Quartz is one of the most common and well-known minerals on the planet. Best known as the principal constituent of glass, quartz offers multiple other uses ranging from construction granulates to solar panels.
Quartz is a hard, crystalline mineral composed of silicon and oxygen atoms and the second most abundant mineral in the planet’s crust, after the feldspar family of minerals.
Quartz is a defining constituent of granite and other felsic igneous rocks. It is common in sedimentary rocks such as sandstone and shale as well as schist, gneiss, quartzite and other metamorphic rocks.
Quartz crystals, which are hexagonal in shape, vary enormously in size and color.
This versatile mineral is both durable and chemically inert and demonstrates excellent heat resistance as well as electric properties. Following transformation into silicon (Si) through gaseous reduction at high temperature, it becomes a valuable metalloid for the production of solar panels, semiconductors and electronics, aluminum and steel alloys and for the construction industry. Silicon tetravalence allows for numerous chemical combinations that are particularly appreciated in silicone applications such as cosmetics, gaskets elastomers, prosthesis.
Imerys owns three quartz extraction and processing sites. One in Sweden and two in southwest France producing high-purity quartz with an extremely high silica (99.8%) and low iron and titanium content.
The quartz is mined in block (Sweden) and pebble (France) form and processed at Imerys sites into high-purity grades before transformation into silicon for the solar panel, semiconductor, electronics, silicones and aluminum and special steel alloys markets or sold directly to the building industry.
The Group also owns a 50% interest in Quartz Corp, a group of companies specialized in the extraction and refining of high purity quartz in the US and Norway to serve the growing solar cell market.
Imerys high purity quartz is an ideal material for manufacturing the crucibles used in the casting of silicon for photovoltaic cells that make up solar panels and semiconductor components. Imerys and Norsk Mineral formed The Quartz Corp through a joint venture in 2011. The Quartz Corp is a key supplier of High Purity Quartz Sand for the solar, semiconductor, and fibre optic markets. The quartz is sourced in Spruce Pine, North Carolina, USA, where the unique geology offers the world’s highest purity quartz deposits. From there, products are shipped to a state-of-the-art facility in Drag, Norway, enabling the production of quartz which is 99.998% SiO2. More information can be found on the Quartz Corp website.
In the aluminum and steel industry, Imerys quartz pebbles, once transformed into silicon, are essential ingredients in the manufacture of ferro-alloys and silicon for aluminum alloy and silicone production.
In refractories, Calderys high-grade, quartzite-based silica products have been benchmarks for decades for production of linings for coreless induction furnaces for melting and holding iron. The main difference between Quartz and Quartzite comes from the way these minerals were formed geologically, which has an influence on their properties. While quartz is a primitive raw material, quartzite is a secondary raw material because it has been changed by further geological modifications after the initial quartz formation.
Imerys also produces quartz aggregates (sand and gravel) and pebbles for decorative use to serve the construction and public works sectors.
The crucible used in the construction of the cells used in the panels is made with quartz sand.
Imerys will continue to focus its research efforts on finding new outlets for its high-purity quartz products that support the use of energy from renewable sources such as solar power cells.