METHOD OF PRODUCING IRON-RICH LIME Russian patent published in 2017 - IPC C21C5/36 

FIELD: metallurgy.

SUBSTANCE: invention relates to metallurgy, in particular, to a method of producing iron-rich lime. Method involves loading in tubular furnace in form of a mixture of limestone and iron-containing additive, firing and pelletizing. Prior to loading into furnace iron-containing additive is produced by granulation of converter sludge to level of humidity no more than 12.0 %, followed by mixing lime and iron-containing additive in ratio: limestone 99.0–99.9 %; iron-containing additive 0.1–1.0 %. Further, obtained charge is loaded in tubular furnace and annealed for 1.5–2 hours at furnace rotation of 1-1.5 rpm, wherein annealing is started at a temperature of 750–850 °C, and completed at temperature 800–900 °C. For preparation of iron-containing additive converter sludge is used with following chemical composition, wt%: Fe₂O₃ not less than 12.0; FeO not less than 29.0; Fe_total. not less than 40.0; balance – unavoidable impurities. Surface of lime pieces has a coating layer based on compounds CaO, MgO, FeO, Fe₂O₃ with thickness of 0.5–3.0 mm.

EFFECT: invention ensures reduction of costs for production of steel due to increased degree and rate of recovery of CaO slag.

3 cl, 1 ex