Search

Non-metallic inclusions significantly influence the properties of steels. Take heavy rail steel as an example, Al2O3 inclusions can become fatigue source under cyclic stress, resulting in the rupture of the steel. Existing technologies and equipment can effectively reduce the amount and harm brought about by such inclusions, but they cannot guarantee the complete removal of large-sized and high-melting-temperature inclusions. Large-sized non-metallic inclusions give rise to instability in high-quality steels; as such, they are one of the bottlenecks in the development of steel. In the steel-making process, refractories in close contact with molten steel are a main source of large-sized non-metallic inclusions. Therefore, adopting appropriate ladle-lining refractories for refining and alloying is vital. This paper summarized the current research and latest developments in refractories used as ladle linings, and analyzed the application background and existing problems of traditional ladle lining refractories. Based on this discussion, future research directions regarding refractories suitable for the smelting of ultra-low-oxygen steel (or clean steel) as well as approaches to precisely control refractory properties via the reasonable selection of material components and structures were then provided. Novel ladle-lining refractories must possess not only excellent thermomechanical properties but also the ability to purify molten steel.

This paper summarizes current developments and ongoing research of MgO-C bricks, both at home and abroad, and especially analyzes antioxidant and low-carbon aspects. A future research direction regarding MgO-C bricks was proposed based on the discussion. Specifically, the property improvement of traditional MgO-C bricks through component optimization and structural design, the development of a new antioxidant, improvement of MgO-C bricks in low-carbon methods, and evaluation of corresponding properties, were proposed.

The viscosity of solid-containing slags can be calculated using the Roscoe equation combined with the calculation functions of multi-component & multi-phase equilibria and pure-liquid slag's viscosity in FactSage software. An FeO-SiO2-Fe3O4-CaO-Al2O3-MgO system used in copper smelting was studied in this paper. Firstly, the parameters of the Roscoe equation were fitted using the measured viscosities of analogous slag in the literature, and the accuracy of viscosity calculated by the method for this slag system was verified additionally. Then, the effect of slag components' contents on the equilibrium phase-composition and viscosity was investigated based on the calculation model. Accordingly, the reasonable proportions of components in the slag were obtained. When the mass fractions of slag components are FeO 40%~60%, SiO2 25%~40%, Fe3O4 0%~15%, CaO 0%~10%, Al2O3 0%~8%, and MgO 0%~4%, the molten slag with good liquidity and fewer solids can be obtained in the smelting process.

The oxidation kinetics of iron sheet in CO2 -CO mixture was studied by on-line measuring the composition change of the reaction gas using a gas mass spectrometer under different CO2 partial pressures in the temperature range of 1273 to 1473 K. It is found that the oxidation rate increases linearly with CO2 paltial pressure, the rate constant decreases with the increase of COJCO volume ratio, and the apparent activation energy of the oxidation of iron sheet is (137.7±15.8)k J·mol-1. Compared with the results reported, this on-line mass spectrometry analysis can get reliable resuhs, so it can be used to study the gas-solid reaction kinetics.