Hydrogen Reduction of Tellurium Oxide in a Rotary Kiln, Initial Approaches for a Sustainable Process
In the recycling of semiconductor materials like Bi<sub>2</sub>Te<sub>3</sub> or CdTe, TeO<sub>2</sub> may form as a by-product that can be directly reduced to recover metallic Te. The hydrogen reduction of TeO<sub>2</sub> offers an eco-friendly altern...
Saved in:
| Main Authors: | , , , |
|---|---|
| Format: | Article |
| Language: | English |
| Published: |
MDPI AG
2025-05-01
|
| Series: | Crystals |
| Subjects: | |
| Online Access: | https://www.mdpi.com/2073-4352/15/5/478 |
| Tags: |
Add Tag
No Tags, Be the first to tag this record!
|
| _version_ | 1849711267325935616 |
|---|---|
| author | Hanwen Chung Semiramis Friedrich Mengqi Qu Bernd Friedrich |
| author_facet | Hanwen Chung Semiramis Friedrich Mengqi Qu Bernd Friedrich |
| author_sort | Hanwen Chung |
| collection | DOAJ |
| description | In the recycling of semiconductor materials like Bi<sub>2</sub>Te<sub>3</sub> or CdTe, TeO<sub>2</sub> may form as a by-product that can be directly reduced to recover metallic Te. The hydrogen reduction of TeO<sub>2</sub> offers an eco-friendly alternative to conventional carbothermic reduction by avoiding CO by-products. This study investigates the reduction of 99.99 wt.% purity level TeO<sub>2</sub> using hydrogen in an oscillating kiln furnace (200–800 °C, 2–7 h), with phase composition and microstructure analysed via XRD and SEM. Results demonstrate conversions of up to 89% (solid–gas) and 100% (liquid–gas), revealing that kinetics dominate over thermodynamics in controlling reaction progress. The work proposes a reaction mechanism based on morphological evolution observed in SEM images, suggesting that further parameter optimisation could enhance scalability. As the first lab-scale demonstration of hydrogen-assisted TeO<sub>2</sub> reduction, this study establishes a preliminary process window (temperature/time) and underscores the potential for industrial adoption. Future work should verify the proposed mechanism and refine operational parameters to maximize efficiency. |
| format | Article |
| id | doaj-art-5e4b5bab3b194d96a3baee2bacbc6870 |
| institution | DOAJ |
| issn | 2073-4352 |
| language | English |
| publishDate | 2025-05-01 |
| publisher | MDPI AG |
| record_format | Article |
| series | Crystals |
| spelling | doaj-art-5e4b5bab3b194d96a3baee2bacbc68702025-08-20T03:14:39ZengMDPI AGCrystals2073-43522025-05-0115547810.3390/cryst15050478Hydrogen Reduction of Tellurium Oxide in a Rotary Kiln, Initial Approaches for a Sustainable ProcessHanwen Chung0Semiramis Friedrich1Mengqi Qu2Bernd Friedrich3IME Process Metallurgy and Metal Recycling, RWTH Aachen University, 52072 Aachen, GermanyIME Process Metallurgy and Metal Recycling, RWTH Aachen University, 52072 Aachen, GermanyIME Process Metallurgy and Metal Recycling, RWTH Aachen University, 52072 Aachen, GermanyIME Process Metallurgy and Metal Recycling, RWTH Aachen University, 52072 Aachen, GermanyIn the recycling of semiconductor materials like Bi<sub>2</sub>Te<sub>3</sub> or CdTe, TeO<sub>2</sub> may form as a by-product that can be directly reduced to recover metallic Te. The hydrogen reduction of TeO<sub>2</sub> offers an eco-friendly alternative to conventional carbothermic reduction by avoiding CO by-products. This study investigates the reduction of 99.99 wt.% purity level TeO<sub>2</sub> using hydrogen in an oscillating kiln furnace (200–800 °C, 2–7 h), with phase composition and microstructure analysed via XRD and SEM. Results demonstrate conversions of up to 89% (solid–gas) and 100% (liquid–gas), revealing that kinetics dominate over thermodynamics in controlling reaction progress. The work proposes a reaction mechanism based on morphological evolution observed in SEM images, suggesting that further parameter optimisation could enhance scalability. As the first lab-scale demonstration of hydrogen-assisted TeO<sub>2</sub> reduction, this study establishes a preliminary process window (temperature/time) and underscores the potential for industrial adoption. Future work should verify the proposed mechanism and refine operational parameters to maximize efficiency.https://www.mdpi.com/2073-4352/15/5/478hydrogen reductiontelluriumtellurium dioxidesolid–gas reactionsemiconductorthermoelectric materials |
| spellingShingle | Hanwen Chung Semiramis Friedrich Mengqi Qu Bernd Friedrich Hydrogen Reduction of Tellurium Oxide in a Rotary Kiln, Initial Approaches for a Sustainable Process Crystals hydrogen reduction tellurium tellurium dioxide solid–gas reaction semiconductor thermoelectric materials |
| title | Hydrogen Reduction of Tellurium Oxide in a Rotary Kiln, Initial Approaches for a Sustainable Process |
| title_full | Hydrogen Reduction of Tellurium Oxide in a Rotary Kiln, Initial Approaches for a Sustainable Process |
| title_fullStr | Hydrogen Reduction of Tellurium Oxide in a Rotary Kiln, Initial Approaches for a Sustainable Process |
| title_full_unstemmed | Hydrogen Reduction of Tellurium Oxide in a Rotary Kiln, Initial Approaches for a Sustainable Process |
| title_short | Hydrogen Reduction of Tellurium Oxide in a Rotary Kiln, Initial Approaches for a Sustainable Process |
| title_sort | hydrogen reduction of tellurium oxide in a rotary kiln initial approaches for a sustainable process |
| topic | hydrogen reduction tellurium tellurium dioxide solid–gas reaction semiconductor thermoelectric materials |
| url | https://www.mdpi.com/2073-4352/15/5/478 |
| work_keys_str_mv | AT hanwenchung hydrogenreductionoftelluriumoxideinarotarykilninitialapproachesforasustainableprocess AT semiramisfriedrich hydrogenreductionoftelluriumoxideinarotarykilninitialapproachesforasustainableprocess AT mengqiqu hydrogenreductionoftelluriumoxideinarotarykilninitialapproachesforasustainableprocess AT berndfriedrich hydrogenreductionoftelluriumoxideinarotarykilninitialapproachesforasustainableprocess |