Phase transfer of Pyrophyllite to Riversideite, Sodic Zeolites and Hibschite Hydrogrossular under Alkaline Hydrothermal Conditions

Miri, Elaheh; Kananian, Ali; Badiei, Alireza

doi:10.52547/gnf.6.2.465

Volume 6, Issue 2 (Autumn&Winter 2021) KJES 2021, 6(2): 465-481 | Back to browse issues page

‎ 10.52547/gnf.6.2.465

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Miri E, Kananian A, Badiei A. Phase transfer of Pyrophyllite to Riversideite, Sodic Zeolites and Hibschite Hydrogrossular under Alkaline Hydrothermal Conditions. KJES 2021; 6 (2) :465-481
URL: http://gnf.khu.ac.ir/article-1-2732-en.html

Phase transfer of Pyrophyllite to Riversideite, Sodic Zeolites and Hibschite Hydrogrossular under Alkaline Hydrothermal Conditions

Elaheh Miri¹

, Ali Kananian ^*

², Alireza Badiei¹

1- University of Tehran
2- School of Geology, College of Science, University of Tehran , kananian@ut.ac.ir

Abstract: (1456 Views)

In this research, pyrophyllite phase transfer to tobermorite group and sodic to calcic zeolites was investigated in presence of NaOH and CaCl₂ solutions. The experiments were carried out in three separate stages under constant hydrothermal conditions (temperature 150 °C, time 72 h) in the Teflon-lined autoclaves. The chemical composition of the initial sample was determined by XRF. Morphology and mineralogy of samples were characterized by SEM and XRD, respectively. The results showed that leucite and sodic zeolites (analcime, sodalite) were formed at variable concentration of NaOH (1–8 mol/l). The calcic zeolite was not synthesized in the presence of Na⁺ (1.5–2.5 mol/l) and Ca⁺² (0.25-1 mol/l), but riversideite, hibschite, halite, hydroxycancrinite and trikalsilite were detected. Riversideite (a member of tobermorite group) and hibschite (a type of hydrogrossular) were formed at highest concentration of Ca⁺² (1 mol/l), and halite was produced as a main product at lowest concentration of Ca⁺² (0.25 mol/l). The concentration of Ca⁺² and Na/Ca ratio are the main factors in the synthesis of these products.

Keywords: Pyrophyllite, Phase transfer, Hydrothermal alteration, Sodic zeolites, Alkaline solution

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Subject: Petrology
Received: 2020/01/28 | Accepted: 2021/02/20 | Published: 2021/02/28