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.
Introduction of larger amounts of biocarbon reductants increases the amount of undesired elements in the furnaces. The removal of such elements by classical ash removal technologies and process conditions has been investigated for each process stage to identify synergetic effects during biocarbon production. Furthermore, element distribution factors are investigated based on the physicochemical properties of the reductants, and new model tools will be developed to predict the qualitative and quantitative distribution of impurities. Moreover, analytical procedures were developed for tailor-made reductants to characterise weathering and aging effects, minimize the risk of local pollution and degradation by low temperature oxidation.
Effects of biocarbon on Microsilica® grade are investigated by statistical analysis during industrial scale production. The various grades of Microsilica® are based on impurity concentration levels and their location and can be affected differently. While medium grade Microsilica® is less affected by biocarbon as a substitute, high grade Microsilica® requires an analysis in greater detail. Therefore, advanced analysis techniques were tested and support identifying potential upgrading routes for high-value applications.
As more biocarbon is introduced into the smelting process, understanding its impact on key products such as Microsilica®, silicon, and ferrosilicon becomes critical. Advanced characterization techniques have been applied to monitor changes in chemical composition, particle properties, and elemental distribution. Moreover, industrial-scale trials combined with statistical and multivariate analysis are helping us identify key trends and correlations between raw material properties, furnace parameters, and product quality during the BioC trials. These insights are forming the basis for predictive tools and control strategies to ensure that products remain within specification as biocarbon use increases."
The formation of silica fume takes place at very high temperature in a very chaotic environment that is almost completely inaccessible. This makes any direct measurements of the particle formation and growth nearly impossible. Instead, we have to turn to fundamental mathematical modelling of the underlying chemistry and physics that govern the formation process. Using advanced mathematical numerical simulation techniques such as Direct Numerical Simulation (DNS) and Computational Fluid Dynamics (CFD) the project will simulate the formation of silica fume in both minute detail and on a larger scale. Using DNS we are able to investigate which chemical and physical mechanisms that govern the particle formation and growth. Whereas CFD is used to simulate the entire furnace process to investigate how furnace operation and raw material properties influence the silica fume formation.”
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.
