Silicon metal is used, among other things, as an aluminium alloyant; it is also employed in the chemicals industry for the manufacture of siloxanes and silicones. Silicon metal can also be used as essential material in the electronics and solar industries (silicon chips, semi-conductors,solar panels). It can improve the already useful properties of aluminum such as castability, hardness and strength. Adding silicon metal to aluminium alloys makes them light and strong. So, they are increasingly used in the automotive industry. Used to replace heavier cast iron parts. Automotive parts such as engine blocks and tire rims are the most common cast aluminum silicon parts.
Silicon metal is extracted from quartzite, aided by the addition of wood chip and coal, in electric arc furnaces at temperatures of around 2,000 degrees Celsius. Our plant obtains its key raw material quartzite primarily from PCC’s own quarry in Zagórze, Poland. However, the related logistical costs are more than outweighed by the advantages of electricity procurement. And the dust emissions generated during silicon metal production are almost completely removed from the ambient air by high-performance filter systems installed in the PCC plant. Taken as a whole, therefore, the production process offers exceptional sustainability credentials.
The plant in Bakki is designed to produce ≥ 98.5% pure silicon metal from imported raw materials, that is, quartz and carbon; reactive coals with low ash content, wood chips, and a small amount of limestone.
In Phase 1, production takes place in two submerged arc furnaces. Each of them utilizes 24 MW of electrical power for the annual production of a total of approx. 32,000 metric tons of the final product, that is, silicon metal. For the production, we use pre-baked graphite electrodes.
In addition to the electricity used for the silicon metal production, 4 MW is needed to drive the gas cleaning plants (GCP) which treat the exhaust from the furnaces. The total power consumption of the plant in Phase 1, is therefore 52 MW.
PCC BakkiSilicon hf. has been designed as one of the most climate-friendly and environmentally compatible silicon metal plants in the world. The use of Iceland´s geothermal resources in the silicon metal production cuts greenhouse gas emissions by around two-thirds as compared to other plants around the world. With silicon metal production at the PCC plant powered entirely by renewable energy, the overall CO2 footprint of the whole process is drastically reduced.