Influence of Elemental Sulfur on the Production of Materials for Road Surfacing

Coke plant tar is oxidized at 220°C in air current at 1.8 L/min for 4.5 h. In this process, elemental sulfur is added in quantities of 20, 30, and 40 wt %. With increase from 20 to 40 wt %, penetration declines from 55 to 38 mm; and the softening temperature (determined by the ring and rod method) declines from 52 to 45°C. The change in the physicomechanical properties of the mixture when adding 20, 30, and 40 wt % S is studied by X-ray phase analysis. With 30 wt % S, the reaction of sulfur with the aromatic rings forms 2-naphthanol-6-sulfonic acid (OHС₁₀Н₆SO₃H).