A development of the adaptive technology of sinter production at PJSC MMK

The adaptive technology of sinter production and pig iron smelting at PJSC MMK was studied when replacing the pellets of Sokolov-Sarybai Mining Production Association (SSGPO) JSC (further referred to as SSGPO) with pellets from other producers in the blast furnace charge and when increasing their share in the charge. Technological adaptation of the sinter production and cast iron production processes aiming at the manufacture of products with required properties has the following main components: adaptation of the composition and properties of the components of sinter and blast furnace charge; adjustment of the sinter and blast furnace production parameter level (parametric adaptation); change of the sequence and/or the set of technological operations (structural adaptation).In the blast-furnace shop, the consumption of SSGPO pellets was lowered and then increased with a reverse change in the consumption of pellets from other producers. The content of pellets in the furnace charge was first increased and then lowered. The consumption of pellets of all types was in the range of 515 - 649 kg/t of pig iron, which corresponded to the content of pellets in the iron ore portion of the charge 31.8 - 42.0 %. The development of an adaptive technology for sinter production increased its basicity by CaO/SiO₂ in the range 1.68 - 2.01 with a decrease in the share of SSGPO pellets and an increase of pellets total share in the furnace charge.As a result, a 0.1 unit increase in basicity coincided with 0.047 % absolute decrease in the content of 5 - 0 mm class fines in sinter. The increase in impact strength according to GOST 15137-77 was 0.89 % abs., the decrease in abrasion was 0.149 % abs. At the same time, a 0.1 unit increase in basicity coincided with a 0.29 % abs. increase of "hot" strength LTD+6,3 according to ISO 13930: 2007. The increase in sinter strength had a positive effect on the gas dynamics of the blast-furnace process, which allowed smelting with an increased consumption of natural gas.Keywords: sinter, pellets, cold and hot strength, charge basicity, sinter machine productivity