Measuring the Concentration of Mercury for Automotive Shredded Residues Using the Direct Mercury Analyser

Abstract

The mercury content is among the parameters that characterise the quality of Solid Recovered Fuels (SRFs), which constitute alternative solid fuels of increasing interest. In this study, a direct mercury analyser was utilised in the analyses of SRF samples originating from Automotive Shredded Residues (ASRs). Two SRFs and one liquid reference material were measured to test the accuracy and sensitivity of the instrument. The mean values of the two SRFs and one liquid reference material (RM) were 0.171, 0.324 mg/kg, and 0.141 mg/L. These values were compared with the reference ones as follows: 0.168, 0.382 mg/kg, and 0.137 mg/L. Mercury content was detected in the analysis samples of four different particle sizes (8 mm, 2 mm, 1 mm, 0.5 mm, and 0.25 mm) for each SRF sample in order to demonstrate the direct mercury analyser operation and to compare it as an alternative to mercury determination via atomic absorption spectrometry. The measurements showed that grinding down to 1 mm was sufficient for most SRF cases while grinding down to 2 mm might be enough for a few cases. As an overall conclusion, the direct mercury analyser can be regarded as an efficient laboratory tool, offering a robust alternative to the atomic absorption spectrometry procedure, especially in terms of accuracy, speed, safety, and cost-effectiveness.

Keywords

• mercury
• SRF
• particle size
• sample fraction
• ASR
• waste to energy