Production of recycled aluminum 4.1 typical process
4.1.1 secondary aluminum smelting process features
Recycled aluminum is recycled from scrap parts or manufacturing aluminum process scrap and scrap line as the main raw material, produced by melting aluminum ingots formulated to meet the various requirements of the standard. Such ingots recycled aluminum, and has lower production costs, but it is the re-use of natural resources, it has a strong vitality, especially in the current rapid development of technology, continuous improvement of the quality of people's lives today, product updates replacement rate accelerated recovery and utilization of waste products has become an important issue for sustainable development of mankind, recycled aluminum production is in this form came into being and has excellent prospects.
Since recycled aluminum raw materials mainly aluminum scrap, aluminum scrap in scrap cast (in Al-Si based alloy), aluminum forgings (Al-Mg-Mn, Al-Cu-Mn alloy), profiles (Al-Mn, Al-Mg alloy) cable scrap (with aluminum based) and other kinds of material, sometimes even mixed waste into non-aluminum parts (such as Zn, Pb alloys, etc.), which gives Preparing Recycled aluminum has brought great inconvenience. How to formulate a variety of complex components such raw materials as components of qualified renewable recycled aluminum ingots are produced core issues, therefore, recycled aluminum production process of the first link is aluminum scrap sorting classification process. Sorting the more detailed, the more accurate classification, the chemical composition of recycled aluminum control more easily achieved.
Scrap parts tend to have a lot of inserts, these inserts are some steel or copper alloy-based non-aluminum parts, not promptly raked in the smelting process, it will lead to increased recycled aluminum content in some unwanted components (such as Fe, Cu, etc.) So, at the beginning of secondary aluminum smelting, ie when melting aluminum scrap just have to have a grilled insert a step (known as Pa iron step). The aluminum scrap parts of the insert Bachu, picking the more timely, more clean, recycled aluminum chemical composition more easily controlled. Grilled molten iron when the temperature is not too high, the temperature will insert the Fe, Cu elements dissolved in liquid aluminum.
Around the collected aluminum scrap material due to various reasons can not help but have a dirt surface, and some serious rust, the dirt and corrosion surface melt will enter the bath when the slag phase and the formation of oxide inclusions, serious damage to the quality of recycled aluminum metallurgy . Clear the slag phase and mixed oxide of aluminum smelting process is one important step regeneration. Using multi-stage purification, which is to conduct a crude purified by secondary rare earth changed after fine adjustment component, and then blowing inert gas to further strengthen refining effect, can effectively remove the aluminum melt inclusions.
Oil and water adsorption of scrap material surface, the aluminum melt contains a lot of gas, do not effectively remove these gases causes the metallurgical quality declined significantly, to strengthen the production of recycled aluminum to reduce outgassing link containing gas is recycled aluminum get an important measure of the quality of recycled aluminum.
