By Kevin Collins, President and CEO

We have completed our investigation of an incident that occurred Monday night at our coal refinery in Gillette, Wyoming.  In line with our procedures we asked that two of our employees be examined at the hospital . They were examined, released, and returned to work the following morning.

The incident happened at 5:05 pm MT on the “B Processor” side of the plant. The B Processor was not operating at the time.  We were doing maintenance and conducting some timing tests under engineering supervision. This incident was not related to the K-Fuel® process itself.

An ignition event occurred in the area known as the coal hopper , which is below our bottom product lock and before rotary cooler. 

The incident occurred when our staff was testing cycle times.   Both the upper and lower product locks were open during testing, which is not the case when we are making K-Fuel®.  A small amount of coal apparently dropped from the top lock into the processor, and cascaded down into the coal hopper. 

It connected with an ember from some residual coal, to the coal hopper, which was functioning as normal, and moved along through the system, into rotary cooler, where the damage occurred between 5:05 and 5:07pm yesterday.

The lock hopper is akin to a submarine hatch.  It allows batches of coal to exit the pressure vessel without reducing the pressure inside the vessel. Keep in mind, however, that the B Processor was not operating at the time of the incident, so there was no pressure inside it. The rotary cooler is a long, nearly horizontal metal cylinder that rotates slowly. It’s positioned at a slight downward angle so that as it turns the processed coal slowly passes through it and cools down.

A pressure wave moved into the rotary cooler and blew open a 2 by 4 foot access hatch at one end of the cooler.  Two of our workers near the door suffered effects from the pressure wave and, as I said, they were checked out at the hospital and returned to work yesterday morning.

The seal on the door is damaged.  There may be some other minor damage to temperature sensors or seals. We repaired the area last night and we are throttling the plant back up today. 

We have filed a report with the Mining Safety and Health Administration.  

There are media reports quoting local law enforcement officials who are speculating that a coal dust explosion was set off by a welder’s torch.  While there was maintenance-related welding going on in the area at the time, we cannot draw a link between the welding and the incident.

While no industrial facility wants incidents, even minor ones  like this one, it’s important to note that the B Processor was down for maintenance and testing when this happed. This incident was not related to the K-Fuel® process itself, which we have run at the plant for thousands of hours without incident.