Unraveling the Effects of Strontium Incorporation on Barite Growth—In Situ and Ex Situ Observations Using Multiscale Chemical Imaging

• DOI: 10.1021/acs.cgd.8b00839
• Publication Date: 2018-07-26T07:45:48Z
• Authors: Juliane Weber; Jacquelyn N. Bracco; Jonathan D. Popla...; Anton V. Ievlev; Karren L. More; Matthias Lorenz; Angela L. Bertagni; Sarah A. Jindra; Vitaliy Starchenko; Steven R. Higgins; Andrew G. Stack
• Keywords: Hillock; Barium

Impurity ions influence mineral growth rates through a variety of kinetic and thermodynamic processes that also affect partitioning the impurity ion between solid solution. Here, effect an ion, strontium, on Barite (BaSO4) (001) was studied using combination high-resolution in situ microscopy with ex chemical imaging techniques. In presence ⟨120⟩ steps roughened bifurcated. The overall rate decreased increasing aqueous strontium-to-barium ratio ([Sr]/[Ba]aq) < 1. Analysis reacted solids techniques indicated strontium incorporated uniformly across all step orientations into hillock for [Sr]/[Ba]aq However, at > 5, apparent [010] orientation were expressed direction led to increase surface. Strontium became preferentially direction, rather than being homogeneously distributed. [Sr]/[Ba]s newly grown found correlate directly solutions but not higher [Sr]/[Ba]aq. Solid composition analyses indicate equilibrium achieved. transport modeling successfully reproduces shift mechanism.