Synthesis and physicochemical properties of β-silicon carbide prepared with reproduced carbon black and semiconductor packing waste by integrated mechanical and thermal activation (IMTA) process

Abstract

Approximately 130,000 tons of tires are wasted annually and up to 3000 tons of waste assembly compounds containing 60–70 % silicon oxide from the semiconductor packing industry are produced in Taiwan. These huge amounts of waste materials have caused considerable environmental problems. Therefore, the current research focused to prepare the β-silicon carbide (β-SiC) synthesis using an integrated mechanical and thermal activation (IMTA) process with carbon black and waste assembly compounds from the waste tire industry and semiconductor packing industry, respectively. Four synthesis parameters including the C/Si molar ratio, ball-milling time, pyrolysis temperature, and pyrolysis time were investigated. The X-ray diffraction spectra confirmed that the granular- and whisker-like SiC were successfully synthesized. The research findings confirmed the formation of granular-like SiC at pyrolysis temperature of 1300 °C for 1 h. Either increased pyrolysis temperature or pyrolysis time, whisker-like SiC was formed with 280–375 nm in diameter and 7.5–20 µm. The C/Si molar ratio was the most critical parameter for improving the SiC quality. Based on the systematic analysis using Taguchi method, the optimum parameter for the SiC yield was determined with a C/Si molar ratio of 6:1 after 4 h of ball milling and a heating temperature of 1450 °C for 1.5 h. By comparing of physicochemical properties, the use of carbon and silicon recycled materials was verified to successfully synthesize β-SiC in this study.