On November 8, 2018 an overhaul of the 2-nd category of blast furnace No. 4 was completed at PJSC “MK AZOVSTAL”.
A general designer and performer of all design and survey works was the company “M TECHNOLOGY” LLC. As part of this overhaul a modern automated cooling of the bosh and blast furnace stack has been implemented, the tuyere zone cooling system has been changed from seawater to a closed loop chemically treated water, copper and steel cooling staves with silicon carbide brick pre-lining  and  modern water / air heat exchangers have been installed. This modernization will make provision for the blast furnace operation during a period of 15 years under the condition of  intensive pulverized coal injection  (up to 180 kg per ton of hot metal) without shutdowns for repairs, saving electricity and coke, and refusal from sea water for tuyere zone, bosh and stack cooling, which will favorably affect the environmental situation in the region.