Research on the Process of Iron-Bearing Dust's Self-Reduction to Produce Iron Nuggets

Abstract

Under normal temperature iron-bearing dust was mixed with coal and compacted to form pellets as per different ratio. After pellets were self-reduced in carbon tube furnace, the influence of C/O ratio, slag basicity, temperature on the separating behavior of metal phase from slag phase, metallization rate, dephosphorization and desulphurization rate was studied. The results indicate that self-reduced products can spontaneously separate when slag basicity is more than 1.8. The optimum inner ratio of C/O and slag basicity for complete separation of iron and slag is 1.1 and 2.0 respectively. Under those conditions and temperature at above 1350°C, such results that product can reach: iron yield is more than 95%, iron nuggets within size of 5~20mm is more than 80% and desulphurization rate is more than 85%.

Carbothermal Reduction of Stainless Steel Dust and Laterite Nickel Ore: Slag Phase Behavior Regulation and Self-pulverization Control Mechanism

“…At the same time, it reacts with SiO 2 for ( 15) and ( 16) to form Ca 2 SiO 4 and Ca 3 SiO 5 . The Gibbs free energy ΔG of reaction (17) is less than 0 as the temperature is higher than 1 303°C, the reaction proceeds in a forward direction, and CaCO 3 decomposes. Throughout the high temperature reactions, reactions ( 15) and ( 16) are easy to occur, and Ca 2 SiO 4 and Ca 3 SiO 5 are easy to form.…”

“…[12][13][14][15] In the reduction process for the treatment of iron containing solid waste, in addition to the decisive effect of reduction conditions on the metal recovery, the composition of reduction slag also has a significant effect on the metal reduction and subsequent treatment process. [16][17][18][19][20][21] Tang et al carried out the thermal reduction experiment of mixing and compacting iron containing dust and coal into pellets at high temperature. The effects of C/O ratio (carbon oxygen ratio), slag basicity and temperature on metal recovery and reduction product separation efficiency were studied.…”

“…The Fe recovery ratio can reach more than 95% after the reduction temperature is higher than 1 350°C. 22) Zhang et al studied the reaction mechanism of smelting slag through thermodynamic analysis and coal based direct reduction experiment. The recoveries of metal Fe are 91.55%, 44.53% and 88.48%, respectively, corresponding to the basicity of slag of 1.00, 2.00 and 3.85, respectively.…”