Overview
Stage | Production |
Mine Type | Open Pit |
Commodities |
|
Mining Method |
- Truck & Shovel / Loader
- Hydraulic mining
|
Production Start | ...  |
U.S. Silica's Ottawa plant is North America's largest silica production facility, mining fine grain, nearly pure quartz sandstone. |
Source:
Contractors
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Summary:
The reserves are part of the St. Peter Sandstone Formation that stretches north-south from Minnesota to Missouri and east-west from Illinois to Nebraska and South Dakota.
The deposit has a minimum silica (SiO2) content of 99%. The controlling attributes are grain crush strength, iron (Fe2O3) content and grain size distribution. Iron is concentrated near the surface, where orange iron staining is evident and also increases where the bottom contact becomes concentrated in iron pyrite. Maximum average full-face iron content is 0.045%. The deposit tends to exhibit a coarser grain size distribution in the top half of deposit
Mining Methods
- Truck & Shovel / Loader
- Hydraulic mining
Summary:
At the Ottawa property, the St. Peter Sandstone is mined by conventional surface mining methods. Blasted St. Peter Sandstone is mined mechanically and then hauled to a location in the pit where it is further processed by hydraulic methods and mixed with water to produce a slurry product that is pumped to the processing plant.
Source:
Summary:

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Production:
Commodity | Units | 2021 | 2020 | 2019 | 2018 | 2017 |
Silica
|
k tons
| ......  | ......  | ......  | 4,093 | 4,367 |
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Operational Metrics:
Metrics | 2021 |
Annual mining capacity
| ......  |
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Reserves at December 31, 2021:
Category | Tonnage | Commodity |
Proven
|
66,926,671 k tons
|
Silica
|
Probable
|
33,002,024 k tons
|
Silica
|
Proven & Probable
|
99,928,695 k tons
|
Silica
|
Financials:
| Units | 2021 | 2020 |
Book Value
|
M USD
| ......  | ......  |
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