The outer casting is cast directly from the ladle to the casting machine, mainly when the casting equipment can not meet the production or the quality of the incoming material is too poor to directly enter the furnace. Because there is no external heating source, it is required to carry the bag with a certain temperature, usually at 690~740 C in summer and 700~760 C in winter to ensure the good appearance of the aluminum ingot. The mixing furnace is first cast through the ingredients, then poured into a mixing furnace, stirring evenly, then adding flux to refine. Casting alloy ingots must be cleared for more than 30min, and slag can be cast after clarification.
When casting, the furnace of the mixing furnace is aligned with the second or third moulds of the casting machine, so that the liquid flow changes and the mobility of the mould is ensured. The furnace eye and casting machine are connected with the slot, and the slot is better. This can reduce the oxidation of aluminum, avoid the vortex and spatter. When the casting machine is stopped over 48h, the casting mould should be preheated 4H before restarting. The aluminum liquid flows into the mold through the chute, and the oxide film on the surface of the molten aluminum is removed by means of a shovel. After a mold is filled, the groove is moved down to a mold, and the casting machine is continuous.
The mold is progressively advanced and the molten aluminum gradually cooled. When the middle reaches of the casting machine, the molten aluminum has been solidified into aluminum ingots, and the melting mark has been made by the printer. When the aluminum ingot reaches the top end of the casting machine, it has completely solidified into aluminum ingot. At this time, the mold is turned over, the aluminum ingot is out of mould, and it falls on the automatic ingot trolley. The stacker is stacked and bundled to become the finished aluminum ingot. The foundry machine is cooled by water spray, but it must be turned round when the casting machine is turned to full circle. Each ton of molten aluminum consumes about 8-10t of water. In summer, it needs blowing to cool the surface. The ingot belongs to the flat mold casting, the solidification direction of the aluminum liquid is from bottom to top, and the middle part of the upper part is solidified later, leaving a groove shaped depression. The solidification time and condition of each part of aluminum ingot are different, so the chemical composition of aluminum ingot will be different.
