Synthesis of a new three-dimensional cross-linked network dust suppressant and its mechanism of coal-dust inhibition

A new dust suppressant was proposed and studied by numerical calculations and experiments to control dust. The synthesis of suppressant required three steps. First, Polyvinyl alcohol starch was synthesized by the dehydration condensation of carboxymethyl starch and polyvinyl alcohol under the initiation of ammonium persulfate, requiring 288.8 kJ/mol energy. Second, polyvinyl alcohol caprolactam starch was synthesized by the dehydration condensation of caprolactam and polyvinyl alcohol starch under the initiation of ammonium persulfate, requiring 172.8 kJ/mol of energy. Third, the suppressant had the optimum wetting and bonding effects by 30 g/L polyvinyl alcohol caprolactam starch and 20 g/L sodium dodecylbenzene sulfonate. The suppressant–lignite system exhibited increased hydrogen bonds which were formed between the –OH and –COOH groups of the suppressant and the –OH, –COOH, and –NH2 groups on the coal surface. The solidified layer formed on the coal dust surface did not raise dust at wind speed of 10 m/s.