The Project
How we produce zinc and lead
Sasa is an underground zinc and lead mine that produces approximately 800,000 tonnes of ore each year.
The mine consists of three orebodies: Svinja Reka, Kozja Reka and Golema Reka.
Svinja Reka ore body is accessed via two adits from surface and currently it is the only ore body that is being exploited.
There is also an operational shaft for service and material transport needs connected with Svinja Reka but located in Golema Reka.
The ore is drilled using jumbo drillers, followed by blasting and then mucked with underground loaders. The main haulage levels are at 80 metre intervals by hight, with sub-levels every 7 to 10 metres depending on the mining methods.
From 2023, the Sasa team is in a transitioning process from the historical top-down SLC mining method to the new bottom-up methods of C&F and LHS. The voids previously left behind as well as new excavations will be backfilled with paste material made of cemented tailings.
60 to 70% of the ore transportation is sent via ore passes to the 830-metre level where it is transported by rail wagons to the Golema Reka shaft which is afterwards transported to the surface with a conveyor belt. The remaining 30 to 40 % is hauled to surface using UG trucks via the decline infrastructure. This ratio will change as the new Central Decline will extend to the bottom of the mine, providing a more productive transport system.
Once at surface, ore is crushed in three stages followed by a milling process that involves two parallel sets of ball mills, spiral classifiers and rod mills to ensure the extracted material is the appropriate size for liberation by flotation at approximately 74 microns.
The processing plant then operates with lead and zinc flotation processes, producing separate concentrates that are filter pressed to generate products containing 5-9% moisture. The lead concentrate contains, on ca. 73% lead and the zinc concentrate contains ca. 49% zinc. The concentrates are stored in two separate bays before being loaded into haulage trucks for sale to smelters.
INVESTING IN THE MINE
SASA IS CURRENTLY TRANSITIONING TO NEW MINING METHODS TO CREATE A SAFER AND MORE SUSTAINABLE UNDERGROUND MINING OPERATION FOR THE LONG TERM
Construction of a Paste Backfill Plant and associated reticulation pipes
Construction of a Dry Stack Tailings Plant and preparation of an associated landform
Development of a new, wider and direct-access decline known as the Central Decline
The purpose of the investments is to:
• Facilitate the transition of Svinja Reka’s mining method from sub-level caving (SLC) to a combination of SLC, cut and fill stoping (C&F) and long-hole stoping (LHS).
• Maximise the extraction of the underground resources at Sasa by utilising paste backfill to improve the geotechnical characteristics of the mine and more selective mining methods.
• Create a safer and more sustainable underground mining operation whilst also extending the life of mine (LOM).
• Reduce the environmental footprint by ensuring that Sasa does not have to build and operate another downstream tailings facility following TSF4 during its life of mine to 2039. Instead, tailings will be stored on the new dry stack tailings facility or utilised as as paste backfill underground.
• Allow CAML to set a target of 70% of Sasa’s life of mine material waste being stored in a more environmentally responsible manner by the end of 2026 and a long-term target of 75% reduction in surface water abstraction by the end of 2026.
