large amount of lead-containing ettringite, lead-containing zeolites, lead-containing C-S-H and lead (Pb,H) (Al3, Fe3, Fe2) _ 3 (SO42-,) Macromolecules such as AsO43-) 2 (OH) 6) were precipitated by double salt to solidify lead ions to prevent their leaching.
【学位授予单位】：北京科技大学
【学位级别】：博士
【学位授予年份】：2015
【分类号】：TD853.343

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