About Us | Help Videos | Contact Us | Subscriptions



This article in SSSAJ

  1. Vol. 21 No. 2, p. 154-157
    Received: July 27, 1956
    Accepted: Oct 3, 1956

Request Permissions


Reactions between Phosphates and Kaolinite Decomposition Products1

  1. Alfred T. Perkins,
  2. R. Dean Dragsdorf and
  3. Mahendra S. Bhangoo2



Kaolinite mixed with mono, di, or tribasic calcium phosphate or calcium carbonate was ball-milled in porcelain jars for periods of time up to 170 days. Changes in chemical reactions such as capacity to fix phosphates and the solubility of aluminum, calcium and magnesium were determined. pH values were recorded and identification of products produced by grinding was undertaken by use of X-ray and electron microscope techniques.

Correlations were found between phosphate fixation and increasing pH value, and phosphate fixation and solubility of aluminum. The addition of large amounts of the phosphate increased the rate of clay decomposition when the pH value was over 6.6. Tribasic phosphate caused a more rapid decomposition of the clay than did calcium carbonate when the pH values were in the same range. The fixation of phosphate by kaolinite is correlated with time of reaction, pH, amount of phosphate added and the amount of soluble Al2O3 (R2O3).

  Please view the pdf by using the Full Text (PDF) link under 'View' to the left.

Copyright © . Soil Science Society of America