China Academy of Railway Science Corporation Limited
the National Natural Science Foundation of China (U1934206)；Technological Research and Development Programs of China Academy Railway Science (2020YJ049)；Research and Development Programs for Science and Technology of China Railways Corporation (P2019G001)
以石英岩、石灰岩、花岗岩和玄武岩为对象研究了典型岩性机制砂对水、亚甲蓝和聚羧酸减水剂的吸附规律，采用Zeta电位、吸脱附曲线和压汞曲线分析了机制砂吸附特性，结果表明：玄武岩机制砂比表面积大、孔隙率高，对水和亚甲蓝的吸附性明显大于其他岩性机制砂，且随着石粉含量的增加，玄武岩机制砂吸附性显著增大. 机制砂石粉表面负电荷与溶液中阳离子形成双电层吸附减水剂分子，机制砂石粉对聚羧酸减水剂吸附率的大小是：玄武岩＞石灰岩＞花岗岩＞石英岩. 在双电层吸附和物理吸附的双重作用下，玄武岩机制砂对减水剂吸附率显著大于其他岩性机制砂.
The adsorption regularities of typical lithologic manufactured sands to water, methylene blue and polycarboxylate superplasticizer were studied by taking the quartzite, limestone, granite and basalt as research objects. The adsorption characteristics of manufactured sands were analyzed by Zeta potential, adsorption-desorption isotherm and intrusive mercury curve. The results show that the adsorptions of basalt manufactured sand to water and methylene blue were significantly higher than those of other lithologic manufactured sands due to its larger specific surface area and higher porosity. And the adsorption capacity of basalt manufactured sand was increased significantly with the increase of stone powder content. The double electric layer formed by the surface negative charges of stone powder and cations in solution could adsorb superplasticizer molecules. The adsorption ratio of polycarboxylate superplasticizer by stone powders was shown as follows: basalt > limestone > granite > quartzite. With the coupling effect of electric double layer adsorption and physical adsorption, the adsorption ratio of basalt manufactured sand for superplasticizer was significantly higher than those of other lithologic manufactured sands.