Study On Wettability Of Coal Dust And Complex Program Of Dust Agent

Wettability of coal dust is one of the important parameters of coal, which is very important for coal dust treatment, flotation technology and coal slurry preparation, especially in the field of coal dust treatment. Dust agent is mainly composed by surfactants which can improve the efficiency of coal dust processing by increasing the coal surface wettability.In this paper, the influence factors on wettability of coal dust and complex program of dust agent are systematic studied from both wettability and surfactant. Firstly, the influence factors on wettability of coal dust is analyzed by contact angle measurement of coal dust, industry analysis, elemental analysis, fourier transform infrared spectroscopy (FTIR), particle size analysis, density analysis, Zeta potential measurement, and to establish the best regression equation between the physical and chemical properties of coal dust and wettability of coal dust. Secondly, safe and efficient surfactant is selected as the raw material for complex experiments, and through single factor experiment, the impact factor test, uniform experiment and orthogonal experiment to get the optimal complex program of dust agent.Through studying the relationship between the physical and chemical properties of coal dust and its wettability, and analyzes the influencing factors on the coal dust wettability. The research shows that carboxyl, hydroxyl and other oxygen-containing functional groups on the surface of coal dust can make it have some hydrophilic; Surface potential of coal dust reflects the ionization of hydrophilic groups of coal dust surface; Fixed carbon, volatile, carbon content and hydrogen content are higher, the wettability of coal dust is worse; Ash, moisture and oxygen content are higher, the wettability of coal dust is better; Sulfur and nitrogen content have less impact on the wettability; particle size and density of coal dust is smaller, the wettability is worse. Finally, optimum regression equation on the wettability of coal dust can get by stepwise linear regression.Research on dust agent complex programs can come down to the following conclusions. The surfactant remixed with salt helps to improve the wettability of the solution within a certain range of concentration. The reason is the inorganic generates ions by ionizing which can reduce the distance of the electric double layer, thereby improving the wettability of the solution; The surfactant remixed with HCl helps to improve the wettability of the solution within a certain range of concentration; Different coal dust have different complex program of dust agent. Due to the different physical properties and surface chemical properties of coal dust, the wetting mechanism of dust agent is not the same, targeted complex program is an important means to solve the dust problem.