Abstract:
The short term stability of mica, feldspar and apatite in different geochemical
conditions were tested in the laboratory. Different proportions of powdered minerals (<125 pm)
were mixed with organic matter with water, water and 2% citric acid. The mixtures were kept
under room conditions, using controlled moisture content. The water soluble ionic concentrations of each mixture were measured and their variations with the time were studied.
The study revealed that the dissolution of minerals is controlled by mineralogical characteristics
of them and the chemical nature of solutions. Both mica and feldspar release higher amounts of
potassium compared to other ions when they are in water or in moist organic matter. Feldspar is
stable whereas mica and apatite are significantly unstable in the citric acid. However, mica
released considerably higher amount of iron in the acidic media (pH-2-3). The dissolution of
apatite and K-feldspar is low when mineral mixtures contain biotite. Biotite mica and apatite
have high potential to use as fertilizers for crops growing in acidic soils.
Citation:
Amaraweera, T.H.N.G., Pitawala, H.M.T.G.A., & Fernando, G.W.A.R. (2007). Stability of mica, k-feldspar and apatite in water, organic matters and citric acid. In S. Karunaratne (Ed.), Proceedings of the 2nd Annual Conference on Minerals for a Better Future – A Multidisciplinary Approach (pp. 25-28). Department of Earth Resources Engineering, University of Moratuwa.
