Reduction demonstration experiment to realize recycling-oriented steelmaking using carbon-neutral reduced gas

Background and Objectives

Although the blast furnace method is widely used as an ironmaking method, there are still some problems such as the limitation of coke grade and high CO2 emissions. We propose a new ironmaking method, the "CO gas melting and reduction method. In this ironmaking method, iron ore and flux are fed into a melting furnace, and CO gas is blown into the molten slag inside to obtain granular iron.

Characteristics of the CO gas fusion reduction method

The CO2 generated from the reduction of iron ore is electrolytically min to CO using a SOEC1) solid oxide min cell and reused, and this ironmaking process is expected to be a carbon-circulating ironmaking process that does not emit CO2 outside. In addition, because this ironmaking process uses CO gas, it can be used regardless of the grade of coal. Since the operating temperature is below the melting point of iron, impurities such as carburization, phosphorus, and sulfur are unlikely to solidly dissolve in the produced grain iron, and refining is not expected to be necessary.

Research

In order to confirm the practicality of this ironmaking process, it is necessary to measure the reduction rate of iron oxide by CO gas injection. In this study, we measured the reduction rate of iron oxide when CO gas is blown into FeO-MxOy pseudo binary molten slag, in which one type of oxide is added to iron oxide, to investigate the change in reduction rate depending on the concentration of the additive.

GX Expected effects of technological development

Steel, the nation's key industry, is the model case where GX's open innovation can be most easily realized, as it is the most effective in reducing CO2 emissions and can be achieved through collaboration with industries that create zero-carbon energy. It can also serve as a bridgehead for Japan to lead the world's industrial structure.