Graphite refers to a naturally occurring carbon ore, which is a carbonaceous non-metallic mineral, usually existing in metamorphic rocks, and its symbiotic minerals are more complex, mainly accompanied by feldspar, quartz, biotite and other impurity minerals.
3 types
The process characteristics of graphite mainly depend on its crystalline form, according to the different crystalline forms, the industry usually divides natural graphite into dense crystalline graphite (bulk graphite), cryptocrystalline graphite (soil-like graphite) and flake graphite, these three types of graphite ore are different in mineralogy, morphology, carbon content and purity.
Massive graphite is relatively rare in nature, and it is the most valuable graphite mine, and its crystalline state is the best, but its plasticity and smoothness are not as good as flake graphite;
The particle size of soil-like graphite is extremely fine, the content of impurities is more, the crystallization state is the worst, the floatability is poor, and the utilization is more complicated.
Flake graphite is one of the best floatable ores in nature, although the raw ore grade is not high, but after many times of grinding, multiple separation, high-grade graphite concentrate can be obtained, the floatability, lubricity, plasticity and so on of this kind of ore are better than other types of graphite, so its industrial application value is the greatest.
6 ways
Because natural graphite ore often contains a variety of impurities, so it is necessary to improve its purity and application value through the beneficiation process, the common graphite beneficiation methods include flotation separation, gravity separation, acid leaching, heat treatment, electrostatic separation and combined beneficiation, among which gravity separation, flotation, electric separation are widely used in graphite production.
There are various types of graphite, and the structural characteristics are not the same, and the applicable beneficiation scheme is naturally different. For example, flake graphite has good floatability, so most of them are separated by flotation method, while for graphite ore with a variety of gangue, a combined process of gravity separation and flotation can be used.
In addition, the specific type and quality of graphite ore has an important impact on its suitability for various industrial applications, and in actual production, each industrial sector also has its own requirements for the purity of graphite, so it is necessary to use a relative graphite beneficiation process to purify it before use.
Commonly used equipment
The hardness of graphite ore is generally medium hard or medium hard and soft, and jaw crusher is generally used for coarse crushing, and cone crusher or hammer crusher is used for medium and fine crushing; Wet ball mill and lattice ball mill are used for grinding; JJF, XCF and XJB flotation machines are commonly used for flotation; Hydrocyclones or belt filter presses are commonly used for mineral processing and dehydration.
It should be noted that graphite is not only required to have a high concentrate grade in mineral processing, but also to protect the crystal structure of graphite as much as possible, therefore, considering that the large-diameter mill throws stronger, has a greater impact on graphite ore, and is more prone to destroy the scale state of graphite, the diameter of 2 is generally used in on-site productionBall mill with specifications below 7m, and adopts a multi-stage re-grinding and re-selection process to protect the large graphite flakes from damage.
From industrial manufacturing to aerospace, from new energy technologies to modern communications, graphite plays a key role, so it is crucial to ensure the quality of graphite products by extracting high-purity graphite through the beneficiation process.