More sustainable production of Silicon from quartz
News from 2020
The project SisAl Slag Valorisation coordinated by prof. Gabriella Tranell receives funding from the EU body EIT Raw Materials. Prof. Ann Mari Svensson and Assoc. Prof. Jafar Safarian will also be active in the project. The project is an acceleration action within the thematic area: Increased resources efficiency in mineral and metallurgical process. The duration of the project is three years and the total budget is about 4.8 M Euro.
The project aims to produce Silicon (Si) from quartz (SiO2) in a more sustainable manner by replacing carbon with secondary aluminium sources (i.e. scrap and dross) as reductant and in parallel making an intermediate slag, which is a perfect precursor for High Purity Alumina (HPA) processing, see figure below. Silicon and HPA are vital raw materials for the transition to the low carbon society; Si as a dominant photovoltaic (PV) material for solar energy applications and as an important ingredient in light-weight applications (automotive and others), while HPA is a key material in Light Emitting Diodes (LEDs) and increasingly in Lithium Ion Batteries (LIBs).
Today, both Si and HPA are produced non-sustainably; for each tonne of Si produced high amounts of CO2 and other harmful pollutants are realised. Similarly, HPA is today made from ultrapure primary aluminium, having a large CO2 footprint. In the SisAl process these two products will be produced with a much lower environmental impact. In order to lower the already superior low CO2 footprint of the SisAl process, an integrated CO2 looping will also be introduced in the SisAl slag valorisation project. Si and HPA produced through these processes will be validated for market introduction towards the end of the project. The project consortium covers the value chain from raw materials provider to product user, with partners from SME´s, companies, institutes and universities: