Assessment of screening mineral wool waste from market by using handheld X‐ray fluorescence

Abstract

AbstractStone wool from construction, renovation, demolition and horticultural applications is reclaimed for reuse and recycling. Variation of chemical composition of reclaimed material creates a challenge, especially with increasing quantities from construction and demolition sectors. Therefore, an assessment of handheld/portable X‐ray fluorescence (XRF) spectrometer was carried out with the objective to quickly discriminate various type of man‐made vitreous fibres (MMVF). The evaluation concerned mainly light element analysis. Therefore, the effect of disturbing factors, such as moisture, organic matter, surface roughness and sample density were evaluated. Direct measurement on mineral wool product or granulate gives a precision of ±1.5% for Al2O3 and ±2.1% for SiO2 after calibration. Precision is enhanced by preparing pressed pellets, resulting in precision down to ±0.9% for Al2O3 and ±1.5% for SiO2 after correction. Provided correctly calibrated, handheld XRF analysis gives a quick indication, though not necessarily conclusive, whether the reclaimed material applies to so called “old wool,” manufactured prior to the EU legislation requiring increased bio‐solubility. A quick indication is very relevant for the renovation and demolition sector and subsequent re‐use or recycling of mineral wool because it affects transport and handling requirements. In case the analysis is not obviously discriminative, desktop analysis is still required. Presence of moisture and organic matter influence the detection of lighter elements, which especially affects analysis of horticultural recycling substrate granulate.