provided is a process for bleaching pulp with ozone . the process involves preparing a slurry of cellulosic pulp having a consistency in fibers of from 1 - 5 weight %. such a low consistency slurry is then mixed with ozone under high shear conditions . the ozone is then maintained in contact with the cellulosic fibers to effect bleaching of the fibers . the present process offers the advantages of bleaching using a low consistency slurry , with the added advantages of employing ozone .