Experimental Research On The Oxidation Inhibition Of Bituminous Coal At Low Temperature By New Pattern Polyacrylate Sodium Phase-Changing Sol

As the safety situation of coal fire is severe and the fire accidents occur frequently in our country,it is of great practical significance to study the fire fighting theory and measure actively and effectively.The research about the fire prevention materials and techniques is an important part of coal mine fire prevention technology.Combining with the advantages of aerosol resistance and gel fire prevention technology,this paper explores the oxidation inhibitory effect of new pattern polymer acrylic acid sodium phase-changing sol on Bu Lianta bituminous coal at low temperature.In order to illustrate the oxidation resistance and inhibitory effect of phase-changing sol on coal samples at low temperature,this paper presents a series of macroscopic experimental parameters and microscopic experimental results at low temperature oxidation process,and designs the traditional MgCl2 and NH4H2P04 inorganic salt aerosol inhibitor as control experiments.The main contents of this paper include:(1)The technical characteristics and resistance mechanism of new pattern sodium polyacrylate polymer phase-changing sol: The low molecular weight sodium polyacrylate sol,boric acid solution and mixed solution of boric acid and MgCl2 are atomized step by step by using high-pressure micro mist technology and ultrasonic atomization technology.Then small molecular weight fine water droplets sol,which is broke by high pressure,is phase changed into high molecular weight gel under the action of cementing agent.Then the coal samples are resistanced.Sodium polyacrylate polymer phase-changing sol can achieve the effect of physical and chemical resistance at the same time(2)The comparative and analysis about macroscopic experimental parameters.Due to the physical and chemical structure of coal will be changed in different ways by refractory material,the macroscopic experimental parameters will present great discrepancy in low temperature oxidation process.In order to obtain the experimental data of physical and chemical oxygen consumption and CO production,the physical adsorption and temperature programmed experiments are designed.Then the experimental data is soluted by the means of mathematical processing and curve fitting.And the operation results and curves,include the oxygen consumption rate,CO generating rate,critical temperature,activation energy and other parameters,indicate that the coal samples,which are resistanced by sodium polyacrylate polymer phase-changing sol,consume more oxygen,generate more CO,have more fast consumption and generating rate than raw coal samples and resistanced coal samples by MgCl2 and NH4H2PO4 at the same temperature.Meanwhile the critical temperature and apparent activation energy is highest.The conclusions show that the inhibition effect of sodium polyacrylate polymer phase-changing sol is better and MgCl2 can enhance the inhibition effect.(3)Thermal analysis.The feature temperature parameters and quality discrepancy at low temperature oxidation process are determined by comparing and analyzing the difference of TG and DSC(differential scanning calorimetry)curves at each temperature section,so as to study the changes of quality and heating with temperature rising.The results indicate that the coal samples which are resistanced by sodium polyacrylate polymer phase-changing sol,have lower weight loss,which is 3.48%,and higher critical temperature,which is about about 84 degrees,and MgCl2 can make the inhibition effect better.The inhibition time is longer by analysising the TG and DSC curves of phase change material(4)Microstructure analysis.In order to explain why the inhibition effect is better for sodium polyacrylate polymer phase-changing sol with MgCl2,this paper compares the difference of resistance coal samples in surface microstructure and active group by scanning electron microscopy and Fourier transform infrared spectrometer.Sodium polyacrylate polymer phase-changing sol resistance coal sanmples mainly by physical inhibition,including covering and filling,and the chemical inhibition effect is weaker.The materials of MgCl2 can enhance the inhibition effect by consuming the Oxygen-containing functional groups,for example hydroxyl and carboxyl in the molecular structure of coal.