Temporal-Spatial Distribution of Vehicle Transportation Pavement Dust Migration in an Open-Pit Mine.

To investigate the dust source of the most polluted equipment in the open-pit mine, this paper studied the temporal-spatial distribution laws of dust migration in the vehicle transportation pavements in the open-pit mine via theoretical analysis and a field test. The results show that the dust concentration of the same horizontal distance from the pavement centerline remains roughly stable, which proves that the dust above the pavements is a continuous line source. In the horizontal direction, the maximum dust and baseline concentration reached heights of 1-3 and 20 m away from the wheels, respectively, while they are obtained at heights of 0.5 and 2.2 m away from the pavement in the vertical distance, respectively. The spatial concentration distribution of the dust clearly proves that the dust movement mode is a jumping mode. It takes 6 and 30 s after the vehicle had passed to achieve the maximum dust and baseline concentration, respectively. The dust concentration of a fully loaded vehicle is 2-3 times greater than that of a no-load vehicle. Meanwhile, the dust concentration of a sprinkling pavement is as 10% as that of an un-sprinkling pavement. The results of the migration of transportation dust and temporal-spatial distribution provide useful references for the analysis of dust source intension and pollutant diffusion in open-pit mines. Furthermore, the efficient and low-cost moisturized dust suppressant would be the future direction to develop in different mining areas.

Preparation of a Composite Calcium Silicate Board with Carbide Slag and Coal-Based Solid Waste Activated by Different Alkali Activators.

Overall performance of composite calcium silicate boards (CCSBs) was investigated to further promote their application. The alkali activators were used to fully hydrate the calcium and silicon raw materials, which further improved the comprehensive performance of the CCSBs made of four pure industrial solid wastes. Within the range of dosage in this study, single doping of different proportions of the alkali activator improved the flexural strength of the CCSB. Based on this, the mechanical properties of the CCSB were further improved as the compounded alkali activator was optimized. Flexural strength is improved when the average pore diameter was refined. The freeze-thaw cycle test shows that a compound-doped alkali activator can effectively reduce the mass loss and strength loss, thereby improving the frost resistance of this material. This research discussed an economically affordable approach to prepare the CCSB material made of industrial solid waste.