Enhanced Effect of Mining Dust Diffusion on Melting of the Adjacent Glacier: A Case Study in Xinjiang, China

Abstract

Given the typical disturbances in the aqueous environment in the alpine area because of mining activities in Northwest China, a case study highlighting the enhanced effect of mining dust diffusion on the melting of the adjacent glacier is presented here. Initially, a three-dimensional numerical model of the local airflow field was established by considering the effects of both mines and glaciers using the FLUENT software. Then, the diffusion path and size range of dust particles from the mines were simulated by feeding the mining dust parameters into the above numerical model. Finally, a physical simulation experiment was performed to evaluate the influence of mining dust coverage on the glaciers. The major conclusions of this study were as follows: (1) The local airflow field in the target alpine area is controlled by the ‘heat and cold double-island effects’ formed by the mine and the glacier, and the wind circulation always takes place in a clockwise direction between the mining pit on the left and the glacier on the right. (2) In a given airflow field, there is a spread of mining dust from the mine to the glacier along the upper airflow. The arrival rates of the dust are 16.9% and 13.3% in winter and summer, respectively, and the horizontal distance of dust diffusion is inversely proportional to its particle size. (3) For an ice sample with a sectional area of 225 cm2 and a volume of 1000 mL, the melting rate increased by 4.5 mL/h with an increase of dust coverage by 10%. Furthermore, when compared with a control group without dust cover, the effect of a 28% increase in dust coverage is approximately equivalent to the effect of a 1 °C increase in temperature on the ablation speed of the glacier. The study results can provide a useful reference for the selection of mining sites and the control of mining dust diffusion in alpine regions with glaciers, thereby facilitating environmentally friendly mining in alpine regions.