Graphite is a gray black opaque solid with stable chemical properties and corrosion resistance. Chemical formula: C CAS accession No. 7782-42-5 Melting point 1300 ℃ to 3500 ℃ Boiling point 4830 ℃ Density 1.5g/cm --- 2.5g/cm
Graphite powder is a widely used industrial raw material, classified into various specifications based on purity, particle size, and other indicators. It is applied in metallurgy, electrical engineering, batteries, coatings, lubrication, and many other fields.
一、It can also be classified according to the size and morphology of graphite crystals：
（1）Flake graphite powder:Crystal particle size is greater than 1μm, appearing as flakes or fish scales. This type of graphite exhibits excellent properties, including good high-temperature resistance, electrical conductivity, thermal conductivity, lubricity, and plasticity, making it the most widely used. The classification of high-purity, high-carbon, medium-carbon, and low-carbon graphite primarily refers to this type of product.
|
规格Grade |
粒度% 筛上 Size (On Screen) |
粒度% 筛上 Size (Passing Rate) |
固定碳% Fixed Carbon |
水分 % Moisture |
|
中碳 Medium Carbon |
≥75 |
≤25 |
80-93 |
≤0.5 |
|
中碳 Medium Carbon |
≤20 |
≥80 |
||
|
高碳 High Carbon |
≥75 |
≤25 |
94-99.99 |
|
|
高纯 High Purity |
≤20 |
≥80 |
（2）Amorphous graphite powder (microcrystalline/cryptocrystalline graphite): Crystal particle size is less than 1μm, forming microcrystalline aggregates. Its crystals are small and have poor selectivity, but it is chemically stable and contains low levels of harmful impurities (such as sulfur and iron), making it widely used in casting, batteries, and refractory materials.
|
规格 Grade |
灰分% Ash |
固定碳% Fixed Carbon |
硫含量% Sulfur |
粒度 Size （Mesh） |
|
1 |
≤22 |
≥75 |
≤0.3 |
-100 ,-200 -250, -325 |
|
2 |
≤17 |
≥80 |
≤0.2 |
|
|
3 |
≤13 |
≥85 |
≤0.2 |
二、Classification by Purity (Fixed Carbon Content):
（1）High-purity graphite（≥99.9%）：Semiconductors, nuclear reactors, high-end sealing materials, aerospace.
（2）High-carbon graphite（94%-99.9%）：Flexible graphite sealing materials, high-grade lubricant base materials, precision casting.
（3）Medium-carbon graphite（80%-94%）：Ordinary refractory materials, crucibles, pencil leads, battery carbon rods.
（4）Low-carbon graphite（50%-80%）：Foundry coatings, metallurgical carbon raisers, low-end refractory materials.
三、Classification by Particle Size (Powder Fineness):
Particle size determines the adhesion, lubricity, and dispersibility of graphite powder, and is an important parameter for application selection.
（1）Ultrafine graphite powder (colloidal graphite powder): Particle size is typically between 1μm and 38μm (equivalent to 325 mesh to 12500 mesh). It possesses better adhesion, lubricity, and conductivity, and is commonly used in high-end greases, conductive coatings, and graphite emulsions.
|
规格 Grade |
固定碳% Fixed Carbon |
粒度 Size |
水分 % Moisture |
|
A-1 |
95-99.99 |
D50:1-15um D90:2-30um |
≤0.5 |
（2）Ordinary mesh graphite powder: Classified by sieve mesh size, common specifications include 100 mesh, 200 mesh, 325 mesh, 800 mesh, 1200 mesh, 2000 mesh, etc. The higher the required fineness, the larger the mesh number.
四、Besides the above three main categories, in actual production and applications, the following are also used:
（1）Artificial graphite: artificial graphite (such as graphite electrodes) is made from petroleum coke and other raw materials through high-temperature graphitization treatment.
|
固定碳% Fixed Carbon |
粒度 Size (Mesh） |
水分 % Moisture |
|
90-99.99 |
20-40 ，40-60， 60-80 |
≤0.5 |
（2）Expandable graphite/expanded graphite: Refers to graphite that has undergone special chemical treatment and can expand instantly (up to hundreds of times its original volume) when exposed to high temperatures. It is an intermediate product in the production of flexible graphite sealing materials.
|
固定碳% Fixed Carbon |
挥发% Volatile |
膨胀率% Expansion Rate |
水分 % Moisture |
PH |
|
90-99.99 |
≤15 |
100-400 |
≤1 |
3-8 |
