Some impure mixed metal slag is produced during smelting, but there is still a certain amount of aluminum, which can be separated and refined to obtain some aluminum. The solid waste generated in the production process of aluminum mainly includes slag generated in processes such as electrolytic aluminum, cast aluminum and recycled aluminum. The composition of aluminum slag is complex, mainly including metal aluminum, alumina, silicon, magnesium, sodium, iron, calcium and other oxides.

SOURCE AND TREATMENT METHOD OF ALUMINUM SLAG

‌Electrolytic aluminum aluminum ash‌: generated during the smelting process of liquid electrolytic aluminum water.

‌Melting aluminum ash‌: generated during the smelting process of remelting aluminum ingots.

‌Recycled aluminum aluminum ash‌: generated during the smelting process of recycled aluminum products.

The methods for treating aluminum slag include separation and refining, crushing, screening and melting, and finally it can be cast into finished aluminum ingots, thereby realizing the recycling of aluminum slag. In addition, there is also a harmless treatment process of "one-stage dissolution + two-stage sintering", which processes aluminum ash through "wet method" and "dry method" and finally turns it into alumina.

COMPOSITION AND PROPERTIES OF ALUMINUM SLAG

The main components of aluminum slag include metal aluminum, aluminum oxide, silicon, magnesium, sodium, iron, calcium and other oxides. The composition of aluminum slag from different sources is different. For example, aluminum oxide accounts for a large proportion in electrolytic aluminum slag, while recycled aluminum slag contains more mixed metals. These components make aluminum slag have a certain recycling value, and valuable metals and compounds can be extracted through proper treatment.

PRODUCT USE

It is mainly used for the recycling of metals in non-ferrous metal smelting waste slag such as aluminum ash, aluminum slag, lead ash, and lead slag.

1. Recycling of valuable elements

‌Metal aluminum recycling‌: The aluminum content of aluminum ash can reach more than 60% at one time. After separation by ash roasting machine, aluminum ingots are generated to realize the recycling of metal aluminum.

‌Fluorine resource extraction‌: Fluoride salts such as cryolite in electrolytic aluminum slag can be purified and returned to the electrolytic cell for use, or sold as high-purity fluoride salt products.

‌Lithium resource recovery‌: Aluminum slag containing lithium additives can extract lithium fluoride and convert it into lithium salts such as lithium carbonate for use in the lithium battery industry chain.

‌Carbon resource utilization‌: The residual carbon in anode slag has a high calorific value and can be used as cement kiln fuel, metallurgical reducing agent or raw material for carbon products

2. Production of building materials and refractory materials

‌Refractory materials‌: Aluminum ash is mixed with calcium oxide, magnesium oxide, etc. and sintered to prepare calcium aluminum feldspar/magnesium aluminum spinel composite refractory materials; doping with rare earth oxides can improve material performance.

‌Ceramic products‌:

Mixed with rutile powder to make magnesium aluminum titanate ceramics for high temperature resistant parts.

Combined with fly ash to produce mullite ceramics, replacing traditional raw materials to reduce costs.

‌Cement raw materials‌: Replace high-alumina bauxite to produce aluminate cement, or used for casting steel drum linings.