Experimental study on oxygen consumption and resistance performance of deoxidizer to inhibit coal combustion

In order to improve the inhibitory effect of the inhibitor on the spontaneous combustion of coal,an deoxidizer with rapid oxygen consumption and resistance and inhibition was prepared by orthogonal test and composed of iron powder,chloride inorganic salt and diatomite.According to the sum of the maximum inhibition ratio (0.75) and the oxygen consumption concentration (5%),the deoxidizers with different inhibitors (NaCl,CaCl2,and MgCl2) are coupled in the analysis of the best results the rapid oxygen consumption and inhibition.The results show that the effect of the deoxidizers containing three inorganic salts of NaCl,CaCl2 and MgCl2 on the rapid promotion of oxygen consumption and inhibition is significant from large to small as MgCl2,NaCl and CaCl2.Therefore,the deoxidizer with CaCl2 as inhibitor is the most effective in inhibiting coal spontaneous combustion.Well,the optimum ratio is 1.5 g of reducing iron powder,0.6 g of diatomite and 0.3 g of CaCl2,and the mass ratio is 5∶2∶1.By measuring the deoxidizer’s effect on the consumption of oxygen and CO production in coal samples with different particle sizes,the results show that the larger the coal particle size,the greater the inhibition rate,the faster the oxygen consumption,and the best effect on inhibiting spontaneous combustion of coal samples.For a mine with a distance of 300 m from the closed wall to No.21102 work face,oxygen volume fraction is still as high as 14%.After the deoxidizer is injected into the deoxidizer spraying system,the oxygen volume fraction is reduced from 14% to 4%,and the effect of rapid suppression of coal spontaneous combustion is achieved.