Effect of Soluble Salt on Thermal Conductivity of Saline Soil

Abstract

Soil thermal conductivity (λ), as one of the key thermal properties of soil, has become a research focus in fields such as energy, engineering, earth sciences, and geology in recent years. This paper primarily analyzes the influence and mechanisms of different types of soluble salts on the thermal conductivity of saline soil, based on experimental studies conducted by domestic and international scholars. The results indicate that different types of salts have varying effects on the thermal conductivity coefficient of saline soil. The combined effect of salt and temperature influences the thermal conductivity of soil, mainly manifested in certain soluble salts lowering the freezing point of water. This leads to an increase in the unfrozen water content during the freezing process of saline soil at low temperatures, thereby reducing its thermal conductivity. Furthermore, the flocculation effect of salt ions on soil particles in certain saline soils changes thermal conduction pathways, thereby affecting the thermal conductivity of the soil. Some researchers have refined existing thermal conductivity theories and semi - empirical parameterized models, enhancing their applicability to saline soils.