Overview
| Stage | Permitting |
| Mine Type | Open Pit |
| Commodities |
|
| Mining Method |
|
| Mine Life | 34 years (as of Jan 1, 2018) |
June 28, 2022 – Star Diamond Corporation (“Star Diamond”) announces that, at a meeting of the Fort à la Corne joint venture management committee held earlier today, Rio Tinto Exploration Canada Inc. (“Rio Tinto”) exercised its voting power to place the Star – Orion South Diamond Project (the “Project”) on care and maintenance through December 31, 2022. Star Diamond intends to work with Rio Tinto in assessing alternatives regarding the Project. |
Source:
p. 2
Star Diamond holds, through a joint venture arrangement with Rio Tinto Exploration Canada Inc. (“Rio Tinto Canada”, a wholly-owned subsidiary of Rio Tinto plc, “Rio Tinto”), a 25% interest in certain Fort à la Corne kimberlites (which includes the Star – Orion South Diamond Project, or “Project”).
Contractors
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Summary:
Star Kimberlite Geology And Mineralization
The Star Kimberlite was deposited within the Cretaceous sedimentary rocks of the lower Colorado and Mannville groups, which unconformably overlie Paleozoic limestones and dolomites. The glacial overburden thickness ranges from 90 to 130 m with an average of 92 m (Table 7-2). Portions of the Star Kimberlite have been emplaced contemporaneously with the deposition of the Mannville and lower Colorado sediments. However, the majority of the Star Kimberlite is interpreted to have erupted through the Mannville and into the early parts of the lower Colorado Group sediments (Joli Fou Formation time). The local lower Colorado and Mannville interface is situated approximately 170 m. The Mannville Group and Paleozoic interface lies approximately 340 m, as interpreted from the Company’s core drill holes.
The Star Kimberlite consists of two distinct types of kimberlite: dominant eruptive kimberlite and subordinate kimberlitic sediments. The eruptive kimberlite deposits at the Star Kimberlite are sub-divided into five main kimberlite phases emanating from a single vent, each with distinctive physical and chemical properties, which enable mapping and stratigraphic correlation of units.
Orion South Kimberlite Geology And Mineralization
Like the Star Kimberlite, the Orion South Kimberlite was deposited within the Cretaceous sedimentary rocks of the lower Colorado and Mannville groups, which unconformably ........
Summary:
Mining is carried out using conventional open pit mining. The Orion South kimberlite is mined first, followed by the Star kimberlite.
Pre-Stripping
There is a considerable amount of unconsolidated overburden that is removed during a four-year prestripping period. The vast majority of this overburden is removed using three bucket-wheel excavators (“BWEs”).
Merchantable timber is harvested prior to stripping. A fleet of excavators and articulated trucks excavates a 20-30-metre-deep starting “key” or “slot” for a BWE. After that BWE has progressed for a period, enough space will be cleared behind it to allow a second, deeper key to be excavated – again using the excavator and articulated truck fleet. Then, the second BWE starts operating. The same procedure is used to establish the third BWE.
BWE spoil is removed from the pit on overland conveyors and delivered to a single, large spreader. This crawler-mounted spreader places the spoil on the waste pile.
Kimberlite Mining
Hydraulic shovels load the kimberlite into rigid-frame trucks. It is estimated that seventy percent of the kimberlite will require drilling and light blasting. The powder factor will be quite low to avoid diamond breakage.
The trucks transport the kimberlite to an in-pit mineral sizer, which crushes larger lumps before placing the kimberlite onto an overland conveyor for transport to the mill stockpile.
Backfilling
Source:
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Flow Sheet:
Summary:
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Projected Production:
| Commodity | Units | LOM |
|
Diamond
|
M carats
| 66 |
All production numbers are expressed as mineral.
Operational Metrics:
| Metrics | |
|
Ore tonnes mined, LOM
| 528 Mt * |
|
Total tonnes mined, LOM
| 2,976 Mt * |
|
Daily processing rate
| 45,000 t * |
|
Tonnes processed, LOM
| 470 Mt * |
|
Annual processing capacity
| 14.3 Mt * |
* According to 2018 study.
Reserves at November 9, 2015:
Grade values are rounded to nearest whole number.
An effective 1 mm lower cut-off for diamond recovery is assumed, and only diamonds larger than +1 DTC diamond sieve
are included.
| Category | Tonnage | Commodity | Grade | Contained carats |
|
Indicated
|
393,170 kt
|
Diamond
|
14 cpht
|
55,402 k carats
|
|
Inferred
|
129,029 kt
|
Diamond
|
9 cpht
|
11,565 k carats
|
Corporate Filings & Presentations:
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