Improvements relating to the oxidation of carbon black pellets

摘要

A process for oxidizing carbon black pellets comprises contacting a fluidized bed of pellets with an O2-containing gas at a temperature of from 550 DEG to 825 DEG F. for 30-240 minutes to lower the pH of the black and the increase the surface area and volatile content thereof and thereafter cooling the oxidized black. The gas may contain 5-30 volume per cent of oxygen. Prior to oxidizing the pellets may be dried to a moisture content of less than 1% by weight by contact with a non-oxidizing gas at from 1000 DEG to 1400 DEG F. In Fig. 1 an oxidizing vessel 10 comprises a shell 12 housing a first stage oxidizing chamber 14 and a last stage oxidizing chamber 16 separated by gas distribution plate 18. More chambers may be present. Pellets are added at 20 and withdrawn through 42 to a fluidized lead cooling vessel 44. Other arrangements of apparatus are shown.