A method of refining cellulose pulps by bleaching or extraction is disclosed, in which the pulps at a consistency of 10 - 65% and in a finely divided form are treated with chemicals at a temperature of 10 to 250'C. The finely divided pulp is fed, impregnated with chemicals and at a consistency of 30 to 65% continuously into a processing apparatus in which an excess system pressure of 5 to 400 kPa prevails and which includes an atmosphere substantially consisting of steam having an oxygen content of less than 1% by volume and a temperature of 100 to 150'C. The pulp is moved rapidly, but without alteration of its fibre characteristics, continuously through the processing apparatus under a substantially turbulent flow and with substantially unaltered solids content. The chemicals charged to the pulp are caused to react so completely with the pulp during its rapid movement through the processing apparatus that they are substantially consumed when the movement is terminated. The pulp is then discharged from the processing apparatus and dried, optionally after further chemical treatment steps.
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