Why iron in battery powder matters
Trace metallic iron in cathode or anode powder can bridge the separator inside a cell, create a local internal short and become a heat source. It is therefore a safety risk, not just a quality defect. Iron enters from worn milling media, corrosion in slurry tanks and pipes, and raw-material carry-over, so control works best as several de-ironing stages along the line rather than one machine at the end. Our article iron in cathode powder and battery safety goes deeper.
Materials covered
Lithium cobalt oxide, lithium manganate, lithium carbonate, ternary materials, lithium iron phosphate (LFP), graphite and activated carbon.
The dry iron removal machine
PTMS dry electromagnetic separators pull weakly magnetic particles out of free-flowing powder without adding moisture and without changing particle size distribution. The machines used on battery lines are built with:
- special medium nets with a micron-level wear-resistant coating, so material flows smoothly and the raw material is protected;
- water-oil double cooling for a stable field in long runs;
- fast demagnetisation of the medium for clean iron discharge;
- all-stainless-steel versions where contamination from the machine itself is a concern.
The current models on our dry separator page are PT3A160, PT20A600, PT25A600 and PT1000; the PT20A600 is published at 2.5 T and 2–4 t/h (see the dry separator model guide). All-stainless-steel versions are available, and battery-specific datasheets are issued on request.
A multi-stage de-ironing layout
- Raw materials: permanent magnetic rod boxes or drawer separators catch tramp iron in incoming powders. The lithium iron phosphate rod-box separator publishes a 10,000 Gauss field on its 25 mm rods, and rod boxes can be built with 3, 5, 8 or 12 layers.
- Powder de-ironing: the dry electromagnetic separator removes weakly magnetic particles.
- Slurry de-ironing: wet or pipeline electromagnetic separators clean electrode slurry.
- Powder line protection: stainless steel drawer-type separators catch fine iron in powders and granules before packing.
Exact positions depend on your process; this is the multi-stage concept we use as a starting point. See the full lithium battery solution.
What to send
Material (cathode, anode, additive), particle size and whether it is free-flowing, throughput, current iron level and the target, whether stainless contact surfaces are required, and your destination. A sample test confirms the configuration before we finalise a quotation.
Next step: send us your material details (or WhatsApp +86 139 2990 7491) and we reply with a matched model and a quotation. Our FAQ states that a test on a sample of your material comes first, and that no iron-reduction figure is quoted without a test.