China's resources for nickel and chromium, used in the smelting of stainless steel, are scarce. In the past, the application of stainless steel in China was far less than it is now, and the production of stainless steel was small, with an insufficient self-sufficiency rate of less than 30%, mainly reliant on imports. The amount of waste stainless steel generated annually is minimal, and the supply and demand矛盾 of waste stainless steel and resources like nickel and chromium is becoming increasingly prominent. In China, the scarcity of waste stainless steel is even more acute, with almost no waste stainless steel available for recycling each year. Additionally, stainless steel has a long service life, often not becoming obsolete for several years or even decades. Therefore, the availability of waste stainless steel is further diminished. Consequently, a significant portion of China's waste stainless steel is dependent on imports.
The classification of scrap stainless steel is closely related to its applications, primarily originating from the following sources:
1. Waste from Daily Life:
Scrap stainless steel utensils used in daily life, such as those imported from Japan and South Korea, are mainly of this type and can only be recycled as furnace material. Kitchen equipment and tableware primarily use steel grades SUS304 and 430. The food processing industry mainly manufactures food processing machinery and containers, such as grain, beer and beverage processing equipment, and quick-freezing and refrigeration equipment, with the main steel grades being 304, 321, 1cr13, and antibacterial ferritic stainless steel.
2. Industrial Waste:
Scrap materials, such as pipes, rods, and plates, generated during the industrial production process through cutting and stamping are limited in quantity. Urban landscape projects primarily utilize 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 primary steel grade is 18/8 stainless steel.
