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Side-blown smelting technology has been widely adopted in the copper smelting process. In this study, the stirring uniformity of molten bath and the smelting efficiency of the copper smelting process was improved by a computational fluid dynamics method. Simulation of the gas–slag–matte three-phase flow in the furnace was performed by the volume of a fraction multiphase model coupled to a realizable k–ε turbulence model. The flow field can be divided into five zones, high-speed injection, strong-loop, weak-loop, gas overflow and separation, and settlement zones. Three improved gas injection modes, including oblique, horizontal staggered, and vertical staggered, have been proposed to improve the flow field of the weak-loop zone in the center of the molten bath. Of these methods, the oblique injection mode showed the best improvement effect. The stirring intensity and the slag splashing amount were nearly twice and only one-quarter of the original condition, respectively.

Medium oxygen-enriched blast furnaces that utilize reducing gas injections are a feasible new ironmaking process that can significantly reduce the coke ratio and carbon dioxide emissions. To better inject the reducing gas into the blast furnace, two injection methods were designed in this study, and the effects of the reducing gas on the combustion of pulverized coal in three types of medium oxygen-enriched processes were studied using a three-dimensional lance-blowpipe-tuyere-raceway model. The reducing gas was injected into the blowpipe from a sleeve spray lance, which was suitable for injecting a small amount of reducing gas. The optimal coal burnout was 6% higher than that of a traditional blast furnace (TBF). The reducing gas was also directly injected into the raceway from a spray lance, which was suitable for injecting a large amount of reducing gas. The optimal coal burnout was 13% higher than that of a TBF using this system.

The flow, solidification, and solute transport behaviors in the 380 × 280 mm 2 bloom center under the effect of final electromagnetic stirring (F-EMS) were investigated using a mathematical model. The results of nail shooting tests and infrared carbon-sulfur analyses are in good agreement with the simulated solidification and carbon concentration results. When F-EMS was installed 13.6 m below the meniscus with a frequency of 8.0 Hz, the maximum tangential velocity at the solidification front increased from 0.013 m/s to 0.023 m/s, and the liquid fraction at the computational outlet decreased from 0.7827 to 0.7256 as the current intensity increased from 300 A to 600 A. For each 100 A increase in the current intensity, the temperature of the mushy steel in the bloom center decreased by an additional 2.4 K. When the current intensity was maintained between 300 A and 400 A, the negative segregation band in the newly solidified shell was eliminated, the uniformity of the carbon distribution around the bloom center was enhanced, and the centerline segregation was noticeably improved.

To predict slag corrosion numerically, a transient 3D mathematical model that considers the fluid flow, heat, and mass transfer was developed. A dynamic corrosion experiment using the rotating immersion approach was carried out to assess the overall corrosion activation of the MgO-C refractory. An expression for the corrosion rate was determined based on the wall shear stress, slag viscosity, sample size, overall corrosion activation, and difference in MgO content. A greater corrosion rate was observed at the bottom corner of the refractory sample compared to other parts, and it was concluded that higher temperatures and speeds encourage slag corrosion. The averaged corrosion rates at the sample wall with different rotating speeds and holding periods were compared. The relative error varied from 1.92% to 12.19%, which is within the acceptable range. It is expected that the proposed computational framework can be potentially extended to other refractory corrosion scenarios in metallurgical reactors.

Insights into dispersed phases, such as bubbles and droplets, and multiscale interfaces in a gas-stirred ladle are of great significance to multiphase systems of metallurgical reactors, but are still challenging and not fully understood. A direct numerical simulation of dispersing phases was developed, coupling a sub-grid-scale large-eddy simulation for turbulence in fine grids with local refinement tactics. After validation with experimental data, the model was applied to investigate the bubble formation process at small length scales to understand the mechanism of bubble breakup and coalescence, to reveal the interaction of bubbles with surrounding fluid and the evolution of heterogeneous vortexes structures, to compare transient phenomena and time-averaged behavior, and to resolve the large-scale interface profile and the large number of small droplets formed by the interaction of metal, slag, and gas. The availability of results from the bubble/droplet scale using the current simulations should help advance new closure relations for the average or large-scale flows toward a multiscale model.

A particle-free surface coupled model has been developed using the Eulerian–Eulerian approach for revealing the gas–steel–slag multiphase flow in the vacuum chamber of a 210-ton RH degasser. The particle submodel preferred to predict the gas–steel and gas–slag interpenetrating phenomena, while the free surface submodel focused on tracking the steel–slag interface flow. The mesh sensitivity analysis has been investigated, and the coupled model was validated by the measured values. Using this coupled model, some previously unknown problems about multiphase flow in the vacuum chamber were revealed, such as the effect of the free surface fluctuation, variation of the liquid level, and slag flow behavior.

Top blown O 2  + CO 2 mixed injection technology with a swirling oxygen lance nozzle, which supports a larger jet radial velocity than the conventional oxygen lance nozzle, improves the impact area of the jet and thus the process efficiency of converter smelting. In this study, the jet characteristics of a 90% O 2  + 10% CO 2 mixture injected through a full-scale four-hole swirl nozzle was simulated and the effects of preheating temperature and gas flow rate on the jet characteristics were analyzed. Increasing the preheating temperature and gas flow rate increases the axial velocity of the jet, the core section, and the mixing degree of multiple jets. At the same injection distance, increasing the preheating temperature of the mixture increases the impact strength and area of the jet. These results can be used to adjust the gas flow rate and preheating temperature of the mixed gases in large-scale smelting operations.

Different drag laws and turbulence models were compared to evaluate gas distribution and fluid flow velocities in a Rheinstahl–Heraeus (RH) reactor. The discrete phase model was adopted to track injected gas bubbles, and the volume of fluid model was applied to describe a more actual free surface. The prediction accuracy of the numerical model was evaluated by the measured flow velocity in an air-water model and the measured circulation flow rate of molten steel in a real RH system. Results indicate that Morsi’s drag law predicts more accurate local velocity compared with Schiller’s and Harmathy’s laws. The influence of turbulent dispersion on the injected gas bubbles is non-negligible for predicting the gas–liquid flow in a RH reactor. In addition, although the large eddy simulation (LES) approach predicts more actual free surface fluctuation, the realizable k - ε model shows better agreement with the measured local velocity in the furnace.

The Peirce–Smith (PS) converter is one of the pyrometallurgical copper smelting processes, in which the flow field in the converter has an important influence on production efficiency. In this study, a CFD simulation of the air–oil–water cold model with a ratio of 1:5 was adopted to investigate the gas–liquid–liquid three-phase flow characteristics. The effect of nozzle height on the flow field, velocity, phase, and wall shear stress have been described. The optimal nozzle height is 0.105–0.125 m, under which the flow field distributed uniformly and the gas–liquid mixing was sufficient. The shear stress on the lining wall above the nozzles is larger than in other places, so the nozzle height can be changed regularly during the injection process to make the lining near the nozzles be scoured evenly so prolonging the furnace service life. The optimal nozzle height for an industrial PS converter was suggested to be from 0.525 m to 0.625 m.