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Experimental Study Of Inhibitor On Suppressing Coal Spontaneous Combustion

Posted on:2012-08-30Degree:MasterType:Thesis
Country:ChinaCandidate:F C XieFull Text:PDF
GTID:2131330335453295Subject:Disaster Prevention
Abstract/Summary:PDF Full Text Request
Coal spontaneous combustion is one of the most important factors to coal mine fire, which threaten coal mine safety and bring about huge economy losing to coal industry. Inhibitor is one of vital measures to prevent fire. At percent, a few covers of mechanism research about chemical inhibition suppressing coal oxidation at home and abroad stop only at surface, which are only the qualitative analysis. In this text, the suppressive characteristics and mechanisms of chemical inhibitors MgCl2 and antioxygen A to three kinds of coal with greater different characteristic were studied qualitatively and quantitatively on the basis of predecessors, which is very significant to prevent coal spontaneous combustion.Firstly, the TG-DTG-DSC curves of coal oxidation were obtained by using thermal analyzer. The characteristic temperature values of natural coal and inhibited coal in oxidation progress were comparatively studied in the condition of both invariable and changing heating rate and coal granularity. From kinetics analysis of curves, the apparent activation energy of coal were obtained. Afterwards, infrared spectrum analyzer was used, and the compose, internal structure and surfactivity radical of coal were studied from microcosmic angle. In the end, a self-made oxidation experimental installation was used for testing inhibit efficiency of inhibitor to coal oxidation from macroscopic angle.The results indicate that: MgCl2 mainly plays a physics part, such as absorbing moisture, diminishing contactarea between air and coal and depressing temperature, in inhibiting coal oxidation. In microcosmic aspect, metalepsy and complexation can happen between MgCl2 and coal molecular, which make coal molecular more stable, improve activation energy and reduce oxidation rate. MgCl2 has a finer inhibition effect to various coal samples in earlier stage, and the inhibition effect weaken with lessening of deoxidization degree of coal in later stage. Antioxygen A plays a chemistry role in suppressing coal oxidation. It can capture activity radical that produced in the process of coal oxidation, which prevent coal oxidation, so as to reach the purpose of antiflaming. It has a weak inhibition effect in earlier stage and the inhibition effect strengthen with lessening of deoxidization degree of coal in later stage. In the weight increment stage, Yima and Pingdingshan coal with MgCl2 have more activation energy increment. In the pyrogenic decomposition, Yangquan coal with antioxygen A has the most activation energy increment along with augmentation of both heating rate and coal granularity, every characteristic value of both natural coal and inhibition coal moves backwards, and the range of retroposition of inhibition coal's values is slightly greater than the range of natural coal, but the augmentation range of maximum-weight-losing rate and maximum-heat-losing quantity of inhibition coal is close to natural coal.The studies in this text will provide theoretical basis for rightly understanding the action rules of inhibitor, searching high-efficiency and green inhibitor and establishing measures on preventing and treating coal spontaneous combustion.
Keywords/Search Tags:coal spontaneous combustion, inhibitor, thermoanalysis, activity energy, microstructure, inhibiting mechanism
PDF Full Text Request
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