Overview
| Stage | Production |
| Mine Type | Underground |
| Commodities |
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| Mining Method |
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| Production Start | ...  |
| Mine Life | 8.25 years (as of Jan 1, 2022) |
The Mpama North mine is part of Bisie Tin Complex which includes the Mpama North Mine, the Mpama South development Project and the Bisie Ridge exploration target.
Mpama South is expected to increase annual contained tin production from the current 12,000tpa to ~20,000tpa.
The underground mine design has been finalised and approximately 677 metres of underground development on 2 levels connecting Mpama North and Mpama South has been completed.
The Mpama South development project is targeted for commissioning in December 2023. |
Source:
p. 3
The Bisie Tin mine occurs within Permis de Exploitation (Mining Permit) PE13155, along with 3 research permits granted to Alphamin’s DRC-registered subsidiary, Alphamin Bisie Mining SA (“ABM”). ABM is an 84.14% indirect controlled subsidiary of Alphamin, with the remaining 15.86% owned by the DRC government (5%) and the Industrial Development Corporation of South Africa Ltd (“IDC”) (10.86%).
Contractors
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Deposit Type
- Breccia pipe / Stockwork
- Vein / narrow vein
Summary:
Deposit Types
The Bisie tin deposit is a cassiterite-bearing stock-work or vein system adjacent and possibly distal to underlying source granite. The mineralization at Bisie is unusual and different from other classic tin deposits. The deposit has up to 0.5 % rare earth elements (REE) and very high grade tin (with some sample assays reaching greater than 60 % Sn).
Mpama North Geology
3D Mineral Resource modelling delineated one main continuous discrete tin (with minor copper) mineralized zone at Mpama North, named the Main Vein, along with two subordinate smaller mineralized zones named the Footwall Vein (restricted to the southern areas) and the Hangingwall Vein (in the northern areas).
o The Main Vein mineralization consists of a number of uncorrelated cassiterite veins within pervasively chloritised schist. This zone generally occurs over thicknesses of between 2 m and 22 m with an average thickness of approximately 9 m. This zone is generally the highest grade and most consistent.
o Hangingwall Vein (HW Vein) mineralization occurring within partly chloritised schist and micaceous schist between 1 m and 20 m above the Main Vein. This zone of mineralization is generally between 0.5 m and 4 m wide and occurs in the northern area of the deposit and tapers out northwards. The middling between the Hanging Wall Vein and the Main Vein decreases in areas. It is possible that this vein merges into the Main Vein in some parts of the deposit.
o Footwall Vein (FW Vein) mineralizatio ........
Summary:
Mine Design
A mining method selection study considered a number of possibilities before trading off sub level caving (SLC) and cut and fill (C&F). Alphamin Bisie Mining (ABM) then implemented a mining method that uses long hole drilling and blasting methods to excavate the ore before backfilling the open stopes with waste rock. This method has been in use since 2020 and has proved successful.
Mining Method Description
The stoping blocks have been designed to include the full width of the ore body. Level waste drives or footwall drives are positioned along strike in the footwall of the orebody. Access to the levels is via the central decline or ramp, developed at minus 90 . Stope crosscuts are developed from the waste drive to the hangingwall contact of the orebody. Ore drives are then developed from the stope crosscuts, along strike (and parallel to the footwall drives).
All stoping takes place in a longitudinal formation, i.e. an ore drive is developed parallel to the strike direction of the orebody. The mining takes place in a bottom up sequence within an echelon. An echelon consists of four levels, three production levels and a top holing level at the top of the echelon, directly below the sill pillar. Sill pillars separate the echelons from each other.
Dip pillars, or rib pillars, are located along strike and will be spaced at distances ranging from 20m to 50m depending on geotechnical guidelines. The spacing of the rib pillars ........
Source:
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Flow Sheet:
Summary:
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Reserves at June 30, 2022:
Bisie Mpama North Mineral Reserve at 1.0% Sn Cut-Off Grade.
Bisie Mpama North Mineral Resource at 0.50% Sn Cut-Off Grade.
| Category | Tonnage | Commodity | Grade | Contained Metal |
|
Proven & Probable
|
2.62 Mt
|
Tin
|
4.64 %
|
121.4 kt
|
|
Measured
|
0.04 Mt
|
Tin
|
2.16 %
|
0.9 kt
|
|
Indicated
|
3.09 Mt
|
Tin
|
5.02 %
|
154.9 kt
|
|
Measured & Indicated
|
3.13 Mt
|
Tin
|
4.98 %
|
155.7 kt
|
|
Inferred
|
0.55 Mt
|
Tin
|
7.56 %
|
41.2 kt
|
Source:
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Corporate Filings & Presentations:
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