Real Case: Achieving High Purity and Zero Powder Loss with Ceramic Flat Sheet Membrane System

Weclean is currently supporting a famous electronic powder manufacturer in high-purity Spherical Alumina powder production with a lot of challenging technical issues on the final washing process and iron removal process.

The client’s main difficulties were:

• Significant loss of valuable fine powder and poor efficiency during the traditional washing/sieving process
• Difficulty consistently reaching conductivity ≤10 μS/cm
• Iron impurities affecting product whiteness and the performance in the client-end
• Risk of contamination from mechanical stirring
• Need to use 40–50°C hot water to accelerate ion dissolution, which organic PVDF membranes cannot reliably handle for long periods

WECLEAN team successfully developed an integrated Ceramic Flat Sheet Membrane System to address these issues directly. Up to now, four lines of this integrated system are in operation, pretty robust at this client factory.

How the system works in this project:

• The spherical alumina slurry, with approximately 30% solid content, is washed in the membrane tank using 40~50°C hot water.
• Under controlled acidic/alkaline washing conditions and elevated temperature, impurity elements are promoted to dissolve and ionize. These impurity ions are then continuously removed with the permeate water, while the purified spherical alumina powder is retained in the tank.
• Our inorganic ceramic flat sheet membranes, with a pore size of 80±20 nm, efficiently separate high-conductivity wastewater while retaining nearly 100% of the valuable powder.
• Air bubbling provides gentle mixing and anti-settling, eliminating the risk of mechanical contamination.
• The system integrates electromagnetic iron removal, allowing washing and iron removal to run simultaneously.
• Online monitoring of conductivity, pH, and pressure ensures stable process control.