Study On Preparation And Performance Of New Gel Foam For Preventing Coal Spontaneous Combustion

The spontaneous combustion of coal will induce gas and coal dust explosions,seriously endangering the lives of underground personnel.The main methods of traditional coal mine fire management include grouting,inert gas injection and three-phase foam injection.These technologies have played an important role in ensuring the safety of coal mine production,but they still have shortcomings.Therefore,in view of the deficiencies in existing coal mine fire extinguishing technologies,all countries are committed to researching new generation fire extinguishing materials.Gel foam has good fire extinguishing effect and is regarded as an excellent new mining material with great market potential.However,the gel foams in the current research have some shortcomings such as poor foamability,poor thermal stability,and insufficient flow properties.To this end,the paper conducts research from the screening and compounding of foaming agents,foam stabilizers,gelling agents,cross-linking agents,etc.,and develops a new fire-extinguishing gel foam.And targeted research on foaming performance,thermal stability,flow properties and flame retardant properties.Using the Waring Blender method to test the foaming ability of twelve surfactants,three kinds of foaming agents with stronger foaming ability were selected and a compounding test was carried out to determine a foaming agent with strong foaming ability.On this basis,multiple comparison tests were carried out on the foam stabilizer and gel-forming system,and the best components of gel foam stabilizer,gelling agent and cross-linking agent were selected.By designing four-factor three-level orthogonal experiments,the final test determines the formula of the new gel foam.The thermal stability of the gel foam was investigated by designing the temperature resistance experiment and the constant temperature water loss rate experiment of the gel foam.It was concluded that the temperature resistance time of the gel foam increased by 55min compared with that of the ordinary foam and 35min compared with that of the foam with foam stabilizer;The flow properties of gel foam were studied by measuring the viscosity of gel foam at different temperature and concentration.The experiment shows that the temperature has a negative correlation with the viscosity of the gel foam,and the concentration of the foam stabilizer has a negative effect on the gel foam.The effect of viscosity is positively correlated;Finally,the flame retardant properties of gel foams are studied using a coal spontaneous combustion temperature program.The experimental results show that the gel foam has good thermal stability and flame retardant properties,can effectively inert the coal body,and can significantly slow down the coal-oxygen recombination process.The inhibition rate of gel foam at 100? is 62.18%.At 170?,the difference in CO generation rate of the raw coal samples with small,medium and large particle sizes and their gel foam treatment coal samples are in turn:111.458×10-11 mol/(cm3·s),94.628×10-11 mol/(cm3·s),47.202×10-11 mol/(cm3·s),Gel foam has good flame retardant property for coal,especially for coal with high crushing degree.