Study On The Performance And Mechanism Of Compound Additive To Inhibit The Secondary Reaction Of Alumina Clinker

In order to solve the problem of A1₂O₃ and Na₂O loss caused by secondary reaction during the dissolution of alumina clinker in sintering process,the performance of inhibiting secondary reaction of alumina clinker by compound additives was systematically studied in this paper,and the mechanism of inhibiting synergistic action of the mixture was explored.The results have positive significance for improving the dissolution rate of alumina in clinker and improving the technical and economic benefit index of alumina production.The main research results are as follows:On the basis of the previous study of our group,we optimized the synthesis scheme to prepare new multifunctional group additives,acrylate-vinyl alcohol copolymer?PAV?and acrylate-hydroxypropyl acrylate copolymer?PAH?.The functional groups of the synthesized products were detected and characterized by infrared spectroscopy and hydrogen nuclear magnetic resonance spectroscopy,and then the components of the products were obtained by gel chromatography.The calculated polymerization degree of PAV was PVOH₂₈₅-PAA₆₄₀,and that of PAH was PAA₁₂₁-HPA₂₇₇.The inhibition effect of compound additive on secondary reaction of alumina clinker was investigated.It was found that the compound of polymer PAV and polymer PEG?PAV:PEG=3:2,that was,AVEG?.When the additive amount was 0.05%of the clinker mass,the alumina leaching rate was 4.01%higher than the blank.The amount of different additives to increase the leaching rate of alumina in the aggregate was AVEG?PAV:PEG=3:2?>AHAS?PAH:PAAS=3:2?>PAH>PAV>DBDX>PAAS.The results showed that the new multi-functional group polymer synthesized by the research group and the commercially available mono-functional group polymer had a strong ability to inhibit the secondary reaction,and the synergistic effect between the polymers was obvious,which significantly increased the leaching rate of alumina.The adsorption thermodynamics and kinetics of the compound additive on the surface of dicalcium silicate were studied systematically.The adsorption kinetics of the PAV component of the 3:2 combination of polymer PAV and polymer PEG were consistent with that of the single additive PAV,and the adsorption rate increased,indicating that polymer PEG could improve the adsorption rate of PAV.And the type of adsorption isotherm of PEG and PAV in PEG/PAV?2:3?was the same as that of single component,but due to the interaction between molecules,both PAV and PEG in the compound additive were more easily adsorbed on the surface of dicalecalicum silicate,resulting in that the n value of the compound additive component was obviously greater than the n value of the single additive.In this paper,molecular dynamics simulation?MD?was used to study the adsorption behavior of the compound inhibitors of PAV and PEG on the surface of?-C₂S and synergistic mechanism between them during the adsorption process.The results showed that the inhibition effect of the polymer adsorption layer formed by the compound inhibitors of PAV and PEG with a mass ratio of 3:2 is the best,which is consistent with the experimental results in the literature.The radial distribution function analysis shows that the interaction between polymer PAV and PEG complex inhibitor in the surface adsorption process of?-C₂S produces synergistic adsorption effect,which enhances the adsorption effect of the inhibitor on the surface of?-C₂S.