Secondary Processing of Waste Aluminum must face three technical problems: pretreatment of waste aluminum raw materials, accurate control of composition and refining melt. Among them, the pretreatment of waste aluminum raw materials is of great significance as the first step in the production of recycled aluminum, and its quality directly determines whether the subsequent process can be carried out smoothly.
Due to the complexity of its raw materials, the secondary processing of waste aluminum alloy is necessary. The usual pretreatment process needs to achieve the following purposes:
1、 Remove other metals and impurities from waste aluminum.
2、 The oil, oxide and paint on the surface of waste aluminum shall be removed.
3、 According to the composition of waste aluminum, the classification basis is to make it close to the composition of a certain brand of aluminum alloy.
The pretreatment technology includes impurity separation, sorting, packing, cleaning, and drying. The final result is to treat the waste aluminum into a furnace charge which meets the furnace charging conditions. The most influential process for the subsequent process of waste aluminum regeneration is the impurity separation and classification separation of waste aluminum.
Waste aluminum is divided into two categories: new scrap and old scrap. The new waste aluminum mainly refers to the waste aluminum produced in the production process of aluminum and its alloy. The old waste aluminum mainly refers to the aluminum and aluminum alloy parts or the whole product scrapped after the service life. The former has a clear composition and high utilization value. The general practice is to store the alloy according to the grade classification, and the original alloy is melted by the manufacturer himself. The latter is what we usually call waste aluminum, which needs to be classified and sorted.
Refining melt is an important step for getting new pure aluminum, it is the key for casting aluminum alloy products.