Аңдатпа
Abstract The action of ozone in the low-temperature ozonization of coal tar from the semicoking of Shubarkol coal (Kazakhstan) is analyzed. Two mechanisms are possible: the electrophilic addition of ozone by π bonds to the molecules of unsaturated compounds; or radical-chain reactions with the formation of a broad spectrum of oxygen-bearing products (carboxylic acids, alcohols, aldehydes, etc.). The presence of each mechanism in tar ozonization is approximately the same. Ozone plays a positive role, by doubling the content of β fraction in the tar; and decreasing the content of the unreactive α1 fraction. The β fraction determines the binding and clinkering properties of pitch, while the α1 fraction prevents the appearance of anisometric needle-coke structures in pitch coking.