BioCarbon for Silicon and MicroSilica Quality

The project is part of Elkem’s work to reduce the use of fossil reductants (coal and coke) in smelting furnaces for silicon and ferrosilicon production. Elkem has developed biocarbon with very specific properties that include high mechanical strength both at normal and high temperatures as well as a balance between high porosity and high reactivity. Elkem’s biocarbon pilot plant is now producing material for full-scale testing in industrial smelters. It is important to understand the effect these new raw materials will have on the quality of the silicon, ferrosilicon and Microsilica® produced. The research in this area is difficult to perform in lab scale since the processes involved are scale-dependent. Therefore, the project will be based on full-scale experiments. Samples taken before, during and after introduction of new biocarbon will be compared with predictions from modeling tools. An important R&D task is to optimize raw material properties such as particle size distribution, mixing ratio and identify improved process conditions for the treatment of intermediates for subsequent production steps for high-value biocarbon products. By-product streams have the potential for chemical or energetic utilization. However, a precise characterization is necessary to be able to utilize this potential. The project therefore continues the work with advanced analysis of complex by-product streams. Introduction of larger amounts of biocarbon reductants increases the amount of undesired elements in the furnaces. Element distribution factors will be investigated, and new model tools will be developed to predict the qualitative and quantitative distribution of impurities. The project seeks to gain a more fundamental understanding of the formation of Microsilica® under the smoke hood in the furnace. This will be achieved by analysis of Microsilica® and advanced modeling of Microsilica® formation in the smelting furnace.

The overall objective of the BioSiMS project is to ensure that silicon, ferrosilicon and microsilica quality can be kept within or close to current specifications when reducing CO2-emissions from the process. Elkem's strategy is to be the world's most sustainable producer of ferrosilicon and silicon alloys and through this contribute to the zero-emission society. Changing the reduction material from fossil carbon (coal and coke) to biogenic reduction materials in the production process is a key part of the strategy. Elkem has establised the first pilot plant for production of newly developed biocarbon agglomerate developed through a series of earlier research projects. BioSiMS seeks to further support this development going into full scale and at the same time investigate the effect on chemistry and quality of Elkem's products silicon, ferrosilicon and microsilica. The overall goal is that the project will fast track the transition from pilot to full-scale production by omitting the majority of bottlenecks and risks and ensure that Elkem can maintain its position as a pioneer in renewable reductants in the metallurgical segment. The ultimate goal of the Project is to support Elkems work in the transition from fossile based carbothermic reduction to a mainly biobased production process, and at the same time ensure that product quality remains at today's high level through fundamental experimental R&D work and advanced modelling.