In a complex industrial batch processes such as the top-blown BOF steelmaking process, it is a complicated task to monitor and act on the progress of several important control parameters in order to avoid an undesired process event such as "slopping" and to secure a successful batch completion such as a sufficiently low steel phosphorous content. It would, therefore, be of much help to have an automated tool, which simultaneously can interpret a large number of process variables, with the function to warn of any imminent deviation from the normal batch evolution and to predict the batch end result. One way to compute, interpret, and visualize this "batch evolution" is to apply multivariate data analysis (MVDA). At SSAB Europe's steel plant in Luleå, new BOF process control devices are installed with the purpose to investigate the possibility for developing a dynamic system for slopping prediction. A main feature of this system is steelmaking vessel vibration measurements and audiometry to estimate foam height. This paper describes and discusses the usefulness of the MVDA approach for static and dynamic slopping prediction, as well as for end-of-blow phosphorous content prediction. Multivariate data analysis (MVDA) methods have been applied on the top-blown BOF steelmaking process, with the main aim to create industrially applicable static (i.e., prior to blow), as well as dynamic in-blow batch models for predicting the slopping probability. The MVDA approach has also been investigated in regard to in-blow prediction of end-of-blow phosphorous content.

Recycling of materials is of major interest in steelmaking for environmental reasons as well as economical ones. This work evaluates new methods for recycling of waste materials in an integrated steel site. The study estimates how much material can be recycled and which order that would be the most beneficial with respect to costs, energy and deposits. The work shows conflicting results, where a decrease in deposits will increase the energy use in the system. However, according to the analysis, implementation of additional cases should improve the material efficiency, and cases are planned to be tested in the near future.

Recycling of materials is of major interest in steel making for environmental reasons as well as economical. All process units produce by-products which are either recycled sold or put on landfill. The products have been selected into the categories slags, dusts and sludges. This work evaluates new methods for recycling of by-products in an integrated steel site. The study estimates how much material can be recycled and in which order that would be the most beneficial with respect to costs, energy and deposits. Main focus has been on by-products produced in significant quantities and those difficult to use because of their physical or chemical nature. The work show conflicting results and a pareto front was constructed comparing deposits with increased energy use and costs in the system. Chosen case studies have been tested in industrial scale and results from test periods have been used to compare modelling with process parameters. The results show that improved resource efficiency can be achieved by keeping the energy consumption constant or even receiving small energy credits. Major cost savings can be found if internal recirculation can replace raw material such as iron ore, coke and lime stone. Before the new methods will be implemented careful considerations will be made according to test results and predictions through modelling.