Ores of almost all graphite deposits can rarely be used raw by consumers. Virtually all of them are subjected to a particular pretreatment in order to convert the ore into finished products.
The technological classification of graphite ores coincides with the classification of natural types.
Explicitly crystalline ores are processed mainly by flotation schemes due to the good flotation of graphite.
The cryptocrystalline graphite raw material is represented by finely dispersed minerals in a very complex germination with empty rocks. Therefore, such types of graphite ores almost do not lend itself to mechanical enrichment. They are mainly used in ore mining and, in special cases, methods of chemical, thermal or other processing methods. Due to the fact that these processes are expensive, it is rarely used.
The main indicators on which graphite products are evaluated are: texture-structural, carbon, ash, moisture, volatile components, harmful impurities (iron, sulfur, copper, etc.), granulometric composition.
In the foundry industry preference is given to cryptocrystalline graphite, since for this production the dispersion of the powder is important, providing a smooth surface of the molds and facilitating the removal of the castings after cooling.
High-quality, clearly crystalline graphites are widely used in special steel casting.
Crucible graphite is represented by three brands. Zoning does not exceed 7, respectively; 8.5 and 10%, the mass fraction of iron in terms of Fe2O3 for all brands is not more than 1.6%, volatiles – less than 1.5%; Moisture – no more than 1%.
For the production of graphite-ceramic melting crucibles and refractories, high-quality, clearly crystalline graphite is used.
In accordance with the requirements for lubricating graphite, the products are manufactured in the form of several grades, each of which has its own direction of application and is characterized by a number of indicators. Common to all brands are only indicators of the concentration of hydrogen ions of water extract and humidity.
The production of pencils, as well as the electro-carbon, makes the highest demands on the quality of graphite. In the world practice for the best varieties of pencils used a mixture of Ceylon and other crystalline or cryptocrystalline graphite, which is most often used for the production of ordinary varieties of pencils.
In the electric coal industry, graphite of three types is used: natural fine and concealed and artificial and artificial. Artificial graphite has become widespread due to its high purity and consistency of composition.
In the production of lubricants as solid substances, natural crystalline graphite is widely used and, together with it, graphite is artificial. This production requires graphite of usually high purity and very fine grinding, sometimes of colloidal dimension. Lubricants are most often aqueous or oil suspensions made of natural crystalline and artificial graphite.
A number of graphite grades do not allow clogging impurities, including graphite from other deposits. These grades include crucible, elemental and electro-carbon graphite.