The invention discloses high-strength glass-ceramic-based lightweight aggregates and the preparation method thereof. The mass ratio of raw material components is 50-70 parts of engineering muck, 20-40 parts of glass, 3-7 parts of calcium carbonate, 3-7 parts of magnesium oxide, and 2-10 parts of a nucleating agent; the nucleating agent is at least one of calcium fluoride, titanium dioxide, and chromium oxide. After crushing, mixing, and granulating, spherical particles with a particle size of 10-12 mm are formed; and then the product can be obtained after drying, sintering, and cooling. The obtained lightweight aggregate from the invention has a diopside matrix which provides high strength and a low water absorption rate at low densities. Moreover, waste glass and engineering muck could be utilized with high value.

A method of manufacturing a heat exchanger core from glass ceramic matrix composite includes placing one or more reinforcing fibers around one or more mandrels into a mold cavity. A glass matrix material infiltrates the one or more reinforcing fibers to produce an infiltrated core and the one or more mandrels is removed to create one or more passages passing through the infiltrated core.

A silica-titania glass substrate comprising: (i) a composition comprising 5 weight percent to 10 weight percent TiO.sub.2; (ii) a coefficient of thermal expansion (CTE) at 20° C. in a range from −45 ppb/K to +20 ppb/K; (iii) a crossover temperature (Tzc) in a range from 10° C. to 50° C.; (iv) a slope of CTE at 20° C. in a range from 1.20 ppb/K.sup.2 to 1.75 ppb/K.sup.2; (v) a refractive index variation of less than 140 ppm; and (vi) 600 ppm OH group concentration or greater. The substrate can have a mass of 1 kg or greater and less than 0.05 gas inclusions per cubic inch via a method comprising (i) forming the substrate from soot particles comprising SiO.sub.2 and TiO.sub.2, and (ii) subjecting the substrate to an environment having an elevated temperature and an elevated pressure for a period of time until the substrate comprises less than 0.05 gas inclusions per cubic inch.

Method for manufacturing slab articles from a mix, comprising the steps of a) preparing a mix comprising a preponderant amount of a glass frit and a binder, b) distributing the mix in a support, c) compacting the mix, d) drying the mix, e) sintering the mix and f) cooling the article. The glass frit comprises a weight amount of silica (SiO.sub.2) comprised between 62% and 68%, a weight amount of alumina (Al.sub.2O.sub.3) comprised between 3% and 5%, a weight amount of potassium oxide (K.sub.2O) comprised between 3% and 5%, a weight amount of calcium oxide (CaO) comprised between 18% and 26% and a weight amount of magnesium oxide (MgO) comprised between 1% and 4% The cooling step is performed in a controlled manner by modulating the cooling speed in a temperature range not p greater than 1.160° C. and not less than 1.000° C. in order to perform the at least partial devitrification and crystallization of the glass frit. The invention also relates to a glass frit and an article in slab form.

A method of making a glass-ceramic article includes synthesizing a feedstock gel that includes a base oxide network comprising Na.sub.2O, CaO, and SiO.sub.2, in which a molar ratio of Na.sub.2O:CaO:SiO.sub.2 in the gel is 1:2:3, and then converting the feedstock gel into a glass-ceramic article such as a container or a partially-formed container. The conversion of the feedstock gel into a glass-ceramic container may be performed at a temperature that does not exceed 900° C. and may include the steps of pressing the feedstock gel into a compressed solid green-body, sintering the green-body into a solid monolithic body of a glass-ceramic material, deforming the solid monolithic glass-ceramic body into a glass-ceramic preform, and cooling the preform. A glass-ceramic article having a glass-ceramic material that has a molar ratio of Na.sub.2O:CaO:SiO.sub.2 that is 1:2:3 is also disclosed.

Glass ceramics having SiO.sub.2 as main crystal phase and precursors thereof are described which are characterized by very good mechanical and optical properties and in particular can be used as restoration material in dentistry.

Methods for making articles comprising crystalline material. Exemplary articles made by a method described herein include electronics enclosure (e.g., a watch case, cellular phone case, or a tablet case).

A glass ceramic and a preparation method thereof include a step of melting calcined electrolytic manganese slag to obtain molten glass. The molten glass is sequentially molded, nucleated, and crystallized to obtain the glass ceramic. The calcined electrolytic manganese slag is taken as a raw material, so that harmful gases are not generated in the raw material melting process, and secondary pollution is not caused. The preparation method provided by the present invention has the advantages of simple operation, high utilization rate of electrolytic manganese slag and low cost. Moreover, the prepared glass ceramic has good mechanical properties and corrosion resistance.

The present disclosure provides a method for fabrication of a glass preform. The method includes production of soot particles in a combustion chamber using a precursor material. The heating of the precursor material produces the soot particles along with one or more impurities. In addition, the method includes agglomeration of the soot particles. Further, the method includes separation of the soot particles from the one or more impurities. Also, the separation of the soot particles is performed in a cyclone separator. Furthermore, the method includes collection of the soot particles. Also, the soot particles are compacted with facilitation of a preform compaction chamber. Also, the compacted preform is sintered with facilitation of a sintering furnace. The compaction of the soot particles followed by sintering results in formation of the glass preform.

The invention provides a process for preparing a porous glass, comprising mixing borosilicate glass powder with calcium carbonate particles to form a mixture, sintering the mixture at a temperature in the range from 750 to 850 C. to obtain a sintered body, cooling the sintered body and leaching calcium carbonate from the cooled sintered body with the aid of an acid. The invention also provides a process for the preparation of one or more alkaline earth metal silicates by reacting a vitreous material and an alkaline earth carbonate, optionally in the presence of a transition metal or post-transition metal oxide, at a temperature lower than 1200 C., to form a composite consisting of one or more alkaline earth metal silicates and a residual glass, and optionally recovering the one or more silicates.