INFLUENCE OF SOLVENT IMMERSION ON THE OXIDATIVE STABILIZATION OF PITCH SPHERES

The coal tar pitch spheres and petroleum spheres were immersed by alkyl hydrocarbon solvent. The infulence of immersion time and temperature on the yield, breakage and stabilization result of pitch sphere were studied. The results showed that small molecules were effectively removed by immersing pitch spheres with alkyl hydrocarbon solvent at room temperature. The path of oxygen diffusion was obtained and the oxidation difference between surface and center of pitch spheres was minimized, so the stabilization speed was accelerated. If pitch spheres were immersed at higher temperature, their surface would be eroded. The coal tar pitch spheres was easy to be stabilized compared with the petroleum pitch spheres when they had similar softening point and naphthalene content.