阅读说明：本技术 氯硅烷及石英联合制备的方法 (Combined preparation method of chlorosilane and quartz ) 是由 银波 武珠峰 刘兴平 范协诚 宋高杰 于 2019-04-01 设计创作，主要内容包括：本发明公开了一种氯硅烷及石英联合制备的方法,包括以下步骤：(1)对金刚线切割硅片的砂浆进行固液分离,得到成品硅粉；(2)以成品硅粉为原料与氯化剂进行氯化反应,制备氯硅烷,得到第一反应残渣；(3)将第一反应残渣与氧气或氯气进行高温氧化反应或高温氯化反应,进行气固分离,得到第二反应残渣；(4)将第二反应残渣进行酸浸,除去金属氧化物杂质,得到悬浮液；(5)对悬浮液进行固液分离,得到固体二氧化硅；(6)将固体二氧化硅加热至熔融,冷却后得到熔融石英。本发明对金刚线切割硅片的砂浆中的硅元素进行充分的回收利用,降低了硅元素的浪费；实现了多晶硅产业链中硅元素的循环利用,杜绝了环境污染,降低了氯硅烷的生产成本。(The invention discloses a method for jointly preparing chlorosilane and quartz, which comprises the following steps of: (1) carrying out solid-liquid separation on the mortar of the diamond wire cut silicon wafer to obtain finished silicon powder; (2) performing chlorination reaction on finished silicon powder serving as a raw material and a chlorinating agent to prepare chlorosilane to obtain first reaction residues; (3) carrying out high-temperature oxidation reaction or high-temperature chlorination reaction on the first reaction residue and oxygen or chlorine, and carrying out gas-solid separation to obtain second reaction residue; (4) acid leaching the second reaction residue to remove metal oxide impurities to obtain a suspension; (5) carrying out solid-liquid separation on the suspension to obtain solid silicon dioxide; (6) and heating the solid silicon dioxide to be molten, and cooling to obtain fused quartz. The invention fully recycles the silicon element in the mortar of the diamond wire-electrode cutting silicon chip, thereby reducing the waste of the silicon element; the cyclic utilization of silicon element in the polysilicon industrial chain is realized, the environmental pollution is avoided, and the production cost of chlorosilane is reduced.)

1. A method for jointly preparing chlorosilane and quartz is characterized by comprising the following steps of:

(1) carrying out solid-liquid separation on the mortar of the diamond wire cut silicon wafer to obtain finished silicon powder, wherein the finished silicon powder comprises elemental silicon and silicon dioxide;

(2) performing chlorination reaction on finished silicon powder serving as a raw material and a chlorinating agent to prepare chlorosilane, so as to obtain first reaction residues, wherein the first reaction residues comprise metal impurities, residual elemental silicon and silicon dioxide;

(3) carrying out high-temperature oxidation reaction or high-temperature chlorination reaction on the first reaction residue and oxygen or chlorine, and carrying out gas-solid separation to obtain a second reaction residue, wherein the second reaction residue comprises solid silicon dioxide, metal impurities, residual elemental silicon and oxygen react to generate solid metal oxide and solid silicon dioxide, or the metal impurities, residual elemental silicon and chlorine react to generate gas metal chloride and gas chlorosilane;

(4) acid leaching the second reaction residue to remove metal oxide impurities in the second reaction residue to obtain a suspension;

(5) carrying out solid-liquid separation on the suspension to obtain solid silicon dioxide;

(6) and heating the solid silicon dioxide to be molten, and cooling to obtain fused quartz.

2. The method for jointly preparing chlorosilane and quartz according to claim 1, wherein the temperature of the chlorination reaction in the step (2) is 200-600 ℃.

3. The method for jointly preparing chlorosilane and quartz according to claim 1, wherein the temperature of the high-temperature oxidation reaction in the step (3) is 1000-1300 ℃.

4. The method for jointly preparing chlorosilane and quartz according to any one of claims 1 to 3, wherein the high-temperature chlorination reaction in the step (3) is performed in a chlorination furnace, when the first reaction residue and chlorine gas are subjected to the high-temperature chlorination reaction, metal impurities, residual elemental silicon and the chlorine gas are reacted to generate metal chloride gas and chlorosilane gas, tail gas at the outlet of the high-temperature chlorination furnace is hydrolyzed, when no white silicon dioxide hydrolysate is generated after the hydrolysis, the chlorine gas is stopped from being introduced into the chlorination furnace for continuous reaction, otherwise, the chlorine gas is continuously introduced for reaction.

5. The method for combined preparation of chlorosilane and quartz as claimed in any one of claims 1 to 3, wherein the high temperature oxidation reaction in step (3) is carried out in an oxidation furnace, when the content of elemental silicon in a sample in the oxidation furnace is less than 100ppm, the introduction of oxygen into the oxidation furnace is stopped to continue the reaction, otherwise, the introduction of oxygen is continued to react.

6. The combined preparation method of chlorosilane and quartz as claimed in claim 1, wherein the acid used in the acid leaching in step (4) is any one of hydrochloric acid, sulfuric acid and nitric acid, and the concentration of the acid used in the acid leaching is 10-20 mas%.

7. The method for jointly preparing chlorosilane and quartz according to claim 1, wherein the step (5) of solid-liquid separation is carried out by filtering, and the filtered solid is rinsed until the pH value of the rinsing solution reaches above 6.

8. The combined preparation method of chlorosilane and quartz as claimed in claims 1 to 3, 6 and 7, wherein the melting temperature in the step (6) is 1500 to 1800 ℃.

9. The combined preparation method of chlorosilane and quartz as claimed in claims 1 to 3, 6 and 7, wherein the chlorinating agent in the step (2) is chlorine gas and/or hydrogen chloride.

10. The combined preparation method of chlorosilane and quartz as claimed in claims 1 to 3, 6 and 7, wherein the step (6) is followed by the following steps:

(7) and crushing and grading the cooled fused quartz to obtain fused quartz powder.

Technical Field

The invention belongs to the technical field of silicon material production, and particularly relates to a combined preparation method of chlorosilane and quartz.

Background

The multi-wire cutting technology of the diamond wire has the advantages of low silicon consumption, high cutting efficiency and the like, and the sand wire cutting is gradually taken as the mainstream technology of the multi-wire cutting at present. However, in the slicing process of single crystal or polycrystalline silicon, silicon powder generated when the silicon rod is cut by the diamond wire has very high surface energy due to extremely fine particle size, and the temperature is high in the cutting process, so that part of the silicon powder is oxidized into silicon dioxide, and in addition, the waste silicon powder separated from the cutting waste liquid is in contact with air in the storage process to generate oxidation reaction, so that the content of the silicon dioxide is further increased.

The silicon powder recovered from the cutting waste liquid has complex components, contains silicon, oxygen, carbon and metal impurity elements, has large specific surface area and small density, increases the recovery difficulty of the silicon element, and causes waste and serious environmental pollution due to the discarded cutting waste liquid.

Disclosure of Invention

Aiming at the defects in the prior art, the invention provides the method for preparing the silicon-.

The technical scheme adopted for solving the technical problem of the invention is to provide a method for jointly preparing chlorosilane and quartz, which comprises the following steps:

(1) carrying out solid-liquid separation on the mortar of the diamond wire cut silicon wafer to obtain finished silicon powder, wherein the finished silicon powder comprises elemental silicon and silicon dioxide;

(2) performing chlorination reaction on finished silicon powder serving as a raw material and a chlorinating agent to prepare chlorosilane, so as to obtain first reaction residues, wherein the first reaction residues comprise metal impurities, residual elemental silicon and silicon dioxide;

(3) carrying out high-temperature oxidation reaction or high-temperature chlorination reaction on the first reaction residue and oxygen or chlorine, and carrying out gas-solid separation to obtain a second reaction residue, wherein the second reaction residue comprises solid silicon dioxide, metal impurities, residual elemental silicon and oxygen react to generate solid metal oxide and solid silicon dioxide, or the metal impurities, residual elemental silicon and chlorine react to generate gas metal chloride and gas chlorosilane;

(4) acid leaching the second reaction residue to remove metal oxide impurities in the second reaction residue to obtain a suspension;

(5) carrying out solid-liquid separation on the suspension to obtain solid silicon dioxide;

(6) and heating the solid silicon dioxide to be molten, and cooling to obtain fused quartz.

The silicon dioxide in the mortar for cutting the silicon wafer by the diamond wire is in an amorphous state, is convenient to purify compared with crystalline phase silicon dioxide, is a high-quality raw material for preparing fused quartz, and greatly reduces the cost for preparing the fused quartz.

Quartz is an amorphous state (glass state) of silicon oxide (quartz, silica), is a main raw material in industries such as refractory materials, ceramic raw materials, glass raw materials, epoxy resin casting, electronic sealing materials, electric light sources, medical treatment, casting and the like, and is also an ideal filler in chemical industries such as paint, coating and the like.

Preferably, the temperature of the chlorination reaction in the step (2) is 200-600 ℃.

Preferably, the chlorinating agent is in excess in step (2).

Preferably, the temperature of the high-temperature oxidation reaction in the step (3) is 1000-1300 ℃.

Preferably, the temperature of the high-temperature oxidation reaction in the step (3) is 1100-1200 ℃.

Preferably, the high-temperature chlorination reaction in the step (3) is performed in a chlorination furnace, when the first reaction residue and chlorine gas are subjected to the high-temperature chlorination reaction, the metal impurities, the residual elemental silicon and the chlorine gas are reacted to generate metal chloride gas and chlorosilane gas, hydrolyzing the tail gas at the outlet of the high-temperature chlorination furnace, when no white silicon dioxide hydrolysate is generated after hydrolysis, stopping introducing the chlorine gas into the chlorination furnace to continue the reaction, otherwise, continuing introducing the chlorine gas to react.

Preferably, the high-temperature oxidation reaction in the step (3) is performed in an oxidation furnace, when the content of the elemental silicon in the sample in the oxidation furnace is less than 100ppm, the oxygen is stopped from being introduced into the oxidation furnace to continue the reaction, otherwise, the oxygen is continuously introduced to continue the reaction.

Preferably, the acid used for acid leaching in the step (4) is any one of hydrochloric acid, sulfuric acid and nitric acid, and the concentration of the acid used for acid leaching is 10 to 20 mas%.

Preferably, the solid-liquid separation in the step (5) is performed by filtering, and the filtered solid is rinsed until the pH value of the rinsing solution reaches above 6.

Preferably, the melting temperature in the step (6) is 1500-1800 ℃.

Preferably, the chlorinating agent in the step (2) is chlorine gas and/or hydrogen chloride.

Preferably, the step (6) is further followed by the steps of:

(7) and crushing and grading the cooled fused quartz to obtain fused quartz powder.

The method for jointly preparing chlorosilane and quartz has the following remarkable effects:

1. the silicon element in the mortar of the diamond wire cut silicon wafer is fully recycled, so that the waste of the silicon element is reduced; the cyclic utilization of silicon element in the polycrystalline silicon industrial chain is realized, and the environmental pollution is avoided; a low-price silicon source is provided for the production of chlorosilane, and the production cost of chlorosilane is reduced;

2. the silicon dioxide in the mortar for recovering the diamond wire-electrode cutting silicon wafer exists in an amorphous state, the reaction activity is higher, the purification is convenient, the preparation process of fused quartz powder is simplified, and the economic benefit is improved.

Drawings

FIG. 1 is a flow chart of a process for the combined preparation of chlorosilanes and quartz in example 2 of the present invention;

FIG. 2 is a flow chart of a process for the combined preparation of chlorosilane and quartz of example 5 of the present invention.

Detailed Description

In order to make the technical solutions of the present invention better understood, the present invention will be described in further detail with reference to the accompanying drawings and specific embodiments.