Overview
Stage | Production |
Mine Type | Underground |
Commodities |
|
Mining Method |
- Sub-level open stoping (SLOS)
- Paste backfill
|
Processing |
- Smelting
- Crush & Screen plant
- Flotation
|
Mine Life | 2.5 years (as of Jan 1, 2021) |
Lady Loretta mine is part of the Mount Isa Zinc Operation. |
Source:
p. 17
Summary:
Lead-zinc-silver mineralisation occurs in a galena and sphalerite rich massive sulphide lens located in carbonaceous pyritic shales and siltstones. The deposit consists of a tight syncline dislocated by a number of major faults. The deeper and high grade portion of the deposit reaches 500m below the surface.
Mining Methods
- Sub-level open stoping (SLOS)
- Paste backfill
Summary:
The mining method utilized at Lady Loretta is conventional sub-level open stoping (a slot is opened up using a Redbore 30 raisebore raise drill) with paste used to fill the void upon completion.
Ore is removed by Sandvik 621 loaders, using the Sandvik Automine system and is trucked to the surface Run Of Mine using Epirog MT65 articulated dump trucks.
The Mining Lease, ML5568, is current until January 31st, 2026.
Processing
- Smelting
- Crush & Screen plant
- Flotation
Source:
Summary:
Ore mined is roughly crushed on site, then trucked to the Mount Isa mills for processing.
First, the ore is ground into a fine dust via a series of ball mills. This dust is then mixed with water and reagents in our zinc-lead concentrator’s flotation circuit. The reagents help us to separate the valuable mineral content from waste rock. Air is forced through the slurry creating bubbles, which float to the surface and attract and bind to the zinc or lead particles. The glossy, mineral-laden “froth” is then skimmed off the top and dried. What remains once the water content of the froth has evaporated is zinc or lead concentrate. Our zinc concentrates are sold in the domestic market and exported overseas, while our lead concentrate undergoes further processing and smelting on site to become crude lead, or lead bullion.
Lead concentrate is mixed with high grade silica, limestone and copper slag, a by product of our copper smelting operations. These ingredients are kno ........

Combined production numbers are reported under
Mount Isa Zinc Operation
Operational Metrics:
Metrics | 2021 | 2020 | 2019 | 2018 |
Ore tonnes mined
| ......  | ......  | 1.5 Mt | 8 Mt |
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Reserves at December 31, 2021:
Category | Tonnage | Commodity | Grade |
Proven & Probable
|
4.9 Mt
|
Zinc
|
10.6 %
|
Proven & Probable
|
4.9 Mt
|
Lead
|
2.9 %
|
Proven & Probable
|
4.9 Mt
|
Silver
|
55 g/t
|
Measured & Indicated
|
7.1 Mt
|
Zinc
|
11.9 %
|
Measured & Indicated
|
7.1 Mt
|
Lead
|
2.9 %
|
Measured & Indicated
|
7.1 Mt
|
Silver
|
57 g/t
|
Inferred
|
1.1 Mt
|
Zinc
|
8 %
|
Inferred
|
1.1 Mt
|
Lead
|
3 %
|
Inferred
|
1.1 Mt
|
Silver
|
33 g/t
|
HME Type | Model | Quantity | Leased or Contractor | Ref. Date |
Jumbo
|
.......................
|
.......................
|
|
Mar 5, 2019
|
Loader
|
.......................
|
.......................
|
|
Mar 5, 2019
|
Loader
|
.......................
|
.......................
|
|
Jul 30, 2021
|
Loader (FEL)
|
.......................
|
.......................
|
|
Jul 1, 2018
|
Truck (dump)
|
.......................
|
.......................
|
|
Dec 29, 2020
|
Truck (underground)
|
.......................
|
.......................
|
|
Jul 1, 2018
|
Truck (water)
|
.......................
|
.......................
|
|
Dec 29, 2020
|
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Aerial view:
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