2023 Volume 64 Issue 3 Pages 112-123
Mercury, which can be measured in very small amounts, is highly volatile under high temperature conditions deep underground and migrates to form a mercury dispersion halo at the surface. The mercury survey covers soil mercury content（mercury and mercury compounds in the liquid and solid phases）and mercury vapor content（mercury in the gas phase）. The relationship between mercury in the liquid phase of soil and mercury vapor concentration is reported to be a temperature-dependent Henry's law vapor-liquid equilibrium.
In creating a mercury dispersion halo map, it was necessary to consider factors that cause variation in mercury vapor concentrations, and it was reported that, in addition to temperature and sunlight, the concentration of mercury vapor on the ground surface increases when the soil is moistened by rainfall after drying.
However, previous studies have not taken into account the volatilization of mercury during the drying and wetting processes of the soil when creating mercury dispersion halo maps. Measurements taken after rainfall in the field yielded results averaging 18 times greater when dry. The effect of watering after drying was found to be extremely significant. Based on these results, laboratory tests were conducted to determine how mercury fluctuates with water after drying. This paper reports the results and discussion of these indoor and outdoor tests.
We hope that this method will be reevaluated as mercury exploration methods become more sophisticated.
