Aluminum liquid purification equipment configuration of the melting and casting production line mainly includes the refining technology of the holding furnace vent plug in the furnace, so that the aluminum liquid can be effectively purified in the holding furnace. The aluminum liquid obtains good purification indicators before entering the degassing system and the CFF filter system. The hydrogen content of the liquid is controlled below 0.30m1/100gA1. This is a 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 filtration system. For alloys without magnesium, the degassing efficiency can reach more than 50%, the hydrogen content of the aluminum liquid can reach 0.12m1/100g Al or less, and the magnesium alloy can reach 0.14m1/100g Al or less.
The removal of inclusions in molten aluminum includes in-furnace treatment and out-of-furnace treatment. The treatment in the furnace is mainly by adding salt fluxes composed of KCl and NaCl to the molten aluminum in the furnace. Through the adsorption of the flux and the inclusions, the inclusions in the molten aluminum are adsorbed and floated to the surface of the molten aluminum. Remove the slag together.
The on-line filtration outside the furnace mainly uses the CFF filter device, and the ceramic filter is used to filter the aluminum liquid. CFF filtration technology uses the ceramic foam filter, the filter is mostly 50-60pi. For inclusions above 20um, the filtration efficiency can reach 90%, for inclusions above 15μm, the filtration efficiency can reach more than 80%.
The purification effect of liquid aluminum plays a decisive role in the production of ultra-thin aluminum foil. If the hydrogen content in the molten aluminum exceeds the standard, reaching 0.15ml/100gA1 or more, it will cause defects such as pores or loose tissue in the molten aluminum, which will lead to the reduction of the mechanical properties of the product, especially the tensile strength and elongation. In addition, it will have an adverse effect on deep drawing performance. The inclusions in the molten aluminum have a great influence on the performance of the product. The more the shape of the inclusions is similar to the spherical shape, the smaller the influence on the mechanical properties of the metal matrix. When the inclusions are sharp-angled and even surround the product particles to form a film, the damage to the casting performance is greatest.
Improving the purification effect of molten aluminum is a comprehensive process. First, we must choose effective aluminum liquid purification equipment. At the same time, we must strictly control the smelting, casting process and smelting raw materials. In particular, the content of electrolytic aluminum liquid should be controlled below 50%. The clean solid material must reach more than 30%, so that it can be supplemented with effective aluminum liquid purification equipment to ensure the purification effect. This will create good conditions for the production of ultra-thin aluminum foil.