The new recycled material refurbishment chamber has been built on level 1000 at the site of a former sedimentation tank.
“We carried out the adaptation of this site to new uses with the in-house work system, using the knowledge and experience of the mine's employees,” says Marcin Mikołajczyk, Technical Director of KWK Pniówek.
The project was launched in October 2022. In the first stage, the walls were demolished and the infrastructure of the old sedimentation tank was removed. Next, a shaft sink channel was made for the bending and straightening machine, so that maintenance work can be carried out and components protecting the machine from overloading can be replaced. The machine is founded on a reinforced concrete slab. The entire 80-meter-long refurbishment chamber was reinforced with steel beams, and a 15 meter section was covered with sprayed concrete. The chamber along its entire length is illuminated and whitewashed, and the floor is covered with poured concrete. The work was completed by installation of a transport system based on a shunting tractor with hydraulic winches. After the installation of the ODP-6 bending and straightening machine and workbenches in April 2023, successful operational tests and the necessary approvals were carried out with the participation of the machine manufacturer. After that the material refurbishment chamber has started working.
“The ODP-6 bending and straightening machine is a high-tech machine. Straightening of the support elements is carried out by rolling, which restores them to an almost perfect shape. Such a good end result of the refurbishment was not achievable in other machines used so far. The high quality of the strength parameters of the obtained steel support straights has been confirmed by tests of the GIG Research Institute. This is a new quality in the support straightening process at the Pniówek mine,” explains Sebastian Derbis, manager of underground mining operations at KWK Pniówek.
Currently, work in the chamber is carried out in 3 shifts. Each shift is capable of refurbishing 40 support elements with a V32 profile and a length of 3.5 meters, allowing 420 running meters of supports to be refurbished per day. The weight of one running meter of V32-profile supports is 32 kg, so the total weight of supports refurbished in a day is 13,440 kg. The net purchase price of 1 running meter of a new support at the current price level is PLN 131.84, and the net price of scrap metal sold by the mine to the smelter is PLN 1.28 per kg. Thus, from 1 sunning meter of scrap support sold, the mine recovers 40.96 PLN net from selling the scrap. Comparing the scale of profitability of selling scrap supports to its refurbishment at a recovery level of 420 running meters per day, the mine gains PLN 38,169.60 in savings per day, excluding labor costs. After labor costs, the mine gains PLN 30,690.60 in savings per day, without further reducing the capacity and operation of the shaft. Under these assumptions, the purchase of the innovative machine will pay off already after 6 months of operation.
“The new chamber doesn't just straighten the supports. Here, we also refurbish the fastening clamps for connecting the ŁKWH V29 and V32 supports, SD V29 and V32 connectors, sprags for the supports, slings for suspended cable cars, structures, belt conveyor rollers and many other small components,” says Mariusz Bujok, shift foreman of the material and support refurbishment department, adding: “With a view to achieving the highest possible efficiency of the work carried out in the material refurbishment chamber, all workstations have been equipped with a pneumatic wrench, and transport and loading and unloading work is carried out using a shunting tractor equipped with hydraulic hoist equipment.
The Pniówek mine, through a carefully considered investment in a technologically innovative and comprehensively equipped chamber for the refurbishment of gallery supports in underground workings, has become a leader among Polish mines. Currently, the refurbishment chamber is attracting a lot of interest from mining companies from all over the region, and the Pniówek mine is eager to share the experience gained.
