Lundkvist K., Brämming M., Riesbeck J., Wedholm A., 2015, New Methods for Waste Minimization in an Integrated Steel Site, Chemical Engineering Transactions, 45, 739-744.
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.
