基于圆盘制粒工艺的铁尾矿再生细骨料制备及性能研究-《福建理工大学学报》

文章信息/Info

Title:: Preparation and properties of recycled fine aggregate from iron ore tailings

摘要:: 随着铁尾矿堆存量不断增加，不仅占用大量土地，还对生态环境构成严重威胁，同时天然砂石过度开采加剧了资源枯竭。为实现铁尾矿资源化利用、减少天然砂石消耗、缓解铁尾矿堆存带来的环境与安全问题，本研究以铁尾矿、粉煤灰等固废为原料，通过造粒成球方法制备再生细骨料。结果表明，在最优配比下，以铁尾矿、水泥、粉煤灰为原料制得的再生细骨料性能优良。在铁尾矿掺量60%、蒸汽养护12 h时，骨料堆积密度为1167 kg/m3，压碎指标24.87%，饱和面干吸水率11.9%，坚固性6.5%。蒸汽养护可加速水化反应，提升骨料密实度与强度。最佳蒸养时长为12 h，此时骨料生成大量水化硅酸钙和钙矾石，结构更为致密。本研究可为铁尾矿资源化利用以及缓解天然砂石过度开采提供思路。

Abstract:: With the continuous increase in the accumulation of iron ore tailings, a large amount of land is occupied and the ecological environment is seriously threatened. Meanwhile, the excessive exploitation of natural sand and gravel aggravates resource depletion. To realize the resource utilization of iron ore tailings, reduce the consumption of natural sand and gravel, and alleviate the environmental and safety problems caused by tailings stockpiling, this study uses solid wastes such as iron ore tailings and fly ash as raw materials to prepare recycled fine aggregate by granulation. The results show that the recycled fine aggregate prepared from iron ore tailings, cement and fly ash under the optimal mixing ratio exhibits excellent performance. When the iron ore tailings content is 60% and steam curing time is 12 h, the bulk density of the aggregate is 1167 kg/m3, the crushing index is 24.87%, the saturated surface-dry water absorption is 11.9%, and the soundness is 6.5%. Steam curing can accelerate the hydration reaction and improve the compactness and strength of the aggregate. The optimal steam curing time is 12 h, at which a large amount of calcium silicate hydrate and ettringite are generated, making the aggregate structure denser. This study can provide a reference for the resource utilization of iron ore tailings and mitigating the over-exploitation of natural sand and gravel