Pyroplastoid particles, composition and method of production

摘要

Particulate material, composites containing said material, and a method of making said particulate material. The material is composed of at least about 85% (number basis) of regular, well-defined ellipsoidal particles having a size less than about 25 microns, at least 90% and 50% by weight of the particles being less than about 15 and 10 microns in size respectively, a surface area of about 0.75 to about 2.5 square meters per gram and a specific gravity of about 2 to 3. The composites contain this particulate material and up to about 99% of one or more polymeric media. The particulate material is produced by subjecting a diverse mixture of flyash particles to dry air classification in an air classifier controlled to recover particulate particles as described above.