Construction waste mainly consists of a mixture of concrete, bricks, sand and gravel, steel bars, iron wire, plastic, wood, slag, and lime soil.
Core principle of sorting: Separate the “mixture” according to material, size, and weight, and reuse them separately.
1、 Overall process principle
Crushing → Screening → Sorting → Purification → Reuse of Finished Products
One sentence: first crush, then grade, then pick clean, and finally turn into recycled aggregates, recycled bricks, and backfill materials.
2、 Working principle of each link
1. Crushing principle
Equipment: Jaw crusher, impact crusher, hammer crusher
• Principle: Squeezing, impact, shearing
Crush large blocks of concrete, walls, and road surfaces into small particles to prepare for subsequent sorting.
2. Screening principle (separated by size)
Equipment: vibrating screen, drum screen
• Principle: Classification of sieves with different pore sizes
• Separate:
◦ Ultra large block (recycled and broken again)
Coarse aggregate
Fine aggregate
◦ Grey soil dust
3. Sorting principle (separating by material, most importantly)
① Gravity sorting (wind sorting)
Principle: Different weights and weights, separated by the wind
• Light substances: plastic, cloth, paper, sawdust, foam → collected by wind
• Heavy substances: sand and gravel, concrete, bricks → falling
② Magnetic Separation
Principle: Ferromagnetic substances are attracted away by magnetic force
Separate all steel bars, iron wires, nails, and steel plates and recycle scrap steel.
③ Bounce sorting/eddy current sorting (optional)
Bouncing sieve: Separate sheet, block, and granular materials
Eddy current: Separation of non-ferrous metals such as aluminum and copper
3、 Final output
1. Recycled coarse aggregate: replacing natural stones
2. Recycled fine aggregate: replacing yellow sand
3. Scrap steel bars and scrap metals: recycling and smelting
4. Light materials (plastics, sawdust): incineration for power generation or solid waste disposal
5. Lime soil: roadbed backfilling, brick making
4、 Summarize the core principles in one sentence
Reduce volume through crushing → classify by size through screening → separate by weight and material through wind and magnetic separation → achieve resource utilization and reuse.