腐殖酸钠对石英分散性能影响的机理研究

采用沉降试验、zeta电位、FTIR光谱和颗粒间相互作用分析,研究了介质pH值和腐殖酸钠对石英分散性能的影响及作用机理。结果表明,随着pH值升高,石英在水介质中的分散性随之提高,表面zeta电位随之下降。当pH值为11.5,腐殖酸钠用量为0.5 g/L,进一步提高了石英的分散性,表面zeta电位则下降至-67.5 m V;光谱结果表明,石英谱线在2923 cm-1处出现了-CH2的不对称伸缩振动吸收峰,2855 cm-1处出现了-CH2的对称伸缩振动吸收峰,说明石英与腐殖酸钠发生了物理吸附作用;颗粒间相互作用结果表明,当pH值为11.5,颗粒间双电层排斥能高于范德华吸引能,同时腐殖酸钠增强了石英表面的亲水性,提高了水化膜作用势能。

Study on the Mechanism of the Effect of Sodium Humate on the Dispersibility of Quartz

The sedimentation tests,zeta potential tests,FTIR spectrum tests and intermolecular interactions analysis were carried out to study the effects of pH value and sodium humate on the dispersion of quartz and its mechanism.The results show that,the dispersibility of quartz in aqueous media increases and the surface zeta potential decreases with the increasing of pH value.The dispersibility of quartz is further improved and the zeta potential drops to-67.5 mV when pH value is 11.5 under the dosage of sodium humate of 0.5 g/L.The FTIR spectrum results show that the asymmetric stretching vibration absorption peak of-CH2 appeares at 2923 cm-1,and the symmetrical stretching vibration absorption peak of-CH2 appeared at 2855 cm-1,which proves that the physical adsorption of sodium humate onto quartz is observed.The analysis of particle interactions show that electric double-layer repulsion between particles can be much higher than Van Der Waals attracting energy,and sodium humate enhances the hydrophilicity of quartz surface and improves the hydration membrane potential energy when pH value is 11.5.