Effects of Mineral Spatial Patterns on Magnesite Dissolution Rates
This data set archives several years’ data of flow-through column experiments exploring the largely unknown effects of mineral spatial distribution on dissolution rates using columns packed with the same magnesite mass but with different distributions within a quartz matrix. Variables include the spatial distribution of the reactive mineral magnesite, orientation of the magnesite zone to the main flow direction, length scale, flow rates, and size contrast between magnesite and quartz grains. The columns with lengths varying from 5 to 22 cm were flushed with acidic solutions (pH 4.0) at flow velocities varying from 0.015 to 7.2 m/d. The largest rate difference was observed between a “Mixed” column containing uniformly distributed magnesite and a “One-zone” column containing magnesite in one cylindrical zone in the center of the column (“flow-parallel One-zone” column). Breakthrough data show that the zonation in the One-zone columns, especially when the grain sizes of magnesite are smaller than that of the quartz, limits magnesite dissolution by a factor of 1.5 – 4.0 compared to the Mixed column. The magnitude of the rate difference increases with increasing flow rates. Under low flow rate conditions, the pore fluids reach chemical equilibrium and reaction kinetics does not play an important role. For those conditions, the mineral distribution does not make a difference. Under high flow conditions, however, the effects of the mineral distribution are maximized because column-scale rates exhibit kinetic control due to low residence times. The rate differences between the Mixed and the flow-parallel One-zone cases are much larger than the 14% maximum difference observed between the Mixed column and the “flow-perpendicular One-zone” column. Thedata set identifies general principles that govern mineral dissolution rates in heterogeneous porous media. It will advance our models of the multi-component geochemical reactions in natural, heterogeneous porous media and will provide valuable insights on the laboratory-field rate discrepancy.
How to cite this dataset:
Salehikhoo, F., Li, ., Brantley, S., 2015. Effects of Mineral Spatial Patterns on Magnesite Dissolution Rates, Version 1.0. Interdisciplinary Earth Data Alliance (IEDA). https://doi.org/10.1594/IEDA/100494.
DOI Creation Date:
Salehikhoo, F.; Li, L.; Brantley, S. L., (2013), “Magnesite dissolution rates at different spatial scales: The role of mineral spatial distribution and flow velocity.” Geochimica Et Cosmochimica Acta, 108: 91−106. Li, L., Salehikhoo, F., Brantley, S.L., Heidari, P., (2014), “Spatial zonation limits magnesite dissolution in porous media.” Geochimica et Cosmochimica Acta, 126: 555-573. Salehikhoo, F.; Li, L., (2015), “The role of spatial pattern in dictating magnesite dissolution: when does it matter?“ Geochimica et Cosmochimica Acta, 155: 107-121. Salehikhoo, F., (2014), "The role of spatial patterns in dictating magnesite dissolution: when does it matter?", PhD Dissertation, The Pennsylvania State University.
Creative Commons Attribution-NonCommercial-Share Alike 3.0 United States [CC-BY-NC-SA-3.0]
Coverage Scope: Other
User Contributed Keyword(s):
magnesite, spatial distribution, dissolution, reaction rate, column experiment
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