In this study, the physicochemical properties of free sulfur, isolated by chemical devulcanization of vulcanized rubber waste, were comprehensively studied. The devulcanization process was carried out using a mixture of FeCl3 and CH3COOH, and the effectiveness of the process was assessed using iodometric titration, IR spectroscopy, TGA/DTA, SEM-EDS, and XRD methods. The results showed that the optimization of devulcanization parameters (reaction time, temperature, acid concentration) directly affects the degree of C-C and C-C bond breaking. Based on iodometric analysis, up to 80% of the bound sulfur was converted to free state. The results of IR spectroscopy and thermogravimetric analysis showed changes in the structural and thermal stability of sulfur, while SEM-EDS clearly described morphological changes. The obtained results revealed the possibility of using devulcanized sulfur as an environmentally safe and promising raw material for industry.