The present application provides a system and method for producing a silicon-containing product by using a silicon sludge, which is produced by a cutting silicon material with a diamond wire. The method utilizes a high oxide layer on the surface of a silicon waste particle produced during diamond wire cutting. The surface oxide undergoes a disproportionation reaction with adjacent internal elemental silicon to form silicon monoxide, which is removed in a vapor to achieve a physical chemical reaction with a metal, a halogen gas, a hydrogen halide gas or hydrogen to form silicon-containing products of higher added value. The process realizes the large-scale, high-efficiency, energy-saving, continuous and low-cost complete recycling of silicon waste produced by diamond wire cutting of silicon material.

The present application provides a system and method for producing a silicon-containing product by using a silicon sludge, which is produced by a cutting silicon material with a diamond wire. The method utilizes a high oxide layer on the surface of a silicon waste particle produced during diamond wire cutting. The surface oxide undergoes a disproportionation reaction with adjacent internal elemental silicon to form silicon monoxide, which is removed in a vapor to achieve a physical chemical reaction with a metal, a halogen gas, a hydrogen halide gas or hydrogen to form silicon-containing products of higher added value. The process realizes the large-scale, high-efficiency, energy-saving, continuous and low-cost complete recycling of silicon waste produced by diamond wire cutting of silicon material.

A system and a method for producing silicon from a SiO.sub.2-containing material that includes solid SiO.sub.2. The method uses a reaction vessel including a first section and a second section in fluid communication with said first section. The method includes: heating the SiO.sub.2-containing material that includes the solid SiO.sub.2 to a SiO.sub.2-containing material that includes liquid SiO.sub.2, at a sufficient temperature to convert the solid SiO.sub.2 into the liquid SiO.sub.2; converting, in the first section, the liquid SiO.sub.2 into gaseous SiO.sub.2 that flows to the second section by reducing the pressure in the reaction vessel to a subatmospheric pressure; and reducing, in the second section, the gaseous SiO.sub.2 into liquid silicon using a reducing gas. The reducing of the pressure is performed over a continuous range of interim pressure(s) sufficient to evaporate contaminants from the SiO.sub.2-containing material, and removing by vacuum, the one or more evaporated gaseous contaminants.

A system and a method for producing silicon from a SiO.sub.2-containing material that includes solid SiO.sub.2. The method uses a reaction vessel including a first section and a second section in fluid communication with said first section. The method includes: heating the SiO.sub.2-containing material that includes the solid SiO.sub.2 to a SiO.sub.2-containing material that includes liquid SiO.sub.2, at a sufficient temperature to convert the solid SiO.sub.2 into the liquid SiO.sub.2; converting, in the first section, the liquid SiO.sub.2 into gaseous SiO.sub.2 that flows to the second section by reducing the pressure in the reaction vessel to a subatmospheric pressure; and reducing, in the second section, the gaseous SiO.sub.2 into liquid silicon using a reducing gas. The reducing of the pressure is performed over a continuous range of interim pressure(s) sufficient to evaporate contaminants from the SiO.sub.2-containing material, and removing by vacuum, the one or more evaporated gaseous contaminants.

The present disclosure relates to a negative electrode material including, as an active material, silicon flakes with a hyperporous structure, represented by the following chemical formula 1:
xSi.(1−x)A  (1) where 0.5≤x≤1.0, and A is an impurity, and includes at least one compound selected from the group consisting of Al.sub.2O.sub.3, MgO, SiO.sub.2, GeO.sub.2, Fe.sub.2O.sub.3, CaO, TiO.sub.2, Na.sub.2O K.sub.2O, CuO, ZnO, NiO, Zr.sub.2O.sub.3, Cr.sub.2O.sub.3 and BaO, and a preparing method of the silicon flakes.

A method for preparing an amorphous silicon powder for an anode material of a lithium-ion battery is disclosed. The amorphous silicon powder is prepared by reducing an oxide of silicon, wherein an X-ray diffraction peak of an amorphous silicon material is weak, and the amorphous silicon material is of an amorphous structure. A structural formula of the oxide of silicon is SiO.sub.x, wherein 0<x≤2. The reduction refers to vapor phase reduction, a vapor phase reduction atmosphere is a mixed gas of hydrogen and carbon monoxide, a reduction temperature ranges from 100° C. to 700° C., and a reduction time ranges from 2 h to 72 h.

A method for preparing an amorphous silicon powder for an anode material of a lithium-ion battery is disclosed. The amorphous silicon powder is prepared by reducing an oxide of silicon, wherein an X-ray diffraction peak of an amorphous silicon material is weak, and the amorphous silicon material is of an amorphous structure. A structural formula of the oxide of silicon is SiO.sub.x, wherein 0<x≤2. The reduction refers to vapor phase reduction, a vapor phase reduction atmosphere is a mixed gas of hydrogen and carbon monoxide, a reduction temperature ranges from 100° C. to 700° C., and a reduction time ranges from 2 h to 72 h.

An apparatus and a process for the production of high purity silicon from silica containing material such as quartz or quartzite, using a vacuum electric arc furnace, are disclosed.

An apparatus and a process for the production of high purity silicon from silica containing material such as quartz or quartzite, using a vacuum electric arc furnace, are disclosed.

The invention relates to a process for the production of silicon and alumina Aluminium is contacted with a molten slag of a calcium oxide and SiO.sub.2 under conditions facilitating an aluminothermic reaction, thereby forming silicon and an aluminate slag in two phases which are separated. The aluminate slag is converted to alumina and calcium oxide, which is re-fed in the reaction. The aluminium is provided by melting of aluminium scrap or a combination of different aluminium alloys at a temperature of 700 to 1000° C. The primary aluminium melt is adjusted to a content of 8 to 14% of silicon and then cooled to below 660° C., whereby precipitates are formed, and high purity aluminium is obtained to be introduced into the reaction.