Modelling the reduction of quartz in a quartz–carbon pellet

Abstract Traditional refining of silicon generates carbon dioxide emissions that are released into the atmosphere. An alternative process under experimental exploration uses quartz particles coated in a layer porous as raw material, instead lumps and carbon. The quartz–carbon pellets processed at lower temperature than an industrial furnace, hence, different chemical reactions dominant, reducing greenhouse gas emissions. core shrinks it is consumed, converted to carbide, which can subsequently be silicon. We develop model for transfer processes within single pellet. derive governing equations concentration monoxide, dioxide, conservation on moving interface. Furthermore, we then focus reduced industrially relevant distinguished limit, solve numerically resulting leading-order system. show examples reaction-limited behaviour well diffusion-limited behaviour. Both regimes physically admissible due large potential range parameters. Finally, sweep through parameter space, characterize dynamics based utilization yield. find regime best yield, monoxide reacts with before transported out