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.
Silicon metal (CAS 7440-21-3) is commonly known as metallurgical grade silicon or metallic silicon because of its shiny metallic colour. In industry it is mainly used as an aluminium alloy or a semiconductor material.
Silicon metal is also used in the chemical industry to produce siloxanes and silicones. It is considered to be a strategic raw material in many regions of the world.
The economic and application significance of silicon metal on a global scale continues to grow. Part of the market demand for this raw material is met by a producer and distributor of silicon metal – PCC BakkiSilicon hf. which conducts its business activities on the picturesque island of Iceland.
Silicon metal is also known as metallurgical silicon or, most commonly, simply as silicon.
Silicon itself is the eighth most abundant element in the universe, but it is rarely found in pure form on Earth. The US Chemical Abstracts Service (CAS) has given it the CAS number 7440-21-3.
Properties of silicon metal
The silicon metal offered by the manufacturer PCC BakkiSilicon is produced from quartzite (the naturally occurring mineral SiO2), coal and wood. During the production process, quartz (SiO2) is reduced by carbon (C) to silicon carbide (SiC). The silicon carbide becomes a reducing agent for the rest of the quartz that has not reacted in the electric arc produced by three electrodes.
In the initial stage of the process, production takes place in two resistance-arc furnaces, where the temperature reaches 2,000°C. Graphitised electrodes are used in the production.
The total amount of energy used by the furnaces is 25 MW. An additional 4 MW is used to operate the flue gas cleaning plant.
The final result of the process is ≥ 98.5% pure silicon metal.
A by-product of its production is microsilica, which is separated from the flue gases thanks to the special bag filters with which the factory in Iceland is equipped. Thanks to these types of filters, the dust from the air generated during the production process is almost completely removed.
The vast majority of the raw material is converted into silicon metal, so the production process generates very few solid by-products. A small part of the raw material is also obtained in the form of slag.
It is worth mentioning that microsilica, which is produced as a by-product of silicon metal production, is a popular and widely used additive for concretes and mortars. It is also used in the production of various ceramic and refractory products.
Silicon steel also known as laminated steel or silicon electrical steel, is a material used in the manufacture of some magnetic cores such as rotors in transformers and motors.
Silicon steel is also an essential material for the power, electronics and defence industries.
Non-oriented electrical steel typically contains 2% – 3.5% silicon. It has similar magnetic properties in all directions, known as isotropy.
Oriented grain steel usually contains 3% silicon and is processed to achieve ideal properties in the rolling direction.
What are the properties of silicon steel?
The supply of silicon metal from domestic sources and from imports, is not sufficient to completely cover the global industrial demand. Silicon metal is globally recognised as a scarce and critical raw material.
Guaranteeing the security of a country’s raw material supply is based on securing the supply of the mineral and systematically gathering knowledge and data on the abundance of local deposits.
According to the report entitled ‘Silicon Metal Market Size & Share Report, 2020–2027’, it is mainly aluminium production that drives the demand for silicon metal.
Growing demand for silicones (especially in developing countries), may also benefit silicon metal production. Asia-Pacific plays a significant role in this regard as it is a huge processing base for silicon metal for various industries.
Demand from European producers is also high, as Europe is one of the key producers of silicones. The COVID-19 pandemic, however, has left a strong mark on North American markets. This region has seen a temporary decline in the aluminium industry.
Silicon metal, which is used in the production of photovoltaic panels, will play a key role in the coming years, for example in Saudi Arabia, where a large photovoltaic project is in progress. It is expected to be completed in 2030. This huge investment, and others like it, is expected to benefit the further development of the silicon metal market.
The price of silicon metal depends on production costs. The production of 1 tonne of silicon requires about 6 tonnes of raw material, including 2.7 tonnes of quartz, 1.5 tonnes of reducing agents (low ash coal or charcoal) and 1.5 tonnes of wood.
Another important factor on which the price depends is energy. The price per kilogram of silicon metal is also controlled by the cost of other ingredients such as coal, quartz and oil.
According to research firm PRNewswire, the global silicon metal market is worth about $6.3 billion. It is expected to grow to 8.9 billion by 2027. The raw material crisis that began in 2021 has caused silicon metal prices to increase by around 300%.
An analysis of the global market clearly shows that the importance of silicon metal is constantly growing. So, in which sectors and areas of the economy is this raw material in the highest demand? What is it used for?
It is worth noting that aluminium-silicon car parts are lighter and stronger than parts cast from pure aluminium. Automotive parts such as engine blocks and tyre rims are the most common cast aluminium silicon parts.
Around five tonnes of polysilicon are needed to produce one megawatt of solar modules.
Today, polysilicon solar technology accounts for more than half of the solar energy produced worldwide.
Silicon can be found in virtually all computers, mobile phones, tablets, televisions, radios and other modern communication devices.
It is estimated that more than a third of all electronic devices contain silicon-based semiconductor technology.
The PCC Group, in its extensive product portfolio, offers different a variety of silicon metals. It is easy to find this product in the product catalogue by giving the CAS number: 7440-21-3.
The producer of silicon metal, PCC BakkiSilicon hf., is based in Iceland. The production capacity of the factory is approximately 32,000 tonnes of silicon metal per year. It has one of the most modern production facilities in the world. Importantly, 100 % of the energy used there comes from geothermal sources. Thanks to innovative solutions, the factory in Iceland is considered to be one of the most environmentally friendly. Using Iceland’s geothermal resources for energy cuts greenhouse gas emissions by around two thirds. As a result, the carbon footprint of the entire process is dramatically reduced.
By choosing silicon metal from the PCC BakkiSilicon range, customers are buying a raw material that:
Commercially available products named PCC BakkiSilicon 441 or PCC BakkiSilicon 3303 denote silicon metal. The manufacturer introduces these specifications due to the different content of elemental silicon in the final product, which ranges from 97% to 99%. In addition, iron, aluminium and calcium are also present in the composition. However, these metals represent trace amounts. The aluminium content is a maximum of 0.20% – 0.50%, iron 0.20% – 1.80% and calcium 0.02% – 0.30%.
Silicon metal manufacturer, PCC BakkiSilicon offers the following forms of silicon metal:
Discover our full product range for silicon metal at www.products.pcc.eu.