Patent ID: 8845936
Filing Date: 2014-09-30
Classification: B01J,B22F,C01B,C01F,C01P,C04B,C09C,Y10T

Abstract:
1. A process for preparing hollow ceramic or metal microspheres, comprising: (1) forming ceramic or metal slurry, comprising ceramic or metal powders, water and dispersant and having a certain solid phase content, into a stable foam slurry by using a foaming agent, said solid phase content being in the range of 5-60% by volume; (2) introducing the stable foam slurry into a centrifugal atomization equipment to atomize it into hollow slurry droplets, then spraying the hollow slurry droplets into a molding chamber and drying rapidly in a time of less than 1 second to form hollow microsphere green body; and (3) collecting the hollow microsphere green body and sintering; wherein, in the ceramic or metal slurry having a certain solid phase content, the volume of said powders is 5-60% of the total volume of the solution after the addition of said powders, the dispersant is 0.1-3% of the total volume, the foaming agent is 0.1-1% of the total volume, and balance being water; the dispersant is selected from ammonium citrate, ammonium polymethacrylate, tetramethylethylene diamine, and calgon, and said foaming agent is selected from triton and propyl gallate; and the stable foam slurry has a slurry foaming rate of between 20% and 600% and a diameter of air bubble being between 0.001 mm and 1.5 mm, and is substantially without apparent antifoaming or foam joining phenomenon for 1-10 days shelf time.