umu.sePublications
Change search
CiteExportLink to record
Permanent link

Direct link
Cite
Citation style
  • apa
  • ieee
  • modern-language-association-8th-edition
  • vancouver
  • Other style
More styles
Language
  • de-DE
  • en-GB
  • en-US
  • fi-FI
  • nn-NO
  • nn-NB
  • sv-SE
  • Other locale
More languages
Output format
  • html
  • text
  • asciidoc
  • rtf
Effects of the injection grout Silica sol on bentonite
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
Elsevier, 2011. Vol. 36, no 17–18, 1580-1589 p.
Keyword [en]
Bentonite, Bentonite colloids, Silica sol, Silica colloids, Colloidal stability, Colloid interactions
National Category
Chemical Sciences
Identifiers
URN: urn:nbn:se:umu:diva-129232DOI: 10.1016/j.pce.2011.07.026OAI: oai:DiVA.org:umu-129232DiVA: diva2:1058559
Available from: 2016-12-21 Created: 2016-12-21 Last updated: 2016-12-21

Open Access in DiVA

No full text

Other links

Publisher's full texthttp://www.sciencedirect.com/science/article/pii/S1474706511001422

Search in DiVA

By author/editor
Holmboe, Michael
In the same journal
Physics and Chemistry of the Earth
Chemical Sciences

Search outside of DiVA

GoogleGoogle Scholar

Altmetric score

Total: 6 hits
CiteExportLink to record
Permanent link

Direct link
Cite
Citation style
  • apa
  • ieee
  • modern-language-association-8th-edition
  • vancouver
  • Other style
More styles
Language
  • de-DE
  • en-GB
  • en-US
  • fi-FI
  • nn-NO
  • nn-NB
  • sv-SE
  • Other locale
More languages
Output format
  • html
  • text
  • asciidoc
  • rtf