The difference between graphitized petroleum coke and graphitized crucible scrap

I. Absorption Rate of Graphitized Petroleum Coke (Virgin Material)

- Standard for electric arc furnaces and medium-frequency furnaces: 92%–96%

- With normal molten iron temperature and appropriate charging timing: Stable at around 94%

- High proportion of fine powder or premature charging leading to oxidation: Minimum 88%–90%

II. Absorption Rate of Graphitized Anode Crucible Fragments (Comparison)

Since crucible raw materials consist of graphitized petroleum coke and asphalt, the absorption rates are as follows:

- Premium-grade anode crucible fragments: 86%–90%

- Standard anode crucible chips: 82%–86%

III. Why Does Graphitized Petroleum Coke Have a Higher Absorption Rate?

1. Primary petroleum coke has complete graphitization and good flake structure, allowing molten iron to penetrate and dissolve easily

2. Crucibles contain approximately 20% asphalt coke, which has a lower degree of graphitization, thereby reducing the overall absorption rate

3. Crushed crucible fragments contain a high proportion of fine powder, leading to greater blow-off and burn-off losses

4. Crucibles are formed through extrusion, resulting in dense particles with less developed porosity compared to virgin coke

IV. Key Performance Indicators (Determining Absorption Rate)

- Graphitized petroleum coke: Fixed carbon ≥98.5%, ash content <0.5%, graphitization degree ≥93%

- Crushed anode crucible: Fixed carbon 94%–97%, ash content 0.8%–1.5%, graphitization degree 88%–92%

V. Simplified Comparison

Graphitized petroleum coke > Anode crucible scrap > Old-style clay crucible scrap

Absorption rate difference: approximately 6–8 percentage points