Research on low-temperature solubility of bulk coal dust suppressant and application

Abstract：In order to solve the low solubility of starch based dust suppressant in cold water and its high viscosity during preparation process and spraying application, the heating treatment method was used for non-crystal modification of starch, which is the main raw material for dust suppressant preparation. The effects of heating temperature, time and moisture on cold water solubility and the solution viscosity of non-crystal modification starch were investigated. The XRD and polarizing microscope were employed to examine the crystal structure and particles morphology changes of starch after heat treatment. The results show that morphology and crystal structure of starch granules are significantly changed by heat. The viscosity stability and the dissolvability in low temperature water of the starchy solidifying agent solution are im- proved dramatically. The optimum heat treatment conditions of heating temperature, time and moisture for starch solubility in cold water are 220 ℃, 4 hours, 12.4%, respectively. The ap- plication of the starch based dust suppressant in the railway coal transportation decreases the coal dust concentration inside the tunnel from 256.4 mg/m^3 to 30.5 mg/m^3. The starch based dust suppressant has no effect on coal properties.