Valuable Elements Extracted From Iron Ore Tailing For The Synthesis Of MCM-41 Mesoporous Materials And Their Modification

MCM-41 mesoporous molecular sieve with uniform pore dimension,hexagonal order,larger surface area and adsorption capacity,had attracted extensive attention in the field of absorption,loading,etc.However,due to the lack of chemical activity,pure mesoporous silicon were limited in industry.Therefore,doping of other atoms on mesoporous molecular sieves could improve its catalytic performance,and it could use in more fields.In this paper,we extracted Fe2O3 and SiO2 from iron ore tailing because the raw materials contains high grade of them.In our experiment,high purity iron was separated from iron ore tailings by acid leaching procedure.In order to extract SiO2 from the acid insoluble residue,we used alkali leaching processing to prepare NaSiO3 solution which was used for making MCM-41 mesoporous materials.The modified MCM-41 mesoporous were prepared by doping Fe,and the photocatalytic properties of the composites were also studied.The factors of iron ore tailings leaching process were the amount of hydrochloric acid,the concentration of hydrochloric acid,reaction temperature,reaction time.The results showed that the optimum conditions was obtained when 30%of hydrochloric acid exceeding 10%under 100? for 1.5h.The leaching rate of Fe2O3 was close to 100%.The MCM-41 mesoporous molecular sieve was synthesized by of non-hydrothermal method with silicate from acid insoluble residue at room temperature.We studied the effects of crystallization conditions including the molar ratio of SiO2/CTAB,pH value,crystallization temperature and crystallization time on the structure MCM-41 mesoporous sieve.The results showed that,the optimum synthesis conditions of MCM-41 mesoporous sieve in the condition of CTAB/SiO2=0.10/1,pH of 10,crystallization temperature of 100 C,crystallization time of 48h and calcination at 550? for 3h.Samples were prepared in the optimum conditions with surface area of 882m2/g,pore size of 4.2nm and pore volume of 1.019cm3/g.Besides,MCM-41 mesoporous sieve had good adsorption performance.The degradation of methylene blue solution was used by Fe/MCM-41.After 2 hour irradiation,5%Fe/MCM-41 catalyst showed best prefoumance under UV irradiation.The final degradation efficiency of methylene blue solution(50mL,30mg/L)was close to 100%.Therefore,the modified MCM-41 showed good photocatalytic properties.