Study On The Physcial And Chemcial Characteristic Of Respirable Coal Dust And Application

In this paper, physical and chemical characteristics of the coal dust are systematic analyzed, such as coal dust chemical composition, surface functional groups, surface properties, wettability, cohesiveness and electrochemical properties. According to these properties, a new dust suppression agent is developed. Put the new dust suppression agent to the simulation experiments and obtain good results.In this paper the main findings are described as follows:There are three types of main groups on the coal dust surface, and including aliphatic hydrocarbons, aromatic hydrocarbons and other hydrophobic groups on the coal dust surface. Coal dust is a porous medium, the mesopore which pore diameter between 2nm to 20nm has a large proportion. Coal dust surface fractal studies have shown that coal dust surface roughness and surface pore structure characteristics can be characterization by the surface fractal dimension.Adding a certain amount of surfactant in water, the wetting effect on the coal dust can be significantly improved, but not the higher concentration the better wetting ability, there exist an optimal concentration. Under the same total concentration of additives, the wettability of non-ionic surfactants mixed with anionic surfactants are better than single surfactants. Adding an appropriate amount of salt in anionic surfactants can greatly improve wettability. Multiple stepwise regression analysis indicated that, oxygen content of coal dust, BET surface area, mole fraction of sulfur and total carboxyl content are important factors to impact the coal dust wettability.The change of coal dust surface is negative. With the reduction of hydrogen ion concentration in the solution, the absolute value of Zeta potential is increased. Coal dust Zeta potential change varies in different surfactants. When coal dust in the non-ionic surfactant solutions, the coal dust Zeta potential has small change whereas, the Zeta potential has large change in the anionic surfactant solutions. Organic and inorganic flocculants OF3 and inorganic coagulant IC1 IC2 have good cohesion effect to the coal dust.Simulation experiments show that, the new dust suppression agent can effective removal respirable coal dust. PM10 dust particles mainly depends on the wetting agent to capture, and PM5, PM2.5 dust particles mainly depends on the flocculant and coagulant to capture.