The Synthesis Of A New Type Of Alumina Clinker Leaching Secondary Reaction Inhibitor And Its Inhibitory Mechanism

The clinker produced by the sintering method contains about 30% of ?-2CaO·SiO₂,and reacts with the sodium aluminate solution during the dissolution to form a so-called secondary reaction,so that the dissolved A1₂O₃ and Na₂O are re-precipitated into the red mud.And the loss of their use,the use of additives?surfactants?to inhibit the dissolution of clinker secondary reaction is simple to operate,can reduce the occurrence of secondary reactions without changing the original production process and equipment,the current additive research is limited to a single functional group Additives,multi-functional additive research is relatively rare.In this paper,the synthesis and inhibition mechanism of various functional group inhibitors were studied and analyzed.The full text of the research is as follows:?1?An additive containing two functional groups,an acrylic acid-vinyl alcohol copolymerized PAV and an acrylic acid-hydroxypropyl acrylate copolymer PAH,were synthesized.The effects of different experimental conditions on the molecular weight of PAV and PAH were studied.The polymers PAV and PAH were characterized by infrared spectroscopy?FT-IR?,nuclear magnetic resonance spectroscopy?HNMR?,GPC and TG.?2?The inhibitory effects of PAV and PAH on the secondary reaction were studied and compared with the commercially available additives sodium polyacrylate?PAAS?and polyethylene glycol?PEG?.The results showed that the effect of four additives on the inhibition of secondary reaction was:PAH>PAV>PAAS>PEG.The PAH and PAV inhibition effects were better than PAAS and PEG in the case of less added amount.?3?The mechanism of PAV and PAH inhibition of secondary reaction was investigated by using sintered?-2CaO·SiO₂ as raw material.The adsorption of PAV on the surface of?-2CaO·SiO₂ accords with the first-order kinetic equation Lagergren.The adsorption of PAH on the surface of?-2CaO·SiO₂ accords with the quasi-second-order kinetic equation.The adsorption isotherm data of PAV accords with the Freundlich equation,and the adsorption free energy?GPAV=31.575KJ/mol.PAV has both physical adsorption and chemical adsorption on the surface of?-2CaO·SiO₂.The adsorption of PAH on the surface of?-2CaO·SiO₂ is monolayer saturated adsorption,and the adsorption isotherm data of PAH accords with the adsorption free energy of Langmuir equation?GPAH=41.145KJ/mol.The surface potential of?-2CaO·SiO₂ in deionized water was-17.37mV measured by Zeta potential meter.The?-potential values of?-potential values were-19.43mV and-34.659mV after adsorption of PAV and PAH on the surface of?-2CaO·SiO₂.The adsorption of PAH on the surface of?-2CaO·SiO₂ is stronger than that of PAV.the surface of?-2CaO·SiO₂ is monolayer saturated adsorption,and the adsorption isotherm data of PAH accords with the adsorption free energy of Langmuir equation?GPAH=41.145 KJ/mol.The surface potential of ?-2CaO·SiO₂ in deionized water was-17.37mV measured by Zeta potential meter,and the?-potential values were measured after adsorption of PAV and PAH on the surface of?-2CaO·SiO₂ were-19.43mV and 34.659mV,respectively.This indicates that the surface adsorption of pahs at?-2CaO·SiO₂ is stronger than that of PAV.