Overview
Stage | Production |
Mine Type | Open Pit |
Commodities |
|
Mining Method |
- Truck & Shovel / Loader
- Dragline
|
Processing |
|
Mine Life | 250 years (as of Jan 1, 2015) |
Source:
Summary:
Known as the Suntrana Formation, three seams of coal ranging from an average of 18 to 30 feet thick are covered with layers of overburden that can be more than 100 feet thick. After removal of the overburden, the coal is mined, crushed, and brought to market mainly by rail, though a small amount of coal is trucked to consumers as well.
Mining Methods
- Truck & Shovel / Loader
- Dragline
Summary:
At Usibelli Coal Mine (UCM), mining is primarily from seams 3, 4, and 6 of the Suntrana Formation. These seams average approximately 18' (5.5m), 30' (9.1m), and 24' (7.3m) respectively.
Up to 100 feet of unconsolidated sandstone or overburden must be moved to uncover the top seam (seam number 6) of coal. Another 120 feet of interburden must be moved to uncover the d seam (seam number 4) while roughly another 80 feet of interburden must be removed to uncover the third seam of coal (seam number 3) reaching nearly 400 feet at its deepest point.
Overburden is removed by four different methods:
1. The dragline removes the bulk of the overburden
2. Blasting utilizing explosives loosens and casts the overburden
3. Dozers move overburden short distances prior to drag line operations
4. Shovels strip and load overburden and coal into the haul trucks
The primary pieces of equipment utilized to remove overburden are the Bucyrus Erie 1300W walking dragline, a variety of bulldozers, various large dump trucks and shovels/loaders, and explosives conducting caste blasting operations.
The dragline has several buckets, which are used on a rotational basis. UCM utilizes several different configurations of bucket including 33-, 35-, and a high-production 42 cubic-yard bucket. Each bucket is used on the dragline for approximately 6 to 8 months. After that period, the bucket must be serviced and critical surfaces of the bucket repaired. The bucket is repaired by welding wear plates on vulnerable surfaces that are worn as a result of the abrasive characteristics of the materials that are excavated.
While the dragline does the majority of the excavation work at the mine, additional excavators are needed. Several track-mounted excavators are used to load coal and to strip overburden in areas difficult for the dragline to maneuver. The large shovels have buckets capable of approximately 26 cubic-yards and can load the 150-ton trucks in approximately four passes.
Source:
Summary:
Raw coal is crushed to 2" x 0" (50 mm x 0 mm) but no washing is performed. Screening circuit can reduce minus 1/4" (6 mm) to less than 10% with top size to 6" (150 mm).
Coal is transported to six Interior Alaska electric power generation plants – including five cogeneration plants: Fort Wainwright (U.S. Army), Eielson Air Force Base, Clear Air Force Station, Aurora Energy – a wholesale supplier of electricity and provider of district heat in Fairbanks, and the University of Alaska’s power plant. A mine mouth plant - Healy #1 operated by Golden Valley Electric Association is located adjacent to the mine site and coal is delivered directly from the pit to the plant.
Over the years Usibelli Coal Mine has exported coal to Pacific Rim destinations including: Chile, South Korea, China, Japan, Taiwan, and Russia.
Production:
Commodity | Units | 2020 | 2019 | 2018 | 2017 | 2016 | 2015 | 2014 |
Coal (thermal)
|
tons
| ......  | ......  | 901,641 | 959,068 | 932,122 | 1,177,390 | 1,501,758 |
- Subscription is required.
Operational Metrics:
Metrics | 2016 |
Annual production capacity
| 1.5 M tons of ROM coal |
Reserves at December 31, 2016:
Category | Tonnage | Commodity |
Proven & Probable
|
750 Mt
|
Coal (thermal)
|
Corporate Filings & Presentations:
- Subscription is required.
Aerial view:
- Subscription is required.