1. Magnetic Separation and Sieving
Purpose:
Removal of ferromagnetic contaminants (e.g., steel wires from tires) and coarse solid fractions.
Technology:
Magnetic separators, vibrating screens, air classifiers.

2. Grinding and Micronization
Purpose:
Particle size reduction to required parameters; achieving uniform granulation (often below 10–30 microns).
Technology:
Ball mills, jet mills, hammer mills.
Effect:
Improved dispersibility and specific surface area, resulting in better functional properties.

3. Chemical or Thermal Purification
Purpose:
Removal of residual ash, sulfur, heavy metals, and other inorganic compounds.
Methods:
Acid leaching (most commonly with mineral acids like HCl, H₂SO₄),
Alkaline cleaning (e.g., NaOH),
Heat treatment (e.g., calcination),
Plasma or ozone treatment (less common).
Effect:
Reducing ash content from 15–20% to below 5%; increasing BET surface area.

4. Surface Modification
Purpose:
Improving compatibility of rCB with polymer matrices (e.g., in elastomers).
Methods:
Oxidation (e.g., nitric acid, ozone),
Silane or organic compound modification,
Plasma or chemical activation.
Effect:
Enhanced mechanical and rheological properties of final products.

5. Granulation or Pelletizing
Purpose:
Facilitating transport, storage, and dosing in further processes.
Effect:
Final product in granular form with high flowability and low dustiness.