Study On The Preparation Of A New Type Of Dust Wetting Agent And Its Suppression Mechanism

My country's coal industry has played an important role in guaranteeing the development of the national economy.But the large amount of coal dust generated during the development of coal resources can easily cause coal dust explosions and pneumoconiosis,which seriously threaten human life.Therefore,it is necessary to reduce the coal dust concentration to an acceptable range.Aiming at the low dust reduction efficiency of ordinary wetting method,this paper proposes a method containing anionic surfactant sodium dodecyl sulfate(SDS)and polymer polyoxyethylene(PEO)through a combination of theoretical analysis and experimental research.And an inorganic salt(Na Cl)compound solution,and a comprehensive and systematic study on the dust suppression mechanism of the compound wetting agent.Using industrial and elemental analysis,scanning electron microscopy and other instruments,the coal quality analysis and apparent morphology of Shanxi Datong coal,Inner Mongolia Ordos coal,and Shanxi Shenmu coal have been studied.The results show that moisture and ash are hydrophilic components and are positively related to the wettability of coal,while volatile components and fixed carbon are hydrophobic components and are negatively related to the wettability of coal dust.In the experiment,the Ordos coal of Inner Mongolia showed strong hydrophobicity,so it was selected as the research object.Orthogonal experiment table L₉(3⁴)is selected for orthogonal experiment of different factors and levels,and the wetting agent with the best wetting effect is compounded.The DSA-100 contact angle tester was used to study the influence of the surface tension and contact angle of different concentrations of Na Cl-SDS composite solutions.The results show that within the set concentration range,when the Na Cl concentration is 0.3g/L,the minimum contact angle is the surface tension of the 26.2°solution no longer increases with the increase in concentration.A Fourier transform infrared spectrometer was used to compare and analyze the coal samples wetted with different concentrations of Na Cl-modified surfactants.The results showed that the oxygen-containing functional groups on the coal surface increased after the wetting agent was added,and the peak area of the oxygen-containing functional groups increased.With the increase of,the contact angle gradually decreases and the hydrophilicity increases.The fluorescence spectra of the SDS/PEO compound system and the Na Cl-SDS-PEO compound solution at room temperature were measured by a fluorescence spectrophotometer.The results show that when the solution concentration is 6g/L,the interaction between SDS and PEO starts;when the concentration is 20g/L,stable micelles are formed.After adding Na Cl solution,the fluorescence absorption intensity decreases.When the Na Cl mass concentration is 0.3g/L,the solution reaches the critical micelle concentration,which is consistent with the previous study.The results of this paper further verify the influence of the action of inorganic salts and surfactants on the wettability of coal dust,and provide theoretical and experimental support for subsequent studies on the wettability of coal dust.