After groggily arising to the bright 5:30am sun, today the crew embarked on its second mine tour of the trip. We bussed from Krakow to the village of Olkusz, which has a rich mining heritage, having seen mining activity in the surrounding area since the 16th century. Here, there is a large underground lead-zinc mine called Bolesław, which is owned and operated by ZGH.
Approaching the facility with the early sun burning through the trees, we arrived at the main office, where we were greeted and led into a presentation room. The Superintendent of the mine spoke lots of interesting polish words (which sounded great!), so it was up to Maria to translate the information to us. Normally not a topic of such fun, when the Chief Geologist talked about the surrounding rock structures and stratification “lawyers”, hilarity ensued. Language barriers aside, the presentation was actually quite informative and allowed us to understand the two mining methods (Room & Pillar, Face Mining) before actually going underground.
Time for the underground part of the tour, the exciting part! Suiting up with the required boots, hard hat, prone-to-tearing painter’s suits and ugly vis-vests, we proceeded to file down a beige hallway leading to a bright, cheery, grey, distribution room where we were handed cap-lamps and emergency breathing apparatuses. Our main guide casually pointed out that in the 24 years that he’s worked at the mine they’re never been a fire, so everything should be fine! We still had to lug the metal canisters around though, but they were very light, so no real complaints. In fact, the whole tour was handled smoothly and I was impressed by their level of coordination.
Lamps and safety equipment were distributed to everyone
Two Landrover Defenders were used to transport us underground
Vehicle of choice: Land Rover Defender. All 30 of us squished into just two of these beasts as we prepared to enter the mine’s ramp decline. Hurtling down into the dark, we spent about 15 minutes driving down to reach the production levels (mine has operated for a long time). Due to the high grades present in this mine, we could actually see veins of the silver-coloured Galena (PbS) as we inspected a recently blasted area in the “exploitation levels”. After seeing some underground equipment in action, we were showed the mine’s most interesting problem: water. Cascading in this particular area at 260m3/min, water poured out of the walls and, like a river, ran down through the mine. This kind of thing has plagued the surrounding countryside with dramatic reductions in the water table. As a result, they told us the company is responsible for processing and cleaning the water and redistributing it to the villages.
This drift had around 6″ of water wall to wall coming down it
Source of the inflow, the orange is from hydrous ferrous oxide precipitating from solution
Mobile rock breaker backing out so we could look at the grizzly and ore pass
Grizzly above ore pass
LHD dumping load in ore pass
Group shot inside LHD bucket
Structure to hold back sand backfill in mined area
High grade ore with a lot of mineralization visible
Back on surface
Exiting the vehicles, headframe in background
Group shot. Big thank you to our sponsors!
After the underground tour, we posed for a quick picture and left to view the mineral processing facilities. Walking by an imposing headframe, containing the ore-moving skip, we saw large structures containing a jaw crusher, conveyors, preconcentration/crushing facilities, gypsum removal tanks with acid, grinding mills, giant spiral classifiers, flotation tanks, thickeners, and a filter pres. The final lead concentrate produced is sold to another smelter, whereas the zinc concentrate they smelt themselves nearby.
The ore is transported underground to another shaft where it is then brought to surface for processing
Ore is hauled up in skips which is then dumped into jaw crushers and then onto a conveyor system
Gypsum must be precipitated using acid before flotation, this is done in these large tanks
Spiral classifiers and ball mills
Lead flotation impellar
Lead flotation froth
Lime/reagent addition for zinc flotation. Zinc is floated after lead and must be activated using copper sulphate solution
Empty flotation cell
Thickener. There were a variety of thickeners for different purposes.
Belt filter press between presses
Belt filter press in operation
Dinesh sat in the wrong place
All in all, this was a unique tour that allowed us to experience aspects of eastern flavour shown in the mining and processing here in Poland!
Words and photos by James Sovka and Fraser Foulds