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SiC porous ceramics (SPCs) are key functional medium materials, which are widely applied as porous burners. However, SPCs produced via the polyurethane sponge replica technique usually exhibit a randomly distributed cellular structure, leading to vulnerability and a low combustion efficiency for the porous burners. In this study, SPCs were structurally designed via novel 3D printed resin template technique; this endowed the SPCs with synergistically optimized strength and combustion characteristics. SPCs containing tetrakaidecahedron, octahedron and cubic cells were successfully prepared via SiC slurry coating and sintering in air. The cell parameters determined the strength and combustion properties of the SPCs. The SPCs containing cubic cells exhibited the largest strength and strain, because more struts were present parallel to the loading direction; this is more advantageous for stress bearing compared to those vertical to the loading direction. The tetrakaidecahedron cell facilitated the formation of a disturbance effect within the SPCs to a higher extent than the cubic and octahedron cells, thereby enhancing the heat exchange performance between the fluid and porous framework. Hence, the SPC with tetrakaidecahedron cells exhibited the best combustion properties, which resulted in the highest surface temperature and lowest pollution emission.

Purging plug with slits is widely used in the secondary refining process, and its service life determines the downtime and production efficiency. To achieve a good performance in service life, optimizing the geometric structure of the slit, which can alleviate the stress concentration around the slit, was employed using the finite plate model. Furthermore, the performance of the purging plugs with different shapes of slits in the refining effect was investigated by conducting the water model experiments. The numerical simulation results showed that the appropriate shapes of slits could alleviate the stress concentration phenomena. In the water model experiment, the mixing time of the purging plug with circular slits is lesser than that of the purging plug with rectangular slits when the gas flow is less than 6.02 L/min. Compared with the rectangular slits, the circular slits are detrimental to smaller and well-distributed bubbles. Thus, the inclusion removal rate of the purging plug with circular slits is approximately 10% larger than that of the purging plug with the rectangular slits.

The new route for recycling fly ash was proposed to prepare SiC reticulated porous ceramics (SRPCs) with high strength and increased efficient filtration for molten metal filtration. The effects of fly ash on the rheological characteristics, microstructure evaluation and wetting behavior between SRPCs and molten metal were investigated. It was found that the fly ash was beneficial to thixotropic property of SiC slurry when its content was less than 30 wt%. Furthermore, fly ash in SRPCs was completely transformed into mullite with needle-shape at 1300 °C, forming a porous structure containing micro pores and windows. SRPCs containing 20 wt% fly ash exhibited a higher strength because of the improved rheological properties of SiC slurry and the optimized microstructure in skeleton. In addition, the added fly ash in SRPCs could increase the contact angle between skeleton substrate and molten metal via microporosization of skeleton, thus exhibiting the potential ability to improve the filtration efficiency.

The hot metal desulfurization in Kanbara Reactor (KR) metal treatment was simulated in this study via a transient-coupled 3D numerical model of the two-phase flow, heat transfer, and particle motion desulfurization processes. The KR impeller stirring was described via the multiple reference frame model. The volume of fluid approach was employed to capture the air-hot metal interface. The particle motion and aggregation were defined by the two-way coupled Euler–Lagrangian method. A desulfurization kinetic model was simultaneously introduced to represent the sulfur mass transfer rate. The effect of the initial diameter of desulfurizing agent (DA) particles on the desulfurization efficiency was quantitatively assessed. The lowest sulfur content was observed in the impeller vicinity and the highest one in the inactive colder liquid metal at the vessel bottom. With the DA particle initial diameter reduction from 3.0 to 0.5 mm, the overall desulfurization rate was increased from 83.2 to 97.1 pct. Insofar the specific surface area of smaller particles exceeded that of larger ones, they had higher motion velocities and heating rates, creating a greater reactivity for the desulfurization. However, desulfurization at the vessel bottom was only slightly enhanced using smaller DA particles, so the overall improvement did not exceed 20 pct. Further enhancement is envisaged by refining the impeller design and particle-adding technique.