# IGNITION OR EXPLOSION OF GAS OR DUST
> MSHA accident `220061910012` · 07/06/2006 · Heidelberg Materials US Cement LLC
## Details
- **Degree of injury:** ACCIDENT ONLY
- **Classification:** IGNITION OR EXPLOSION OF GAS OR DUST
- **Accident type:** Accident type, without injuries
- **Occupation:** —
- **Activity:** —
- **Injury source:** —
- **Nature of injury:** —
- **Body part:** —
- **Days lost:** 0
- **Mine experience:** — years
## Operator
- **Controller:** Heidelberg Materials AG
- **Operator:** Heidelberg Materials US Cement LLC
- **Mine:** [1200063](https://api.ai-analytics.org/mine/1200063)
## Narrative

The #2 coal mill drive shaft coupling broke causing the coal mill and coal mill system fan to stop.  Due to the coal mill system fan stopping the primary air fan intake air became very hot (>300 F) and ignited the pulverized coal dust in the fan or ductwork causing an overpressure in the system and rupturing the coal mill rupture disc.  There were no personal injuries.

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*Source: [MSHA Open Government Data](https://arlweb.msha.gov/OpenGovernmentData/) · AI Analytics · CC0 1.0*