Recycled Cathode Precursor Physical Characterization Techniques
Physical characterization of recycled cathode precursors requires screening tap density, internal porosity, and particle friability to prevent calcination failures.
Air Jet Sieving
Meaning
Particle separation through controlled fluidization isolates fine powder fractions under negative pressure. In active cathode material production, air jet sieving measures the size distribution of cohesive agglomerates without mechanical shear damage. The procedure stops at a lower boundary of five micrometres where electrostatic forces overcome pneumatic drag forces.
Fluidization Profile
Pneumatic nozzles rotate below a single mesh screen to lift fine particles into a suspended cloud. High velocity air currents drawn by downstream vacuum pumps pass through the mesh, carrying particles smaller than the mesh opening through the screen while air jet sieving keeps cohesive particles separated. Pressure differentials between two hundred and six thousand pascals control the kinetic energy of the impact against the chamber lid.
Continuous airflow maintains constant dispersion across the screen surface throughout the analytical cycle.
Aperture Blinding
Screen blockages occur when near-size particles wedge into wire mesh openings under continuous downward suction. Fluidized reverse flow generated by the rotating slotted nozzle clears trapped grains from below, ensuring that air jet sieving maintains open passage area throughout the analytical cycle. Ultrasonic transducers added to the sieve frame assist in dispersing fine agglomerates without elevating thermal energy within the sample.
Yield Limit
Material loss on housing surfaces limits total mass recovery during micro-particle evaluation. Fine precursor fractions below ten micrometres require anti-static treatment or specialized grounded collection chambers when air jet sieving is used for commercial quality control. Quality criteria establish a maximum mass loss threshold of zero point five percent per test run.