How to Reduce Aluminum Casting Loss: reduce the contact force between liquid aluminum and air. The greater the contact force between liquid aluminum and oxygen, the more serious the oxidation loss, and the greater the aluminum casting loss.
How to Reduce Aluminum Casting Loss
1) Reduce the contact time between liquid aluminum and oxygen
Under the production requirements, the aluminum in the furnace should be made into finished products as soon as possible, and the liquid aluminum should not stay in the furnace for too long.
Place the casting equipment reasonably and shorten the length of the launder as much as possible to reduce the exposure time of liquid aluminum in the air. At the same time, the upper part of the launder is covered with an aluminum silicate insulating plate, which has a certain thermal insulation effect and also reduces the oxygen content in the launder.
In short, in order to prevent molten aluminum from being stored in the mixing furnace for a long time, workers reduce the contact time between molten aluminum and oxygen to reduce casting losses.
2) Control the mixing method of liquid aluminum
Whether it is manual large-scale stirring or mechanical stirring, it is carried out with the furnace door open, which not only brings huge fluctuations in the liquid level, increases the contact area with oxygen, but also increases the oxygen content in the furnace. This will accelerate the above-mentioned chemical reaction, and the combustion loss will increase.
Electromagnetic stirring can be carried out in a closed state, the liquid level fluctuation is small, and the corresponding disadvantages are effectively avoided. At the same time, the moisture in the air entering the furnace is reduced, and the possibility of liquid aluminum absorbing hydrogen is reduced.
3) Control the bubble height during the refining process of liquid aluminum
The general refining method is to manually spray the refining agent into the furnace, and then stir and refine. However, for some alloy production, nitrogen blowing is required for refining (up to 30 minutes), and there must be a certain bubble height to drive the larger fluctuations of liquid aluminum. Therefore, it is best to adjust the nitrogen pressure and control the bubble height at 10- 15mm.
