The aluminum liquid purification equipment configuration of the melting and casting production line mainly includes the refining technology of the furnace holding furnace exhaust plug, so that the aluminum liquid can be effectively purified in the holding furnace. The molten aluminum obtains a good purification index before entering the degassing system and the CFF filter system. The hydrogen content of the liquid is controlled below 0.30m1 / 100gA1. This is the prerequisite for ultimately improving the purification effect of molten aluminum. The on-line processing system outside the furnace includes a degassing refining system and a CFF filter system. For alloys that do not contain magnesium, the degassing efficiency can reach more than 50%, the hydrogen content in the molten aluminum can reach 0.12m1 / 100g Al or less, and the magnesium alloy can reach 0.14ml / 100g Al or less.
The purification effect of liquid aluminum plays a decisive role in the production of ultra-thin aluminum foil. If the hydrogen content in the aluminum melt exceeds the standard and reaches 0.15ml/100gAl or higher, it will cause defects such as pores or loose structure in the aluminum melt, resulting in a decrease in the mechanical properties of the product, especially the tensile strength and elongation. Long rate. In addition, it will adversely affect deep drawing performance. The inclusions in molten aluminum have a great influence on the performance of the product. The closer the shape of the inclusions is to the spherical shape, the smaller the impact on the mechanical properties of the metal matrix. When the inclusions are at an acute angle and even form a film around the product particles, the damage to the casting performance is greatest.
Improving the purification effect of molten aluminum is a comprehensive process. First of all, we must choose effective aluminum liquid purification equipment. At the same time, smelting, casting process and smelting raw materials must be strictly controlled. In particular, the content of electrolytic aluminum liquid should be controlled below 50%. The clean solid materials must reach more than 30%, so that effective aluminum liquid purification equipment can be added to ensure the purification effect. This will create good conditions for the production of ultra-thin aluminum foil.
Degassing refining system is installed between the holding furnace and the casting machine. In the degassing unit, the nitrogen blown into the aluminum alloy melt is chopped by the rotating graphite rotor to form a large number of dispersed bubbles. Therefore, the aluminum alloy liquid and nitrogen are in complete contact in the treatment bath. According to the principle of air pressure difference and surface adsorption, the bubbles absorb hydrogen in the melt and absorb oxidized slag. It rises to the surface of the melt to form scum. The aluminum alloy melt flows from the outlet of the degassing device to the casting machine. The aluminum alloy liquid continuously enters the degassing device, and nitrogen is continuously blown in. Through the purification process, the purpose of purifying the aluminum alloy liquid is achieved.