Optimized use of biochar and metallic residues for efficient production of cast iron

Important results from the project

The project analyzed samples of biochar and fossil carbon. Reactivity tests with air identified the most promising biochar for further work. We evaluated methods for mixing biochar and briquettes with mill scale into the melt, compared reactivity against fossil alternatives, and mapped the availability of biochar and binders. A literature review on flammability and safe handling was produced. The results provide a strong basis for decision-making for fossil-free, circular metal production.

Expected long term effects

The project is expected to contribute to sustainable and circular production of ferritic ductile iron by optimizing the use of scale in combination with biochar and scrap. By replacing primary raw materials with residual materials and fossil-free carbon sources, the climate footprint and costs can be reduced. The results can be disseminated to more foundries and metal companies, strengthening resource efficiency, competitiveness and climate-neutral production.

Approach and implementation

The project was headed in the right direction from the start but was mainly a feasibility study to identify suitable materials, focusing on biochar. The work was carried out mostly by Swerim and RISE, while the companies´ efforts mainly consisted of meetings and some participation. Experimental activity from the companies was limited. The budget was initially evenly distributed, but some companies took greater responsibility and financial follow-up from some came late, only at the end.