Overview

Mine Type	Underground
Stage	Restarting
Commodities	Silver Zinc Lead
Mining Method	Hydraulic mining Longhole open stoping Sub-level open stoping (SLOS) Cut & Fill
Backfill type	...
Production Start	...
Mine Life	...
Snapshot	The Endeavor Project is endowed with extensive infrastructure, in good condition, ready to be utilised once mining recommences. Surface infrastructure includes a 1.2Mtpa processing plant, rail loading facility, raw water and electricity connections to local grids, workshops, partly stocked stores warehouse, offices, and a laboratory. Underground infrastructure includes a tower mounted friction winder for hauling ore to the surface, a truck haulage decline from surface to 9135mRL, underground crushing station, workshops, refuelling station, dewatering pump station, refuge chambers and reticulated water and air. The Project Restart Study is based on a mine plan and optimised mining schedule that includes initial mining from three zones in the underground mine as well as the later retreatment of high-grade Sector 1 tailings that were produced during the early years. Mining of underground ore extends from Years 1 to 6 and re-treatment of Sector 1 tailings commences in Year 5.

Deposit type

• Tailings
• Vein / narrow vein

Summary:

The Endeavor zinc-lead-silver mine (initially known as the Elura) is located 43km NNW of Cobar. The mine contains two styles of mineralisation: above about 900m depth an irregular sub-vertical sheet is hosted by a turbidite sequence and broadly coincides with an anticline axial plane; at the bottom of this sheet mineralisation bifurcates into grossly concordant zones.

Six main ore types have been identified within the Endeavor Mine orebody:
• Pyritic mineralisation (PY),
• Pyrrhotitic mineralisation (PO),
• Silicious pyrrhotitic ore (SIPO),
• Silicious Pyritic ore (SIPY),
• Vein ore, and
• Mineralised altered CSA siltstone (MINA).

Mineralisation at the Elura deposit is hosted by a fine grained turbidite sequence of the Cobar Basin and comprises multiple sub-vertical elliptical shaped pipe-like pods that occur within the axial plane of an anticline and are surrounded by an envelope of sulphide stringer mineralisation, in turn surrounded by an envelope of siderite alteration extending for tens of metres away from the sulphide mineralisation. Around 150m below the base of the main mineralised pods/lodes, mineralisation is hosted within the western limb of a folded limestone unit, occurring in veins and fractures. A zone of supergene enrichment occurs at the top of the Main Lode. Recent reviews favour a syngenetic formation model of an original stratiform deposit that was later emplaced by tectonic force into a favourable structural site during deformation.

The Elura deposit is hosted by a limestone breccia overlain by a turbidite sequence of interbedded shale and sandstone/siltstone. The carbonate rocks have been interpreted as belonging to the Brookong Formation of the Kopyje Group and the turbidites are thought to be lithologically equivalent of the CSA Siltstone.

The main orebody is massive sulphide hosted by the fine grained turbidite sequence and comprises multiple sub-vertical elliptical shaped pipe-like pods with an envelope of sulphide stringer mineralisation, in turn surrounded by an envelope of siderite alteration extending for tens of metres away from the sulphide mineralisation. Above about 900m depth, the sulphide stringer mineralisation occurs as a large continuous 15 - 120m wide sheet within the axial plane of an anticline and extends over a strike length of at least 800m. Below 900m depth the stringer zone breaks up and occurs as grossly concordant zones paralleling the limbs of the anticline.

The orebody is generally divided up into the main lode, which consists of two elliptical pods that merge together around 10 000 m RL and the northern Pods which consist of five smaller crudely elliptical orebodies that trend towards the NNW and dip approximately 80° - 85° towards the west. The crusher pod, which is located on the eastern side of the main lode, is a small apophysis that merges into the Main Lode at the 9500 m RL.

Mineralisation in the orebody is complex. The primary lead and zinc bearing minerals from all orebodies processed are galena (~13 per cent wt) and sphalerite (~14 per cent wt). Pyrite and pyrrhotite (~60 - 70 per cent wt in total) are the main floatable gangue in the ore. Tetrahedrite is the major host of silver, apart from galena and chalcopyrite. The average grain size of galena and sphalerite are relatively very fine, ranging from 10 - 40 µm.

Tailings
Mineralised material in the tailings storage facility consists of clay to fine sand sized particles deposited in sub-horizontal layers from centrally located outflow sites. The particles contain remnant sulphides that were not captured during processing of the Endeavor Mine silver-zinc-lead ore. The primary lead and zinc bearing minerals from all orebodies processed are galena (~13%wt) and sphalerite (~14%wt). Pyrite and pyrrhotite (~60 to 70%wt in total) are the main floatable gangue in the ore. Tetrahedrite is the major host of silver, apart from galena and chalcopyrite.

The mine commenced operations in 1983 and tailings were pumped exclusively into Sector 1 from March 1983 until April 1989 (with the exception of tailings from concurrent Ag supergene mining which were pumped to a separate, smaller TSF southwest of the mine) when Sector 2 of the TSF was commissioned. No further tailings have been added to Sector 1 since 1989.

The northern portion of Sector 1 was rehabilitated in 1991 when the surface was re-contoured, covered with plastic, clay capped, and topsoil emplaced.

The TSF is a raised “turkey’s nest” type dam, with Sector 1 measuring approximately 550m by 850m and an average depth of around 7m.

Mining Methods

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Comminution

Crushers and Mills

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Processing

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Production

Operational metrics

Metrics		2017	2016	2015
Annual ore mining rate	....
Annual processing rate	....
Annual processing capacity	....
Ore tonnes mined, LOM	....
Tonnes processed, LOM	....
Tonnes milled	....	133,904 tons of ore	219,430 tons of ore	767,314 tons of ore

Personnel

Job Title	Name	Profile	Ref. Date
.......................	.......................		Jan 26, 2024
.......................	.......................		Jan 26, 2024
.......................	.......................		Jan 26, 2024
.......................	.......................		Jan 26, 2024

Employees	Total Workforce	Year
	......	2023
......		2021
......		2020
......		2019
	......	2018