Recycled carbon black from waste of tire industry: thermal study

Carbon black from waste of tire industry has potential to be recycled through two steps i.e. pyrolysis and demineralization. The treatment without and with pyrolysis prior to demineralization is done to identify the effect of temperatures on agglomerate size, morphology, elemental analysis, and surface function group. Based on DTA analysis, temperatures at 225 and 410 °C were chosen to show the difference of effect from decomposing organic in material of waste. This research reported that increasing temperature pyrolysis could decrease agglomerate size. However, the agglomerate size of carbon black recycled was larger than carbon black waste caused by carbonaceous which form from pyrolysis. In addition, pyrolysis gave effect on surface function group of carbon black recycled and morphology. Increasing temperature pyrolysis could activate surface function group. It is showed by absorption with medium/strong intensity at 1382.96 and 1381.03 cm⁻¹ as C–O stretching of carboxyl group in carbon black recycled at 410 °C seemed carbon black standard N660. IR spectrum of carbon black waste before and after treatment without and with pyrolysis at 225 °C showed weak intensity at 1382.96, 1382.96, and 1386.82, respectively as stretching of aromatic compounds. Pyrolysis at high temperature (410 °C) could form agglomerate which has uniform pores. After demineralization, inorganic impurities such as Zn could be removed by acid solution using hydrochloric acid 1 M for 2 h.