Research on the Physical and Chemical Characteristics of Dust in Open Pit Coal Mine Crushing Stations and Closed Dust Reduction Methods

Abstract

As an important link in open-pit mining production, the crushing station produces a large amount of dust during the production process. Dust has the characteristics of a wide spread area, great harm, and difficult governance. Therefore, dust control has become a key issue that needs to be solved in open-pit mining. In this article, we assess results after high-speed cameras and dust concentration detectors are installed around the crushing station to monitor the dust concentration in the surrounding air. It is found that in the air, dust with a particle size of less than 2.5 μm accounts for 67.43%, less than 10 μm accounts for 17.30%, and less than 100 μm accounts for 15.27%. In settled dust on the ground, particles with a particle size of less than 100 μm account for 42.69% of the sample, and particles less than 10 μm account for 16.60% of the sample. Secondly, physical and chemical properties testing is conducted on the dust. XRD test results show that SiO2 in the dust accounts for 65.80%; XRF test results show that the oxide Al2O3 in the dust accounts for up to 46.84%; ICP test results show that the element Al accounts for 42.62% of the total amount of trace elements detected; and Si accounts for 35.11%, clarifying the content of harmful substances to the human body. Finally, Fluent software, Ansys 2020 R1, is used to simulate the diffusion law of dust under different states of the crushing station, including an open state, a closed state, and the installation of a dust removal system. Based on the simulation results and the actual situation on site, the optimal dust reduction method suitable for the crushing station is proposed, and the diffusion law of dust under this method is simulated. The tracked dust shows that the dust removal efficiency of PM2.5 reaches 97.00%, PM10 reaches 99.60%, and TSP reaches 98.30%.