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Interactions of Monomeric Silicic Acid with Copper and Zinc and Chemical Changes of the Precipitates with Aging

Leggett, G.E. (1978) Interactions of Monomeric Silicic Acid with Copper and Zinc and Chemical Changes of the Precipitates with Aging. Soil Science Society of America Journal. 42(2):262-268.

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Abstract

Precipitates were formed by titrating dilute, acidic solutions of
monomeric silicic acid [Si(OH)?] and copper (Cu) or zinc (Zn) to
various pH values. Those containing Cu formed above pH 6.0; those
containing Zn formed above pH 7.0. Periodically, during 2 years of
aging in their mother liquor, the liquid phase was sampled and
analyzed and the Cu/Si or Zn/Si molar ratios of the precipitates
calculated. The Cu/Si ratios of those containing Cu stabilized readily
near 0.78 and were unaffected by pH. The Zn/Si ratios of the Zn-containing
precipitates, however, changed as a result of Si enrichment
from near 1.80 soon after their formation to near 0.80 after aging 2
years. The systems with the lowest pH changed first and most rapidly
and became stabilized within 6 months; those above pH 8.0 changed
more slowly.

The Zn-containing precipitates gave diffuse X-ray diffraction
patterns indicative of a 2:1 layer silicate, whereas those containing Cu
were amorphous.

Item Type: Article
NWISRL Publication Number: 0373
Subjects: Mass Import - unclassified
Depositing User: Dan Stieneke
Date Deposited: 20 Nov 2010 21:51
Last Modified: 09 Feb 2017 18:20
Item ID: 318
URI: https://eprints.nwisrl.ars.usda.gov/id/eprint/318