Study Of Adding Waste Plastics In Carbon Bearing Briquettes Of High Phosphorus Iron Ore By Direct Reduction And Magnetic Separation

With the rapid development of steel industry in recent years,crude steel production continues to grow,and the iron ore imports of china had reached 10.24 billion tons in 2016.However the huge reserves of high phosphorus iron ore resources are still not economic and efficient development and utilization.In this paper,the direct reduction and magnetic separation study of waste plastics addition in carbon bearing briquettes of high phosphorus iron ore was investigated,and the direct reduction mechanism of carbon bearing briquettes of high phosphorus iron ore was carried out,which provides theoretical support for the development and utilization of high phosphorus iron ore in China.The results show that under the experimental conditions of the basicity at 0.8,the amount of coke fines at 16% and the amount of sodium sulfate at 4%,agglomerates of adding 25% waste plastics instead of coke fines(total C content of 13.19%)was reduced at 1150 ? for 40 min,the metallization rate of 88.77% of the roasted briquettes were obtained,and under the experimental conditions of the magnetic separation strength at 0.08 T,grinding fineness of reduced briquettes at 90% passing 0.074 mm,the final metallic iron powder assaying 91.99% TFe with the metallization rate of 92.26 % of metal iron fine was obtained,at the iron recovery of 86.74%.The results of study on microstructures of roasting briquettes under the based conditions,adding 4% sodium sulphate and adding 4% sodium sulfate at the same time to waste plastics instead of 25% coke fines show that: The sodium sulfate can strengthen the iron grain migration,aggregation grow of high phosphorus iron ore in the direct reduction process,which effectively enrich the iron;When add waste plastic instead of 25% coke fines,the direct reduction process of iron grain migration aggregation effect good.The results of the energy spectrum analysis show that,compared with the based conditions,the metal iron particles is pure,and the metal iron grain appear a small amount of P element when adding waste plastic instead of 25% coke powder.The results of reduction kinetics of carbon bearing briquettes based conditions,adding 4% sodium sulphate and adding 4% sodium sulfate at the same time to adding waste plastics instead of 25% coke fines under the conditions of reduction temperature at 1000?-1150 ? for 40 min and the atmosphere N2/CO2=14/1.The restraint of its reduce restraint is gas diffusion and their apparent activation energies of the reduction reactions were 130.06 kJ / mol,100.23 kJ / mol and 109.80 kJ / mol.After adding sodium sulfate,the apparent activation energy was reduced,which improved the reduction reaction.After adding 25% coke fines,the apparent activation energy was increased,which prevented the reduction reaction.