The basic oxygen furnace oxygen lance tip is a critical piece of equipment that controls the oxygen steelmaking process and the quality of the steel, and plays a large role in the life of the vessel refractory. Lance tip life varies greatly from shop to shop, and understanding and reducing lance failures is important for production, quality and safety. To better measure lance tip wear, an experimental laser scanning method was developed that can create 3D models of lance tips. Used lance tips from ArcelorMittal Burns Harbor were scanned and modeled using the experimental method, and lance tip wear was compared to the original surface. Lance tip wear was also correlated against process data to identify any events that may have contributed to the wear pattern and life result.
Intensive process and technology improvements related to the basic oxygen furnace converter — the key process to increase steel plant productivity and stability — have been performed at Ternium Brazil. This paper details the road map for process developments and investments in equipment technology, as well as the results achieved. The main topics of this development are the process control and optimization systems, slag forming model, oxygen blowing pattern, end-of-blow point control and slag carryover control. The outcomes of this development are improvements in the reblow rate, end-of-blow oxidation, direct tapping, slag carryover, slopping ratio, metallic yield and lining life.
Post-combustion distributor (PCD) lances, while not universally adopted, have been used in basic oxygen furnace steelmaking for many decades. A portion of the main oxygen reacts with carbon from the process and combusts to generate heat, thus preventing cone, mouth and lance skull buildup. Liberty OneSteel Whyalla, as with many plants, experienced delays related to cleaning of the cone, tap pad and lance. In 2017, PCD lances were introduced at its 130-ton converter. Operating experiences in a unique environment with secondary oxygen will be reported, as well as process measurements relevant to the application of PCD lances.
Bottom blowing in the basic oxygen furnace (BOF) process provides higher metal bath agitation, improving the refining reactions. Steel–slag mass transfer is a key step in the reaction of different steel components, such as phosphorus, manganese and others. In the present work, experiments were carried out in a cold model of a Ternium Brazil BOF converter, aiming to evaluate bath homogenization and mass transfer. Based on similar criteria, it is possible to apply the laboratory results to the industrial practice. The model evaluated the influence of the tuyeres’ flowrate and configuration on processes that involve a mass transfer between metal and slag.
Fully automatic detection of moving vessels such as ladles, slag pots, torpedoes, etc., is a common requirement in the steel industry. Extensive heat, dust, smoke and changing lighting conditions are common problems that complicate this task. A new approach to overcome these problems is based on a three-dimensional measurement of the vessel surface. The recognition and evaluation of characteristics and unique features leads to the identification of the equipment. This method is described in detail using the experience gained at a pilot installation. Achieved results conclude the paper.
Steel is the most widely used raw material in the world due to its high tensile strength and low cost. Globally we recycle 630 million tons per year of steel. One of the unique properties of steel is that it can be recycled over and over again. However, as it is recycled, residual levels in the scrap escalate and scrap is downgraded. At some point, it becomes uneconomical to recycle scrap. Greater control over residuals in obsolete scrap is required. This paper will describe the challenges to quantifying, tracking and controlling scrap residuals to make recycle activities sustainable in the long term.