OZONE BLEACHING PROCESS

Method and apparatus for ozone bleaching a medium consistency cellulosic fib er suspension include feeding the fiber suspension and an ozone in carrier gas stream under pressure into a fluidizing mixer (14); intimately and uniformly mixing the fiber suspension with the ozone to achieve a bleaching reaction; passing the mixtu re into a first reaction vessel (22) to permit the bleaching reaction to proceed and to consume a major part of the ozone; addi ng a second bleaching chemical to the mixture; separating the excess ozone and carrier gas from the mixture in a second considerably larger vessel (32) and removing the fiber suspension from the second vessel after the effective second bleaching reaction.