Application of Combined Developments in Processes and Models to the Determination of Hot Metal Temperature in BOF Steelmaking

José Díaz,Francisco Javier Fernández

doi:10.3390/pr8060732

Abstract

Nowadays, the steel industry is seeking to reduce its carbon footprint without affecting productivity or profitability. This challenge needs to be supported by continuous improvements in equipment, methods, sensors and models. The present work exposes how the combined development of processes and models (CDPM) has been applied to the improvement of hot metal temperature determination. The synergies that arise when both sides of this research are simultaneously approached are evidenced. A workflow that takes into account the CDPM approach is proposed. First, a thermal model of the process is developed, making it possible to identify that hot metal temperature is a key lever for carbon footprint reduction. Then, three main alternatives for hot metal temperature determination are compared: infrared thermometry, time-series forecasting and machine learning prediction. Despite considering only few process variables, machine learning techniques succeed in extracting relevant information from process databases. An accuracy close to infrared thermometry is obtained, with a much higher applicability. This research shows that process-model alternatives are complementary when judiciously nested in the process computer routines. Combining measurement and modelling techniques, 100% applicability is achieved with an error reduction of 7 °C.

Highlights

IntroductionThe increasing demand for steel cannot be met only by recycling, and new metallic iron must enter the global cycle, either through the direct reduction of iron ores or through integrated steelmaking
The mean absolute errors (MAEs) of the predictions are represented in Figure 6 as a function of the training window width w
MAE reduction has a direct connection to environmental improvements

Summary

Introduction

The increasing demand for steel cannot be met only by recycling, and new metallic iron must enter the global cycle, either through the direct reduction of iron ores or through integrated steelmaking. This prevailing route uses the blast furnace (BF) to produce iron from iron ore; in a second step, a basic oxygen furnace (BOF) converts this crude iron, with some scrap and other material additions, into steel. The EAF route is simpler, uses fewer natural resources, consumes less energy and generates fewer CO2 emissions This is the paradox and challenge of the steel industry. Steel is a material that fits perfectly into the circular economy, but the need to introduce new metallic iron into the global cycle causes a significant carbon footprint

Methods

Results

Discussion

Conclusion