Jiangxi University of Technology,
为解决铬铁渣堆存占地面积大、污染土壤与水体、资源化利用水平低的问题，以矿渣-石灰-脱硫石膏-水泥熟料协同激发制备四元体系新型充填材料，揭示料浆流变性能、力学性能的变化规律，结合扫描电镜阐述充填体水化机理，通过毒性浸出试验探明充填材料固化/稳定化机理。结果表明：料浆流变曲线符合Hershel-Bulkley模型，随着减水剂掺量的增加，料浆屈服应力显著降低，铬铁渣掺量是影响料浆屈服应力变化的非显著性因素。随着铬铁渣掺量的增加，充填体抗压强度呈降低趋势；减水剂掺量从0.1%增加至0.4%的过程中，抗压强度呈先上升后降低的趋势；随着脱硫石膏掺量的增加，早期强度呈上升趋势，后期强度呈先上升后降低的趋势；石灰掺量从5%增加至20%的过程中，抗压强度呈快速上升趋势，且掺量越大，上升幅度越明显。当铬铁渣:矿渣:石灰:脱硫石膏:水泥:减水剂为30:30:20:8:12:0.3，抗压强度达最优值。充填体微观结构形貌以柱状钙矾石和团聚状C-S-H凝胶为主，二者紧密黏结形成强度整体。水化28 d充填体毒害离子浸出浓度满足GB 8978-1996《综合污水排放标准》要求，对Cr3+和Cr6+具备显著的固化/稳定化效果。
In order to solve the problems of large storage area of ferrochrome slag, pollution of soil and water bodies, and low level of resource utilization, a new filling material of quaternary system was prepared by synergistic excitation of slag-lime-desulfurization gypsum-cement clinker to reveal the changes of rheological properties and mechanical properties of the slurry, combined with scanning electron microscopy to elaborate the hydration mechanism of the filling body, and the mechanism of curing/stabilization of the filling material was investigated by toxic leaching test. The results showed that the rheological curves of the slurry conformed to the Hershel-Bulkley model, and the yield stress of the slurry decreased significantly with the increase of superplasticizer dosing, and the dosing of ferrochrome slag was a non-significant factor affecting the change of yield stress of the slurry. The compressive strength of the filling body tends to decrease with the increase of chromium-iron slag doping; the compressive strength tends to rise and then decrease when the water reducing agent dosing increases from 0.1% to 0.4%; the early strength tends to rise and the later strength tends to rise and then decrease when the desulfurization gypsum dosing increases; the compressive strength tends to rise rapidly when the lime dosing increases from 5% to 20%, and The larger the doping amount is, the more obvious the rise is. The compressive strength reached the optimum value when the dosing of ferrochrome slag:slag:lime:desulfurization gypsum:cement:superplasticizer was 30:30:20:8:12:0.3. The microstructural morphology of the filler is dominated by columnar calcium alumina and agglomerated C-S-H gel, both of which are closely bonded to form a strong whole. The toxic ion leaching concentration of the 28-d hydration filler met the requirements of GB 8978-1996 "Integrated Wastewater Discharge Standard", and had significant solidification/stabilization effects on Cr3+ and Cr6+.