超细全尾砂新型胶结充填料水化机理与性能

董璐^{1, 2}，高谦^{1, 2}，南世卿³，杜聚强^{1, 2}

(1. 北京科技大学 土木与环境工程学院，北京，100083；2. 北京科技大学 金属矿山高效开采与安全教育部重点实验室，北京，100083；3. 河北钢铁集团矿业有限公司，河北 唐山，063000)

摘 要：针对全尾砂含泥质量分数较高、粒度低的特点，根据充填体作用机理，实验制备出以水淬渣为主要胶凝组分的全尾砂胶结充填材料。利用X线(XRD)和扫描电镜(SEM)对该充填材料的水化产物和微观结构进行研究。研究结果表明：该新型充填料克服水泥全尾砂充填体强度低、充填砂浆黏度大以及成本高等技术难题，抗压强度R₂₈=5.30 MPa是水泥胶结材料的4.7倍，满足矿山充填要求。所配制的充填料有良好的流动性，可以实现浆体自流输送。新型胶结材料的主导水化产物为钙矾石和C—S—H凝胶。大量钙矾石在水化初期形成，是原材料具有较高早期强度的主要因素；钙矾石微观形貌特征为网状或针棒状结构，随着养护时间的增加，水化产物不断发育长大，孔隙逐渐被填充，浆体结构更加致密，具有良好的力学特性。

关键词：超细全尾砂；水淬渣；胶结；充填

Performance and hydration mechanism of new super fine cemented whole-tailings backfilling materials

DONG Lu^{1, 2}, GAO Qian^{1, 2}, NAN Shiqing³, DU Juqiang^{1, 2}

(1. Civil and Environmental Engineering Institute,University of Science and Technology Beijing, Beijing 100083, China;2. State Key Laboratory of High-Efficient Mining and Safety of Metal Mine (Ministry of Education),University of Science and Technology Beijing, Beijing 100083, China;3. Hebei Iron and Steer Group, Tangshan 063000, china)

Abstract:Aimed at resolving high sediment percentage and low grain size of the mine backfilling materials, whole tailings backfilling materials were prepared with slag as the main component in cementitious according to the characteristics of filling. The hydration products and their microstructures of the samples were analyzed by XRD and SEM. The results show that this new backfilling overcomes technical problem of the cemented whole tailings backfilling materials, such as the low body strength, higher viscosity and cost mortar. The component strength of samples cured for 28 d is 5.30 MPa, which is 4.7 times cementitious materials and meets the requirements of materials for mine backfilling. The new backfilling materials have good liquidity, which can flow automatically. The main hydration products are ettringite and C—S—H gel. Ettringite microstructure characteristics for mesh or needle bar structure, which formed in the early hydration, are the main factors of high early strength. As hydration goes on, hydration products grow up, pores gradually are filled, the structure becomes denser, and thus processes good mechanical properties.

Key words:super fine wholetailings; slag; cementation; backfilling