Development of a Continuous Desiliconization Process in the Hot Metal Runner of a Blast Fyrnace

摘要

An efficient continuous desiliconization process equipped with a mechanical stirrer in a hot metal runner was newly developed. The facility was installed during the revamping of No.3 blast furnace at Kobe Works, and the commercial operation started up successfully in January 2008. Before the installation of the commercial facility, the reaction behaviour was investigated under various experimental conditions for the application of a mechanical stirring method to continuous desiliconization treatment in the hot metal runner. Hot metal experiments at laboratory scale showed that the stirring intensity was an important factor for the process performance, and the mechanical stirring method was available for the improvement of reaction efficiency. As a result of plant tests, it was confirmed that a higher oxygen efficiency of desiliconization was achieved by the combination of runner arrangement and mechanical stirrer compared with the conventional injection of the desiliconizing agent. According to the reaction analysis of continuous desiliconization in the hot metal runner using the semi-batch reaction model, it was estimated that the average slag-metal residence time in the reaction region is improved due to an increased entrainment of foamed slag into the stirred metal bath in the mechanical stirring method, and therefore, it leads to a high desiliconization efficiency. Based on the experimental results, the equipment specifications and the runner design for this process were determined.