Overview
Stage | Production |
Mine Type | Underground |
Commodities |
|
Mining Method |
- Ramp & Fill
- Overhand Cut & Fill
- Sub-level stoping
- Hydraulic backfill
|
Processing |
|
Mine Life | 2046 |
Source:
p. 189
On 9 December 2016, Sibanye-Stillwater announced it had reached a definitive agreement to acquire Stillwater Mining Company for US$18 per share in cash, or US$2,200 million in aggregate. The effective date of the implementation of the Stillwater Transaction was 4 May 2017, when Sibanye-Stillwater took over legal ownership of Stillwater.
Summary:
Mineralisation characteristics:
• The J-M Reef is a magmatic reef type PGM deposit defined as the palladium-platinum rich stratigraphic interval, mainly occurring within a troctolite (OB-I zone) of the Lower Banded Series.
• Palladium and platinum are the main PGMs, both constituting between 7g/t to 40g/t over a variable thickness with economic mineralised thickness ranging from 0.9m – 2.7m and averaging 1.8m.
• Ratios of palladium to platinum in metallurgical concentrate are known to range from 3.4:1 (in situ 3.5:1) at Stillwater to 3.5:1 (in situ 3.6:1) at East Boulder.
• By-products of gold, rhodium, copper and nickel are recovered at the concentrators, smelter and refinery.
• Other associated PGMs such as iridium, ruthenium and osmium occur in low quantities and are generally not evaluated by Stillwater.
• The visual identification of the J-M Reef is facilitated by the presence of approximately 0.25% to locally 3% visible associated disseminated copper-nickel pathfinder sulphide minerals.
Mining Methods
- Ramp & Fill
- Overhand Cut & Fill
- Sub-level stoping
- Hydraulic backfill
Summary:
Source:
Summary:
The Company processes ore from the Stillwater Mine through a surface concentrator facility (mill) adjacent to the Stillwater Mine shaft. Crushed mine ore is fed into the concentrator, mixed with water and ground to slurry in the concentrator’s mill circuits to liberate the PGM-bearing sulfide minerals from the rock matrix. Various reagents are added to the slurry, which then is agitated in a froth flotation circuit to separate the valuable sulfides from the waste rock. In this circuit, the sulfide minerals are successively floated, recycled, reground and refloated to produce a concentrate suitable for further processing. The final flotation concentrate, which represents approximately 2.0% of the original ore weight, is filtered, placed in large bins and then transported by truck to the Company’s metallurgical complex in Columbus, Montana.
Recoveries & Grades:
Commodity | Parameter | 2016 | 2015 | 2014 | 2013 | 2012 |
Platinum
|
Recovery Rate, %
| ......  | ......  | ......  | ......  | ......  |
Platinum
|
Concentrate Grade, oz/ton
| ......  | ......  | ......  | ......  | ......  |
Palladium
|
Recovery Rate, %
| ......  | ......  | ......  | ......  | ......  |
Palladium
|
Concentrate Grade, oz/ton
| ......  | ......  | ......  | ......  | ......  |
2E (Pt, Pd)
|
Recovery Rate, %
| ......  | ......  | ......  | ......  | ......  |
2E (Pt, Pd)
|
Head Grade, oz/ton
| 0.49 | 0.46 | 0.5 | 0.5 | 0.58 |
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Production:
Commodity | Product | Units | 2019 | 2018 | 2017 | 2016 | 2015 | 2014 | 2013 |
2E (Pt, Pd)
|
Metal in concentrate
|
koz
| ......  | 364 | 228 | 327 | 320 | 341 | 366 |
Platinum
|
Metal in concentrate
|
koz
| | | | ......  | ......  | ......  | ......  |
Palladium
|
Metal in concentrate
|
koz
| | | | ......  | ......  | ......  | ......  |
2E (Pt, Pd)
|
Concentrate
|
kt
| | | | 15,336 | 15,605 | 14,935 | 15,399 |
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Operational Metrics:
Metrics | 2019 | 2018 | 2017 | 2016 | 2015 | 2014 |
Daily milling capacity
| ......  | 3,100 t | | 3,000 tons | 3,000 tons | |
Daily milling rate
| ......  | | 3,100 t | | | |
Annual milling rate
| ......  | | 680 kt | | | |
Tonnes milled
| ......  | | | 715.2 k tons | 747.9 k tons | 748.6 k tons |
Daily mining rate
| ......  | | | 1,954 tons | 2,049 tons | |
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Reserves at December 31, 2019:
Category | Tonnage | Commodity | Grade | Contained Metal |
Proven
|
3.8 Mt
|
2E (Pt, Pd)
|
19.2 g/t
|
2.326 M oz
|
Probable
|
23 Mt
|
2E (Pt, Pd)
|
19.5 g/t
|
14.39 M oz
|
Proven & Probable
|
26.8 Mt
|
2E (Pt, Pd)
|
19.4 g/t
|
16.716 M oz
|
Measured
|
5.6 Mt
|
2E (Pt, Pd)
|
19.5 g/t
|
3.499 M oz
|
Indicated
|
31.3 Mt
|
2E (Pt, Pd)
|
17.9 g/t
|
17.993 M oz
|
Inferred
|
48.1 Mt
|
2E (Pt, Pd)
|
17.3 g/t
|
26.706 M oz
|
Total Resource
|
85 Mt
|
2E (Pt, Pd)
|
17.6 g/t
|
48.199 M oz
|
Commodity Production Costs:
| Commodity | Units | 2016 | 2015 | 2014 | 2013 |
Total cash costs
|
2E (Pt, Pd)
|
USD
|
437 / oz†
|
487 / oz†
|
533 / oz†
|
484 / oz†
|
† Net of By-Product.
Operating Costs:
| Units | 2016 | 2015 | 2014 | 2013 |
Total operating costs ($/ton milled)
|
USD
| 200 | 208 | 243 | 221 |
Financials:
| Units | 2016 | 2015 | 2014 |
Sustaining costs
|
M USD
|
38.3
|
52.4
|
60.1
|
Corporate Filings & Presentations:
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Aerial view:
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