干法超细研磨中黑滑石的机械力化学效应

Mechanochemical Effects of Black Talc in Dry Superfine Grinding

为揭示机械力化学作用对黑滑石晶体结构、微观形貌和理化性质的影响,指导其矿物综合利用,以江西广丰某黑滑石纯矿物为原料,通过XRD、FTIR、SEM、TG、BET等表征技术,系统地研究了干法超细研磨中黑滑石的机械力化学效应。超细研磨会破坏黑滑石矿物的晶体结构,引发晶格畸变,Mg^(2+)和OH^(-)可以从固相脱出成为自由离子。矿物颗粒棱角消失、形状趋于统一,比表面积下降,但当研磨作用过大时颗粒会发生二次聚团。研磨过程中,黑滑石表面官能团振动特性发生变化,红外吸收峰出现移动。由于粉体内能的累积,黑滑石的热分解效率也会明显提升,在较低温度下就可脱除结构羟基。在合理的强度范围内,机械力化学作用可有效增强黑滑石的界面反应活性。

In order to reveal the effect of mechanochemical action on the crystal structure,micromorphology and physicochemical properties of black talc,and to guide its comprehensive utilization,the mechanochemical effects of pure black talc from Guangfeng by superfine dry grinding was systematically studied by XRD,FTIR,SEM,TG and BET characterization techniques. The superfine grinding would destroy the crystal structure of black talc and cause the lattice distortion,while the Mg^(2+)and OH^(-)ions were released from the solid phase to become free. The edges and corners of mineral particles disappeared,the shape tend to be uniform and the specific surface area would decrease. However,the secondary agglomeration of particles would be triggered by excessive grinding. During the grinding process,the vibration characteristics of the functional groups on the surface of black talc changed,along with the shift of FT-IR peaks. Due to the accumulation of internal energy of the powder,the thermal decomposition efficiency of black talc improved significantly,the structural hydroxyl group was removed under low temperature. The mechanochemical action could effectively enhance the surficial reaction activity of black talc.