Change search
ReferencesLink to record
Permanent link

Direct link
Effects of the injection grout Silica sol on Bentonite
KTH, School of Chemical Science and Engineering (CHE), Chemistry, Nuclear Chemistry.
KTH, School of Chemical Science and Engineering (CHE), Chemistry, Nuclear Chemistry.
KTH, School of Chemical Science and Engineering (CHE), Fibre and Polymer Technology, Fibre Technology.ORCID iD: 0000-0002-5444-7276
2011 (English)In: Physics and Chemistry of the Earth, ISSN 1474-7065, E-ISSN 1873-5193, Vol. 36, no 17/18, 1580-1589 p.Article in journal (Refereed) Published
Abstract [en]

Silica sol, i.e., colloidal SiO2, may be used as a low-pH injection grout for very fine fractures in the construction of deep geological repositories for radioactive waste in Sweden and in Finland. If the bentonite barrier encounters SiO2-colloid particles under conditions favorable for aggregation, there is concern that it will modify the bentonite barrier at the bentonite/bedrock interface. In this study qualitative experiments were performed with mixed dispersions of SiO2-colloids and bentonite or homo-ionic Na/Ca-montmorillonite. Samples were prepared at different colloid concentrations and treated under various conditions such as low and high ionic strength (0.3 M NaCl), as well as dehydration and redispersing. Free swelling and settling experiments were performed in order to qualitatively compare the conditions in which SiO2-colloids affect the bulk/macro properties of bentonite. In order to study specific SiO2-colloid/montmorillonite interactions and preferred type of initial aggregation, dilute dispersions of homo-ionic montmorillonite dispersions mixed with varying concentrations of SiO2-colloids were prepared and selected samples were characterized by PCS, SEM/EDS, AFM and PXRD. The results from this study show that bentonite and montmorillonite particles can be modified by SiO2-colloids when mixed in comparable amounts, due to dehydration or high ionic strength. Some indications for increased colloidal stability for the SiO2-colloid modified clay particles were also found. From the AFM investigation it was found that initial attachment of the SiO2-colloids in Na+ dominated samples seemed to occur on the edges of the montmorillonite layers. In Ca2+ dominated samples not subjected to excess NaCl, SiO2-colloid sorption onto the faces of the montmorillonite layers was also found. In all, contact between the bentonite barrier and ungelled Silica sol should preferably be avoided.

Place, publisher, year, edition, pages
2011. Vol. 36, no 17/18, 1580-1589 p.
Keyword [en]
Bentonite, Bentonite colloids, Silica sol, Silica colloids, Colloidal stability, Colloid interactions
National Category
Physical Chemistry
Identifiers
URN: urn:nbn:se:kth:diva-34046DOI: 10.1016/j.pce.2011.07.026ISI: 000299195200016ScopusID: 2-s2.0-82955187651OAI: oai:DiVA.org:kth-34046DiVA: diva2:418868
Note
Updated from in press to published. QC 20120214Available from: 2011-06-08 Created: 2011-05-24 Last updated: 2012-04-02Bibliographically approved
In thesis
1. The Bentonite Barrier: Microstructural properties and the influence of γ-radiation
Open this publication in new window or tab >>The Bentonite Barrier: Microstructural properties and the influence of γ-radiation
2011 (English)Doctoral thesis, comprehensive summary (Other academic)
Place, publisher, year, edition, pages
Stockholm: KTH Royal Institute of Technology, 2011. iv, 81 p.
Series
Trita-CHE-Report, ISSN 1654-1081 ; 2011:38
National Category
Inorganic Chemistry
Identifiers
urn:nbn:se:kth:diva-34048 (URN)978-91-7501-001-4 (ISBN)
Public defence
2011-06-15, F2, entréplan, Lindstedtsvägen 28, KTH, Stockholm, 10:00 (English)
Opponent
Supervisors
Note
QC 20110608Available from: 2011-06-08 Created: 2011-05-24 Last updated: 2011-08-10Bibliographically approved

Open Access in DiVA

Article 6(991 kB)686 downloads
File information
File name FULLTEXT01.pdfFile size 991 kBChecksum SHA-512
f4d322777a0e88e192724d92873adc9316f391ecc23e6a4bcb7250489fe971d82d7ef4490187fdae30091e64e2115e8d83a69a369ac44b123464f0439febed7c
Type fulltextMimetype application/pdf

Other links

Publisher's full textScopus

Search in DiVA

By author/editor
Holmboe, MichaelWold, SusannaPetterson, Torbjörn
By organisation
Nuclear ChemistryFibre Technology
In the same journal
Physics and Chemistry of the Earth
Physical Chemistry

Search outside of DiVA

GoogleGoogle Scholar
Total: 686 downloads
The number of downloads is the sum of all downloads of full texts. It may include eg previous versions that are now no longer available

Altmetric score

Total: 123 hits
ReferencesLink to record
Permanent link

Direct link