Study On Inorganic Solidified Foam Fire-fighting Materials And Properties

Coal fire is one of the main disasters in mine,which brings serious harm to the safety of national property and personnel.In order to prevent coal spontaneous combustion,grouting,inert gas injection,gel injection,and inhibitor spraying are mainly used at home and abroad.These technologies have advantages but have their own conditions.In order to ensure fire extinguishing and filling effect,the material should have good resistance,fluidity and permeability,which can not only guarantee the treatment effect of goaf fire area,but also improve the overall jacking effect of goaf after filling,and enhance the strength of surrounding rock,thus playing a good supporting effect on overlying strata.Inorganic solidified foam material has a good application prospect in the field of mine fire prevention and extinguishing because of its non-heating during the reaction,fire resistance,suitable supporting strength and economic efficiency.Based on the subtask of Classification of Project"accumulation inorganic solidified foaming filling plugging construction technology of fire prevention materials and equipment development",this paper studied inorganic solidified materials,analysed the composition and function principle of the foam material,and explored the material ratio of substrate,liquidity,field exploration on the fire extinguishing performance through laboratory experiment,numerical simulation and field experiment,and the main results were as follows:?1?through the study of the inorganic solidified material substance composition and its types and mechanism,the sulphur aluminate cement was selected as the material of the basic material to meet the requirements of engineering application.Besides,anionic surfactant was used as foaming agent and foam stabilizer for foam preparation,and calcium chloride was chosen as an accelerating agent to adjust the setting time of the material.?2?based on the study of the composition of foaming agent,and taken the foaming power and 50%water drainage time,settlement distance,and bleeding water into consideration,the fatty alcohol sodium sulfate was selected as foaming agent.LAS,SDS,animal glue,plant soap powder materials can improve the stability of foaming agent,but plant soap powder was better.The optimal ratio of additive amounts of several substances is 0.25%,0.25%,0.1%and 0.4%.Through the orthogonal test of settlement distance and bleeding water,the order of affecting settlement distance was the amount of stabilizer,the amount of thickener and the amount of surfactant.The order of affecting the amount of bleeding water was the amount of surfactant,the amount of stabilizer and the amount of thickening agent.?3?through the experimental analysis of several indexes of setting time,fluidity and compressive strength of inorganic solidified materials,it is concluded that the primary and secondary order affecting the result of setting time is the amount of water-reducing agent,the water-solid ratio,the amount of accelerating agent and the amount of early strength agent,among which the amount of water-reducing agent has the most significant effect on the setting time.The primary and secondary order influencing on the fluidity results is the amount of foam agent,the water-solid ratio and the amount of water-reducing agent.The less foam agent is used,the greater the water-solid ratio is,and the better the slurry flow performance is.From the analysis of compressive strength test results,in the early stage the most important factor is the amount of foam agent.In the later period,the most important factor affecting the strength is the ratio of cement to fly ash.The more cement is used,the better the strength of the material will be.Through experiments and primary and secondary analysis of influencing factors,the ratio was determined for field application.?4?by means of infrared spectroscopy,SEM,XRD and other modern testing methods,it can be found that the presence of carboxyl group,carbonyl group and sulfuric acid radical group in the foam agent can better realize hydrophilic grafting modification,which is conducive to the stability enhancement of the foam's sustainable time.Hydration products of early inorganic solidified materials were mainly flocculent and wavy.As time went by,they began to develop into acicular and rod shapes,and staggered connections formed skeleton structures,thus forming mechanical strength and more stable hydration products.Most of the bubble holes are micron size.The more foam agent is added,the more the number of bubble holes will be and the size will be larger.The disconnected bubble holes can absorb heat to cool down and hinder heat conduction.?5?according to the construction site conditions,and combined with the results of numerical simulation,the upper pipe flow velocity is slow in the first vertical pipeline elbow and in a horizontal pipe flow,where is the pipe of cavitation erosion area.In addition,the flow rate of the slurry is the largest and greater than 2m/s at the lower side of the first vertical elbow and the outer side of the second horizontal elbow of the pipeline,where is the erosion area.The two areas are easy to wear and field application should be required for special protection.When the water-solid ratio is 0.5 and the pipe diameter is 89mm,the slurry flow rate at the outlet of the pipeline is relatively uniform,and the pipeline is not easy to jam,which can be used as a parameter in the field.?6?through the grouting engineering application,it is found that compared with the traditional mud,the fluidity of inorganic solidified material is much better than traditional mud,and the usage can save nearly half.At the same time,the setting time is shorter,which can achieve rapid condensation in engineering requirements.The sample strength test was found that it has a certain strength,consistent with the early strength measured in laboratory index.In addition,through the observation of the observation hole,it can be seen that the borehole temperature is<50?,the CO concentration is between 0 and 14ppm,the O₂ concentration is stable below 7%,and the fire area tends to be stable,meeting the expected requirements of the material.