steel research international

The rotary multi-nozzle cup atomizer is proposed to granulate the molten slag at a high cooling rate without water consumption in this study. The disintegration mechanism, flight trajectory and heat transfer models of the droplet have been successfully developed. The results can provide guidance for designing the commercialized atomizer and optimizing the operation parameters of atomizer.

Mixture of waste iron oxide fines and lime fines are micro-pelletized without binder using CO₂/industrial waste gas at room temperature that can provide a good handling strength. Subsequently, the developed micro-pellets are sintered without using coke breeze. Waste materials itself provides heat for sintering. The produced sinter would be useful as a synthetic flux in basic oxygen process for early formation of oxidizing slag to make refining faster.

The partition ratios of phosphorous between CaO–SiO₂–Fe_tO–P₂O₅ slag with Na₂O or K₂O addition and solid pure iron were measured at different temperatures to learn about those between the same slag and carbon-saturated iron. The experimental results shows that both Na₂O and K₂O addition can improve the dephosphorization ability of the experimental slag and they have similar dephosphorization ability under the same experimental conditions.

In present work, adiabatic carbon rates are compared between smelting reduction and direct reduction along idealized conditions. Both oxygen-enrich and pre-heating air are optimized methods to decrease carbon rate of hot metal production. From the figure, the total adiabatic carbon rate of “Direct reduction-Melting” process may be lower than 440 kg tHM⁻¹.

Inclusion morphology, composition and number at different times of RH vacuum treatment are investigated on API-X70 pipeline steel with ASPEX. It is found that the inclusions are mainly globular CaO–Al₂O₃–MgO. The inclusion number decreases with time and the final number is highly associated with the initial number. Furthermore, non-liquid inclusions decrease much more quickly and thoroughly than liquid ones. Interfacial property is employed to explain the different removal behaviors.