Experimental Study On The Green And Environmental Protection Composite Inhibitor For Preventing Coal Spontaneous Combustion

The western area is the main coal mining base in the future,and most of the coal seam mining in this area is easily spontaneous combustion coal seam.In the process of mining,this area is confronted with serious disaster of coal spontaneous combustion.In the process of prevent and control coal spontaneous combustion,the inhibitor is a commonly used technology for prevention and control of coal spontaneous combustion.But among the existing inhibitors,the physical inhibitors have short effective time and low efficiency,and the chemical inhibitors are expensive.Therefore,it is particularly important for prevent and control coal spontaneous combustion to research and develop high efficient and low-cost inhibitor.At the same time,the western area is also the main grape producing area.A large amount of cheap grape seed meal is produced every year.The grape seed meal has the effect of strong antioxidant and free radical removal.In this paper,a kind of coal spontaneous combustion inhibitor with low price,green environmental protection and obvious effect was developed by enzymatic treatment of grape seed meal and chelation and compound of its treatment products.The main achievements and conclusions obtained are as follows:The effects of the amount of cellulase in the grape seed meal and the treated time on the removal of hydroxyl radicals and peroxides in grape seed meal（polyphenols mixture）were analyzed by spectrophotometer.The results showed that when the addition of cellulase was 5%and the treated time was 4h,the effect of polyphenols mixture remove hydroxyl radicals and peroxide is most obvious.The ability of chelating agent to remove the active substance from the chelating agent of metal ion A and polyphenol mixture in different proportions is studied.The results show that the removal rate of hydroxyl radical and peroxisome by the chelating agent is greatly improved when the proportion of the polyphenol mixture and A is 1:3.It increased by75%and 70%than grape seed meal respectively,and 60%and 25%higher than that of the conventional chemical inhibitor respectively.The effect of the chelating agent formed by the grape polyphenols mixture and metal salt A on the coal heat release parameters was analyzed by SDT-Q600 type synchronous heat analyzer.The best inhibition effect on the heat production of coal at low temperature was obtained when the grape polyphenols mixture and A was 1:5.The effect of composite inhibitor maked up with the chelating agent and the strong water absorbent inorganic substance PA on the heat production of coal at low temperature was analysised.The results show that 1:3 is the best proportion of these two materials for coal resistance.After test coal sample treated with the composite inhibitor,the low temperature discharge is lower than the raw coal by more than 60%.By testing the water retention,heat release and environmental protection of the composite inhibitor,the results show that the composite inhibitor has the water retention property equal to the inorganic salt,and has no heat release and good environmental protection.The inhibitory effect of composite inhibitor on the active functional groups during coal oxidation was analyzed by infrared spectrometer.The change law of hydroxyl,methyl and methylene in the oxidation process of raw coal and treated coal was studied.The results showed that the composite inhibitor effectively inhibited the reaction of active substances in coal and accelerated the destruction of hydroxyl active substance,lowered the oxidation rate of methyl and methylene,and reduced the formation of CO,CO₂ and other gases.In addition,the composite inhibitor can also lock water in the surface and the gap of coal,and slow down the reaction of coal and oxygen.The temperature programmed experimental system was used to analyze the influence of the injected ways of the composite inhibitor on coal.The crossing point temperature,the oxygen consumption at 70℃and the release of CO and other index gases were studied in several ways,such as water,foam,gel foam,toppled composite inhibitor solution,atomized spray composite inhibitor solution,foam with composite inhibitor,gel foam with composite inhibitor.It shows that the combination of gel foam and composite inhibitor has the best effect on coal,which greatly reduces the release of CO,C₂H₄ and other indexes gas in the process of coal oxidation,also,making the spontaneous combustion tendency from easily spontaneous combustion to spontaneous combustion,which essentially changes the spontaneous combustion tendency of coal.