The effect of the electrolyte concentration and pH on the rheological properties of the original and the Na2CO3-activated Kutahya bentonite

Yildiz N., Sarikaya Y., Calimli A.

APPLIED CLAY SCIENCE, cilt.14, sa.5-6, ss.319-327, 1999 (SCI-Expanded, Scopus) identifier identifier

  • Yayın Türü: Makale / Tam Makale
  • Cilt numarası: 14 Sayı: 5-6
  • Basım Tarihi: 1999
  • Doi Numarası: 10.1016/s0169-1317(99)00006-x
  • Dergi Adı: APPLIED CLAY SCIENCE
  • Derginin Tarandığı İndeksler: Science Citation Index Expanded (SCI-EXPANDED), Scopus
  • Sayfa Sayıları: ss.319-327
  • Anahtar Kelimeler: bentonite, montmorillonite, soda activation, rheology, thixotropy, viscosity, COLLOIDAL PROPERTIES, ORGANIC-COMPOUNDS, SODIUM MONTMORILLONITE, DISPERSIONS
  • Ankara Üniversitesi Adresli: Evet

Özet

The effect of the Na,CO, activation on the rheological properties of a bentonite from Kutahya (Turkey) was investigated. The bentonite was activated with Na2CO3 at different dosages (1-15 g Na2CO3/100 g bentonite). The activated samples were examined by chemical and X-ray diffraction analysis. The calcium bentonite was completely converted to sodium bentonite when the Na2CO3/bentonite ratio was 2.5%. The rheological values showed a maximum after addition of 2.5% Na2CO3 (bentonite concentrations 2-6% w/w). At 2.5 g Na2CO3/100 g bentonite, the shear stress was also measured at several NaCl and Na-hexametaphosphate concentrations. NaCl addition decreased the rheological properties up to NaCl concentrations of 0.005 mol l(-1). Further addition of NaCl increased the rheological properties again. The addition of Na-hexametaphosphate caused a decrease in the rheological properties to a constant value higher phosphate concentrations. The lowest yield stress was obtained around pH 7. (C) 1999 Elsevier Science B.V. All rights reserved.