China's resources for nickel and chromium, used in stainless steel smelting, are scarce. In the past, the application of stainless steel in China was not as widespread as it is now, and the production of stainless steel was also low, with an insufficient self-sufficiency rate of less than 30%, largely relying on imports. The amount of waste stainless steel generated annually is minimal, and the supply and demand矛盾 for waste stainless steel and resources like nickel and chromium is increasingly prominent. In China, the scarcity of waste stainless steel is even more acute, with almost no waste stainless steel available for recycling annually. Additionally, stainless steel has a long service life, often lasting for years or even decades before becoming obsolete. Consequently, there is even less waste stainless steel. Therefore, a significant portion of China's waste stainless steel depends on imports.
The classification of scrap stainless steel is closely related to its applications, with the following main sources:
Waste from Daily Life:
Scrap stainless steel utensils used in daily life, such as those imported from Japan and South Korea, are mostly of this category, which can only be recycled as furnace materials. Kitchen equipment and tableware primarily use steel grades like SUS304 and 430. The food processing industry mainly manufactures food processing machinery and containers, including equipment for grain, beer beverages, dairy products, and quick-freezing and refrigeration units, with primary steel grades being 304, 321, 1Cr13, and antibacterial ferritic stainless steel.
2. Industrial Waste:
Scrap materials, such as pipes, rods, and plates, from the shearing and stamping processes in industrial production are in limited quantities. Urban landscape projects primarily use stainless steel welded pipes, while the automotive industry mainly employs ferritic stainless steel 409 for exhaust pipes. Other industries, including urban water supply, environmental protection, petrochemical, and power sectors, also generate considerable amounts of waste stainless steel. The pump and container market for oil, gas, and acid produces a large volume of waste stainless steel tanks, pipes, pumps, and valves. The main steel grade is 18/8 stainless steel.
