Resource circulation by Social Bridge
Social Bridge has been operating a used-resource collection since Matsuzawa was founded in Kobe in 1953. We have been in business for approximately 70 years, deeply connecting with the local community. As a registered company by Kobe City, it aims to accelerate resource circulation through a variety of initiatives, including used-resource collection such as waste paper, metal scrap, and industrial wastes.
Our Journey to Resource Circulation vol.2 ~ Social Bridge’s Initiatives for metal recycling~
Continuing from the previous article on “waste paper”, this time we would like to introduce the metal recycling that Social Bridge/Matsuzawa is working on.
History of metal recycling in Japan
When talking about recycling in Japan, we can’t help but mention its history…! Similar to waste paper, it dates back to the Edo period, when a “circulating society” was formed.
1. Edo period (1603-1868)
Its recycling culture in Japan originated in the Edo period. At that time, in urban areas, collectors called ”kuzuya (屑屋)” collected various scrap materials including metal, and sold them to blacksmiths and foundries. Since metals were particularly valuable, broken nails and cutlery fragments were recovered and turned into new products by blacksmiths. Therefore, The Edo period is truly considered as the pioneer of a “sustainable society.”
- Reuse of metals on a daily basis
- Reuse of nails and swords: Repair and reuse broken items at a blacksmith
- Recasting of copper and iron: Melting down and reusing temple bells, pots, agricultural tools, etc.
- Gold and silver recycling: melting down and reusing old coins for coin minting
- Kuzuya, a major player in recycling
- Kuzuya is similar to what we would call a “junk collector” today, and they go around town collecting scrap metal and selling it to craftsmen.
- The following items were mainly collected:
- Metals (nails, knives, pots, kettles, chains, etc.); melted and reused by blacksmiths
- Paper (used books, used washi paper, etc.); paper makers make recycled paper
- Cloth (used clothes, rags); remade into futons and rags
- Pottery shards: Glue and reuse or crush and return to soil
- Among the junk shops, there were those who specialized in purchasing and those who also repaired items.
2. Meiji and Taisho eras (1868-1926)
In the Meiji period, steel production began in earnest in Japan due to the influence of the Industrial Revolution.With the development of the modern steel industry, the demand for iron scrap increased. As the shipbuilding and railway industries developed, the recovery of iron scrap also became more active. Furthermore, due to the Russia-Japanese War and World War I, securing metal resources became important as a national policy.
3. Showa (1926-1989)
During World War II, metal resources were in short supply for the manufacture of munitions, and therefore the government issued a “Metal Supply Order”. Under this order, temple bells, iron fences, and even household pots and cauldrons were collected, recovered and used as materials for weapons and warships. After the war, recycling of steel scrap supported Japan’s recovery. Metals from abandoned buildings and machinery were reused and turned into new steel products. During the period of rapid economic growth that began in the 1950s, demand for automobiles and building construction expanded, and steel recycling technology improved dramatically.
- Wartime (1937-1945):
- The “Metal Supply Order” was issued under the National General Mobilization Act (1938).
- Temple bells and household pots and cauldrons were donated and reused for military purposes.
- Postwar reconstruction (1950s-60s)
- Reuse of steel scrap becomes important and the steel industry develops
- High economic growth period (1960s-1980s)
- Automobiles, home appliances, and construction industries are rapidly growing, producing large amounts of metal scrap.
- The scrap market is revitalized and the number of metal recovery companies is increasing across the country.
In Kobe City, where Social Bridge currently operates, Kobe Steel Works (KOBELCO) was established in 1911 and has become the center of Kobe’s steel industry. At that time, steel manufacturing and metal processing companies gathered near Kobe Port, forming an industrial cluster centered on the steel industry. Additionally, during the post-war reconstruction period, the demand for steel increased, leading to further development of the steel and shipbuilding industries in the Hanshin Industrial Zone including Kobe. In particular, Kobe’s waterfront area was home to steel-related factories and logistics facilities, taking advantage of its location, which was suitable for importing raw materials and exporting products.
4. Heisei-present (1989-)
Currently, Japan has one of the highest metal recycling rates in the world. In particular, steel scrap has a high domestic recycling rate, over 90%, and steel mills use electric furnaces to produce recycled steel with less environmental impact. Additionally, a system has been introduced that uses the latest technology to sort metals using AI and robots, making recycling more efficient.
- In 1991, the “Resource Effective Utilization Promotion Act” was enacted, making recycling mandatory for companies.
- In 2001, “Home Appliance Recycling Law” enacted, making it mandatory to recycle refrigerators, washing machines, and air conditioners
- In 2013, “Small Home Appliance Recycling Law” → Promotion of rare metal recovery from smartphones and PCs
- Currently, the steel industry is focusing on recycling that reduces CO2 emissions in order to achieve carbon neutrality.
Looking at present Kobe City, due to environmental measures and economic changes, large-scale steel factories in Kobe City have been downsized or withdrawn, and relocated to other areas in Hyogo Prefecture (such as the Kakogawa Steel Works in Kakogawa City). Instead, Kobe is involved in the steel recycling industry, metal processing, and steel-related technology.
Initiatives in Kobe by Social Bridge
Japan has a history of metal recycling dating back to the Edo period, and metal recycling is still actively being carried out today.
- Main metals targeted for recycling
- Steel (scrap): recovered from construction waste, automobiles, home appliances, and industrial waste
- Non-ferrous metals
- Aluminum: beverage cans, auto parts
- Copper: electric wires, piping
- Rare metals: electronic devices (smartphones/PCs), car batteries
- Flow of collection and reuse
- Emissions by consumers and businesses
- Household: Home Appliance Recycling Law, recyclable garbage collection
- Companies/factories: Treated as industrial waste
- Disassembly, separation and compaction by collection and scrap companies
- At smelting and refining factories, impurities are removed and recycled into new metal products
- Remanufacturing (new steel products, aluminum products, electronic parts, etc.)
- Emissions by consumers and businesses
Social Bridge plays the role of recovering the discharged metals in this recycling loop. The metal collected by Social Bridge is sorted by size and type. After that, it is processed by cutting, compression, etc. to make it easier for steel manufacturers to use it as raw material, and then used by steel manufacturers as raw material for steel manufacturing.
- Metals handled by Social Bridge (examples of actual items brought in)
Iron as high potential material in resource circulation
Of all the metals discussed above, iron is actually the most suitable for recycling among the many resources available. As shown in the diagram above, once steels are manufactured from natural raw materials and used, it can be recycled and reused again with almost same quality as its virgin materials.
Figure 1 Conditions necessary for independent and sustainable recycling and characteristics of iron
| # | Conditions necessary for independent and sustainable recycling | Characteristics of iron |
| 1 | Ease of sorting and sorting | Steel is magnetic and can be easily separated from other materials by magnetic sorting, and can also be recovered from shredder dust and incineration ash. |
| 2 | Low environmental burden | Steel is renewable with less energy and environmental impact, making it more environmentally friendly than manufacturing from natural resources. |
| 3 | Recycling system with high economic rationality | Many countries, including Japan, have systems in place to efficiently collect and recycle steel scrap, leading to a high level of economic rationality from collection to recycling. |
| 4 | Renewability into a variety of products | Even after steel is recycled, it can be recycled into a variety of products, and reprocessing can create products with new properties. |
| 5 | Less deterioration in material quality | Impurities can be easily removed from steel and it can be recycled indefinitely with minimal loss of quality. |
Many recycled materials have a significant quality deterioration compared to materials made using newly mined natural resources (virgin materials). Therefore, they cannot be used in products similar to those before recycling, applied to other products which require lower quality of the material. On the other hand, iron’s quality hardly deteriorates before and after recycling, making it possible to recycle it indefinitely.
There are some items which use recycled steels in our society.
- Building materials (rebar/steel frame)
- In the construction industry, large amounts of steel scrap are recycled and turned into reinforcing bars and H-beams (high-rise buildings, bridges, tunnels, condominiums, etc.)
- Recycled iron is also used in the Tokyo Sky Tree and the New National Stadium.
- Automobile (body/engine parts)
- Steel scrap from scrapped cars is melted down and turned into frames and engine parts for new cars.
- Approximately 40% of new cars are made from recycled iron, and Japan’s scrapped car recycling rate is over 95%.
- Railway rail/train body
- Recycled iron is used for railway rails and train bodies.
- Japan’s railway rails are replaced every 30 to 40 years. After that, it is often reborn as a railway rail.
- Beverage cans (steel cans)
- Used steel cans (such as coffee cans) are often recycled and used again as cans.
- The recycling rate of steel cans is approximately 90%.
In fact, our lives are supported by recycled materials without us even realizing it. Would you like to take the culture of resource circulation since the Edo period one step further with Social Bridge?