腐植酸类物质对成浆(土般)土界面动电性质的影响

本文研究了腐植酸钠和磺化腐植酸钠对(土般)土胶体粒子动电性质的影响。用激光Zeta电位仪测出粒子的电泳迁移率,并运用Smoluchowski公式计算出Zeta电位。在(土般)土的成浆过程中,随着Na₂CO₃的加入,pH值增大,改变了粒度分布和表面电荷,从而使电泳迁移率和Zeta电位增加。在中性电解质NaCl和CaCl₂存在下,得出了Zeta电位和电解质浓度间的关系,随着腐植酸钠和磺化腐植酸钠的加入,体系的Zeta电位显著增大,泥浆性能(包括粘度、切力和滤失水量)得到了改善。

INFLUENKCE OF HUMIC SUBSTANCES ON THE ELECTROKINETIC PROPERTIES OF BENTONITEDRILLING MUDS

The effect of sodium humate and its sulfonated product on the electrokinetic property of colloidal particles of bentonite has been studied. The mobilities of the particles were measured with a laser-zeta meter and their values were converted into zeta potentials ξ by using Smoluchowski equation. During the process of mud-making, the mobilities of the particles or |ξ|potential increases with the addition of Na₂CO₃ and the increase in pH as a result of the improvement in the dispersion of the particles and the increase of negative charges on the surface of the particles. In the presence of neutral electrolytes, Nad and CaCl₂,the relation between ξ and the electrolyte concentration can be expressed as follows, ζ=A+Blog[NaCl], ξ=A+B(log[CaCl₂]²; where A=-37.8±0.5 and -9.1±0.5, B=2.0±0.2 and -1.5±0.2, for NaCl and CaCl₂ respectively. With the addition of sodium humate and sulfonated sodiun humate, the |ξ| of the system increses quite significantly and the properties of the processed drilling-mud; such as apparent viscosity, plastic viscosity, yield value, shear stress and filtration loss, are improved.