Cast-aluminum motor shell-dirty

Aluminum scrap from engine housings is often classified according to the level of impurities it contains, such as clean/2% impurities/5% impurities/8% impurities, etc. Generally, the impurity rate of completely disassembled aluminum engine housings is less than 2%, while those with a visible large number of residual iron screws have an impurity rate generally above 8%. If stainless steel cylinder liners and bearings are present, the impurity rate can exceed 15% and even reach 30%.
Aluminum scrap from engine housings can be subdivided into:
1. Transmission shells. These are typically pure aluminum shells, with almost no impurities except for the sleeve section, as shown in the image below.

2. Cylinder (middle cylinder) shells, where cylinder liners are often steel, and the overall impurity content is high. The middle cylinder is the main item, with impurities over 15%, as shown in the image below.

3. Cylinder heads (cylinder heads), which contain a large amount of steel and iron, have the most impurities, with impurities ranging from 20% to 30%. This does not meet the definition of Trump and can easily lead to disputes.

Aluminum scrap from engine housings comes from the disassembly of automotive engines or defective engine parts during the manufacturing process of automotive engines. Therefore, these scrap materials are often associated with the automotive industry.
Firstly, they come from auto repair shops, scrap yards, and dismantling plants. When automotive engines are damaged or reach the end of their life, these facilities typically handle the scrap in a centralized manner. There are also specialized scrap dealers or suppliers responsible for dismantling entire engines, who specifically sell relatively clean aluminum engine housings after they have been dismantled and processed.
Furthermore, defective products from engine manufacturers that are discarded are also a significant source of this type of scrap. It should be noted that some aluminum engine housings that have been scrapped may have steel components installed, such as piston sleeves and shaft sleeves, and some may even have been assembled with gears that contain hard stainless steel bearings. A strict inspection is required.

In general, the value of aluminum engine housing scrap is: transmission shell > cylinder (middle cylinder) > cylinder head (cylinder head). The more round transmission aluminum shells, the better; the fewer cylinder shells, the better. Carefully inspect for any residual sleeve and bearing components.

1. Manual disassembly
   For aluminum engine housing scrap with impurities, different downstream buyers have different tolerances for impurity content and special conditions (such as iron impurities). For buyers with strict impurity requirements, further manual disassembly is needed to remove iron screws, stainless steel sleeves, bearings, and other components as thoroughly as possible.
2. Mechanical crushing
   When dealing with large volumes of goods and where quality control is extremely strict regarding impurities, mechanical crushing can often replace manual disassembly. The advantage of mechanically crushing aluminum engine scrap lies in high efficiency; compared to manual disassembly, a large volume of aluminum engine housing scrap can be processed within a unit of time. For components difficult to remove manually, such as sleeves and cylinder liners, sorting after crushing can remove as much as possible. However, similar to all mechanical crushing, there is material loss during the crushing process, approximately 1-2% of the material is consumed during crushing.
3. Furnace use
   Some processing plants will directly melt uncleanly disassembled aluminum engine scrap containing iron in the furnace and skim off iron and slag at the furnace bottom. The advantage is a reduction in the labor and cost of disassembly and impurity removal, but the downside is quite significant. Impurities form slag at the bottom of the furnace, which also adsorbs aluminum, resulting in material waste. Around 2% of the material is lost due to adsorption. Additionally, regularly stopping the furnace to skim iron impacts production efficiency.

The common detection methods for aluminum scrap from engine housings primarily target the content of iron impurities. The detection method is random sampling inspection. A random sample of scrap, usually 100-500kg, is taken and sorted to obtain iron impurities and calculate the ratio. Alternatively, iron content can be calculated after directly melting and skimming iron from the furnace.

Aluminum scrap from engine housings is suitable for aluminum ingot manufacturers that produce die-cast aluminum ingots like ADC12 and A356, allowing for the best utilization and saving significantly on the cost of producing ADC12. The factory should have a certain pre-processing capability, such as manually disassembling iron-containing aluminum engines. Some factories with strict quality standards that specifically use aluminum engine housing scrap may be equipped with special crushing and sorting equipment to remove as much iron impurities as possible during the pre-processing phase, reducing the iron content in the product.

The proportion of impurities in the middle cylinder (cylinder) is high. Inside the middle cylinder are a large number of hard stainless steel sleeves with high manganese content, closely connected to the cylinder body structure, which are very difficult to remove without mechanical crushing.
For aluminum engine housings (Trump) this type of scrap, it has a relatively high probability of problems during transactions. In the transaction process, rigorously review the images provided. Be vigilant about non-spot physical images provided by suppliers. While requiring suppliers to guarantee the impurity rate, it is best to provide clear, detailed spot photos during container loading. If any abnormalities are found, immediate feedback should be given to the buyer, and transactions should be terminated in cases of severe discrepancies. As shown below, the more middle cylinder (cylinder) shells there are, the more stainless steel impurities there may be.