System and method for producing silicon-containing product by utilizing silicon mud byproduct of cutting silicon material with diamond wire
View Patent ↗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.
1. A method of producing silicon monoxide, the method comprising:
providing precursor particles having elemental silicon coated with an initial layer of silicon dioxide necessary to produce silicon monoxide;
oxidizing the precursor particles to produce a raw material including a thicker coating of silicon dioxide on surfaces of the precursor particles, the thicker coating having a thickness greater than the initial layer;
subjecting the raw material to a disproportionation reaction at a reaction temperature of 1200° C. to 1800° C., such that silicon dioxide and elemental silicon in the raw material react to sublimate silicon monoxide into sublimated silicon monoxide vapor; and
performing a deposition condensation process and collecting the sublimated silicon monoxide vapor onto an external surface of a collection plate, a rod, or particles in a particle bed to obtain silicon monoxide solid from the sublimated silicon monoxide vapor.
2. The method of claim 1 , wherein, after oxidizing the precursor particles, the molar ratio of elemental silicon to silicon dioxide in the raw material is approximately 1:1.
3. The method of claim 1 , wherein the silicon monoxide is SiOx, wherein x is between 0.5 and 1.5.
4. The method of claim 1 , wherein the silicon monoxide is sublimated, via the disproportionation reaction, at a reaction pressure of 0.01 to 100 Mpa.
5. The method of claim 1 , wherein the deposition condensation process of the silicon monoxide solid is carried out in a collection chamber, the collection chamber being a fluidized bed, a dilute phase flow bed, a spray spouted bed, a fixed bed, a moving bed, or a combination thereof.
6. The method of claim 1 , wherein, prior to providing precursor particles, the precursor particles are subjected to at least one of air drying, spray drying, fluidized bed drying, rotary flash drying, infrared drying, microwave drying, freeze drying, impact drying, collision drying, superheat drying, pulsation combustion drying, heat pump drying, or a combination thereof.
7. The method of claim 1 , wherein the silicon monoxide vapor is collected onto the exterior surface of a collection plate or rod; and wherein the collection plate or rod onto which the sublimated silicon monoxide vapor is condensed is incorporated into a lithium-ion battery as a negative electrode after collection of the sublimated silicon monoxide vapor onto the collection plate or rod.
8. The method of claim 1 , wherein the subjecting the raw material to a disproportionation reaction at the reaction temperature occurs in a vacuum.
9. The method of claim 1 , wherein the precursor particles comprising elemental silicon coated with silicon dioxide are the byproduct of cutting a silicon wafer with a diamond wire.
10. The method of claim 4 , wherein the silicon monoxide is sublimated, via the disproportionation reaction, at a reaction pressure of 0.01 to 0.1 Mpa.