Effects of meteorological conditions on the air quality in deep open - pit mines in Vietnam

Abstract

Air quality in open - pit mines is the big concern relating to the occupational safety and healthy, as well as the surrounding environment. In the past years, management of the air quality in open - pit mines is challenge due to the limit of science and technology in the assessment of the effects of meteorological conditions and toxics in open - pit mines. Therefore, this study assessed the effects of meteorological conditions on the air quality in deep open - pit mines. The air velocity distribution and the dispersal mechanism of the air quality were evaluated at the Coc Sau open - pit coal mine (Vietnam) based on the measured and simulated datasets. Two fixed stations were set up in the ground to monitor the wind direction, wind speed and the temperature to evaluate the stable of the actual ozone layer based on the Pasquill ozone layer. The datasets were also used to analysis and 3D simulate to understand the air pollution mechanism in the Coc Sau open - pit coal mine. On the other hand, the change of the temperature in vertical was measured to determine the to determine the existence of a temperature inversion layer. It is considered as the main reason for the air quality reduction and the natural air circulation in deep open - pit mines. The findings indicated the existence of the temperature inversion layer and they are useful for proposing the artificial ventilation in deep open - pit mine, aiming to improve the air quality in open - pit mines. The 3D simulations also revealed that the high dust and gas concentrations in open - pit mines are due to the stable of the ozone layer.