MMK revamps cold-rolling shop’s pickling line

Magnitogorsk Iron and Steel Works (MMK) has completed the reconstruction of continuous pickling line (CPL) No. 1 at its sheet rolling shop No. 5.

As part of the overhaul, the Company completely replaced the line’s process equipment, including its pickling baths, rinsing baths, circulation tanks, heat exchangers, pumps, acid lines, steam lines, condensate line, and grease and liquid lubricant lines. The electrical assembly as well as the exhaust and air purification system, used to remove hydrochloric acid vapour produced by the pickling and rinsing baths, were also revamped. The overhaul, which took 120 days to complete, involved the dismantling of 2,100 tonnes of metalwork and the assembly of 2,000 tonnes of metal structures.

With a capacity of up to 2 million tonnes per year, CPL No. 1 at sheet rolling shop No. 5 was commissioned in November 2004. It uses a hydrochloric acid solution to remove scale from the surface of hot-rolled coils. The launch of CPL Nos. 1 and 2 was one of the stages involved in the comprehensive reconstruction of sheet rolling shop No. 5 carried out in the early 2000s. The modernisation of the pickling department at the time included the reconstruction of both continuous pickling lines, which were converted from sulphuric acid to hydrochloric acid, for which a hydrochloric acid recovery unit was also built. The new technology increased their pickling capacity to 3.2 million tonnes, making it possible to produce high-quality cold-rolled sheet metal with extra high surface finishes as well as to virtually eliminate the formation of neutralization sludge. In addition, the reconstruction of the pickling department at sheet rolling shop No. 5 had a significant environmental impact.