Reactions of kaolinites and metakaolinites with NaOH—comparison of different samples (Part 1)
Source abstract
Abstract
Abstract Reactions with aqueous sodium hydroxide of eight different kaolinites and of metakaolinites derived from them were studied under hydrothermal conditions. All the kaolinites gave basic hydrosodalite 8:2:2 (8Na+/2OH−/2H2O) as the primary product. The metakaolinites reacted to produce mainly zeolite A, in some of the samples associated with minor amounts of zeolite X. After 5 days, all the metakaolinites were converted to hydrosodalite. The kinetics of the reactions of the samples differed, but no correlation could be established between the rates of the reactions and the crystallinity of the kaolinites, the impurities present or any other observed feature of the starting material.
Source: openaire · Quality: candidate unverified · Source record ↗
Research context
OpenAlex topics: Clay minerals and soil interactions · Mineralogy and Gemology Studies · Analytical chemistry methods development
SciVX discovery tags are terminology-based. OpenAlex topics are source-provided classifications.
References (20)
Show source-provided references
1. Mineralogical interference on kaolinite crystallinity index measurements10.1346/CCMN.1999.0470102 ↗
2. Barrer · 1982
3. 29Si and 27Al MAS NMR study of the zeolitization of kaolin by alkali leaching10.1180/0009855033810078 ↗
4. Breck · 1974
5. The crystallization kinetics of sodalites grown by the hydrothermal transformation of kaolinite studied by 29Si MAS NMR10.1016/S0926-2040(97)00052-0 ↗
6. Influence of metakaolinization temperature on the formation of zeolite 4A from kaolin10.1180/claymin.1996.031.2.11 ↗
7. Synthesis of 4A zeolite from calcined kaolins for use in detergents10.1021/ie00079a033 ↗
8. Infrared evidence for the formation of an intermediate compound during the synthesis of zeolite Na–A from metakaolin Intern10.1016/S1466-6049(99)00020-3 ↗
9. The hydrosodalite system Na6+x[SiAlO4]6(OH)x·nH2O10.1021/ja00030a008 ↗
10. Flanigen, E.M., Khatami, H., Szymanski, H.A., 1971. Molecular Sieve Zeolites: 1. Adv. Chem. Ser. vol. 101. Am. Chem. Soc., Washington DC. pp 201–229.
11. Influence of the starting material on alkali-activated materials based on metakaolin. Study of the reaction parameters by isothermal conduction calorimetry10.1023/A:1026790924882 ↗
12. Kinetics of formation of zeolite Na–A [LTA] from natural kaolinites10.1007/s002690050032 ↗
13. Variability in “crystallinity” values among the kaolin deposits of the coastal plain of Georgia and South Carolina10.1346/CCMN.1962.0110122 ↗
14. 29Si and 27Al NMR study of zeolite formation from alkali-leached kaolinites. Influence of thermal preactivation10.1021/j100365a046 ↗
15. Synthesis of zeolites from thermally activated kaolinite. Some observations on nucleation and growth10.1180/claymin.1992.027.1.12 ↗
16. Formation of zeolite from the system Na2O–Al2O3– SiO2–H2O in alkaline medium (pH>10)10.1016/0144-2449(93)90229-V ↗
17. Solid-state NMR studies of the structure and reactivity of metakaolinite10.1002/anie.199005531 ↗
18. Synthesis of zeolite Na–A from metakaolinite revisited10.1039/ft9918703091 ↗
19. Synthesis of molecular sieves from Chilean kaolinites: 1. Synthesis of NaA type zeolite10.1002/(SICI)1097-4660(199904)74:4<358::AID-JCTB40>3.0.CO;2-E ↗
20. Quantitative analysis of anatase in Georgia kaolins using Raman spectroscopy10.1016/S0169-1317(03)00129-7 ↗