Improvements in manufacture of carbon black

摘要

Carbon blacks having oil absorption values in excess of 24 and structure indices of over 300 are made from normally non-gaseous hydrocarbons by injecting the hydrocarbons in the form of a spray into a localized region of a furnace, introducing coaxially around said spray a quiescent current of a free oxygen-containing gas in a proportion sufficient to maintain only partial combustion of said hydrocarbons, subjecting the hydrocarbons to a rapid partial combustion so as to form a flame in said localized region, and passing the products emanating from the flame through a zone of the furnace at carbon-black-forming temperatures in a non-turbulent state. Substantial amounts of products of combustion or pyrolysis of hydrocarbons or gases of a reducing nature are prevented from contacting the hydrocarbon spray and free oxygen-containing gas prior to mixture thereof and during partial combustion of the spray. The free oxygen-containing gas may be air and it may be caused to flow around the spray at a relatively lower velocity. The furnace may be at 1100-2500 DEG F. The hydrocarbon may be preheated to 220-500 DEG F. before being sprayed into the furnace. The carbon black formed in the furnace may be further heat-treated, e.g. by mixing with hot gaseous products of combustion or with a free-oxygen-containing gas so as to generate additional heat by combustion. The hydrocarbon feedstock may comprise at least 50% by weight of aromatic hydrocarbons.