Dr. Dosmurat Aitkulov

Abstract:

Present study determines conditions for titanium magnetite concentrate processing with fairly complete titanium conversion to the slag and iron and vanadium separation in the hot metal. It is quite difficult to process titanium magnetite concentrate in the blast furnaces due to low fusibility of charge and direct electrical melting causes process instability. Present work is devoted to development of concentrate double stage smelting process with little soda additions, including solid-phase recovery at the first stage using specific coke as a reductant, avoiding concentrate oxidation and including its preliminary thermooxidation.

Mix charge made of concentrate, soda and specific coke was granulated in water, dried at 130°C, pellets were placed in graphite crucible, and later on it was set up in the centre of the furnace in alundum crucible. Temperature regimen was fixed under following parameters: temperature at the first stage is 1250^оС; soaking time is 50 min; temperature at the second stage is 1500 - 1650^оС; soaking time is 35 min. It is established that little soda additive (estimated 3-4% Na₂O) to the charge of titanium magnetite concentrate recovery smelting performs as coagulant during briquetting, as catalyst in course of solid-phase recovery, as inhibitor of DRI briquettes secondary oxidation as slag thinner during smelting. In course of titanium magnetite concentrate reduction smelting process soda interacts to SiO₂, Al₂O₃, TiO₂ oxides forming sodium silicates and titanates.

Double-stage technology of titanium magnetite concentrate reduction smelting both with soda addition and without oxidation and preliminary iron oxidation of titanium magnetite concentrates till hematite was developed. Optimal process parameters were determined. Following parameters were obtained: hot metal yield was ~55% out of concentrate weight, slag yield – 23,3-25,8%, carbon-free slag content, wt. %: Fe=1,0-1,6; TiO₂=62,7-61,9. TiO₂ yield in the slag is 89,6-94,1%. Hot metal contains, %: 5,51 С; 0,36 Ti; 0,35 Mn; 0,04 Si; 0,23 V.  Vanadium yield in iron was 53,0%.