The recovery of magnesium alloy scrap includes two main aspects, namely classification and smelting. The main pollution sources of magnesium alloys are: processing oil and water; dissimilar metals; abrasives, sand and other impurities; surface oxidation and coating. According to the difficulty of removal, it can be divided into removable foreign sundries, removable paint and oil stains, and difficult-to-remove oil and water. Waste should be separated and stored according to classification standards to prevent secondary pollution. The storage environment should be dry and ventilated, and stored separately in a waste building. Various grades of alloys are randomly mixed and the waste that has been placed for a long time is screened out and then dried. The samples are put into the smelting furnace for melting, and the composition of the samples is analyzed to determine which grade of magnesium alloy to smelt.
The process of waste recycling is mainly: incoming material control (classification, determination of waste type, screening, etc.) –> pretreatment (removal of impurities, paint, water, oil, degreasing and drying, etc.) –> melting –> melt treatment (purification, The process of removing impurity elements and adding alloy elements) –> casting.
Magnesium alloy scrap recycling process: A large number of oxides and Fe/Ni/Cu impurity elements in scrap are the main processing objects of scrap recycling. The commonly used method is the dissolution method, and the process flow is: melting – removal of oxides – removal of iron – adjustment of chemical composition – degassing – ingot casting.
The dissolution method is divided into: solvent method and solvent-free method. The solvent method is suitable for chips, powders, thin plates, and contaminated, corroded, and surface-treated magnesium alloy scraps with oil, release agent, and lubricant attached to the surface. The role of the solvent is to adsorb impurities and completely separate them from the alloy melt. There are mainly 1 crucible method; 2 salt bath method;
