The Reduction Study Of Carbon Coating On Iron Ore Powder

In the iron ore reduction production practice,the growth of iron whiskers is a negative factor in production.Based on the previous studies,it mainly studies the reduction kinetics of carbon-coated slag,and verifies whether the growth of iron whiskers can be effectively inhibited by the carbon coating method,providing theoretical basis for the future iron ore powder and solid carbon reduction process.It uses single variable method to study the reduction behavior of carbon-coated iron ore powder.First,the kinetics of reduction of carbon-coated iron ore powder at 20?~1300?were studied by differential thermal analysis.The TG-DSC curve of the two pulverized coal-coated iron ore powders can be obtained by the differential thermal analysis experiment and the data of the TG curves by the FWO method and the Coats-Redfern method.The results show that the carbon-coated slag the initial activation energy and reaction limits.Secondly,on the basis of differential thermal analysis,five reduction temperatures of 800?,900?,1000?,1100?and 1200?were selected to conduct the reduction experiments in the shaft furnace.The initial activation energy of the carbon coated slag under isothermal condition.Thirdly,the reduced ore powder was scanned by phase and XRD,and the characterization and composition analysis of the phase were used to infer whether the carbon-coated slag could inhibit the growth of iron whiskers.Studies results are as follows:1)Proper lengthening of the grinding time can help to increase the carbon coating amount,and the carbon deposition rate is the highest when the grinding time is 105 s.2)The initial activation energy of iron ore powder coated with bituminous coal is 311 k J/mol~337k J/mol by thermal analysis kinetics.The initial activation energy of iron ore powder coated with anthracite coal is 317 k J/mol~460 k J/mol.3)The initial activation energy of iron ore powder coated with bituminous coal under laboratory conditions was 52.317 k J/mol.The initial activation energy of iron ore powder coated with anthracite coal was 91.377 k J/mol.The limiting reaction was gas diffusion.4)Carbon coated ore can inhibit the growth of iron whiskers.The inhibitory effect of bituminous coal coated iron ore fines is better than anthracite coated iron ore fines.