赤泥基似膏体充填材料水化特性研究

Hydration characteristics of red-mud based paste-like backfill material

以赤泥、煤矸石等工业固废为主要原料制备赤泥基似膏体充填材料,采用X射线衍射分析、傅氏转换红外线光谱分析、热重-示差扫描量热分析和扫描电子显微镜-能谱分析等测试手段研究赤泥基似膏体充填材料的水化特性.结果表明,本试验条件下,赤泥基似膏体充填材料的最优配比为编号E03试验,即胶结料∶赤泥∶煤矸石∶添加剂质量比为1∶16∶5∶11,固相的质量分数为70%,28 d单轴抗压强度为5.49 MPa.赤泥基似膏体充填材料不同龄期的水化产物主要为斜方钙沸石(Ca Al2Si2O8·4H2O)和钙矾石(AFt),随着水化反应的进行,水化产物的数量明显增多,且钙矾石由水化初期的针状逐渐转变为棒状,有助于充填体强度的发展.

Preparation of red-mud based paste-like backfill material using red mud,coal gangue,and other industrial solid wastes was accounted. In order to understand the hydration characteristics of red-mud based paste-like backfill material,X-ray diffraction,Fourier transform infrared spectroscopy,thermogravimetric-differential scanning calorimetry,and scanning electron microscope-energydispersive X-ray spectroscopy techniques were used to investigate the hydration products of the hardened paste,which was formed after hydration of raw materials. The results show that the most optimized proportion is the number E03 experiment,in which the mass ratio of cementing material,red mud,coal gangue,and additive agent is 1 ∶ 16 ∶ 5 ∶ 11,the solid mass fraction is 70%,and the uniaxial compressive strength after 28 days is 5. 49 MPa. The hydration products of red-mud based paste-like backfill material are mainly gismondine（ Ca Al2 Si2 O8·4 H2 O） and ettringite（ AFt）. As the hydration reaction proceeds,the quantity of hydration products increases significantly. Needle-shaped ettringite forms during the early hydration period and gradually transforms into rod-shaped ettringite; this transformation is helpful in the strength development of the red-mud based paste-like backfill material.