Research and industrial testing of truck road moisturizing dust suppressant for North Open-pit Coal Mine

Truck road transport is one of the largest sources of dust in open-pit coal mines, especially in the high-temperature environment in summer where road moisture evaporation is extremely high and truck disturbance intensity is extremely high. Taking truck pavement of Horin River North Open-pit Coal Mine as the research background, the stress state and dust production mechanism of NET200 dump truck tire adhesion dust were analyzed; the moisture content, chemical functional groups and particle size distribution of the road soil were collected and tested, and the functional positioning of moisture, wetting and coagulation of the developed dust suppressant was determined. Monomer preference experiments were carried out to determine the humectant glycerol (B), wetting agent sodium dodecylbenzene sulfonate (T) and coagulant polyacrylamide (N) as the orthogonal test materials, with evaporation as the main control index. The range method was used to determine the best formulation of humectant dust suppressant as 3.0% glycerol, 0.25% sodium dodecylbenzene sulfonate and 0.05% polyacrylamide. Through the observation of the dust surface film-forming state and water content changes under different spraying volumes, the best spraying volume was determined to be 1.6-2.0 L/m² per unit of road surface. The results of the 12 d dust suppression industrial test in North Open-pit Coal Mine showed that the concentrations of total dust and respirable dust in all sections of the single test cycle were gradually increasing, and the concentrations of total dust and repairable dust in the dust suppressant sprayed load-bearing and non-load-bearing sections during the three tests were significantly lower than the corresponding sections of conventional water sprinkling, and they were lower than the specified limits of 4 mg/m³ of total dust and 2 mg/m³ of respirable dust, respectively, indicating that the independently developed moisturizing type dust suppressant spraying effective dust suppression time of single time was 3-4 d. Spraying dust suppressant could effectively increase the proportion of large particles in the dust, and condensation and agglomeration effect was significant. The average water content of the soil in spraying dust suppressant load-bearing and non-load-bearing section was 14% and 12%, respectively, more than 2 times the conventional sprinkling section. The research shows that the moisturizing dust suppressant can significantly extend the effective dust suppression time of a single spraying, and has significant applicability to dynamic working conditions such as mining roads.