Aluminum ingot process description

In the casting process of aluminum ingots, molten aluminum is injected into the mold. After cooling into a billet and taking it out, the injection process is a key step in the quality of the product. The casting process is also the physical process of crystallization from liquid aluminum into solid aluminum. Commonly used casting methods are divided into continuous casting and vertical semi-continuous casting

Continuous casting

Continuous casting can be divided into mixed furnace casting and external casting. All use continuous casting machines. Mixed furnace casting is to pour aluminum liquid into the mixing furnace, and then pour it from the mixing furnace. It is mainly used to produce aluminum ingots and casting alloys for remelting. The outer casting is directly cast to the casting machine by the ladle, mainly used when the casting equipment cannot meet the production requirements, or the quality of the incoming materials is too poor to directly enter the furnace. Since there is no external heating source, the ladle is required to have a certain temperature, generally 690 to 740 °C in summer and 700 to 760 °C in winter to ensure a good appearance of the aluminum ingot.

Mixing furnace casting, first go through ingredients, and then pour into the mixing furnace, stir evenly, and then add flux for refining. The casting alloy ingot must be clarified for more than 30 minutes, and the slag can be cast after clarification. When casting, the furnace eye of the mixing furnace is aligned with the second and third molds of the casting machine, which can ensure a certain degree of flexibility when the liquid flow changes and the mold is changed. The furnace eye and the casting machine are connected with a launder. It is better to have a shorter launder, which can reduce the oxidation of aluminum and avoid vortex and splash. When the casting machine is stopped for more than 48 hours, the mold should be preheated for 4 hours before restarting. The molten aluminum flows into the mold through the launder, and the oxide film on the surface of the molten aluminum is removed with a shovel, which is called slag removal. After one mold is filled, the launder is moved to the next mold, and the casting machine is continuously advanced. The molds advance in sequence, and the molten aluminum gradually cools down. When it reaches the middle of the casting machine, the molten aluminum has solidified into aluminum ingots, which are marked with a smelting number by the printer. When the aluminum ingot reaches the top of the casting machine, it has completely solidified into an aluminum ingot. At this time, the casting mold is turned over, the aluminum ingot is demolded, and it falls on the automatic ingot receiving trolley. It is automatically stacked and bundled by the stacker to become the finished aluminum. ingot. The casting machine is cooled by water spray, but water must be supplied after the casting machine has been turned on for a full turn. Each ton of molten aluminum consumes about 8-10t of water, and it needs to be cooled by air blowing in summer. The ingot belongs to flat die casting. The solidification direction of the molten aluminum is from bottom to top, and the upper middle is finally solidified, leaving a groove-shaped depression. The solidification time and conditions of each part of the aluminum ingot are different, so its chemical composition will also be different, but it is generally in line with the standard.