Study On The Suppression Of Dust Dispersion By Foam Sol

As an important energy source for economic development in China,the main position of coal will remain for a long time.However,a large amount of coal dust will be generated in the process of coal resource development and utilization,which will trigger the production safety of enterprises.In this paper,based on the original dust suppression technology,a new foam sol compound solution composed of anionic surfactant(SDS),polymer(PEO),inorganic salt(Cacl₂)and cross-linking agent is proposed,and the theoretical and experimental research on the suppression mechanism of this new foam sol is conducted.The surface morphology,pore structure and wettability of lignite(Coal A),low volatile coal(Coal B)and high volatile coal(Coal C)were investigated by using industrial and elemental analyzer and pore size analyzer.The results surface that the degree of coalification of the three coal samples is Coal B,Coal C and Coal A in order;the higher the degree of coalification,the smaller the pore volume,pore area and evaluated pore size of the coal;the molecular model electrostatic potential of water and the three coal samples are calculated using Gaussian09.The positive potentials of water,Coal A,Coal B and Coal C are 41.647230,52.647186,18.007036,50.548995kcal/mol,and the negative potentials are-39.622762,-42.082034,-19.888955,-22.448239kcal/mol,indicating that the three coal samples wettability size in order of Coal A,Coal C,Coal B.The contact angles of the foam sols with cross-linker ratios of 1 Wt.%,1.5 Wt.%,2 Wt.%,2.5 Wt.%and 3 Wt.%were measured using a contact angle meter,and it was concluded that the wettability of the foam sols decrea sed with increasing cross-linker mass rate,but the wettability increased with increasing cross-linker mass rate for cross-linker mass rates greater than 2%.Molecular dynamics simulations were performed using Materials Studio 8.0 software,and the electrostatic potential analysis of SDS and PEO,as well as the study of molecular mobility,concluded that the hydrophobic tail chains of SDS can adsorb coal molecules,and the alkyl chains of PEO molecules are helical,indicating that SDS has strong wettability and PEO has good adhesion;the water molecular mobility decreased from 12.3 decreased to 7.81,indicating that SDS and PEO improved the wettability of lignite.The orthogonal experiment Table L₉(3⁴)was selected to conduct a three-level four-factor orthogonal experiment for the experimentally selected surfactants,inorganic salts and cross-linking agents.The best combination of the four reagents can be obtained from the test results as A₁B₃C₃D₁,that is,the amount of SDS added is0.2g,PEO added is 0.3g,Cacl2 added is 0.6g,and the amount of cross-linking agent added is 0.2g,for the minimum surface tension of the solution at this time is28.14m M/m,and the contact angle is 18.4°.The air foam preparation device with air compressor as the only power source is designed,and it is obtained by experimental research:at the air pressure of 0.2MPa and gas flow rate of 6.12m³/h,the gas utilization rate reaches 86%,the foaming multiplier is about 6.3 times,the foam sol is stable and uniform,and it can completely cover the surface of coal pile,compared with the existing foaming device,the foam prepared by this foam generation device can achieve a higher Compared with the existing foam generator,the foam prepared by this foam generator can achieve higher efficiency of dust suppression.