Preparation and performance evaluation of an efficient microbial dust suppressant for dust control in disturbed areas of blast piles in open-pit coal mines.

Abstract

Open-pit coal mining creates large rock piles as a result of removing overlying strata. When disturbed by loading operations and wind, these rock piles release considerable dust, leading to significant environmental pollution. This study aims to develop an environmentally friendly and cost-effective method for dust control in disturbed areas of open-pit coal mines, using Sporosarcina pasteurii as a microbial dust suppressant to explore its potential application and development. Laboratory experiments were conducted to simulate the growth characteristics of Sporosarcina pasteurii in the microenvironment of blast pile dust. The effectiveness of the microbial dust suppressant was evaluated under conditions of impact disturbance and rainfall erosion through wind and rain erosion tests. Results showed that under optimal conditions, the wind erosion resistance of treated samples improved significantly, with an increase of 98.24%, 86.99%, 64.08%, and 40.98% after 1, 2, 3, and 4 impact disturbances, respectively. Additionally, rain erosion resistance improved by 75.55% after 35 min of simulated rainfall. The growth conditions of Sporosarcina pasteurii in blast pile dust leachate were similar to those in sterile water, demonstrating robust growth and consistent urease activity of 7.78 mmol L⁻¹ min⁻¹ after 24 h. The mineralization product was calcite-type CaCO₃ with uneven particle sizes. This work confirms the feasibility of microbial dust suppressants for managing dust in disturbed areas of open-pit coal mine blast piles, offering a promising approach for dust control in such environments.