Process safety and constant quality of manufactured products are the key assumptions of the recently completed modernization of the pickling line in the cold rolling mill in Krakow. The sheets cleaned here are then used to produce structural elements: gas cylinders or by the automotive industry for the production of e.g. steel car rims. The products from the cold rolling mill are also sold to customers from the household appliances segment - to produce washing machines, refrigerators and dishwashers. The investment, which is part of the development plan for the downstream operations in the Krakow unit of ArcelorMittal Poland cost almost PLN 8 million.
Sheet up to 2 kilometers long produced at the hot rolling mill in Krakow, one of the most modern plants of this type in Europe, is coiled and then delivered to the customer or for further processing – at the cold rolling mill in Krakow.
Hot rolled coils must be cleaned of the so-called scales, i.e. mixtures of iron oxides formed during hot rolling. Pickling i.e. cleaning the sheet metal from surface defects in a hydrochloric acid solution, takes place on a 250-metre long pickling line.
It was this part of the plant - the acid regeneration plant – that was modernized. - Hydrochloric acid used to clean metal sheets circulates in a sealed closed circuit. The used solution goes to a regeneration station, where its properties are restored so that we can use it again - explains Wojciech Koszuta, COO of the Quality and Flat Products at ArcelorMittal Poland.
Replacing the tanks at the hydrochloric acid regeneration plant was a real challenge. In order to place these tanks in the bay - columns with a height of several meters - it was necessary to rebuild the roof and install special openable covers. The very process of producing the columns was unusual, because due to the fact that they could not be made of steel the technology of their production was applied based on a method similar to that used in the construction of the hulls of sailing yachts. A glass mat soaked in a special resin is applied in layers to the mould. Then the resin is chemically hardened, providing the walls of the tank with the required strength and a guarantee of operational reliability and tightness for 30 years. The investment cost almost PLN 8 million.
- As we have declared, we are consistently investing in the development of the downstream operations in our unit in Krakow. The assortment produced by the cold and hot rolling mill is of really high quality, which is why it is appreciated not only on the local but also foreign markets - emphasizes Sanjay Samaddar, chairman and CEO of ArcelorMittal Poland. - Our sheets are used to produce white goods, which all of us use every day: cookers, washing machines, dishwashers, but also automotive parts, e.g. steel rims. Without them it is difficult to imagine our everyday life.
Do you know that…
• the thinnest hot-rolled sheet in coil is approx. 2 kilometers long after unfolding. This is as much as the planned western bypass of Zielonki will be - Wolbromska Route.
• the pickling line is 250 meters long. That is as much as the railway bridge over the Vistula between Kraków Nowa Huta Północ and Podgrabie Wisła train stops.
• the cost of modernization of the hydrochloric acid regeneration station is over PLN almost 8 million - as much as the city of Krakow plans to spend on the redevelopment of the market in Stary Kleparz.
• over 20 tons of resin and glass mat were used for the construction of new columns and process channels, which is the weight of more than 10 "heads" - sculptures by Mitoraj standing on the Main Square in Krakow.
• to install the tanks used a crane with a lifting capacity of 130 tons, which could lift 5 papal stones such as the one located in Krakow's Błonia Park.
