Overview
Stage | Production |
Mine Type | Open Pit |
Commodities |
|
Mining Method |
|
The largest lignite mine in the United States. |
Source:
p. 5, 9, 11
Company | Interest | Ownership |
NACCO Industries Inc.
|
100 %
|
Indirect
|
Coteau Properties Company
(operator)
|
100 %
|
Direct
|
The Freedom Mine is owned and operated by the Coteau Properties Company. The coal reserves at Coteau Properties Company are owned or controlled by the NACCO Industries Inc.
Deposit Type
- Unconformity related
- Sedimentary
Summary:
The reserves are located in Mercer County, North Dakota, starting approximately two miles north of Beulah, North Dakota. The center of the basin is located near the city of Williston, North Dakota, approximately 100 miles northwest of the Freedom Mine. The economically mineable coal in the reserve occurs in the Sentinel Butte Formation, and is overlain by the Coleharbor Formation. The Coleharbor Formation unconformably overlies the Sentinel Butte Formation. It includes all of the unconsolidated sediments resulting from deposition during glacial and interglacial periods. Lithologic types include gravel, sand, silt, clay and till. The modified glacial channels are in-filled with gravels, sands, silts and clays overlain by till. The coarser gravel and sand beds are generally limited to near the bottom of the channel fill. The general stratigraphic sequence in the upland portions of the reserve area consists of till, silty sands and clayey silts.
Type of Mine: Surface Lignite
Coal Seam: Beulah-Zap Seam
Average Seam Thickness: 18 feet
Average Depth: 130 feet
Average Coal Quality (As received):
Heat Content - 6,700 BTUs/lb
Sulfur - 0.90%
Ash - 9%
Moisture - 36%
Summary:
The Freedom mine - dragline operation with 3 dragline.
At Coteau, overburden is mainly removed by draglines, which have bucket capacities of up to 124 cubic yards. Other machinery, such as loading shovels, excavators and large trucks also help with overburden removal.
After coal is exposed, it is either ripped or blasted to prepare for loading into coal hauling trucks. Once coal is loaded into haul trucks, it is taken to the truck dump and crushers. From there, coal is delivered to the customers by trucks and conveyors or rail.
Once coal has been removed from an area, the spoil piles are graded to the approximate original contour of the land prior to mining. Once the regraded spoil contours are approved by the North Dakota Public Service Commission, suitable plant growth material (SPGM) is respread over the area. When the SPGM and topsoil is in place, grasses or crops are seeded using standard farming techniques and equipment. This reclamation process occurs contemporaneously with the advancing mining process.
Production:
Commodity | Units | 2019 | 2018 | 2017 | 2016 | 2015 | 2014 | 2013 |
Coal (thermal)
|
tons
| ......  | 14,183,313 | 14,716,777 | 14,109,960 | 14,294,690 | 14,432,335 | 13,782,716 |
Heat Content | BTU/lb | 6,700 | 6,700 | 6,700 | 6,700 | 6,700 | 6,700 | |
Sulfur | % | 0.9 | 0.9 | 0.9 | 0.9 | 0.9 | 0.9 | |
All production numbers are expressed as ROM coal.
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Operational Metrics:
Metrics | 2019 | 2018 | 2017 | 2016 | 2015 | 2014 | 2011 |
Coal tonnes mined
| ......  | ......  | 14.7 M tons | 14.1 M tons | 14.3 M tons | 14.4 M tons | 13.6 M tons |
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Reserves at December 31, 2019:
Category | Tonnage | Commodity |
Proven & Probable
|
432.8 M tons
|
Coal (thermal)
|
Heavy Mobile Equipment as of December 1, 2020:
HME Type | Model | Size | Quantity |
Dragline
|
.......................
|
120 cu. yd
|
3
|
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Corporate Filings & Presentations:
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Aerial view:
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