Authors have presented a study on the formation of structure of partially reduced pellets and their metallurgical properties. 3 types of pellets were used in the study of partial reduction processes. One has examined the reduction kinetics, reactive capacity and metallurgical properties of the samples. Higher reduction gas temperature intensifies the reduction process in the first stages of oxygen removal (in the range ϕ = 5...25%). With further increase in reduction degree the effect of temperature is negated by the formation of fusible compounds on the pellet surface. The strength of pellets with varying reduction degrees depends on the initial composition of the pellet mix components. Addition of calcium-containing additives helps increase the strength of reduced pellets. It was found that the pellets with 10% reduction degree have the highest compression strength values. Regardless of temperature and pellet grade, pellets with 20...40% reduction degree have demonstrated low compression strength values, probably due to the formation of new phases and the presence of residual content of the original hematite phase. Increase in the metallic iron content in pellets improves the compression strength, which can be seen starting from a reduction degree of 50%. Disintegration indices (LTD) of reduced pellets demonstrate high values, with a maximum difference of 2,5 % r.t. Increasing the initial reduction degree of the samples from 50% to 70% contributes to an increase in the whole pellet yield (LTD+6.3) and a corresponding decrease in fines generation (LTD-3.15; LTD-0.5). The softening onset temperature of reduced pellets is 7 % higher relative to oxidised pellets, which helps bring the cohesion zone in a blast furnace closer to the hearth. With the increasing in reduction degree, the propensity for secondary oxidation of partially reduced pellets decreases, possibly due to the high FeO content in the pellets at ϕr = 70 %. Unfluxed pellets have lower reactive capacity than fluxed pellets by a factor of 2,4 at ϕr = 50 % and by a factor of 1,6 at 70 %.
Translated title of the contributionFORMATION OF THE STRUCTURE AND METALLURGICAL PROPERTIES OF PARTIALLY REDUCED PELLETS
Original languageRussian
Pages (from-to)2-11
Number of pages10
JournalСталь
Issue number10
Publication statusPublished - 2022

    GRNTI

  • 53.00.00 METALLURGY

    Level of Research Output

  • VAK List
  • Russian Science Citation Index

ID: 31801094