Porous zeolite molecular sieve adsorbents were prepared by acid treatment-alkali melting-hydrothermal crystallization using titanium-containing blast furnace slag produced during smelting process of vanadium titanium magnetite concentrate as raw material,and characterized by XRD,SEM and FTIR,with the influence of NaAlO2 addition on its structure analyzed.The CO2 adsorption performance of the adsorbents obtained were evaluated via dynamic adsorption method,while the effects of pretreatment temperature,adsorption temperature and CO2 flow rate on its CO2 adsorption performance were further investigated and the adsorption behavior was analyzed by kinetic models.The results showed that,with the increase of NaAlO2 addition,the hydrothermally crystallized product exhibited zeolite structure transforming from"amorphous→preliminary crystallization→FAU type→LTA type".The prepared adsorbent(Z-4)activated at 350℃exhibited the best adsorption performance at adsorption temperature of 25℃and CO2 flow rate of 1.4 mL/min(fixed bed reactor)or 50 mL/min(simultaneous thermal analyzer),with the CO2 breakthrough and saturation adsorption capacities reaching 2.16 and 3.39 mmol/g,respectively.The CO2 adsorption behavior conformed to the pseudo-second-order kinetic model,mainly dominated by physical and chemical adsorption,while the adsorption rate constant could reach 0.0785 mmol/(g·s).After 5 cycles of adsorption/regeneration,the retention rate of CO2 saturation adsorption was 96.8%.
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