The effect of carbon dissection of waste plastics on inhibiting the adhesion of fine iron ore particles during hydrogen reduction

Abstract

In this research, Australian fine iron ore was reduced by combining pressurized and energy-bearing waste plastics in a fluidized bed. This research aims to obtain preferable operating parameters by synthetically researching the effect of temperature, linear velocity, pressure, size, and mass content of energetic waste plastics, and to clarify the sticking mechanism and the inhibitory mechanism of fine iron ore during the reduction process. The experimental results show that the preferable operating parameters include a reduction temperature of 923–973 K, linear velocity of 0.8 m/s, reduction pressure of 0.15 MPa, particle size of energetic waste plastics of 0.18–0.66 mm, and mass content of energetic waste plastics of 8%. Under the conditions of theses preferable operating parameters, the sticking mechanism of fine iron ore is caused by the reunion of the metal iron atoms. The occurrence states of carbons deposited from waste plastics can be divided into two types: graphite and carbon from Fe3C. Carbon from Fe3C reduces the sticking of fine iron ore, while the graphite hinders the direct contact of iron atoms, thereby effectively controlling the sticking.