POWDER RIVER COAL COMPANY
GILLETTE, WYOMING
This page was created by Nicole Flohr, Lakeview Elementary School.
COAL MINING PROCESS
When an area has been approved and is ready to be mined, topsoil and
subsoil, also known as overburden, are removed
first. The top soil is stripped down two to five feet. Drilling
and blasting breaks up the dirt. After that shovels,
draglines, and trucks remove the overburden to expose the coal. The
area is drilled and blasted again to break up the coal.
Shovels excavate and load the coal into haul trucks. From there, the trucks
haul the coal to the hoppers. This is the area
where the trucks dump the coal into a checker-board system. This system
allows the chunks of coal to enter the grizzly feeder.
From the grizzly feeder the coal travels to the crushers.
The crushers break the coal into approximately two-inch pieces. A conveyor
belt then takes the crushed coal to the silos
where it is stored until it is loaded onto a train.
Samples of coal are taken to the and is analyzed for moisture, sodium, sulfur,
ash, and Btu content.
An average silo holds approximately 15,000 tons of coal. An average of 12,000
to 13,000 tons of coal are loaded onto each train. These trains have anywhere
from 110 to 115 cars. Each car is capable of holding 100 to 110 tons of
coal. Each ton of coal provides enough energy to heat one home for one month.
Two types of loading techniques are used. One automatically loads the exact
amount of coal that the train is capable of holding. The other, called the
top-off system, partially loads the car. Before the train car leaves the
silo, another area tops off the car with the amount needed to fill it to
fill each car to its capacity. From there, the train takes the coal to the
customer, an electric utility company.
When mining is completed, the coal mine reclaims the land, (see ENVIRONMENTAL
ISSUES) leaving it in the same or better condition.