The foundry fluxes and the molten aluminum must be in contact with each other to the greatest extent, so that the flux can exert the maximum refining effect in the molten aluminum refining process.
In order to achieve the best results, the foundry fluxes should be stirred into the molten aluminum to make it fully in contact with the oxides in the molten aluminum. For the covering agent, avoid stirring the molten aluminum. Then, the molten aluminum is allowed to stand for 5-10 minutes to float the inclusions, and the aluminum released from the scum enters the molten aluminum. Finally, remove the scum completely.
Furnace cleaners are generally used at a sufficiently high temperature to speed up the reaction and soften aggregates. Apply the cleaning agent to the furnace wall, turn on the furnace and close the furnace door. After 10 to 15 minutes, remove the reaction products on the furnace wall and the debris on the surface of the molten aluminum. The holding furnace should stand still to allow the oxides entering the molten aluminum to sink.
When used at normal temperature, after slagging, the furnace cleaning agent should be added to the surface of the molten aluminum near the furnace wall. In the process of tapping the molten aluminum, as the surface of the molten aluminum drops, the cleaning agent is continuously coated on the furnace wall. In this way, during the next melting, the aggregates on the furnace wall can react with the flux and can be easily removed during the slagging process.
In recent years, some new flux adding devices have appeared, such as flux spraying and flux rotary spraying. These methods overcome the shortcomings that the traditional flux addition method cannot make the flux and the molten aluminum fully contact. The flux spraying method uses the sentimental gas as the carrier to blow a certain amount of powdered flux from the blow tube to the bottom of the molten aluminum. Once the flux leaves the torch, it melts into some small droplets, which can provide a large specific surface area. This will greatly improve the effectiveness of the flux.