The ceramic foam filter in China is not expensive for European aluminum plants, and the quality is stable. Swedish Aluminum said that ceramic foam filter in China plants can provide a stable supply cycle.
Swedish Aluminum Corporation said that ceramic foam filters are very important for the purification of aluminum melt.
The so-called purification treatment is to take various measures to reduce the undesirable gas and solid matter in the aluminum melt to the allowable range to ensure that the performance of the material meets the standard or some special requirements.
Filtering is to use filters to filter.
When the alloy solution flows through a ceramic foam filter with straight holes or a filter with three-dimensional meshes, the inclusions in the melt with a particle size larger than the mesh size will be blocked by the filter, and the inclusions with a particle size smaller than the mesh size will be blocked by the filter. Blocked by the filter. The skeleton of the filter prevents the mesh size. And the inner surface of the channel is adsorbed.
When the alloy solution flows through the filter screen and the internal channels, the flow rate is reduced and divided into countless small liquid streams, which tend to be laminar, thereby increasing the chance and speed of floating.
With the continuous accumulation and precipitation of the adsorbent, the mesh size of the filter becomes smaller, so the particle size of the inclusions that can be adsorbed also becomes smaller, thereby improving the filtering effect. Currently, commonly used filters include glass fiber filters, ceramic plates, ceramic tubes and foam ceramic filters.
Of course, the purification of aluminum melt not only uses ceramic foam filters to filter inclusions, but also includes the adsorption and removal of H.
The principle of adsorption purification is to use a degassing device to blow gases such as nitrogen, argon, mixed gases into the melt, or to add flux to the melt to obtain bubbles by reacting with aluminum liquid, and then use these small The bubbles absorb hydrogen and bring the inclusions into the liquid surface during the flotation process to achieve degassing and slag removal. The purification effect of the melt is related to the volume V of the aluminum melt, the bubble radius R, the original hydrogen concentration Co of the aluminum melt, the hydrogen concentration Cp at the interface of the aluminum liquid-hydrogen bubble, the mass transfer related to the coefficient B of hydrogen in the aluminum liquid and each Ventilation volume per unit time gas consumption Q, thermal expansion coefficient K after the gas enters the molten aluminum, and the time for bubbles to rise to the liquid level: related to the ventilation time