Production of carbon black beads, e.g. useful in rubber mixtures, comprises spraying carbon black with water in an annular bed mixer-granulator under defined conditions

摘要

Production of carbon black beads comprises feeding carbon black into an annular bed mixer-granulator at a constant rate and injecting water at 3-5 bar through two double-nozzle spray heads located close to the inlet to produce a spray cone making an angle of 10-90[deg] to the direction of flow of the carbon black. Independent claims are also included for: (1) carbon black beads (B1) having an oil absorption above 100 ml/100 g and a compressed oil absorption above 78 ml/100g and comprising less than 3.5 wt.% of beads with a diameter above 2.5 mm and more than 22 wt.% of beads with a diameter of 0.71-1 mm and a hardness of 7-25 g; (2) carbon black beads (B2) having an oil absorption above 90 ml/100 g and a compressed oil absorption below 78 ml/100g and comprising less than 30 wt.% of beads with a diameter of 0.71-1 mm and a hardness of 7-25 g; (3) rubber mixtures comprising rubber, beads B1 or B2, optionally precipitated silica and/or other rubber auxiliaries.