赤泥基全固废矿井充填材料的制备与性能研究

Fabrication and Performance of Mine Filling Materials Derived from Red Mud Based Full Solid Wastes

为实现拜耳法赤泥的资源化利用,采用拜耳法赤泥、电石渣、矿粉和煤矸石等制备了赤泥基全固废矿井充填材料.研究了不同赤泥、电石渣掺量对充填材料力学性能与工作性能的影响,并采用X射线衍射仪(XRD)、扫描电子显微镜及能谱仪(SEM-EDS)、电感耦合等离子体发射光谱仪(ICP-OES)等微观测试手段,分析了赤泥基全固废矿井充填料浆的水化产物、微观结构演变以及重金属浸出毒性.结果表明:矿井充填材料中,当赤泥占胶凝材料的50%,充填浓度为75%时,充填料浆的流动度可达230 mm,充填料浆硬化体7、28 d的抗压强度分别达到2.29、2.88 MPa,满足大多数矿井充填材料工作性能与力学性能的要求.使用赤泥制备矿井充填材料后,As、Cd、Cr、Pb等重金属离子的浸出浓度显著下降,远低于GB/T 14848—2017《地下水环境质量标准》要求的浸出毒性限制.

To achieve the resource utilization of Bayer red mud,it is used that Bayer red mud,carbide slag,blast furnace slag and coal gangue to prepare red mud based mine filling materials without natural materials.The effects of different content of red mud and carbide slag on the mechanical properties and working performance of the filling materials were investigated.And the hydration products,microstructural evolution,and heavy metal toxicity of the red mud based mine filling materials were analyzed by using microscopic testing techniques such as X‑ray diffraction(XRD),scanning electron microscopy and energy spectroscopy(SEM‑EDS),inductively coupled plasma emission spectrometry(ICP‑OES)and so on.The results show that when the red mud accounts for 50%in binding material,and the solid content of the backfill slurry is 75%,the fluidity of the backfill slurry is 230 mm,the compressive strength of the backfill can reach 2.29,2.88 MPa at age of 7 d and 28 d,respectively,which meet the requirements of most mine backfilling performance and mechanical property.After using red mud to prepare mine filling materials,the leaching concentration of As,Cd,Cr,Pb and other heavy metal ions in it decreased significantly,far lower than the leaching toxicity requirements of standard GB/T14848—2017 Standard for Groudwater Quality.