Structural Features and Thermal Behavior of Ion-Exchanged Clinoptilolite from Beli Plast Deposit (Bulgaria)
The structural features and the thermal behavior of natural, Na-, Ca-, K-, Mg-, and Cd-exchanged clinoptilolite from the Beli Plast deposit (Bulgaria) were studied. Purified clinoptilolite sample was preliminary prepared and ion-exchanged at 100 °C for six days. DSC-TG analyses were performed for al...
| Main Authors: | , , , , |
|---|---|
| Format: | Article |
| Language: | English |
| Published: |
MDPI AG
2022-12-01
|
| Series: | Minerals |
| Subjects: | |
| Online Access: | https://www.mdpi.com/2075-163X/12/12/1576 |
| _version_ | 1797456126838571008 |
|---|---|
| author | Louiza Dimowa Nadia Petrova Yana Tzvetanova Ognyan Petrov Iskra Piroeva |
| author_facet | Louiza Dimowa Nadia Petrova Yana Tzvetanova Ognyan Petrov Iskra Piroeva |
| author_sort | Louiza Dimowa |
| collection | DOAJ |
| description | The structural features and the thermal behavior of natural, Na-, Ca-, K-, Mg-, and Cd-exchanged clinoptilolite from the Beli Plast deposit (Bulgaria) were studied. Purified clinoptilolite sample was preliminary prepared and ion-exchanged at 100 °C for six days. DSC-TG analyses were performed for all studied forms. The effects in the DSC curves show differences with temperature due to release of weakly bound H<sub>2</sub>O molecules and strongly bound ones. The endotherm minima temperatures were between 78 and 115 °C decreasing in the sequence K- < Na- < Natural- < Ca- ≤ Mg- < Cd-clinoptilolite. The hydrate complexes around the exchanged cations also influenced the DSC curves. The cation-coordinating H<sub>2</sub>O molecules and the non-coordinating ones were determined by XRD structural refinement for all exchanged samples. The H<sub>2</sub>O molecules of the cation–hydrate complexes are released at higher temperatures than weakly bound ones and affected the DSC curves differently. The structural adjustments made by the Rietveld method, as well as the applied EDS analyzes for the chemical composition of the samples, allowed us to correlate these data to the thermal characteristics of the studied clinoptilolite samples. |
| first_indexed | 2024-03-09T16:03:54Z |
| format | Article |
| id | doaj.art-14d4b28badaf47caa0204c17cf65c848 |
| institution | Directory Open Access Journal |
| issn | 2075-163X |
| language | English |
| last_indexed | 2024-03-09T16:03:54Z |
| publishDate | 2022-12-01 |
| publisher | MDPI AG |
| record_format | Article |
| series | Minerals |
| spelling | doaj.art-14d4b28badaf47caa0204c17cf65c8482023-11-24T16:52:08ZengMDPI AGMinerals2075-163X2022-12-011212157610.3390/min12121576Structural Features and Thermal Behavior of Ion-Exchanged Clinoptilolite from Beli Plast Deposit (Bulgaria)Louiza Dimowa0Nadia Petrova1Yana Tzvetanova2Ognyan Petrov3Iskra Piroeva4Institute of Mineralogy and Crystallography, Bulgarian Academy of Sciences, Acad. Georgi Bonchev Str., Bl. 107, 1113 Sofia, BulgariaInstitute of Mineralogy and Crystallography, Bulgarian Academy of Sciences, Acad. Georgi Bonchev Str., Bl. 107, 1113 Sofia, BulgariaInstitute of Mineralogy and Crystallography, Bulgarian Academy of Sciences, Acad. Georgi Bonchev Str., Bl. 107, 1113 Sofia, BulgariaInstitute of Mineralogy and Crystallography, Bulgarian Academy of Sciences, Acad. Georgi Bonchev Str., Bl. 107, 1113 Sofia, BulgariaInstitute of Physical Chemistry, Bulgarian Academy of Sciences, Acad. Georgi Bonchev Str., Bl. 11, 1113 Sofia, BulgariaThe structural features and the thermal behavior of natural, Na-, Ca-, K-, Mg-, and Cd-exchanged clinoptilolite from the Beli Plast deposit (Bulgaria) were studied. Purified clinoptilolite sample was preliminary prepared and ion-exchanged at 100 °C for six days. DSC-TG analyses were performed for all studied forms. The effects in the DSC curves show differences with temperature due to release of weakly bound H<sub>2</sub>O molecules and strongly bound ones. The endotherm minima temperatures were between 78 and 115 °C decreasing in the sequence K- < Na- < Natural- < Ca- ≤ Mg- < Cd-clinoptilolite. The hydrate complexes around the exchanged cations also influenced the DSC curves. The cation-coordinating H<sub>2</sub>O molecules and the non-coordinating ones were determined by XRD structural refinement for all exchanged samples. The H<sub>2</sub>O molecules of the cation–hydrate complexes are released at higher temperatures than weakly bound ones and affected the DSC curves differently. The structural adjustments made by the Rietveld method, as well as the applied EDS analyzes for the chemical composition of the samples, allowed us to correlate these data to the thermal characteristics of the studied clinoptilolite samples.https://www.mdpi.com/2075-163X/12/12/1576clinoptiloliteion exchangeRietveld refinementDSC-TG(DTG) |
| spellingShingle | Louiza Dimowa Nadia Petrova Yana Tzvetanova Ognyan Petrov Iskra Piroeva Structural Features and Thermal Behavior of Ion-Exchanged Clinoptilolite from Beli Plast Deposit (Bulgaria) Minerals clinoptilolite ion exchange Rietveld refinement DSC-TG(DTG) |
| title | Structural Features and Thermal Behavior of Ion-Exchanged Clinoptilolite from Beli Plast Deposit (Bulgaria) |
| title_full | Structural Features and Thermal Behavior of Ion-Exchanged Clinoptilolite from Beli Plast Deposit (Bulgaria) |
| title_fullStr | Structural Features and Thermal Behavior of Ion-Exchanged Clinoptilolite from Beli Plast Deposit (Bulgaria) |
| title_full_unstemmed | Structural Features and Thermal Behavior of Ion-Exchanged Clinoptilolite from Beli Plast Deposit (Bulgaria) |
| title_short | Structural Features and Thermal Behavior of Ion-Exchanged Clinoptilolite from Beli Plast Deposit (Bulgaria) |
| title_sort | structural features and thermal behavior of ion exchanged clinoptilolite from beli plast deposit bulgaria |
| topic | clinoptilolite ion exchange Rietveld refinement DSC-TG(DTG) |
| url | https://www.mdpi.com/2075-163X/12/12/1576 |
| work_keys_str_mv | AT louizadimowa structuralfeaturesandthermalbehaviorofionexchangedclinoptilolitefrombeliplastdepositbulgaria AT nadiapetrova structuralfeaturesandthermalbehaviorofionexchangedclinoptilolitefrombeliplastdepositbulgaria AT yanatzvetanova structuralfeaturesandthermalbehaviorofionexchangedclinoptilolitefrombeliplastdepositbulgaria AT ognyanpetrov structuralfeaturesandthermalbehaviorofionexchangedclinoptilolitefrombeliplastdepositbulgaria AT iskrapiroeva structuralfeaturesandthermalbehaviorofionexchangedclinoptilolitefrombeliplastdepositbulgaria |