赤泥渗滤液对钠基膨润土黏土衬垫的渗透机理分析

赤泥渗滤液的高离子强度可以抑制蒙脱石的膨胀,从而导致钠基膨润土黏土衬垫(GCL)的渗透性过强,并无法用作赤泥处理设施中的防渗衬层.通过2种钠基膨润土黏土衬垫与2种赤泥渗滤液的渗透过程,研究强碱性赤泥渗滤液与钠基膨润土黏土衬垫的渗透机理.结果表明:天然钠基膨润土(Na-GCL)和人工钠化钠基膨润土(Ar-GCL)的渗透系...

MECHANISMS CONTROLLING HYDRAULIC CONDUCTIVITY OF BENTONITE CLAY LINERS WITH BAUXITE LIQUOR

The high ionic strength of bauxite liquor could suppress swelling of montmorillonite, which results in sodium bentonite clay liner (GCL) that was too permeable to be used as an impermeable liner in red mud treatment facilities. The mechanism controlling of strongly alkaline bauxite liquor and sodium bentonite clay liner was investigated through the infiltration process of sodium bentonite clay liner and two types of bauxite liquor. The results showed that hydraulic conductivity of natural sodium bentonite (Na-GCL) and artificial sodium bentonite (Ar-GCL) was closely related to ionic strength of bauxite liquor. As ionic strength increased, hydraulic conductivity systematically increased. Hydraulic conductivity of Shandong bauxite liquor with high ionic strength was the largest, 7.8×10-7 and 3.2×10-7 m/s, respectively. Hydraulic conductivity was positively related to swelling index. Through the analysis of the microstructure diagram of SEM scanning, swelling mechanism of bentonite controlled its hydraulic conductivity. High ionic strength caused permeable expansion of bentonite mineral layer, and absorbed a large amount of water, which reduced the porosity and changed the flow path of the fluid, resulting in an increase of hydraulic conductivity.