Overview
Stage | Permitting |
Mine Type | Open Pit |
Commodities |
|
Mining Method |
|
Processing |
- Attrition
- Dry Screening
- Ore sorter (multi-sensor)
- Desliming
- Flotation
- Magnetic separation
- Dewatering
- Filter press
|
Mine Life | 22 years (as of Jan 1, 2023) |
Sayona’s Authier Lithium Project in Québec, Canada is a hard rock spodumene lithium deposit set to play a key role in the Company’s planned multi-project Abitibi lithium hub, as a source of supplementary ore for processing at NAL.
Sayona continues to advance regulatory approvals for the project. With the commissioning of the NAL facility, the approval will be based on a much smaller environmental footprint, with no requirement for a concentrator on-site. |
Source:
p. 1
NAL and Authier are part of Sayona Québec, owned 75% by Sayona Mining and 25% by Piedmont Lithium Inc (Nasdaq:PLL; ASX:PLL).
Contractors
Contractor | Contract | Description | Ref. Date | Expiry | Source |
unawarded or unknown
|
Mining
|
Mining activities will be conducted by a mining contractor for the entire life-of-mine. The mining contractor will be responsible for:
- Mine equipment fleet (production fleet, auxiliary fleet and support equipment);
- Mine equipment operators;
- Mine operations supervision;
- Mine equipment maintenance;
- Overall site maintenance;
- Ore re-handling (loading transport trucks for ore transfer between Authier and NAL).
|
Apr 14, 2023
|
|
|
Deposit Type
- Intrusion related
- Pegmatite
Source:
Summary:
The mineralisation observed at the Authier project in the spodumene-bearing pegmatites is principally lithium with trace amounts of beryllium, molybdenum, tantalum, niobium, cesium and rubidium.
Detailed logging of drill core suggests that the main pegmatite at Authier is composed of several internal phases related to intrusive placement and progressive cooling. The outside border of the pegmatite in contact with the host rocks has been identified as a transition zone or border zone. This transition zone is often significantly less mineralised in spodumene and is characterised by a centimetre-scale fine to medium-grained chill margin, followed by a medium to coarse-grained decimetre to metre-scale zone. The transition zone often includes fragments of the host rock and can also be intermixed with the material from the core zone.
The main intrusive phase observed in the pegmatite is described as a core pegmatitic zone characterised by large centimetre-scale spodumene and white feldspar minerals. The core pegmatitic zone shows internally different pegmatitic phases characterised by different spodumene crystal lengths, ranging from coarse-grained (earlier) to fine-grained (later). The contacts between different spodumene-bearing pegmatite phases are transitional and well defined at core logging scale. Higher lithium grades are correlated with higher concentrations of larger spodumene crystals. Late mineral to post-mineral aplite phases cut earlier spodumene-bearing mineralisation, causing local diminishing of lithium grade. The core zone hosts the majority of the spodumene mineralisation at Authier.
The spodumene-bearing pegmatite is principally defined by one single continuous intrusion, or dyke, that contains local rafts or xenoliths of the amphibolitic host rock, which are a few metres thick and up to 200 m in length at shallow levels within the western zone. The main pegmatite outcrops in a small, 50 m by 20 m, area at the central-eastern sector that orients east-west and is mostly covered by up to 10 m of overburden. Based on the information gathered from the drilling, the pegmatite intrusion is more than 1,100 m in length and can be up to 60 m thick. The intrusion is generally oriented east-west, dips to the north at angles ranging between 35° and 50° and reaches depths of up to 270 m below surface in drilling, to date.
A second spodumene-bearing pegmatite, not visible from the surface, was intersected by diamond hole AL-16-10 at shallow levels, between 15 m and 22 m downhole depth, approximately 400 m north of the main pegmatite. Follow-up drilling in early 2017 and 2018 outlined this new body, the Authier North pegmatite, which has a strike extension of 500 m east-west, 7 m average width, gently dipping 15 degrees to the north. The Authier North pegmatite appears at shallow levels, 15 m to 25 m vertical depth, and is open in all directions.
Source:
p.75,86,89,91
Summary:
The mining operation consists of a conventional surface mining method with drill rigs, excavators and off-highway trucks. The Updated DFS consists of resizing the open pit and infrastructure and producing a 22-year life-of-mine (LOM) plan to feed the NAL crusher at a rate of approximately 530,000 tonnes per year.
The design outlines a pit of ~990 m in length, an average of 640 m width and 200 m in depth.
A LOM plan with a 1,560 tpd crusher capacity was completed for the Authier UDFS using MineSight’s Mine Plan Schedule Optimiser (MPSO). The following constraints and objectives were considered during the development of the LOM plan:
- Project ramp-up in Q3 2025.
- Annual crusher feed of approximately 530 ktpa.
- No long-term stockpile.
- Maximum mining rate of approximately 6.0 Mtpa.
- Crusher feed grade =0.8% Li2O.
- Mine planning strategy: maximise NPV.
The ROM crusher feed contained in the final pit is sufficient for a mine life of 22 years.
Due to the phase designs, very little waste material is mined to supply the mill in the first two years.
The overall pit has a variable strip ratio. The annual mining productivity gradually increases to 6.0 Mt in Year 5, and gradually decreases from Year 13 to the end of the mine life.
The mine will operate 365 days per year with two 12-hour shifts per day. It is expected that the mining contractor equipment operators, mechanics and supervisors will work on a seven-working-day / seven-rest-day schedule. All other mining contractor staff, as well as Sayona’s on-site staff, will work regular 40-hour work weeks.
Flow Sheet:
Source:
p.31,67
A mass balance was produced based on the NAL re-start flowsheet (2022) feeding a blended ore consisting of 36% Authier ore and 64% NAL ore at the rod mill.
The crushing circuit includes conventional primary, secondary, and tertiary crushing combined with primary and secondary ore sorting to remove host rock dilution prior to the mill. A crusher by-pass circuit and a crushed ore storage dome is currently being implemented. Connection to the existing silo feeding the rod mill is expected to be completed by the end of 2023.
The grinding circuit consists of a rod mill and ball mill in closed circuit with sizing screens. The grinding circuit product is deslimed and fed to a magnetic separation circuit to reject iron-bearing minerals.
Processing
- Attrition
- Dry Screening
- Ore sorter (multi-sensor)
- Desliming
- Flotation
- Magnetic separation
- Dewatering
- Filter press
Flow Sheet:
Source:
p.31,107
Summary:
The project considers mining Authier ore for shipment to the NAL site for processing. A mass balance was produced for the NAL concentrator based on feeding a blended ore consisting of 33% Authier ore and 67% NAL ore. The mass balance considers a lithium recovery of 72% for the Authier ore being processed.
The flowsheet incorporated grinding, magnetic separation, de-sliming, mica and spodumene flotation.
The grinding circuit product is deslimed and fed to a magnetic separation circuit to reject iron-bearing minerals. The non-magnetic stream is conditioned prior to spodumene flotation, which comprises rougher and scavenger cells and three stages of cleaning. The spodumene concentrate is dewatered on a belt filter. The tailings streams are thickened and fed to the existing Tailings Storage Facility #1.
When the existing Tailings Storage Facility #1 reaches capacity, tailings will be dewatered in a new tailings filtration plant and dry-stacked in the planned Tailings Storage Facility #2.
Operational Metrics:
Metrics | |
Daily ore mining rate
| 1,560 t * |
Annual ore mining rate
| 530 kt * |
Stripping / waste ratio
| 6.09 * |
Waste tonnes, LOM
| 68,379 kt * |
Ore tonnes mined, LOM
| 11,225 kt * |
Total tonnes mined, LOM
| 79,604 kt * |
* According to 2023 study.
Reserves at March 27, 2023:
Mineral Resource and Reserve: 0.55% Li2O cut-off grade.
Category | Tonnage | Commodity | Grade | Contained Metal |
Proven
|
6.2 Mt
|
Li2O
|
0.93 %
|
57.6 kt
|
Probable
|
5.1 Mt
|
Li2O
|
1 %
|
50.7 kt
|
Proven & Probable
|
11.2 Mt
|
Li2O
|
0.96 %
|
108.3 kt
|
Measured
|
6 Mt
|
Li2O
|
0.98 %
|
59,200 t
|
Indicated
|
8.09 Mt
|
Li2O
|
1.03 %
|
83,400 t
|
Measured & Indicated
|
14.1 Mt
|
Li2O
|
1.01 %
|
142,800 t
|
Inferred
|
2.9 Mt
|
Li2O
|
1 %
|
30,000 t
|
Operating Costs:
| Units | 2023 |
OP mining costs ($/t mined)
|
CAD
| 48.2 * |
G&A ($/t mined)
|
CAD
| 1.9 * |
Total operating costs ($/t mined)
|
CAD
| 75.8 * |
* According to 2023 study.
2023 Study Costs and Valuation Metrics :
Metrics | Units | LOM Total |
Pre-Production capital costs
|
$M CAD
|
74.8
|
Sustaining CapEx
|
$M CAD
|
119.2
|
OP OpEx
|
$M CAD
|
540.6
|
Transportation (haulage) costs
|
$M CAD
|
223.4
|
G&A costs
|
$M CAD
|
21
|
Total OpEx
|
$M CAD
|
851.3
|
Net revenue (LOM)
|
$M CAD
|
1,321
|
Pre-tax Cash Flow (LOM)
|
$M CAD
|
280
|
Pre-tax NPV @ 8%
|
$M CAD
|
58
|
After-tax NPV @ 5%
|
$M CAD
|
43
|
After-tax NPV @ 10%
|
$M CAD
|
-4
|
After-tax NPV @ 8%
|
$M CAD
|
11
|
Pre-tax IRR, %
|
|
14.6
|
After-tax IRR, %
|
|
9.4
|
Mine Management:
Job Title | Name | Profile | Ref. Date |
Chief Operating Officer
|
Sylvain Collard
|
|
Jan 24, 2024
|
Construction Manager
|
Yan Theberge
|
|
Nov 6, 2023
|
Consultant - Mining
|
Melissa Jarry
|
|
Apr 14, 2023
|
Consultant - Recovery Methods
|
Patricia Dupuis
|
|
Apr 14, 2023
|
Engineering Superintendent
|
Jeremie Matte
|
|
Nov 6, 2023
|
VP Exploration
|
Carl Corriveau
|
|
Nov 6, 2023
|
Staff:
Total Workforce | Year |
176
|
2019
|
Corporate Filings & Presentations: