Production equipment: The alu flux mostly contains various Na and Ca-containing components, such as NaF, Na2SiF6, Na3AF6, CaF2, etc. After refining, excess impurity elements Na and Ca be introduced into the melt. In addition, the preparation process of the flux is easily overlooked. At present, the alu flux is prepared by mechanical mixing method, and the flux components are not easily mixed evenly, which will reduce the refining efficiency of the flux, and the melt quality will be unstable. In recent years, domestic scholars have developed a series of rare earth composite fluxes, the main achievements are: (1) RJ series fluxes developed by Fu Gaosheng of Fuzhou University, etc., the main components are: NaCKCl, and various fluorides (Na3 AIF6, NaF) A small number of additives such as carbonate, sulfate and rare earth compounds: (2) JDN-1 flux developed by Ni Hongjun of Shanghai Jiaotong University, etc. The formula is NaCl45.549.5wt%)+KCI45549.5wt%)+ LaF3 or CRF(3wt%)+CaCO3(O-2wt%): (3) The rare earth composite flux developed by Tang Xiaolong of South China University of Technology et al [기, its formula composition is NaC1, KC cryolite, carbonate, sulfate, and Rare Earth Fluoride. The rare earth flux integrates purification, refinement, and metamorphism, and can significantly improve the microstructure and properties of the alloy, but the high price of rare earth restricts its application in flux. Therefore, one of the research contents of this paper is to develop a novel multifunctional refining solvent with high efficiency, environmental protection, and low cost.
The purification effect of recycled aluminum melt is not only related to the physical and chemical properties of the refining flux itself but also the way of adding the alu flux will also affect the final cleanliness of the melt. For a brand-new automatic flux addition technology, KR stirring and purification method (see Figure 1), that is, the required weight of refined flux is delivered to the vortex formed by the rotor through the feeder, and the vortex can make the alu flux In a faster and more uniform mixed λ melt, automatic, quantitative and efficient alu flux addition can be realized, but it is worth noting that when a vortex is formed at the liquid surface, the oxide film and air will be involved, causing secondary pollution of the molten aluminum. , reduce the quality of molten aluminum. Therefore, it can be considered to analyze the characteristics of the single-phase and two-phase flow fields involved in the KR method using numerical simulation of fluid mechanics, and optimize the process parameters, which can not only give full play to the refining effect of the flux but also shorten the duration of the vortex. Therefore, the negative effect brought by the liquid surface vortex can be weakened to the greatest extent, and this is another important content that needs to be studied in this thesis.