Abstract: Using the calcium carbide slag to construct soil overburden to realize waste treatment has important engineering application value. To explore the feasibility of modified calcium carbide slag as a covering material, the saturated permeability coefficient, gas diffusion coefficient and permeability coefficient of bentonite samples mixed with calcium carbide slag of a certain mass were measured by a variable head permeability test device combined with a gas diffusion permeability coefficient tester. The results showed that as the bentonite content increased from 5% to 15% (mass fraction), The saturated permeability coefficient of the sample decreases gradually. When the bentonite content is more than 10%, the saturated permeability coefficient is less than 1×10^-9 m/s, which meets the requirements of the impermeable layer of the covering layer. When the bentonite content is 10%, the gas and diffusion permeability coefficients of the sample decrease significantly with the increase of saturation. When the saturation is more than 85%, the sample has good gas retention performance.

Key words: Carbide Slag, Soil Cover, Saturation Permeability Coefficient, Gas diffusion coefficient, Gas permeability Coefficient