Silicates

Abstract

The article contains sections titled: 1. Structural Chemistry of Silicates 1.1. Structural Classification 1.2. Oligo‐ and Cyclosilicates 1.3. Polysilicates 1.4. Phyllosilicates 1.4.1. Monophyllosilicates 1.4.2. Diphyllosilicates 1.4.3. Alkali Silicates 1.4.4. Crystalline Silicic Acids 1.4.5. Clay Minerals 1.4.6. Intracrystalline Reactions 1.5. Tectosilicates 2. Natural Silicates 2.1. Feldspar 2.1.1. Structure and Composition 2.1.2. Characterization of Individual Feldspars 2.1.3. Production 2.1.4. Properties 2.1.5. Mineral Deposits and their Extraction 2.1.6. Processing and Quality Requirements 2.1.7. Uses and Economic Aspects 2.2. Nepheline and Related Compounds 2.3. Leucite 2.4. Olivine 2.5. Andalusite 2.6. Kyanite 2.7. Sillimanite 2.8. Mullite 2.9. Vermiculite 2.10. Perlite 2.11. Pumice 2.12. Basalt 2.13. Wollastonite 2.14. Toxicology 3. Alkali Silicates 3.1. Introduction 3.2. Raw Materials 3.3. Amorphous Anhydrous Alkali Silicates (Solid or Lump Glasses) 3.4. Silicate Solutions 3.5. Hydrated Water‐Soluble Silicates 3.6. Crystalline Solids 3.7. Uses and Applications 3.8. Economic Aspects 3.9. Storage, Safety, Labelling and Transportation 3.10. Analysis

Portland Versus Alkaline Cement: Continuity or Clean Break: “A Key Decision for Global Sustainability”

“…Sodium silicate owes its large carbon footprint to how it is generally synthesised: fusing siliceous sand with anhydrous sodium carbonate (Na 2 CO 3 ) at temperatures of >1.000°C (although also by directly attacking silica with caustic soda) ( Lagaly et al, 2000 ). The result is a hard material that can be commercialized as a granular solid or an aqueous liquid.…”

Structure and Sodium Ion Dynamics in Sodium Strontium Silicate Investigated by Multinuclear Solid-State NMR

“…It is well-known that glasses can crystallize when heated above their glass transition temperature T g at a speed which depends upon the viscosity of this supercooled liquid. For Na 2 O·2SiO 2 ( T g = 450 °C), previous in situ high-temperature NMR experiments have shown that the supercooled liquid is stable over the course of an NMR experiment up to approximately 700 °C. , Both studies have evidenced exchange between the Q n species ( n = 2, 3, and 4) in the supercooled liquid by 29 Si NMR while Liu et al additionally showed a 23 Na T 1 minimum around 530 °C and an associated activation energy of 67 ± 5 kJ mol –1 , close to measured values for tracer diffusion or electrical conductivity in melts (55 to 75 kJ mol –1 ). − The recent in situ 23 Na NMR investigation by Evans et al performed on the mixed Sr 0.60 Na 0.40 SiO 2.80 composition up to 350 °C yields an activation energy (23 kJ mol –1 ) close to the 31 kJ mol –1 value obtained by impedance spectroscopy .…”

In situ Resource Utilization and Reconfiguration of Soils Into Construction Materials for the Additive Manufacturing of Buildings

“…Almost 95% of the Earth's crust is composed of quartz and rock-forming silicates (Lagaly et al, 2000;Ito and Wagai, 2017). Abundant minerals in the Earth's crust include plagioclase feldspar (39%), alkali feldspar (12%), quartz (12%), pyroxenes (11%), non-silicates (8%), amphiboles (5%), micas (5%), clays (5%), and other silicates (3%) (Hart, 1969).…”

“…Burlewash soil harvested here is fairly typical of soils in terms of clay content and the presence of minerals such as feldspar, quartz, and halloysite. Silica and soda ash are the raw materials needed for producing sodium silicate (Lagaly et al, 2000) which enables formation of the siloxane framework of pivotal importance to holding together the composite. The United States alone produced 12M tons of soda ash in 2018 (Bernhardt and Reilly, 2019).…”