钨尾矿机械-化学活化及其与水泥水化反应机理

Mechanochemistry Activation for Tungsten Tailings andHydration Reaction Mechanism with Cement

尾矿制备辅助胶凝材料是实现尾矿大规模资源化利用的重要途径。本工作研究了机械-化学活化对钨尾矿颗粒粒径和比表面积的影响,探究了不同活化方式、活化剂种类对钨尾矿制备胶砂试块机械强度的影响,通过XRD、SEM、IR对水化产物的物相及微观结构进行表征。结果表明,机械-化学活化能有效降低颗粒平均粒径并增加胶砂试块的活性指数,活化效果最佳的是三元复合活化剂,其次是二元复合活化剂,效果较弱的是单一活化剂。采用H1、C1和G1三元复合活化剂活化钨尾矿后,直径小于10μm的钨尾矿颗粒达到了70.07%,制备的胶砂试块活性指数达88.11%。机械-化学活化的本质是通过破坏矿物表面结构,增加其表面无序物质和振动能,使得水化产物中生成大量六方板状Ca(OH)2,最终形成大颗粒的C-S-H凝胶和钙矾石。

The preparation of auxiliary cementitious materials for tailings is an important way to realize the complete resource utilization of tailings.The effects of mechanochemical activation on particle size and specific surface area of tungsten tailings were studied,the effects of different activation methods and activator types on the mechanical strength of mortar test block prepared by tungsten tailings were studied,and the phase and microstructure of the products were characterized by XRD,SEM and IR.The results show that,the mechanical chemical activation can effectively reduce the average particle size and increase the activity index of the mortar block,the optimal formula is ternary composite activator,followed by binary composite activator,and the weakest is single activator.After activation of tungsten tailings by the ternary composite activators of H1,C1 and G1,the results show that the tailings with diameter less than 10μm can reach 70.07%and the activity index of mortar test block can reach 88.11%.The essence of mechanochemical activation is to destroy the crystal structure of tailings and increase its indicative disordered substances and vibration energy,a large number of six side plate Ca(OH)2 were formed in the hydration products,and finally formed C-S-H gel and ettringite with large particle size.