Linking Automated Scanning Electron Microscope Based Investigations to Chemical Analysis for an Improved Understanding of Ash Characteristics
The movements and efforts of a circular economy, aiming to tap into the resource potential of ash, require an intimate knowledge of the material; often, target elements within this material are part of complex ash phases. This work shows how automated SEM investigations measure up to other laborator...
| Main Authors: | , , , |
|---|---|
| Format: | Article |
| Language: | English |
| Published: |
MDPI AG
2021-10-01
|
| Series: | Minerals |
| Subjects: | |
| Online Access: | https://www.mdpi.com/2075-163X/11/11/1182 |
| _version_ | 1797509242651934720 |
|---|---|
| author | Andrea C. Guhl Sandra Pavón Bernhard Schulz Martin Bertau |
| author_facet | Andrea C. Guhl Sandra Pavón Bernhard Schulz Martin Bertau |
| author_sort | Andrea C. Guhl |
| collection | DOAJ |
| description | The movements and efforts of a circular economy, aiming to tap into the resource potential of ash, require an intimate knowledge of the material; often, target elements within this material are part of complex ash phases. This work shows how automated SEM investigations measure up to other laboratory techniques for the analysis of elemental composition and particle size. Three sewage sludge ash (SSA) samples have been studied in this comparison, showing material variation for SSA and highlighting the strengths and shortcomings of the methods chosen. Inductively coupled plasma optical emission spectroscopy (ICP-OES), X-ray fluorescence (XRF) and scanning electron microscopy with energy dispersive X-ray analysis (SEM-EDX) show relevant phosphate phases, but also a number of other elements. The extent of the accompanying elements, most likely hindering efficient phosphorus (P) recovery, varies. Propensities for detection in fine-grained and largely amorphous material such as ash vary, as is explored in this thorough comparison. ICP-OES data suffers from incomplete sample mobilization, and XRF-derived values suffer from matrix effects. Both are the only techniques studied which show trace elements, such as potentially toxic elements. SEM-EDX automated mineralogy delivers more reliable data for main elements while not reporting traces. By showing SEM-EDX automated mineralogy particle size distributions, alongside laser diffraction derived particle size distributions, the extent of the strain ash puts on traditional techniques is visible. Ashes tend to agglomerate, and the porous nature of particles hinders accurate detection. This work highlights where SSA recycling needs to be careful and hints at the extent of discrepancies between different methods. When understanding ash as a potential resource and designing efficient extraction strategies, this knowledge is crucial. |
| first_indexed | 2024-03-10T05:14:55Z |
| format | Article |
| id | doaj.art-906df3797af34ebfb00a761534ec16bf |
| institution | Directory Open Access Journal |
| issn | 2075-163X |
| language | English |
| last_indexed | 2024-03-10T05:14:55Z |
| publishDate | 2021-10-01 |
| publisher | MDPI AG |
| record_format | Article |
| series | Minerals |
| spelling | doaj.art-906df3797af34ebfb00a761534ec16bf2023-11-23T00:31:31ZengMDPI AGMinerals2075-163X2021-10-011111118210.3390/min11111182Linking Automated Scanning Electron Microscope Based Investigations to Chemical Analysis for an Improved Understanding of Ash CharacteristicsAndrea C. Guhl0Sandra Pavón1Bernhard Schulz2Martin Bertau3Institute of Chemical Technology, Technische Universität Bergakademie Freiberg, 09599 Freiberg, GermanyInstitute of Chemical Technology, Technische Universität Bergakademie Freiberg, 09599 Freiberg, GermanyInstitute of Mineralogy, Technische Universität Bergakademie Freiberg, 09599 Freiberg, GermanyInstitute of Chemical Technology, Technische Universität Bergakademie Freiberg, 09599 Freiberg, GermanyThe movements and efforts of a circular economy, aiming to tap into the resource potential of ash, require an intimate knowledge of the material; often, target elements within this material are part of complex ash phases. This work shows how automated SEM investigations measure up to other laboratory techniques for the analysis of elemental composition and particle size. Three sewage sludge ash (SSA) samples have been studied in this comparison, showing material variation for SSA and highlighting the strengths and shortcomings of the methods chosen. Inductively coupled plasma optical emission spectroscopy (ICP-OES), X-ray fluorescence (XRF) and scanning electron microscopy with energy dispersive X-ray analysis (SEM-EDX) show relevant phosphate phases, but also a number of other elements. The extent of the accompanying elements, most likely hindering efficient phosphorus (P) recovery, varies. Propensities for detection in fine-grained and largely amorphous material such as ash vary, as is explored in this thorough comparison. ICP-OES data suffers from incomplete sample mobilization, and XRF-derived values suffer from matrix effects. Both are the only techniques studied which show trace elements, such as potentially toxic elements. SEM-EDX automated mineralogy delivers more reliable data for main elements while not reporting traces. By showing SEM-EDX automated mineralogy particle size distributions, alongside laser diffraction derived particle size distributions, the extent of the strain ash puts on traditional techniques is visible. Ashes tend to agglomerate, and the porous nature of particles hinders accurate detection. This work highlights where SSA recycling needs to be careful and hints at the extent of discrepancies between different methods. When understanding ash as a potential resource and designing efficient extraction strategies, this knowledge is crucial.https://www.mdpi.com/2075-163X/11/11/1182ashSSAsewage sludge ashphosphorusautomated mineralogymineral liberation analysis |
| spellingShingle | Andrea C. Guhl Sandra Pavón Bernhard Schulz Martin Bertau Linking Automated Scanning Electron Microscope Based Investigations to Chemical Analysis for an Improved Understanding of Ash Characteristics Minerals ash SSA sewage sludge ash phosphorus automated mineralogy mineral liberation analysis |
| title | Linking Automated Scanning Electron Microscope Based Investigations to Chemical Analysis for an Improved Understanding of Ash Characteristics |
| title_full | Linking Automated Scanning Electron Microscope Based Investigations to Chemical Analysis for an Improved Understanding of Ash Characteristics |
| title_fullStr | Linking Automated Scanning Electron Microscope Based Investigations to Chemical Analysis for an Improved Understanding of Ash Characteristics |
| title_full_unstemmed | Linking Automated Scanning Electron Microscope Based Investigations to Chemical Analysis for an Improved Understanding of Ash Characteristics |
| title_short | Linking Automated Scanning Electron Microscope Based Investigations to Chemical Analysis for an Improved Understanding of Ash Characteristics |
| title_sort | linking automated scanning electron microscope based investigations to chemical analysis for an improved understanding of ash characteristics |
| topic | ash SSA sewage sludge ash phosphorus automated mineralogy mineral liberation analysis |
| url | https://www.mdpi.com/2075-163X/11/11/1182 |
| work_keys_str_mv | AT andreacguhl linkingautomatedscanningelectronmicroscopebasedinvestigationstochemicalanalysisforanimprovedunderstandingofashcharacteristics AT sandrapavon linkingautomatedscanningelectronmicroscopebasedinvestigationstochemicalanalysisforanimprovedunderstandingofashcharacteristics AT bernhardschulz linkingautomatedscanningelectronmicroscopebasedinvestigationstochemicalanalysisforanimprovedunderstandingofashcharacteristics AT martinbertau linkingautomatedscanningelectronmicroscopebasedinvestigationstochemicalanalysisforanimprovedunderstandingofashcharacteristics |