If you run a circuit board recycling equipment line, the single number that decides whether you make money is the purity of the copper granules coming off the end of the line. Scrap buyers and smelters pay a premium for clean copper and discount heavily when plastic, fiberglass dust, or resin is mixed in. So what purity can you actually expect from a granulator on a PCB recycling line, and what does it depend on?
In this article we break down realistic purity figures, the factors that push purity up or down, and the practical steps you can take to get the highest value from your recycled copper.
What is granulator copper?
Granulator copper is the metal fraction produced when waste printed circuit boards are crushed and separated. The boards are first shredded and ground into small particles, then passed through air, gravity, and electrostatic separation stages that pull the heavy copper away from the lighter resin and fiberglass. What comes out is a copper-rich granule or powder that can be sold directly to scrap buyers or melted into ingots for further processing.
The term "granulator copper" is often used interchangeably with copper powder or copper rice, depending on the particle size your line produces. Whatever you call it, its market value is set almost entirely by its purity.
What purity can you expect from a PCB recycling line?
There is no single answer, because purity depends on how the line is configured. But based on how modern mechanical separation systems perform, here is a practical range:
- A basic setup with coarse crushing and simple air separation: roughly 85-92% purity.
- A well-configured dry separation line with vibrating screening and electrostatic sorting: 96-98% purity.
- A full line with multiple separation stages and careful process control: up to 99% purity.
For example, San Lan's circuit board recycling plant with dry separator 500-2000kg/hour capacity produces copper powder at 96-98% purity with a metal recovery rate of 95%, and it does so without dust pollution because the whole process runs under negative pressure with pulse bag dust collection.
What determines the purity of granulator copper?
Four factors have the biggest influence on the purity you can achieve:
1. Crushing and grinding quality
Copper is tightly bonded with resin and fiberglass inside a circuit board. If the boards are not ground finely enough, copper stays locked inside non-metal particles and ends up in the waste stream. If they are ground too finely, copper turns into dust that is hard to recover. A good line uses two or three crushing stages so that copper is fully liberated without being over-ground.
2. Separation technology
This is where the biggest purity gains come from. Copper is much denser than fiberglass and resin, so air separation and vibrating gravity tables can already remove most non-metal material. Adding an electrostatic separator takes purity to another level: conductive copper particles are pulled toward an electrode in a high-voltage field while non-conductive resin and fiberglass fall straight down. Lines that combine air separation with electrostatic sorting are the ones that consistently reach 96-98% purity.
3. Feed material
Clean, bare boards give higher purity than boards that still carry components, connectors, or solder. If you process whole boards with components, expect to run them through a pre-shredder and remove large metal parts first. The quality of the input directly sets the ceiling for the output.
4. Maintenance and process control
Dull blades produce uneven granules that are harder to separate. Clogged screens and dust filters reduce airflow and separation efficiency. A line that is cleaned and maintained on schedule will hold its purity spec, while a neglected line will drift lower week by week.
Dry separation vs wet separation: which gives higher purity?
Both approaches can produce clean copper, but they suit different situations:
| Separation method | Typical copper purity | Water usage | Post-processing |
|---|---|---|---|
| Dry separation (air + electrostatic) | 96-98% | None | Minimal, just screening |
| Wet separation (water + gravity) | 90-95% | Continuous water supply | Drying and wastewater treatment |
Dry separation has the advantage of no water bills, no drying step, and no wastewater treatment, which is why it is the preferred choice for most modern PCB recycling plants. Wet separation can still be a good fit where water is cheap and the operator wants a simple gravity-based process, but the extra handling steps tend to eat into the margin.
Why purity matters for your profit
Scrap buyers quote different prices for different purity grades. A 2-3% difference in purity can change the price you are offered by a meaningful margin, because smelters have to pay for the energy and slag handling needed to remove contamination. On a line processing a ton of boards a day, that difference adds up quickly over a year.
Purity also affects recovery. A line that produces 95% recovery with 96-98% purity is recovering more of the copper that was actually in the boards, which means less value is being thrown away with the non-metal residue.
How to push purity higher in practice
- Feed boards through a pre-shredder first so large components and connectors are broken down before the main crushing stage.
- Check the granule size regularly. If you see copper still attached to fiberglass, the grinding stage needs adjustment.
- Keep the electrostatic separator clean and its voltage settings matched to the moisture content of the feed.
- Run a small sample through the line and have the copper powder tested before you commit to a sales contract, so you know exactly what grade you are selling.
- Maintain the dust collection system. Dust carry-over is one of the most common reasons purity drifts down on dry lines.
San Lan's PCB recycling solutions
San Lan Technologies has been building recycling machinery for e-waste since 2007, and its circuit board recycling plants cover a wide capacity range. The WCBD-300A dry separation plant handles 300-500 kg/hour for small operations, the WCBD-1000A and WCBD-2000A air separation plants cover 1000-2000 kg/hour for medium and large facilities, and wet separation models are available for plants that prefer a water-based process. All of them use mechanical crushing and physical separation, so no chemicals are involved and no wastewater is produced.
If you are also processing scrap cable alongside boards, a cable wire granulator can recover copper from cable insulation using the same dry separation principle, giving you a second source of clean copper granules from one facility.
Frequently asked questions
Is 99% copper purity realistic from a PCB recycling line?
It is achievable with a well-tuned line that combines air separation, gravity separation, and electrostatic sorting, especially when the feed is clean bare boards. For most operators, a consistent 96-98% is a more realistic target, and it is already high enough to command a good price from buyers.
Does higher purity mean higher recovery?
Not automatically. Purity is about how clean the copper fraction is, while recovery is about how much of the copper in the feed ends up in that fraction. A good line should deliver both: high purity in the copper output and a high recovery rate, so little copper is lost to the residue.
Do I need chemicals to get high-purity copper from PCBs?
No. Modern mechanical and physical separation achieves 96-98% purity without any chemicals, which keeps operating costs low and avoids the wastewater and safety issues that come with chemical leaching.
Can one line handle both circuit boards and scrap cable?
Yes. Many facilities run a circuit board recycling plant alongside a cable granulator, since both use dry crushing and separation. This lets you process two common e-waste streams and produce clean copper granules from both.
Final thoughts
The purity of granulator copper from a PCB recycling line is not a fixed number. It depends on how well the boards are crushed, which separation stages the line uses, the quality of the feed, and how well the equipment is maintained. With a properly configured dry separation line, 96-98% purity is a realistic and profitable result, and the copper you produce will command a much better price than material from a basic setup.
If you are planning a PCB recycling plant or upgrading an existing line, talk to a supplier about the capacity, separation stages, and dust control you need for your target purity. San Lan can help you size a line for your material and budget, from 300 kg/hour starter plants up to 2000 kg/hour industrial systems.
