THE DISSOLUTION OF KAOLINITE

The dissolution of a natural kaolinite in water systems at 25 degree C having a pH between 3.2 and 4.0 was monitored for 2 years by periodically measuring pH and aluminum and silica concentrations. On the basis of a wet chemical analysis and X-ray diffraction patterms of the kaolinite and on the rate of solution of aluminum and silica, the following conclusions were drawn for the dissolution of the natural kaolinite used in these experiments in water: (1) Silica dissolves from the kaolinite and some form of a silica solid, SiO2(c). (2) The rate of solution of kaolinite is indicated by the rate of solution of aluminum. Therefore, the leveling off of aluminum concentration in these systems represents an approach to equilibrium with respect to kaolinite. (3) Assuming the above hypotheses to be correct, we calculated the free energy of formation of kaolinite to be -903 keal/mole. When based on the same free energy of formation of quartz, this value agrees will with that obtained by Barany and Kelley using the calorimetric technique. /AUTHOR/

• Corporate Authors:

  American Geophysical Union

  2100 Pennsylvania Avenue, NW
  Washington, DC  United States  20037
• Authors:
  • Polzer, W L
  • Hem, J D
• Publication Date: 1965-12

Media Info

• Features: Figures; References; Tables;
• Pagination: p. 6233-40
• Serial:
  • Journal of Geophysical Research
  • Volume: 70
  • Issue Number: 24
  • Publisher: American Geophysical Union

Subject/Index Terms

• TRT Terms: Aluminum; Calculation; Calorimeters; Chemical analysis; Dissolution; Free energy; Kaolinite; pH value; Quartz; Silica; Water; X ray analysis
• Uncontrolled Terms: Computation
• Subject Areas: Geotechnology; Highways;

Filing Info

• Accession Number: 00263474
• Record Type: Publication
• Files: TRIS
• Created Date: Dec 13 1974 12:00AM