The present invention relates to solvothermal vapor synthesis methods for the crystallization of a phase from a mixture of selected inorganic or organic precursors in an unsaturated vapor-phase reaction medium.

Provided is a method of preparing a metal oxide-silica composite aerogel and a metal oxide-silica composite aerogel having an excellent weight reduction property prepared by the method. The method comprises adding an acid catalyst to a first water glass solution to prepare an acidic water glass solution (step 1); adding a metal ion solution to the acidic water glass solution to prepare a precursor solution (step 2); and adding a second water glass solution to the precursor solution and performing a gelation reaction (step 3).

Provided is a method of preparing a metal oxide-silica composite aerogel and a metal oxide-silica composite aerogel having an excellent weight reduction property prepared by the method. The method comprises adding an acid catalyst to a first water glass solution to prepare an acidic water glass solution (step 1); adding a metal ion solution to the acidic water glass solution to prepare a precursor solution (step 2); and adding a second water glass solution to the precursor solution and performing a gelation reaction (step 3).

The present invention relates to inorganic fibres having a composition comprising: 65.7 to 70.8 wt % SiO.sub.2; 27.0 to 34.2 wt % CaO; 0.10 to 2.0 wt % MgO; and optional other components providing the balance up to 100 wt %,
wherein the sum of SiO.sub.2 and CaO is greater than or equal to 97.8 wt %; and the other components, when present, comprise no more than 0.80 wt % Al.sub.2O.sub.3; and wherein the amount of MgO and other components are configured to inhibit the formation of surface crystallite grains upon heat treatment at 1100° C. for 24 hours, wherein said surface crystallite grains comprise an average crystallite size in a range of from 0.0 to 0.90 μm.

The present invention relates to inorganic fibres having a composition comprising: 65.7 to 70.8 wt % SiO.sub.2; 27.0 to 34.2 wt % CaO; 0.10 to 2.0 wt % MgO; and optional other components providing the balance up to 100 wt %,
wherein the sum of SiO.sub.2 and CaO is greater than or equal to 97.8 wt %; and the other components, when present, comprise no more than 0.80 wt % Al.sub.2O.sub.3; and wherein the amount of MgO and other components are configured to inhibit the formation of surface crystallite grains upon heat treatment at 1100° C. for 24 hours, wherein said surface crystallite grains comprise an average crystallite size in a range of from 0.0 to 0.90 μm.

A ceramic composition according to an embodiment of the present invention contains: a main phase component represented by CaMgSi.sub.2O.sub.6 or Ba.sub.4(Re.sub.(1-x), Bi.sub.x).sub.9.33Ti.sub.18O.sub.54; and an additive component containing a Li component and a B component, An observation field, a part of a sectional surface of the ceramic composition, is divided into a plurality of unit observation regions. Among all the unit observation regions, those containing no or little sintering agent component are referred to as the main crystal regions. An area percentage of main crystal regions relative to the observation field is 30% or more, the main crystal regions being the unit observation regions containing 0.5% or less by area of the additive component.

A process for the manufacture of inorganic fibres comprises: (a) selecting a composition and proportion of: (i) silica sand; (ii) lime comprising at least 0.10 wt % magnesia; and (iii) optional additives comprising a source of oxides or non-oxides of one or more of the lanthanides series of elements, or combinations thereof; (b) mixing the silica sand; lime; and optional additives to form a mixture; (c) melting the mixture in a furnace; and (d) shaping the molten mixture into inorganic fibres. The raw materials selection comprises composition selection and proportion selection of the raw materials to obtain an inorganic fibre composition comprising a range of from 61.0 wt % and 70.8 wt % silica; less than 2.0 wt % magnesia; less than 2.0% incidental impurities; and no more than 2.0 wt % of metal oxides and/or metal non-oxides derived from said optional additives; with calcia providing the balance up to 100 wt %; and wherein the inorganic fibre composition comprises no more than 0.80 wt % Al.sub.20.sub.3 derived from the incidental impurities and/or the optional additives.

A method for the alkaline digestion of soda-lime glass comprising forming a mixture of soda lime glass and a hydroxide solution, the mixture having at least 100 grams of glass per litre of H2O, the hydroxide solution having a concentration of 1M or greater to thereby form an aqueous sodium silicate fraction having a silicate concentration of 50 g/L or greater (calculated as SiO2 equivalent) and a ratio of SiO2:M2O of at least 1, wherein M2O is an alkaline metal oxide, by digesting the glass in the mixture; and separating the aqueous sodium silicate fraction from solids. The solids contain calcium silicate hydrate and undissolved glass. The calcium silicate hydrate can be CSH treated with an acid to thereby dissolve soluble metals from the CSH and separating a liquid phase from a solid phase, the solid phase comprising SiO2 or silica gel.

A method for the alkaline digestion of soda-lime glass comprising forming a mixture of soda lime glass and a hydroxide solution, the mixture having at least 100 grams of glass per litre of H2O, the hydroxide solution having a concentration of 1M or greater to thereby form an aqueous sodium silicate fraction having a silicate concentration of 50 g/L or greater (calculated as SiO2 equivalent) and a ratio of SiO2:M2O of at least 1, wherein M2O is an alkaline metal oxide, by digesting the glass in the mixture; and separating the aqueous sodium silicate fraction from solids. The solids contain calcium silicate hydrate and undissolved glass. The calcium silicate hydrate can be CSH treated with an acid to thereby dissolve soluble metals from the CSH and separating a liquid phase from a solid phase, the solid phase comprising SiO2 or silica gel.

Provided are a negative electrode active material which includes negative electrode active material particles which includes a silicon oxide (SiO.sub.x, 0<x≤2); and at least one lithium silicate selected from Li.sub.2SiO.sub.3, Li.sub.2Si.sub.2O.sub.5, and Li.sub.4SiO.sub.4 in at least a part of the silicon oxide. The negative electrode active material particles have a maximum peak position by a Raman spectrum of more than 460 cm.sup.−1 and less than 500 cm.sup.−1. Also provided are a method of preparing the same, and a negative electrode and a lithium secondary battery including the negative electrode active material.