The Importance of Recycling and Utilizing Scrap Iron Resources
1.1 Expanding the utilization of scrap steel resources is an essential requirement to break through the bottleneck of resource constraints and build a resource-saving and environmentally friendly society. Entering the 21st century, the relative scarcity of resources and limited environmental capacity have become fundamental characteristics of China's national conditions. Tension in resource supply, with the supply of primary resources far from meeting the rapidly growing demand for resources, has severely restricted the sustainable development of China's economy and society. For the steel industry, these issues are particularly prominent due to the relatively scarce iron ore resources in China. Over the past decade, China's steel stock has increased nearly 2.8 times, with an average of less than 5 tons per person, compared to more than 30 tons per person in the United States and Japan. Currently, the application of scrap steel in the global steel industry accounts for 40% to 45% of the total crude steel production. Even in 2009, when the scrap steel consumption reached a record high in China, it only accounted for 14.6% of the crude steel production. Moreover, China's current scrap steel utilization rate is only 19.9%, significantly lower than the global average of 48.3%. In terms of per capita steel resource ownership, scrap steel application levels, and recycling rates, China lags far behind the global average.
Utilizing scrap steel resources is a crucial method to reduce carbon emissions and alleviate dependence on iron ore. As a regenerative resource for energy conservation and environmental protection, scrap steel can save 60% of energy and 40% of water compared to steelmaking with iron ore, and reduce emissions of waste gas by 86%, waste water by 76%, and waste residue by 97%. Each ton of scrap steel used can save 1.7 tons of iron ore, 0.68 tons of coke, and 0.28 tons of limestone, and can be recycled indefinitely. Therefore, developing the scrap steel market is the only way to resolve the iron ore crisis. It is predictable that in the future, scrap steel will gradually replace iron ore as the dominant position in steel raw material allocation.
Waste Steel Recycling and Processing Technology
Introduction to Scrap Iron Recycling and Processing Methods
主要包括: magnetic separation, cleaning, preheating, etc.
Magnetic separation is a method of sorting materials based on their magnetic differences within an uneven magnetic field. It is an effective way to separate ferromagnetic metals. After solid waste is fed into the magnetic separator, magnetic particles are magnetized under the influence of the uneven magnetic field and are attracted by the magnetic force, thereby being drawn onto the cylinder and discharged at the discharge end as the cylinder moves. Non-magnetic particles, which experience minimal magnetic force, remain in the waste. The magnetic sources used in magnetic separation are typically electromagnets or permanent magnets.
(2) Cleaning involves the use of various chemical solvents or hot surfactants to remove oil, rust, mud, and sand from the surface of steel components. It is commonly employed for large-scale processing of engines, bearings, gears, and other parts contaminated by cutting oil, grease, dirt, or other adherent substances.
(3) Preheating: Many steel mills use the method of preheating scrap steel, directly roasting the scrap iron and steel with flames to burn off moisture and oils, and then adding them to the furnace. In the metal preheating system, two main issues need to be addressed: one, incomplete combustion of oils can produce a large amount of hydrocarbons, causing air pollution, which requires a solution; two, due to the varying sizes and thicknesses of the scrap steel on the conveyor belt, preheating and combustion are uneven, and pollutants on the scrap steel may not be thoroughly cleaned.
2. Secondary pollution can generally be divided into the following three categories:
① The inherent contamination in scrap steel raw materials poses an environmental threat.
Intermediate products generated during the processing and handling of scrap steel can cause environmental pollution.
③ Pollution caused by outdated processing technology and equipment for scrap steel processing
3. Specific Prevention and Control Measures
① Advanced scrap steel processing technology and equipment effectively prevent secondary pollution, achieve effective separation and comprehensive utilization of impurities, enhance the value-added resource transformation of metallurgical slag, and realize the goal of "zero emissions," all of which depend on the level of industry equipment and the development of core equipment technologies. This is a key link in achieving industrial upgrading. Currently, advanced scrap steel processing equipment includes shears, baling machines, crushers, steel grabbers, electromagnetic equipment, and radiation protection equipment. These advanced processing equipment can effectively prevent the pollution of intermediate products produced during the processing of scrap steel, and can also effectively sort various materials from the scrap steel raw materials. ② Increase the sorting intensity of various materials in the scrap steel raw materials. Through sorting, we aim to minimize the entry of toxic, harmful, flammable, explosive, and radioactive materials into the scrap steel processing process. Additionally, the sorted materials are professionally treated to reduce secondary pollution.
Section III: Introduction to the Scrap Steel Electronic Trading Platform
The Waste Steel Electronic Trading Platform is a professional electronic trading platform specializing in the spot, short-term, and medium-term electronic transactions of waste steel. It integrates comprehensive services such as trading, settlement, information, financing, logistics, product display, and international procurement into a modern, fully-equipped electronic trading platform. The significance of developing the waste steel electronic trading market: Our country has entered the era of electronic information. The traditional model of waste steel spot trading has failed to meet the needs of the supply and demand market. There is a fast-paced, high-efficiency trading demand. Particularly, the steel and other steel materials have successively been listed, making the conditions for the listing of waste steel and the social environment basically mature. The waste steel electronic trading market complements, improves, and develops the spot market, benefiting from sunlight transactions, price transparency, market transparency, three-party comparison, and fair competition. It also helps enterprises shorten the procurement cycle, facilitate capital adjustment, and reduce procurement costs. In accelerating the diversification, scientific development, and reform of the market operation mechanism, it is necessary to promote the brandization of waste steel and enhance the overall quality of the market. The waste steel electronic trading market is the future development trend.
IV. Summary
The gap between the supply and demand of scrap steel resources is significant. Only by accelerating the existing scrap steel recycling efforts, improving the recycling rate, and vigorously promoting the development and utilization of scrap steel can we better meet the needs of China's steel industry. Identifying the causes of secondary pollution in the scrap steel processing process and effectively treating them through reasonable and effective measures will certainly provide excellent scrap steel resources for steelmaking projects. The electronic trading market for recycled resources is a new topic for the resource utilization, networking construction, scaling, financialization, and industrial development of recycled resources, and it is also a forward-looking and strategically significant move.
