Preparation And Researchment Of Porous Spinel Type Ferrite And Magnetoplumbite Type Ferrite

A ferromagnetism metal oxide,ferrite,has the higher resistivity and permittivity than other metals and alloys.In the preparation of ferrite,a precursor is the first synthesis step,and then grinded,washed,dried,calcinated.In this thesis,the studied ferrite belongs to spinel-type?NiFe₂O₄?ferrite and magneto plumbite type(BaFe₁₂O₁₉)ferrite.The nonporous spinel-type?NiFe₂O₄?and magneto plumbite type(BaFe₁₂O₁₉)ferrite with a compact surface morphology were prepared by coprecipitation method.The spinel-type?NiFe₂O₄?and magneto plumbite type(BaFe₁₂O₁₉)ferrite with porous morphology were prepared by self propagating sol gel method.Using XRD analysis and SEM analysis,the influencing factors were investigated to confirm the good crystal structures,surface topography and optimum synthetic conditions.The ferrite prepared by optimum synthetic process were used to adsorb methylene blue?MB?dye.The MB dye adsorbent experiments using the porous ferrite prepared in the optimum synthetic process,was examin how pH,adsorption time and dye density influence the adsorbent property.The factors,such as pH value,adsorption time,dye concentration,adsorbent concentration were the important factors to influence the ferrite's dye adsorption property.The main conclusions were:When the porous nickel ferrite NiFe₂O₄ was prepared by self propagating sol gel method,the optimum synthetic conditions were as follows.?1?The pH value of reaction solution was 8,?2?The calcinating temperature was 800 ?,?3?The calcinating time was1.5 h,?4?The heating rate was 8 ?/min.As to porous nickel ferrite NiFe₂O₄,the results of the adsorption experiments were as follows: according to the results of experiments,the dye removal rate was 87.225 %,the adsorbent amount was 49.783 mg/g and the saturated adsorption capacity of monolayer was 70.668 mg/g,under the condition that the room temperature was 293 K,the dye concentration was 50 mg/L,the pH was 12,the adsorption time was 16 h and the adsorbent concentration was 1.0 g/L.The adsorptionresults corresponded good with the Freundlich isotherm.When the porous barium ferrite BaFe₁₂O₁₉ was prepared by self propagating sol gel method,the optimum synthetic conditions were as follows.?1?The pH value of reaction solution was 8,?2?The calcinating temperature was 900 ?,?3?The calcinating time was 1.5 h,?4?The heating rate was 6 ?/min.As to porous barium ferrite BaFe₁₂O₁₉,the results of the adsorption experiments were as follows: According to the results of experiments,the dye removal rate was 77.498%,the adsorbent amount was 39.793 mg/g and the saturated adsorption capacity of monolayer was 66.386 mg/g,under the condition that the room temperature was 293 K,the dye concentration was 50 mg/L,the pH was 12,the adsorption time was 18 h and the adsorbent concentration was 1.0 g/L.The adsorption results corresponded good with the Langmuir isotherm.When the nonporous nickel ferrite NiFe₂O₄ was prepared by coprecipitation method,the optimum synthetic conditions were as follows.?1?the ratio of actual dosage and the theoretical dosage of precipitant was 1.2:1,?2?The calcinating temperature was 1000 ?,?3?The calcinating time was 1.5 h,?4?The heating rate was 8 ?/min.As to nonporous nickel ferrite NiFe₂O₄,the results of the adsorption experiments were as follows:According to the results of experiments,the dye removal rate was 79.364 % and the adsorbent amount was 7.936 mg/g,under the condition that the room temperature was293 K,the dye concentration was 10 mg/L,the pH was 12,the adsorption time was 6 h and the adsorbent concentration was 1.0 g/L.The adsorbent amount of nonporous ferrite was obviously less than porous ferrite.When the nonporous barium ferrite BaFe₁₂O₁₉ was prepared by coprecipitation method,the optimum synthetic conditions were as follows.?1?the ratio of actual dosage and the theoretical dosage of precipitant is 1.1:1,?2?The calcinating temperature was1100 ?,?3?The calcinating time was 1.5 h,?4?The heating rate was 8 ?/min.As to nonporous barium ferrite BaFe₁₂O₁₉,the results of the adsorption experiments were as follows: According to the results of experiments,the dye removal rate was 68.794% and the adsorbent amount was 6.879 mg/g,under the condition that the room temperaturewas 293 K,the dye concentration was 10 mg/L,the pH was 12,the adsorption time was9 h and the adsorbent concentration was 1.0 g/L.The adsorbent amount of nonporous ferrite was obviously less than porous ferrite.