SSAB coke plant, Luleå

Alternative coke can reduce carbon dioxide emissions

7 November, 2016

Trials with new types of coke are currently under way at LKAB's experimental blast furnace in Luleå. Within Flexcoke, a research project managed by Swerea MEFOS, alternative coke is being developed and tested in pilot scale.

The types of coal used for making high-quality coke are considered critical raw materials for the European steel industry. Limited supply and high costs render the use of alternative coal and carbon-bearing materials all the more important as input for cokemaking.

Swerea MEFOS is project managing and coordinating the Flexcoke project, the aim of of which is to find ways of avoiding increased use of coal and coke in the blast furnace as a result of waning supplies of high-grade coking coal.

"In the project we have produced coke in several different stages, in both laboratory scale and pilot scale, and tested it in different ways including evaluation of basket samples charged into LKAB's experimental blast furnace. Following successful results we have proceeded with production trials at SSAB's coking plant, where the two coke grades that are now being tested in the experimental blast furnace have been produced. If these trials go as planned, we intend to make coke in large scale at the coking plant and test it in industrial scale in SSAB's BF No. 3," says Maria Lundgren, project manager at Swerea MEFOS.

The Swedish contributions to the project are being made in collaboration between Swerea MEFOS, SSAB and LKAB.

Anna Dahlstedt, engineering specialist at LKAB:
"The experimental blast furnace is a unique tool for research and development, and this is an important joint project that gives us an opportunity to assist our customers in their efforts to develop sustainable processes. By verifying the performance of the coke prior to testing in industrial scale the risks associated with full-scale trials can be reduced."

By acquiring new knowledge of the interaction between raw materials in the coal blend, coking properties and coke performance in the blast furnace researchers hope to be able to develop alternative coke with optimal quality for the blast furnace.  This has major, positive implications for reduced carbon dioxide emissions and energy use.

"Test results for the alternative coke are very encouraging. The type that will be selected for production-scale trials depends on the results of trials in the experimental blast furnace. In full-scale trials later in the project, in order to minimize deviations in the process, a successively greater proportion of alternative coke will be used," says Per Lagervall, process engineer at SSAB's Luleå blast furnace.

Funded by RFCS (Research Fund for Coal and Steel), the project will continue through 2017. The total budget is 5.1 million euros. Other project partners include TKSE, one of Europe's biggest steel producers.