Types and uses of natural graphite
In crystalline (flake) graphite ore, the diameter of graphite crystals is greater than 1μm, which is scaly; the grade of the ore is low, but the selectivity is good; the minerals associated with graphite often include mica, feldspar, quartz, tremolite, and transluminescence Stone, garnet and a small amount of pyrite, calcite, etc., and some are also associated with useful components such as rutile and vanadium; the ore has a scaly, granite scaly or granular metamorphic structure, flaky, gneissic or massive structure .
Crystalline (flake) graphite is classified into high purity graphite, high carbon graphite, medium carbon graphite and low carbon graphite according to the fixed carbon content.
High-purity graphite (fixed carbon content greater than or equal to 99.9%) is mainly used for flexible graphite sealing materials, nuclear graphite, instead of platinum crucible for chemical reagent melting and lubricant base materials;
High-carbon graphite (fixed carbon content 94.0%～99.9%) is mainly used for refractory materials, lubricant base materials, electric brush materials, electric carbon products, battery materials, pencil materials, fillers and coatings, etc.;
Medium carbon graphite (fixed carbon content 80%～94%) is mainly used in crucibles, refractory materials, casting materials, casting coatings, pencil materials, battery materials and dyes, etc.;
Low-carbon graphite (fixed carbon content 50.0%～80.0%) is mainly used for casting coatings.
Cryptocrystalline graphite is also called earthy graphite or amorphous graphite. In cryptocrystalline graphite ore, the diameter of graphite crystals is less than 1μm, which is an aggregate of microcrystals. The crystal form can only be seen under an electron microscope; the ore grade is high, but the selectivity is poor ; Minerals associated with graphite often include quartz, calcite, etc.; the ore has a fine scale-cryptocrystalline structure with a massive or earthy structure.
Cryptocrystalline graphite ore is mainly distributed in contact metamorphic deposits. In fact, the diameter of graphite flakes in graphite ore is uneven. The so-called crystalline graphite ore may also contain cryptocrystalline graphite. When the content is large, it is usually called mixed graphite ore, and cryptocrystalline graphite ore may also contain cryptocrystalline graphite. A small amount of flake graphite with a diameter slightly larger than 1μm.
Cryptocrystalline graphite is mainly used for pencils, batteries, welding rods, graphite emulsion, graphite bearing ingredients and battery carbon rod raw materials; cryptocrystalline graphite without iron requirements is mainly used for casting materials, refractory materials, dyes and electrode pastes, etc. raw material.