A method can include reducing a silica starting material to produce a first quantity of at least metallurgical grade silicon and a second quantity of silica comprising elemental carbon doping, wherein the silica starting material is reduced in the presence of a carbonaceous reducing agent. A silica material can be a silica material as prepared according to the method.

Producing a molded body made of opaque quartz glass includes providing SiO.sub.2 grains obtained by comminuting quartz glass having a purity of at least 99.9 wt % SiO.sub.2, forming a slurry containing a suspension liquid and the SiO.sub.2 grains and which has a total solids content, wet grinding the SiO.sub.2 grains in the slurry so as to form ground SiO.sub.2 grain particles, forming a porous green body from the slurry, and sintering the porous green body. To provide a low cost quartz glass, the wet grinding of the SiO.sub.2 grains takes place at least temporarily in the presence of SiO.sub.2 nanoparticles, the proportion of which in the total solids content of the slurry is in the range of 0.1 wt % to 10 wt %, and the slurry has a solids content in the range of 76 to 80 wt % after addition of the SiO.sub.2 nanoparticles and after the wet grinding.

A cristobalite includes: a d50 particle size selected within a range of from 1 μm to 15 μm; an L color coordinate of greater than 96; a color coordinate of less than 1; and a b color coordinate of 1 or less, in which the cristobalite is a powder. Also provided are compositions containing the cristobalite, coatings formed with compositions, and methods of preparing cristobalite.

The present disclosure relates to silica particles comprising repeating units of (SiO.sub.4/2) that are spherical in shape, which has the benefit of compatibility with personal care components and the resulting personal care applications. The present disclosure also relates to methods of preparing silica particles.

A preparation method for a spherical silica powder filler comprises the following steps: S1, providing spherical polysiloxane comprising a T unit by means of a hydrolysis condensation reaction of R.sub.1SiX.sub.3, wherein R.sub.1 is hydrogen atom or an organic group having independently selectable 1 to 18 carbon atoms, X is a hydrolyzable group, and T unit is R.sub.1SiO.sub.3—; and S2, calcining the spherical polysiloxane under the condition of a dry oxidizing gas atmosphere, the calcining temperature being between 850° C. and 1200° C., so as to obtain the spherical silica powder filler which does not contain silica particles of which the diameter is less than 50 nanometers. The spherical silica powder filler does not contain silica particles of which the diameter is less than 50 nanometers, has a low dielectric loss and a low thermal expansion coefficient, and is suitable for high-frequency high-speed circuit boards, prepregs or copper clad laminates, etc.

The present application provide a silicon-oxygen compound, a secondary battery using it, and related battery modules, battery packs, and devices. The silicon-oxygen compound provided by the present application has a formula of SiO.sub.x, in which x satisfies 0<x<2. The silicon-oxygen compound contains both sulfur and aluminum element, and the sulfur element is present in an amount of 20 ppm˜300 ppm. The mass ratio of sulfur element to aluminum element is from 1.5 to 13.0. A secondary battery uses the silicon-oxygen compound provided in the present application, so that the secondary battery can have both long-cycle performance and high initial coulombic efficiency.

A preparation method for a spherical silica powder filler, comprises the following steps: S1, providing spherical polysiloxane comprising T units by means of a hydrolysis condensation reaction of R.sub.1SiX.sub.3, wherein R.sub.1 is hydrogen atom or an independently selectable organic group having 1 to 18 carbon atoms, X is a hydrolyzable group, and the T unit is R.sub.1SiO.sub.3—; and S2, calcining the spherical polysiloxane under the condition of a dry oxidizing gas atmosphere at a calcining temperature between 850° C. and 1200° C., so as to obtain a spherical silica powder filler having a low hydroxyl content. The spherical silica powder filler is composed of at least one selected from Q.sub.1 unit, Q.sub.2 unit, Q.sub.3 unit and Q.sub.4 unit, wherein Q.sub.1 unit is Si(OH).sub.3O—, Q.sub.2 unit is Si(OH).sub.2O.sub.2—,Q.sub.3 unit is SiOHO.sub.3—, Q.sub.4 unit is SiO.sub.4—, and the content of Q.sub.4 unit is greater than or equal to 95%.

A method for the preparation of an amorphous silica-alumina composition is provided that advantageously utilizes as a component oxidized disulfide oil, for example derived from a waste refinery stream of disulfide oil. The amorphous silica-alumina is formed from an aqueous mixture of an aluminum source, a silica source, oxidized disulfide oil, an alkali metal source and optionally a structure directing agent, which is heating under conditions and for a time effective to form the amorphous silica-alumina.

A process for producing solar grade silicon from silica sand employs a plurality of plasma furnaces to perform a sequence of chemical reactions together with other process steps to produce solar grade silicon. The plasma furnace generates a stable dirty air, donut-shaped plasma into which particulate matter can be introduced. The plasma in the first two stages is formed by gases from the chemical reactions and in the third from inert gasses. Cyclone separators are used to extract particulates from the plasma in an inert gas that prevents reverse reactions as the particular cools.

Provided is a method of manufacturing silicon oxide by which an amount of oxygen of the silicon oxide may be controlled. The method of manufacturing silicon oxide may include mixing silicon and silicon dioxide to be included in a reaction chamber, depressurizing a pressure of the reaction chamber to obtain a high degree of vacuum while increasing a temperature in the reaction chamber to a reaction temperature, and reacting the mixture of silicon and silicon dioxide in a reducing atmosphere.