CO/H-2　mixture　gas　may　be　generated　in　the　local　furnace　hopper　area　under　the　condition　of　coal　quality　variation,　and　deflagration　may　be　caused　during　the　high　temperature　coke　dropping　process.　As　for　the　complex　dust　environment　of　furnace　hopper　area,　the　influence　of　dust　of　different　categories,　particle　size　and　concentration　on　CO/H-2　deflagration　characteristics　under　the　half-opened　environment　is　studied　in　this　paper.　The　study　indicates　that:　the　influence　of　dust　on　CO/H-2　deflagration　feature　mainly　results　from　the　release　of　volatile　in　dust　and　the　volatile＇s　participation　in　deflagration　reaction.　As　for　high　volatile　coal　dust,　volatile　releases　out　and　participates　in　deflagration　reaction,　which　makes　the　deflagration　overpressure　of　mixture　gradually　rises　with　the　rising　of　volatile　content;　as　for　low　volatile　coal　dust,　the　influence　of　heat　absorption　for　volatile　release　is　greater　than　the　function　in　which　volatile　participates　in　deflagration　reaction,　thus　reducing　the　deflagration　strength.　As　for　Yinbei　coal,　with　the　increase　of　dust　concentration,　deflagration　strength　declines　firstly　and　then　increases.　Experiment　also　indicates　that　as　for　coke　dust　nearly　without　volatile,　the　change　of　deflagration　intensity　with　dust　concentration　is　not　obvious.　(C)　2014　The　Authors.　Published　by　Elsevier　Ltd.