Study of physicochemical properties of high-quality sinter from factory No. 5 of PJSC MMK during reduction in a hydrogen medium

Abstract

The research on the reduction of iron ore materials with a particle size of 12–15 mm by hydrogen (flow rate 20 l/h) under a load of 60 kPa during isothermal holding at temperatures of 500, 700 and 1050 °C was carried out in the laboratory of the chair for Metallurgy and Chemical Technologies of the FSBEI HE Nosov Magnitogorsk State Technical University. At a temperature of 1050 ºC, the reduction of the factory No. 5 sinter to a reduction degree of 25% proceeded at a rate of 0.0476% O2/min. At the end of reduction, the shrinkage of the sinter sample was 6.1% of the layer height, which provided a gas pressure drop of 0.27 kPa. The rate of recovery of the sinter from plant No. 5 compared to the rate of reduction of the mixture of sinter from plant No. 5 with pellets from SSGPO or Mikhailovsky MPP in equal proportions is higher on average by 5.1% (rel.) and 7.4% (rel.) at temperatures and degrees recovery 700 ºC and 15%, 1050 ºC and 25%, respectively. The shrinkage of the agglomerate compared to that of the pellets with the same reduction parameters was 1.3 and 2 times smaller, respectively. At a temperature of 1050 ºC and a material reduction ratio of 25%, the gas pressure drop in the sinter bed from Factory No. 5 was 3.7% lower than the gas pressure drop passing through the mixture of sinter with pellets from both manufacturers. The reduction rate of the mixture of sinter from plant No. 5 with SSGPO pellets, compared to the mixture of sinter from plant No. 5 with pellets from the Mikhailovsky MPP, is on average 7.6% (rel.) higher at a reduction temperature of 700–1050 ºC and a reduction degree of 15–25 %.The paper was prepared under support of the grant of RF President № MD-1064.2022.4.