Study on microwave selective treatment of mercury-containing acid mud

Abstract

The subject of this paper is acid mud, a hazardous waste containing mercury. The current treatment process for acid mud involves high temperatures and extended roasting times. In order to address this issue, a new method utilizing microwave-assisted treatment was proposed. This method has demonstrated the effectiveness of microwave heating for acid mud treatment. The results of the study indicate that acid mud consists of PbSO4, HgS, HgSe, and HgCl2, with the main microwave absorbing material being the mercury-containing phase. A schematic diagram illustrating the microwave heating process is proposed in this study. After subjecting the acid mud to microwave treatment at a temperature of 600 ℃ for 30min, the volatilization rate of mercury was found to reach 99.94%. This rate is 6.55% higher compared to conventional roasting methods. Additionally, the microwave roasting slag exhibited increased pore size and specific surface area, indicating that microwave energy provided an improved channel for volatilization. These observations support the conclusion that microwave heating selectively targets the mercury-containing components in acid mud, thereby enhancing the volatilization rate of mercury.

Keywords

• Acid mud
• Microwave
• Selective heating
• Mercury