ToF‐SIMS as a tool for mapping reaction products of coupled dissolution–precipitation processes at mineral grain surfaces

Abstract

In this paper, time-of-flight secondary ion mass spectrometry (ToF-SIMS) was investigated as a tool for analyzing changes on mineral grains (siderite and ankerite) caused by dissolution and precipitation processes. Carbon dioxide capture and sequestration is a technique investigated for its possible employment in the reduction of the amount of anthropogenic CO 2 gas emitted into the atmosphere. Deep saline aquifers are one option for storing CO 2 gas streams produced, e.g. by the combustion of fossil fuels at power plants. These gas streams contain different impurities depending on their origin, among them O 2 , NO x , SO x in addition to CO 2 . Geochemical experiments under in-situ pressure and temperature conditions of possible geological storage sites were performed, and preparation techniques for the solid products were developed for 3D analysis. The results show that it is possible to analyze the alterations that occur on the surface of siderite grains during CO 2 or CO 2 /O 2 exposures under CO 2 storage site conditions.

Characterization and identification of minerals in rocks by ToF-SIMS and principal component analysis

“…All of these elements, with the exception of Si and Al, belong to the cations in the mineral crystals. Thus, the 1 location of the spectra in the scores plot is mainly based on the mineral cation composition.…”

“…Sometimes the addition of isotope-labeled CO 2 or other chemicals allows a quantification of the reaction progress (e.g. mineral dissolution) [1,2]. To understand mineral precipitation reactions, the additionally precipitated or altered mineral phases are analyzed.…”