PROCESS FOR OBTAINING CARBON BLACK

摘要

1473516 Carbon black; acetylene black PRODUITS CHIMIQUES UGINE KUHLMANN 3 May 1974 [15 May 1973] 19535/74 Heading C1A Carbon black having the properties of an acetylene black is prepared from at least one hydrocarbon from the general classes of olefins, aromatics unsaturated cyclics and polycyclics, by preheating to above their critical temperatures and then by incomplete combustion with oxygen under reduced pressure at a temperature of at least 1700‹C. The product is a black having a filter index higher than 80, a carbon content of 99% and a particle size of 150-200 Š. The oxygen used in the incomplete combustion may also be preheated. Preferred hydrocarbons are ethylene, benzene, toluene, oxylene or a petroleum cut having a high proportion of unsaturated polycyclics. The process is carried out in a vertical furnace of the type shown in Fig. 2. The hydrocarbon is preheated in preheater (4) to a temperature as high as possible having regard to its thermal stability (the temperature being measured at (12)), and then introduced to the furnace via the burner (2). The oyxgen is introduced to the burner via line 11, after optionally being preheated in preheater 5. The carbon black produced forms agglomerates which are disintegrated by means of a grinder (6). A lowering of the pressure within the furnace by a ventilator (3) carries the aerosol of carbon black and the cracking gases to a set of cyclones (7) where the black is separated and conveyed to a hopper (15). Fig. 3 (not shown) shows the burner unit in detail.