| Air pollution and environmental protection has been a hot pot in recent years.Dust is an important factor leading to air pollution.Therefore,the suppression of dust plays an important role in improving air quality.The waterborne polymer can improve the wetting of particles and promote the particles to gather together,increase the consolidation effect of dust particles and reduce the generation of dust.In this paper,iron ore powder and red soil were used as dust sources to synthesize corresponding waterborne polymer dust suppressant,and the stability effect of polymer dust suppressant on particulate matter was studied.Iron ore powder was used as a dust source.Anionic copolymer dust suppressant was synthesized from acrylic acid(AA)and acrylamide(AM).When the amount of initiator was 1.0%,the mass ratio of AA/AM was 2:1,and the neutralization degree of AA was 80%,the surface tension was reduced to 59.5 m N/m,and the contact angle was reduced to 32.9°,indicating that the dust suppressant has a high wetting effect.The 21-day compressive strength of the dust suppression sample reached 4.58 MPa,7.9 times that of the watered sample.It shows that the dust suppressant can aggregate iron ore powder and reduce the occurrence of dust.Red soil was used as a dust source.The surface of red soil particles is hydrophilic,but red soil tends to lose water.Based on the above formula,the composition of monomer,the ratio of monomer and the amount of mercaptoethanol were changed to improve the water-retaining effect of polymer dust suppressant on red soil.When the mass ratio of AA/AM was 4:3,the amount of mercaptoethanol was 0.06 g,and adjusted by KOH,5.0 g3.0wt% polymer dust suppressant(AA-AM)was sprayed on 10.0 g red soil at 30 ℃ and35% relative humidity.The water loss equilibrium time was 8.0 h,twice as long as that of watered group,which significantly slowed down the evaporation of water in red soil.It was observed by SEM morphology that the red soil particles bonded to each other,and compressive strength reached 3.80 MPa in 7 days and 5.89 MPa in 21 days,which were1.89 times and 3.06 times of watered group,respectively.It shows resistance to wind erosion.The infiltration effect of AA-AM polymer dust suppressant decreased due to the high clay content in red soil.Red soil particles are negatively charged after surface hydration.Therefore,methacryloxyethyl trimethylammonium chloride(DMC),AM and hydroxyethyl acrylate(HEA)were synthesized into waterborne cationic polymer(DMC-AM-HEA)to improve the infiltration and concretion effect of polymer dust suppressant on red soil.The permeability test results showed that when spraying concentration was 3.0wt %,the infiltration rate of AA-AM was 0.1 mm /min,and that of DMC-AM-HEA was 1.1 mm/min,and the infiltration effect of the latter was obviously higher than the former.The results of concretion property test showed that the surface hardness of the red soil sprayed with 3.0wt%dust suppressant was 28.6,7.64 times that of the watered group,after reaching the water loss equilibrium.The compressive strength of drying group for 7 days was 4.26 MPa,which was 2.21 times that of watered group.The concretion effect of red soil particles was improved.SEM and pore structure of consolidated soil particles showed that even if the consolidated soil in dust suppression group was damaged.Its particle size was still larger than that in watered group,which reduced the generation of secondary dust.By comparing the stability effect of red soil,DMC-AM-HEA can improve the infiltration effect of dust suppressant while increasing the adhesion effect between particles by using the electrostatic action of particles.AA-AM uses the consolidation layer composed of water-retaining groups and ions to improve the water-retaining effect.In conclusion,the results show that the addition of waterborne polymers improve the stability of iron ore powder and red soil.This can be used for reference in the development and application of dust suppressant. |
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