电解锰渣-磷石膏-粉煤灰-氢氧化钙混合球磨制备矿井充填材料性能及水化机理研究

Preparation of mine filling materials by co-mechanical treatment with manganese electrolysis residue-phosphogypsum-fly ash-calcium hydroxide mixture:Research on properties and hydration mechanisms

在不添加水泥的情况下,通过电解锰渣、磷石膏、粉煤灰和氢氧化钙混合球磨制备了矿井充填材料(EFM),并对球磨活化混合物料的机理和混合物料球磨后的水化机理进行了探讨。混合原料经混合球磨后颗粒粒度显著降低(D_(50)降低了53.18%),火山灰活性提升,后续水化反应速度和程度均提升,同时生成更多水化产物。当电解锰渣掺量为65%时,经混合球磨后矿井充填材料样品的泌水率、线性收缩率和抗压强度均得到有效改善。同时电解锰渣中的重金属离子在水化产物的物理包封、化学吸附和离子交换等作用下被有效固化。样品重金属离子浸出浓度均远低于标准《地下水质量标准》(GBT 14848—2017)和《无机化学工业污染物排放标准》(GB 31573—2015)中规定的限值。

The mine filling material(EFM)was prepared by ball milling a mixture of electrolytic manganese residue,phosphogypsum,coal fly ash,and calcium hydroxide without adding cement,and the activation mechanism of the mixture by ball milling and the hydration mechanism of the mixture after ball milling were investigated.The raw material mixture was subjected to ball milling with a significant reduction in particle size(D_(50)was reduced by 53.18%),the pozzolanic activity was increased,and both the speed and extent of the following hydration reaction were increased,while more hydration products were generated.The bleeding rate,linear shrinkage and compressive strength of the EFM samples after ball milling were effectively improved when the electrolytic manganese residue dosage was 65%.Simultaneously,the heavy metal ions contained within the electrolytic manganese residue were effectively consolidated by physical encapsulation,chemical adsorption,and ion exchange of the hydration products.The leaching concentrations of heavy metal ions in the samples are significantly lower than the limits defined in the standards GB/T14848—2017 and GB 31573—2015.