Synthesis of Lithium Metasilicate Powders at Low Temperature via Mechanical Milling

Abstract

The Li2SiO3 powder has been successfully synthesized at low temperature via mechanical milling process. By using LiOH·H2O and tetraethyl orthosilicate (TEOS) as raw materials, Li2SiO3 powder with grain size of about 100 nm could be obtained at room temperature (~20°C) after mechanical milling for 120 h. This nano Li2SiO3 powder shows excellent thermal stability that no decomposing reaction or phase change would happen even after calcined at 900°C for 4 h. Experiments show that high concentration of the raw materials is helpful to the forming of Li2SiO3 phase. When the concentration of the raw materials is too low, no Li2SiO3 phase could be obtained. The investigation also shows that small content of B2O3 could accelerate the densifying speed of Li2SiO3 ceramics and decrease the thermal stability of Li2SiO3 phase.

CO2 chemisorption in Li2CuO2 microstructurally modified by ball milling: study performed with different physicochemical CO2 capture conditions

“…As can be seen, the Li 2 CuO 2 structure was preserved in all the ball milled samples; however, the corresponding diffraction peaks became broader than those observed for the solid-state sample. Hence, these Li 2 CuO 2 microstructural variations are expected to induce important improvements in the CO 2 chemisorption process, as has been reported in previous papers for other lithium and sodium ceramics, [25][26][27][28][29][30][31]37 where the CO 2 chemisorption is importantly related to the particle size and surface area. The crystal size of the solid state sample was measured; however, it was larger than 500 A, which exceeds the detection limit.…”

“…[26][27][28][29][30][31] Based on these results, it is clearly evident that the microstructural changes have important inuence at low and moderate temperatures during the CO 2 capture process in Li 2 CuO 2 . On the other hand, at high temperatures, the CO 2 chemisorption observed on the ball milled sample was not as high as that on the Li 2 CuO 2 solid state sample.…”

“…These materials can be separated by their exhibited temperature CO 2 capture ranges as low (<100 C), moderate (100 to 400 C) or high (>400 C) temperature captors. [25][26][27][28][29][30][31] For example, lithium orthosilicate (Li 4 SiO 4 ) and metasilicate (Li 2 SiO 3 ) have been synthesized by ball milling 30 and hydrothermal 26 techniques, respectively. These materials present some of the previously mentioned ideal properties.…”

Thermal stability of lithium metasilicate produced under high pressure from lithium disilicate glass

“…Yang et al proposed an alternative route to produce LS m by mechanical milling during 120 hours of LiOH·H 2 O and tetraethyl orthosilicate as raw materials. They observed that the formation of the LS m phase depended on milling time and concentration of raw materials.…”

Hydrothermal synthesis and methylene blue adsorption performance of novel 3D hierarchical Li2Si2O5 hydrate particles

“…Some methods have been used to synthetize single-phase Li 2 Si 2 O 5 powders with desirable shape, but unfortunately, mixture products among bulk-like Li 2 SiO 3 , Li 2 Si 2 O 5 and SiO 2 , are often inevitably generated via solid-state reaction 17 , combustion approaches 18 and sol-gel method 19 . The residual Li 2 SiO 3 produced by these methods were too stubborn to transform into Li 2 Si 2 O 5 even using excessive molar ratios of Si/Li > 1 (stoichiometric ratio of Li 2 Si 2 O 5 = 1), due to Li 2 SiO 3 aggregates can be obtained easily at low temperature (~20 °C) and exhibit excellent thermal stability even after calcination at 900 °C 20 . Thus, the incomplete solid-phase reaction attributed to the dynamic deficiency of solid-state diffusion with a slow rate at later period, is the emphatic shortcoming for these routes.…”