Process for the control of the ratio DBP number/DBP number after pressing in the manufacture of carbon black pellets

Claim 1

A process for controlling the properties of carbon blacks by bringing about a change in the ratio of DBP number/DBP number after pressing comprising: continuously mixing dry powdered carbon black with water and forming the carbon black and water into pellets by means of a wet pelletizing machine; said machine having at least two sections each section having therein a rotating shaft with spines spirally wound around said shaft and equipped with at least one water entry port in each section, the dry carbon black being added in the first section only and a portion of the water being injected into each of at least two sections of said machine and wherein to obtain a low value for the ratio DBP number/DBP number after pressing, the speed of the rotating shaft of the pellet machine is set at a high rate relative to the speed of the shaft in the second portion and/or the major portion of water is added at a position for the injection of water located in the first section of the machine and wherein to obtain a high value for the ratio DBP number/DBP number after pressing, the speed of the rotating shaft of the pellet machine is set at a low rate relative to the second section and/or the major portion of water is added at a place for the injection of water lying in the second section of the machine; and wherein the wet carbon black pellets are subsequently dried.