Effect of Demineralization and Physical Activation in Enhancing the Porosity and Adsorption Properties of Recovered Carbon Black Pyrolyzed From Waste Tire

This research aims to improve the porosity structure and adsorption characteristics of rCB through demineralization and physical activation techniques. Hydrochloric acid (HCl) at various concentrations (1, 5, 6, and 10 M) was employed for demineralization, followed by the addition of 6 M potassium hydroxide (KOH). Physical activation was conducted at temperature ranges of 300, 350, 400, 450, and 500°C for durations of 1, 2, and 3 h. Characterization of rCB was conducted using Fourier Transform Infrared Spectroscopy (FTIR), ash content analysis, Inductively Coupled Plasma Optical Emission Spectroscopy (ICP-OES), Brunauer-Emmett-Teller (BET), and iodine adsorption number (IAN). Demineralization decreased the ash content from 11.36% to 8.05% and removed iron (Fe3+) and magnesium (Mg2+) metals. Conversely, physical activation markedly enhanced the porosity of rCB, attaining a peak BET surface area of 188.52 m2 g-1 and an IAN of 100 mg g-1 at 450°C for 1–2 h. Increased temperatures led to pore collapse, particularly at 500°C. The findings indicate that the optimum temperature and duration of physical activation enhance the structure of rCB. This phenomenon facilitates the widespread use of treatment for environmental remediation, including the treatment of wastewater containing dyes.