Graphite's main component is carbon (C), making it an allotrope of the element carbon. In natural graphite, carbon atoms are arranged in a specific pattern, forming a layered crystal structure. Pure graphite has a carbon content close to 100%, but naturally mined graphite ore usually contains a certain amount of impurities, and its actual composition is affected by the type of deposit, mineralization conditions, and beneficiation processing techniques. Common impurities in natural graphite include silicate minerals such as quartz, feldspar, and mica, and may also contain small amounts of compounds of elements such as iron, aluminum, calcium, and magnesium. In addition, some graphite ore may also contain small amounts of sulfur and other trace elements. Therefore, the chemical composition and carbon content of graphite from different origins and of different grades may vary.
The carbon content of graphite is one of the important indicators for evaluating its quality and use value. Processes such as crushing, grinding, flotation, and further purification of natural graphite can increase its fixed carbon content and reduce mineral impurities. Depending on the degree of processing and the intended use, the fixed carbon content of graphite products can be increased from a low level to over 99%, with some high-purity graphite products even reaching over 99.9%. High-carbon graphite is typically suitable for applications requiring high purity, such as battery anode materials, electronic materials, precision graphite products, and high-temperature industries. Graphite containing certain impurities can be used in casting, lubricants, and the production of some refractory materials, depending on its properties. It is important to note that the fixed carbon content of graphite is not entirely equivalent to its purity; a specific evaluation requires consideration of testing methods, impurity types, and product standards. Overall, carbon is the core component of graphite, while impurity content and crystal structure further affect its electrical conductivity, thermal conductivity, high-temperature resistance, and practical application performance.
