OSENC Magnetic Separation
Magnetic Separation for Construction and Demolition Waste
C&D waste usually needs staged ferrous removal. Use a suspended magnet before or after crushing for exposed rebar, nails, wire, and steel fragments; review a head pulley or drum later when size-reduced material can be spread into a controlled layer. One magnet cannot address every size and process position.
Typical Ferrous Problems
- Long rebar and wire that wrap around shafts or belts
- Nails, screws, brackets, and reinforcement fragments
- Steel hidden inside concrete, timber, insulation, or composite pieces
- Fine wear metal generated during crushing and screening
Build a Separation Sequence
- Pre-sort oversized steel that can damage or jam the line.
- Use magnetic protection before vulnerable crushing equipment where practical.
- After crushing, screen and spread material to expose liberated iron.
- Use a suspended magnet, head pulley, or drum at a controlled discharge.
- Verify the residual fraction and identify non-ferrous targets requiring other technology.
Product Choice
| Product | Best first use | Limitation |
|---|---|---|
| Suspended/overband magnet | Large iron above a conveyor | Buried iron and deep mixed burden |
| Magnetic head pulley | Continuous removal at belt discharge | Requires replacement interface and controlled trajectory |
| Housed drum | Screened, free-falling fraction | Large impact and irregular feed need review |
Safety and Wear Boundaries
Long wire and sharp rebar can damage cleaning belts or create unsafe hanging pieces. Define guards, iron collection, access, lifting, and clearing procedures. Abrasive concrete and glass may require wear protection, but added cover thickness increases magnetic distance.
How to Verify a Multi-Stage Line
Sample each size fraction and separation stage separately. Record feed composition, layer depth, speed, collected iron, residual ferrous material, and pieces that remained locked in concrete or timber. A total recovery number without stage-by-stage conditions cannot show whether the magnet, liberation, or feeding is limiting performance.
Required Information
Send material composition, size distribution, capacity, bulk density, moisture, contamination photographs, crusher/screen flow diagram, belt data, proposed stages, available space, iron discharge route, and residual-metal target.
C&D Feed Conditions to Review Before Selecting Equipment
Use these inputs to decide whether the proposed separator and process position fit the real operating duty.
| Equipment direction | Use an overband magnet for continuous removal of exposed and partly buried steel from mixed C&D feed; a drum or head pulley may follow screening when smaller liberated ferrous material needs a second separation stage. |
|---|---|
| Material condition | Define concrete, brick, wood, plastic and fines fractions; include largest piece, bulk density, moisture, dust, sharp objects, bulky shapes and changes between incoming loads. |
| Target iron or magnetic fraction | List rebar, mesh, nails, screws, hinges, wire and structural steel; give the longest piece, typical contamination level and risk of wrapping or impact at the separator. |
| Throughput and presentation | Provide normal and peak t/h, belt width and speed, feeder type, burden depth, load surges and whether oversize pieces create local layers higher than the average. |
| Installation and access | Confirm crossbelt discharge direction, bin and chute space, structural support, guarding, dust control and maintenance access for wrapped wire, belt tracking and bearings. |
| Test or acceptance | Test mixed material at realistic depth and distribution. Inspect both captured steel and valuable nonferrous or saleable material carried out with it. |
Engineering Conditions Behind the Recommendation
- Do not select from a surface Gauss value alone.
- Review field strength and gradient at the rated working distance, including the conveyor belt, burden depth and any protective plate.
- Belt speed, feed uniformity, target size, shape and magnetic response determine how much time and force are available for capture.
- Mechanical passage capacity is not the same as effective separation capacity.
- Quote or test conditions must identify material, size distribution, moisture, bulk density, normal and peak rate, feed distribution, speed, layer or flow geometry, contamination loading and cleaning interval.
What We Need to Configure This Project
Input set for Magnetic Separation for Construction and Demolition Waste
- How we use your data: We compare your material, contamination risk, production target and line interface before we configure a proposal or rule out an unsuitable option.
- Material: name and composition; dry or wet; powder, granule, lump, fibre or slurry; minimum, maximum and typical particle distribution; moisture, stickiness, tendency to cake or bridge, abrasiveness, corrosiveness, bulk density, normal temperature and maximum temperature.
- Production and target: normal and peak throughput, continuous or batch feed, feed uniformity, contaminant or recovery target, magnetic response if known, typical and maximum target size, initial concentration, acceptable residual and whether product loss is permitted.
- Installation: belt width and speed, normal and maximum burden depth, magnet position and rated working distance, available suspension and maintenance space, support and lifting arrangement; cleaning method, permitted shutdown, contact-material, wear and corrosion requirements; indoor, outdoor, washdown, high-humidity, dusty or hazardous-area conditions.
- Supporting project files: drive voltage, frequency and phase where a self-cleaning unit is considered; control interface and any site air requirement; destination country; current drawings, site photographs, running video and a representative material/contaminant sample when testing is needed.
- What you receive next: We use the confirmed inputs to prepare a project-specific drawing and inspection plan. We do not treat performance as confirmed until the agreed design and any required representative test or site acceptance establish the result.
Project Support
Send your material and process conditions
We can review the process point, material shape, iron source, capacity, available space and cleaning method before recommending a magnetic separator layout.
Frequently Asked Questions
Why is “Safety and Wear Boundaries” important for this decision?
Long wire and sharp rebar can damage cleaning belts or create unsafe hanging pieces. Define guards, iron collection, access, lifting, and clearing procedures.
How to Verify a Multi-Stage Line?
Sample each size fraction and separation stage separately. Record feed composition, layer depth, speed, collected iron, residual ferrous material, and pieces that remained locked in concrete or timber.
Why is “Required Information” important for this decision?
Send material composition, size distribution, capacity, bulk density, moisture, contamination photographs, crusher/screen flow diagram, belt data, proposed stages, available space, iron discharge route, and residual-metal target.