Bio-Binders and its Carbonization and Interaction with Petroleum Coke during Baking

Abstract

To reduce the carbon footprint in aluminium production, bio-based binders are suggested to replace some or all coal tar pitch in the carbon anodes. In this study, bio-binders based on Norwegian spruce and birch woods were produced in a laboratory setup, which were studied in terms of wetting properties towards petroleum coke. The binders were mixed with petroleum coke and baked to three different temperatures. Graphitization of the binders was investigated on pure carbonized binders by XRD. Optical light microscopy was used to investigate the structures and interactions between coke and binder after baking. The bio-based binders appeared to adhere well to the coke particles, indicating excellent wetting behaviour during mixing. The optical structure of the carbonized bio-binder seemed to be affected by strain due to shrinkage of the bio-binder around the coke grain boundaries.