Experimental Study On Wettability Of Coal Dust And New Wetting Agent

The paper based on experiments, discussing the main factors which influence coal wettability and complexing safe, efficient, and multicomponent wetting agents. The basic properties of 7 types of coal was analyzed including proximate analysis, elemental analysis, pore structure analysis,sem analysis and contact angle determination, in order to analysis the relationship between physical and chemical properties of coal dust and its wettability, using SPSS statistical software to establish the best regression equation of coal dust wettability. Secondly, choosing good wetting effection, high safety and good economical benefit surfactant monomer and the salt solution as the distribution of raw materials and obtain the corresponding optimum adding amount.Research on the physical and chemical properties of coal dust and its wettability, the following conclusions:The aliphatic hydrocarbons, aromatic hydrocarbons contained in dust surface are the root causes that make coal dust with strong hydrophobic,the carboxyl,hydroxyl,carbonyl and other oxygen-containing functional groups on the surface of coal dust make it have some hydrophilic; The moisture, ash content, volatile matter, oxygen and hydrogen content contained in coal dust are higher,the contact angle is smaller,and the wettability of coal dust is better;Fixed carbon and carbon content are higher, the contact angle is higher,and the wettability of coal dust is worse;Sulfur and nitrogen content have less impact on the wettability;The particle size and surface area of coal dust are bigger,the wettability is better;the aperture is bigger,the wettability is worse. Finally, stepwise multiple linear regression analysis,obtain the best regression equation of the wettability of coal dust: ?=72.881-1.774[???]+1.052[??].The oxygen content and aperture are the main factors that influence the wettability of coal dust. The oxygen content is higher,the average pore size is smaller,the wettability of coal dust is better.Research on new wetting agent, the conclusions are as follows:The surfactant added to water can improve water wetting ability of coal dust, but the concentration is not the bigger the better, but there is an optimum concentration; The wetting effect of nonionic and anionic surfactants compound is better than sigle surfactant, in which the rapid T and JFC complex is the best, anionic and non-ionic surfactant compound is better than anion and anionic surfactant compound; Adding salt can improve the wettability of the solution, is stronger, the action to the anionic surfactant is stronger, the action to the nonionic surfactant is weak. Finally two kinds of wetting agents formulations are determined by the orthogonal experiment, and texted the water retention, biological toxicity and corrosion resistance of the new type wetting agent,results show that the water retention of new type wetting agent is good, the toxic and corrosive are very low; After calculation, the cost of using the new wetting agent to spray dust-fall is less than 0.3% of coal output,and the growth of tons of coal cost is about 1.5 Yuan.So the economic benefit of the wetting agent is good.