To achieve an efficient and stable operation of blast furnaces in the steel industry while retaining the proficient human operators’ skills, a human–machine interface based on an ecological interface design (EID) was developed. EID is an interface design framework that reduces the cognitive workload of human operators by providing essential information on the controlled system in an intuitive way. The developed interface allows the operators to explore the possible control actions, by presenting the future predictions of the controlled variables when hypothetical control actions are taken, using a transient model. In addition, a graphical representation of the mass and energy balance that links the manipulated variables and controlled variables is provided to raise the situation awareness of the blast furnace operation. The developed interface is beneficial to determine appropriate control actions that maintain hot metal temperature and production rate near the target values and keep pressure drop below the upper bound while reducing carbon intensity and production costs.

Accurate process control through automation is the key to achieving efficient and stable operation of a blast furnace. In this study, we developed an automatic control system of hot metal temperature (HMT). To cope with the slow and complex process dynamics of the blast furnace, we constructed a control algorithm that predicts eight-hour-ahead HMT using a two-dimensional (2D) transient model and calculates optimal target pulverized coal ratio (PCR) and pulverized coal flow rate by non-linear model predictive control (NMPC). An evaluation in a real plant showed that the developed control system suppressed the effects of disturbances, such as changes in the coke ratio and blast volume, on the HMT. The root mean square (RMS) of the control deviation of HMT was successfully reduced by 1.6 °C compared to the conventional manual operation.