Overview
Stage | Restarting |
Mine Type | Open Pit |
Commodities |
|
Processing |
- Flotation
- Heap leach
- Pressure oxidation
- Carbon in leach (CIL)
- Carbon in column (CIC)
- Solvent Extraction & Electrowinning
- Cyanide (reagent)
|
The Lone Tree Property was acquired by i-80 Gold Corporation from Nevada Gold Mines. This acquisition will provide i-80 with important processing infrastructure including an autoclave, CIL (carbon-in-leach) mill, a heap leach facility complete with an assay lab, and carbon columns, and interim toll processing agreements for i-80 at NGM facilities.
The Lone Tree has been historically mined using surface mining method. A surface mining method is expected. However, a detailed mining plan has not been developed.
In Q1-2022, the Company plans to award the contract to complete a detailed engineering study for the restart of the autoclave and secure key personnel to execute the restart plan. Additionally, permitting for the development of the Buffalo Mountain open pit mine is underway, where gold mineralization is expected to be processed at the Lone Tree leach pad facility. An initial resource for Buffalo Mountain is expected to be complete in H1-2022. |
Latest News | i-80 Launches Comprehensive Plan to Create Nevada Focused Gold Mining Company January 12, 2022 |
Source:
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Reno, Nevada, October 14, 2021- Pursuant to the Exchange Agreement, the i-80 GOLD CORP. acquired from Nevada Gold Mines LLC (“NGM“), by way of an asset exchange, the Lone Tree and Buffalo Mountain gold deposits and certain processing infrastructure, including an autoclave (collectively, the “NGM Properties“).
Deposit Type
- Sediment-hosted
- Epithermal
- Mesothermal
Summary:
The Lone Tree deposit is characterized as a pluton-related or distal-disseminated Ag-Au deposit. The Lone Tree deposit among others in the Battle Mountain district appears to be related genetically to porphyry systems, even though many deposits do not contain obvious near-surface features that would indicate this connection, mainly because the gold-silver mineralization in these deposits may be over one km away from the causative intrusions. This is why the deposit has been characterized as both “distal disseminated” (to intrusive center). Due to complex tectonic and extension in the region, the mineralization in these deposit types may have substantially different geometric relations to the intrusive centers and hosted in different stratigraphic horizons. The mineralization at Lone Tree occurs in intensely fractured three stratigraphic horizons which is similar in other deposits in the region; however, it is not the same in all deposits. Gold is associated with low Ag:Au (<2:1), As, Sb, Hg and Tl as well as elevated Bi, Mo and W. Gold is hosted in arsenopyrite indicating higher temperatures of ore formation in comparison to typical Carlin-type deposits where gold is hosted in arsenian pyrite.
Gold mineralization occurs as sub-micron sized inclusions within a distinct generation of very fine-grained pyrite and arsenopyrite in the sulfide zone. Evidence gathered to date suggests that the main gold deposition event occurred in a temperature range of 200° to 450° (epithermal to mesothermal). The ore mineralogy shows evidence of two overprinted assemblages reflecting at least two hydrothermal episodes at Lone Tree. Partial oxidation of the main stage mineralization occurred prior to a later, epithermal event characterized by open-space filling textures and weakly auriferous pyrite and marcasite. In the oxidized portions of the deposit, and particularly in the Havallah rocks, gold occurs as micron-sized particles in goethite and limonite. Post-mineral oxidation extends as much as 700 feet down major structures such as the Wayne Zone. No supergene effects or gold remobilization have been proven or documented at the Lone Tree Mine (K.C. Raabe, 1995. The Lone Tree Extension Project, Humboldt County, Nevada).
Summary:
The Lone Tree has been historically mined using surface mining method. A surface mining method is expected. However, a detailed mining plan has not been developed.
Processing
- Flotation
- Heap leach
- Pressure oxidation
- Carbon in leach (CIL)
- Carbon in column (CIC)
- Solvent Extraction & Electrowinning
- Cyanide (reagent)
Source:
Summary:
The site has an autoclave and flotation mill, which are currently on care and maintenance.
The list of processing plants includes the following facilities:
• Lone Tree Autoclave, which processes high-grade refractory ore.
• Lone Tree Float Plant, which processes low-grade refractory ore.
• Lone Tree Leach pads, which treats oxide ore in a cyanide heap-leach process.
• North Peak Leach pad, which treats oxide ore in a cyanide heap-leach process.
Mining on the Brooks deposit which lies to the southwest of the main Lone Tree pit was conducted 2015-2019. Approximately 52,000 ounces were placed on the heap leach pad and residual leaching is ongoing.
Projected Production:
Commodity | Units | 2020 | 2019 | 2018 |
Gold
|
oz
| ......  | ......  | 24,253 |
Silver
|
oz
| ......  | | |
All production numbers are expressed as metal in doré.
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Reserves at July 31, 2021:
Mineral resources are shown above a 0.65 g/t Au cut-off grade.
Category | Tonnage | Commodity | Grade | Contained Metal |
Indicated
|
7.2 Mt
|
Gold
|
1.77 g/t
|
410 koz
|
Inferred
|
50.7 Mt
|
Gold
|
1.69 g/t
|
2,764 koz
|
Heavy Mobile Equipment as of December 31, 2018:
HME Type | Quantity |
Truck (haul)
|
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