HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH TABLE OF CONTENTS		QUICK SEARCH:   [advanced] Author: Keyword(s): Year:  Vol:  Page:

This Article Full Text (PDF) Alert me when this article is cited Alert me if a correction is posted Services Similar articles in this journal Alert me to new issues of the journal Download to citation manager Citing Articles Citing Articles via Google Scholar Google Scholar Articles by Barrows, H. L. Search for Related Content PubMed Articles by Barrows, H. L. Agricola Articles by Barrows, H. L.

Effect of Surface Coatings on the Dissolution Rate of Limestone Particles¹

ABSTRACT

High-purity, 12- to 14-mesh calcitic limestone was mixed into acid soils containing relatively large amounts of either P, Al, or Mn. These mixtures were equilibrated for 12 months, undergoing wetting and partial drying cycles. Samples of each mixture were withdrawn periodically and the limestone particles were recovered, examined, and their rates of solution determined. The surface of the particles equilibrated in the high-P soil developed a porous, white granular coating that was associated with a 31% reduction in the dissolution rate.

Limestone and calcite crystals were treated in the laboratory with solutions containing Fe, Al, and P. Particles treated with phosphate solutions developed visible coatings, and their average dissolution rates were reduced by 27%.

It was concluded that limestone particles react with phosphates in the soil solution, resulting in the formation of a coating on the surface of the particle. This coating reduces the efficiency of the limestone by reducing the rate of dissolution of the particles.

¹ Contribution from the US Soils Laboratory, Soil and Water Conservation Research Division, ARS, USDA, Beltsville, Maryland 20705.

² Research Soil Scientist.

Received for publication March 11, 1966. Accepted for publication April 30, 1966.