Graphite beneficiation is generally carried out by means of
flotation separator, which can be harvested with neutral oil. Pay attention to the following points during the flotation process:
(1) First find out the type of graphite ore. Graphite ore is divided into flaky graphite ore and earthy graphite ore. The characteristics of flaky graphite ore are that the graphite is scaly or leaf-like, and the ore grade is not high, generally ranging from 3% to 5%, and the highest is not more than 20% to 25%. This type of graphite has good floatability. After flotation, the grade can reach more than 90%. Therefore, the ore grade can be mined from 2% to 3%.
The flaky graphite has excellent properties and can generally be used to manufacture high-grade carbon products. Earthy graphite is also known as cryptocrystalline graphite ore. The graphite crystal of this ore is small, generally less than 1 μm, the surface is earthy, lacks luster, and the industrial performance is inferior to scaly graphite. The ore grade of this graphite ore is relatively high, generally 60% to 80%, but the floatability is very poor. After flotation, the grade will not be significantly improved.
Therefore, raw ore with a grade of less than 65% is generally not mined, and the grade is between 65% and 80%. It can be used after sorting. Therefore, for graphite ore, you should not only look at the level of the original ore grade, but should first clarify its type, and then decide whether it can adopt the flotation scheme.
(2) High requirements on product quality. Graphite products have higher grade requirements. For example, ordinary scale flake graphite requires grades above 89%, and pencil graphite grades require 89% to 98%. Some electric carbon graphite requires a grade of 99%. In order to obtain high-grade graphite concentrates, in the graphite flotation, the number of selections is generally more.
(3) Pay attention to the protection of large scales during the selection process. Large scale graphite has a wide range of uses, low resources and high value, so care must be taken to protect large scales from being broken during production. Usually large scales refer to scaly graphite of +50 mesh, +80 mesh, +100 mesh. The measure to protect the large phosphorus tablets is to use multiple grinding and multiple sorting processes in the sorting process.
The graphite dissociated from the monomer obtained by each grinding is selected in time. If the ore is ground to a very fine particle size, the large scales are destroyed. For example, China's large graphite mine Nanshu graphite mine, which uses a rough selection, a sweeping, four grinding, six selected processes, not only protects the large scales from damage, but also makes the concentrate grade 90%.