| 摘要 |
1,238,346. Carbon black. ASHLAND OIL Inc. 12 July, 1968, No. 33280/68. Heading C1A. [Also in Division H1] Carbon black may be prepared by contacting a hydrocarbon feedstock with hot combustion gases in a first combustion zone, into which feedstock is injected and turbulently mixed, introducing them into a second zone through a restriction of lesser cross-section than either zone, injecting Ca, Sr, Mg or mixtures of these into the reaction mass in the second zone, cooling the reaction mass at a distance downstream sufficient to provide a contact time between the alkaline earth metal and the black sufficient to increase the surface area of the black, and recovering the product. Alternatively, the feedstock is injected into the first zone as a conical spray having an average included spray angle of 60-180 degrees, the rate of introduction of feedstock and combustion gases being adjusted so that 20-70% of the feedstock is burnt, and the rest converted to carbon black at a temperature of 3000-3400‹ F., and the reaction mass contacted with alkaline earth metal (including Ba) for 10-70 milliseconds, cooling to below 3000‹ F., and recovering the black. The combustion gases are preferably provided in the first zone by igniting a mixture of fuel and air at the upstream end of the first zone as a radially outwardly directed disc-shaped stream which is initially out of contact with the feedstock. The metal may be introduced as a compound, and, if a mixture of metals including barium is used, variation of the weight ratio of Ba to total metal varies the "structure" (as measured by oil adsorption) of the product independently of the surface area. Blacks having surface areas (iodine absorption) of 600-1300 m<SP>2</SP>/g. ; structure levels (oil factor) of 250-450 ml./100 g. C; pH of 6-10 and ash contents 0À5-10% may be produced by these methods. |
