The most direct impact of high or low volatile matter content in petroleum coke on the calcination process is: it determines whether the calcination zone can be self-sustained and whether the furnace condition (especially temperature and coking/blockage) remains stable. In essence, it directly determines the supply of “internal fuel” required for calcination.
This manifests in two directions:
1) Low volatiles → Calcination temperature is hard to maintain (most direct)
The volatiles released from petroleum coke during calcination burn within the fire channels/calcination zone — they are the primary internal heat source for both can (potted) furnaces and rotary kilns.
When volatiles are too low, there is insufficient combustible gas in the fire channels, the calcination zone temperature drops, and the situation of “insufficient fuel, inadequate temperature, and incomplete calcination” easily arises. This directly leads to deteriorated calcined coke quality (low true density, high resistivity, etc.), and additional natural gas/fuel often needs to be supplemented to maintain temperature.
2) High volatiles → Coking, blockage, and furnace condition deterioration (most direct)
When volatiles are too high, large quantities are released in the low-temperature zone (preheating zone, ~200–500 °C), often in a viscous/pasty state. The material easily adheres to the kiln/can walls, causing:
- Severe ring formation and coking blockage at the kiln tail / inside the can
- Volatile passage blockage, discharge port coking, and difficulty in discharging material
- Calcination zone temperature fluctuations or even “fire channel collapse” (localized overheating)
Meanwhile, the greater the amount of volatiles released, the greater the mass loss after calcination, and the yield decreases (there is an engineering rule of thumb: for every ~1% increase in volatiles, the yield decreases by approximately ~1%).
One-sentence summary:
The most direct impact of volatile matter level is: whether the calcination process can stably maintain calcination temperature and smooth coke discharge through self-combustion of volatiles — too low means “no fire to burn, temperature drops,” too high means “coking and blockage, furnace chaos.”
(For rotary kilns, this further manifests as a chain of consequences: ring formation → poor preheating → shortened calcination zone → decreased product true density, increased specific resistivity, etc.; for can furnaces, it is more prominently seen as internal coking and fire channel temperature runaway.)
Post time: May-19-2026