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EVRAZ NTMK JSC has significant amount of blast furnace sludges, that accumulated in dumps. Chemical and phase analysis of that sludges was carried out. It has shown significant amount of zinc sulphate, which prevents such sludge utilization in a blast furnace. Moreover, zinc sulphate requires a high temperature unit for recycling by common schemes. The possibility of zinc sulphate conversation into oxidized zinc with simultaneous metallized residue obtaining under the common for Waelz process temperatures was confirmed in laboratory. The obtained during laboratory experiments metallized residue is suitable for using in blast furnace as charge addition. The results of a thermodynamic analysis of the zinc sulphate conversion to oxide and the physicochemical basis for the extraction of such zinc forms are presented. Theoretical calculations and laboratory experiments confirmed that sludges with zinc sulphate could be suitable materials for blast furnace. But, sludges of different processes allow to obtain fired briquettes with different physical properties. © Published under licence by IOP Publishing Ltd.

Analyse of the blast furnace charge chemical content changing with the JSC EVRAZ NTMK raw materials base alteration was carried out. That expected change would result in TiO2 content increasing in the blast furnace slags. That increasing would lead to carbonitride formation in the upper levels of the blast furnace, which reduce technical parameters of the blast furnace operation by reducing effective volume of the furnace and derange regular charge moving. Possible ways of that problem solving was shown. It was proposed the complex technology, that affect 3 technological stages: agglomeration, blast furnace process and out-of-furnace treatment of steel. Converting of TiO2 into CaO•TiO2 allows to delay carbonitride formation due to increasing required temperature for that process. In that case, carbonitride formation would move to the tuyere zone of blast furnace, where it increase lining durability. The proposed technology was industrially tested, and the main idea was proved. Few problems were found during industrial tests, but theoretical solving of them was proposed. © Published under licence by IOP Publishing Ltd.

The comprehensive methodology for the zinc extraction from sulfide compounds into the oxide form with possible further reduction to metal is presented in this study. It was demonstrated in laboratory conditions during sludge treatment with Zn and ZnO obtaining. The remaining silicate products. It is proposed to recycle this material into Portland cement clinker to ensure a waste-free process.

The mathematical processing results of a number of EAF-135 melts electrical parameters are presented. The influence of the foamy slag formation, molten metal carburization and the harmful impurities oxidation on the change in electrical parameters is analyzed. The methodology for determining the metal oxidation from the electrical melt parameters is characterized. In the presented form, the technique is cumbersome for the rapid assessment of the oxidation process intensity and requires refinement.

Practical methods for extending the life of submersible tubes in vacuum chambers are considered. The structure of periclase-chromite components is studied. Refractories corresponding to optimal vacuum-chamber operation in the converter shop at OAO EVRAZ NTMK are selected. © 2013 Allerton Press, Inc.

Several practical methods of improving the durability of vacuum-chamber linings in the converter shop at OAO Nizhnetagil'skii Metallurgicheskii Kombinat are considered. © 2012 Allerton Press, Inc.