Paper industry sludge could reduce steel industry carbon footprint

The OSMET project is a pre-study to evaluate the potential in using sludges from the pulp and paper industry to make briquettes for the blast furnace. Potential synergies include less material being landfilled, less virgin material being generated (cement and limestone), reduced raw material costs and a more reactive briquette that requires less energy for the reduction process in the blast furnace.

“Merox is always working to develop new products and make sustainable solutions for SSAB. This pre-study is one small piece in that puzzle,” says Research Manager Diana Orrling from Merox. Merox has sent briquette material (according to a standard Merox recipe) to SwereaMefos for lab-scale briquetting using different organic sludges from SCA (hygiene and forest products company). The sludges are evaluated for their suitability in the blast furnace before attempting to make stable briquettes.

Merox’s mission is to optimize the processing of SSAB’s by-products, scrap and waste in Finland and Sweden. Through close cooperation within SSAB, Merox develops new ways to recirculate material within the steel process. Merox sells also products externally. Any material that is of no use today can be stored responsibly with potential future needs in mind. Merox also acts as a “practical tool” for SSAB to achieve its sustainable development targets. Each year Merox processes around four million tonnes of various residual products. Imagine around 100,000 juggernauts from nose to tail. The line would stretch from Oxelösund via Borlänge and Luleå in Sweden around the top of the Bay of Bothnia down to Raahe and Hämeenlinna in Finland, a total of around 1,900 km. This is to describe a true picture of the scale of Merox’s operation.

This OSMET project is one of 36 proposals that were taken up out of 168 that were sent in to Vinnova's Challenge-Driven Innovation Program. “In this case, we are using several different residual streams to increase the economic value for our respective companies: raw material savings, reduced landfill costs, reduced cement costs and reduced energy costs. This also creates ecological benefits by reusing resources instead of traditional lower value applications (liming, structure material, etc.) or landfilling,” says Diana Orrling.

Experts from SSAB, SwereaMefos, SCA, the Biofuel Technology Centre at SLU (Swedish University of Agricultural Sciences), SLU Holdings and Merox make up the pre-study group.

Regardless of the outcome, something has already been achieved: a step forward together to use by-products more effectively. “If the results are positive, the study will continue with a proposal to perform pilot tests to upgrade the biosludges, more lab testing and finally, large-scale tests with briquettes made at Merox for evaluation by SSAB. The environmental impacts, economic impacts and social impacts will be investigated through value chain analysis,” continues Diana Orrling.