A comparative study of the dissolution mechanisms of amorphous and crystalline feldspars at acidic pH conditions

Abstract The dissolution of amorphous and crystalline oligoclase, a Na-feldspar with traces Ca K, was investigated at 90 °C acidic pH 1.5 3 to unravel the impact long- short-range orders on silicate mechanisms. Experiments were conducted in solutions spiked 29 SiO 2 (aq) saturated respect (am). Through morphology, structural, composition characterizations, we showed that samples (glass samples), altered layer mostly formed by leaching, while combination both interfacial precipitation leaching explains layers sample. As expected, thicker most it became passivating sample 3. alteration faster oligoclase than its equivalent due more open structure glass. preferential release Al suggested play key role, weakening network substrates. Finally, this study, large overestimation global materials noticed based solution analyses. Discrepancies solid analyses attributed an underestimation (≥2-fold factor) total reactive surface area.