Over the years, aluminum alloy products have continuously improved the internal quality of ingots, especially cleanliness. Molten aluminum purification treatment is the main method to improve the purity of aluminum melt. Melt purification can be divided into furnace treatment and online purification.
Furnace Molten Aluminum Purification Treatment
Melt treatment in the furnace mainly includes gas refining, flux refining, and powder spray refining. The development of in-furnace treatment technology is relatively slow. Only the powder spraying refining that appeared in the mid-1990s in China is relatively new. Its degassing and slag removal effect is slightly better than gas refining and flux refining, but because the refining rod is moved manually, the refining effect fluctuates bigger.
Foreign advanced furnace purification treatment adopts automatic control. There are two representative ones. One is to insert multiple spray guns from the furnace roof or furnace wall into the furnace melt for powder spraying or gas refining. This technology has the disadvantages that the spray gun is fragile and difficult to seal and has not been widely used. The other is to install multiple replaceable vent plugs evenly at the bottom of the furnace, and the computer controls the refining airflow and refining time. This method is a more effective furnace treatment method.
Online Molten Aluminum Purification Treatment
The purification effect of the furnace treatment on the aluminum alloy melt is limited. To further improve the purity of the melt, especially to further reduce the hydrogen content and remove non-metallic slag, it is necessary to adopt efficient online purification technology.
The online degassing equipment is installed between the furnace and the casting machine, and its role is to remove the hydrogen and other residues contained in the molten aluminum and its alloys that affect its quality and mechanical properties. It has dual functions: processing and heating. Mainly used for melt purification in the production of high-precision aluminum products, such as: computer hard drives, color and black and white photocopier drums, micron aluminum foil wool, PS board base for printing, canning materials, and aircraft landing gears.
Online filtering equipment replaces the high-cost ceramic tube filter and ordinary filter equipment. It filters inclusions and tiny particles in the molten aluminum through a ceramic foam filter. It is especially suitable for the production of high-purity and high-precision aluminum and aluminum alloys.