A Vibrating Bar Technique for Preparing Carbon Microspheres

A process was developed for the preparation of dimensionally stable carbon microspheres from polyfurfuryl alcohol or other resins, using a vibrating bar apparatus for spheroidization. The spheroidized particles (40- to 400-μ diam) were prevented from coalescing by collecting them in mineral oil containing 1% surfactant, where they remained in suspension until partially cured. After coking at 950°C in argon, the resin microspheres were converted to well-rounded carbon microspheres having an open porosity of 0.34%, a particle density of 1.62 g/cm³, and a compressive strength as high as 19.5 lb/particle for an 88-μ diam.