CN110902684A - Preparation process of low-boron-phosphorus high-purity silicon - Google Patents
Preparation process of low-boron-phosphorus high-purity silicon Download PDFInfo
- Publication number
- CN110902684A CN110902684A CN201811088653.4A CN201811088653A CN110902684A CN 110902684 A CN110902684 A CN 110902684A CN 201811088653 A CN201811088653 A CN 201811088653A CN 110902684 A CN110902684 A CN 110902684A
- Authority
- CN
- China
- Prior art keywords
- silicon
- phosphorus
- boron
- percent
- raw material
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Pending
Links
Classifications
-
- C—CHEMISTRY; METALLURGY
- C01—INORGANIC CHEMISTRY
- C01B—NON-METALLIC ELEMENTS; COMPOUNDS THEREOF; METALLOIDS OR COMPOUNDS THEREOF NOT COVERED BY SUBCLASS C01C
- C01B33/00—Silicon; Compounds thereof
- C01B33/02—Silicon
- C01B33/037—Purification
Landscapes
- Chemical & Material Sciences (AREA)
- Organic Chemistry (AREA)
- Inorganic Chemistry (AREA)
- Silicon Compounds (AREA)
Abstract
The invention provides a preparation process of low-boron-phosphorus high-purity silicon, and relates to the technical field of low-boron-phosphorus high-purity silicon production. The method comprises the following steps: preparing raw materials, removing metal impurities by acid washing, oxidizing, refining and removing phosphorus, removing boron by an improved heat exchange method, and reducing and purifying. The invention removes metal impurities in the industrial silicon by adopting an acid washing mode, and removes phosphorus and boron in the industrial silicon by adopting an oxidation refining and improved heat exchange method, so that the phosphorus and the boron are oxidized to form volatile substances, the purity of the silicon reaches more than 99.9 percent, the impurity removal effect is good, and the impurity removal efficiency is high.
Description
Technical Field
The invention relates to the technical field of low-boron-phosphorus high-purity silicon production, and particularly relates to a preparation process of low-boron-phosphorus high-purity silicon.
Background
High-purity silicon is the most basic raw material in the electronic information industry and the solar photovoltaic power generation industry, and is mainly applied to integrated circuits, discrete devices, solar cells and the like. High purity silicon has been used almost entirely in the electronic information industry in the past, and waste materials from the production of electronic silicon wafers have been used as raw materials in the photovoltaic industry. With the rapid development of the photovoltaic industry in recent years, the consumed amount of high-purity silicon far exceeds that of the electronic industry.
High-purity silicon is usually purified from industrial silicon, the silicon content of the industrial silicon generally reaches 97-99%, the industrial silicon of the grade has low purity and limited application range, and the interior of the industrial silicon contains more metals and impurities which are difficult to remove, such as boron, phosphorus and the like. At present, the method for removing boron and phosphorus impurities is unreasonable, so that the purity of the prepared silicon is not high, the conductivity of the silicon is seriously reduced due to the existence of the impurities such as boron, phosphorus and the like, and great troubles are brought to workers.
Disclosure of Invention
Aiming at the defects of the prior art, the invention provides a preparation process of low-boron-phosphorus high-purity silicon, which adopts an acid washing mode to remove metal impurities in industrial silicon, and then adopts an oxidation refining and improved heat exchange method to remove phosphorus and boron in the industrial silicon, so that the phosphorus and the boron are oxidized to form volatile substances, the purity of the silicon reaches more than 99.9 percent, the impurity removal effect is good, and the impurity removal efficiency is high.
In order to achieve the above purpose, the technical scheme of the invention is realized by the following technical scheme:
a preparation process of low-boron-phosphorus high-purity silicon comprises the following steps:
(1) preparing raw materials: putting the industrial silicon raw material into a sand mill for grinding treatment, and grinding until the industrial silicon raw material is sieved by a 200-mesh sieve to obtain silicon powder for later use;
(2) and (3) removing metal impurities by acid washing: putting the silicon powder material obtained in the step (1) into HCl solution for acid washing, adjusting the rotating speed to 130-;
(3) oxidation refining dephosphorization: adding the silicon powder raw material in the step (2) into a smelting furnace for melting, heating and preserving heat, adding a slagging agent A, and then adding gas-phase SiO2And O2The mixed gas A is kept warm for 2 to 2.5 hours to ensure that phosphorus is volatilized after being oxidized, slag extraction treatment is carried out after phosphorus is removed, and H is introduced into the smelting furnace after slag extraction2Reduction of excess SiO2After the tail gas is discharged, pouring the mixed solution into a crucible for directional solidification so as to remove the residual phosphorus in the solution, and after evaporation, cooling the solution to room temperature to obtain a phosphorus and silicon removing raw material for later use;
(4) removing boron by an improved heat exchange method: melting the phosphorus and silicon removing raw material in the step (3) in a reaction kettle, vacuumizing to 1-2KPa, heating, preserving heat, adding a slagging agent B into the silicon melt in sequence, and introducing H2Removing boron in the solution after 3.5-4h of slagging and gas reaction of the mixed gas B and water vapor, carrying out slag extraction treatment after boron removal, and cooling the solution to room temperature after evaporation to obtain a silicon primary product for later use;
(5) reduction and purification: and (4) mixing the silicon primary product in the step (4) with a reducing agent, so that the silicon primary product is reduced to generate simple substance silicon, and obtaining the product.
Preferably, the weight percentage of the HCl solution in the step (2) is 18-20 wt%, and the mass ratio of the silicon powder to the HCl solution is 4: 1.
Preferably, SiO is in gas phase in step (3)2And O2In the volume ratio of 3:2, H in the step (4)2And water vapor in a volume ratio of 2: 1.
Preferably, the temperature in the step (3) is raised to 2000-2100 ℃, the temperature is kept for 2.5 to 3 hours, and the mixed gas A and H are introduced at the speed of 25 to 30L/min2。
Preferably, the slag former A in the step (3) consists of the following components in percentage by mass: CaCO340-50％、CaF225-35 percent of MgO and 20-30 percent of slag former A, and the addition amount of the slag former A is 4-6 percent of the mass of the silicon powder material.
Preferably, in the step (4), the temperature is raised to 2200-.
Preferably, the slag former B in the step (4) comprises the following components in percentage by mass: CaCO350-60％、CaF230-40 percent of MgO and 8-12 percent of MgO, and the addition amount of the slag former B is 3-4 percent of the mass of the phosphorus and silicon removing raw material.
Preferably, in the step (5), the reducing agent is formed by mixing petroleum coke, graphite and carbon black in a mass ratio of 1:1:2, the content of C in the reducing agent is more than 99%, and the adding amount of the reducing agent is 1-1.1 times of the mass of the silicon primary product.
The invention provides a preparation process of low-boron-phosphorus high-purity silicon, which has the advantages that:
(1) according to the invention, metal impurities in the industrial silicon are removed by adopting an acid washing mode, the contact area of the powdery industrial silicon in acid washing is increased, the acid washing speed is increased by heating and stirring, the impurity removal effect is good, and the impurity removal efficiency is high;
(2) the invention adopts a mode of oxidation refining dephosphorization to carry out gas phase SiO2And O2The mixed gas of (2) oxidizes the phosphorus in the molten siliconThe phosphorus is volatile, thereby removing impurity phosphorus, and then H is passed2The excess gas phase SiO2Reducing to generate simple substance silicon, thereby improving the purity of silicon and having good phosphorus removal effect;
(3) the invention adopts an improved heat exchange method to remove boron from H2The mixed gas with the water vapor oxidizes the boron in the molten silicon, and the boron forms volatile gas after oxidation, so that impurity boron is removed, the purity of the silicon reaches more than 99.9 percent, and the impurity removing effect is good.
Detailed Description
In order to make the objects, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention are clearly and completely described below in conjunction with the embodiments of the present invention, and it is obvious that the described embodiments are some embodiments of the present invention, but not all embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.
Example 1:
a preparation process of low-boron-phosphorus high-purity silicon comprises the following steps:
(1) preparing raw materials: putting the industrial silicon raw material into a sand mill for grinding treatment, and grinding until the industrial silicon raw material is sieved by a 200-mesh sieve to obtain silicon powder for later use;
(2) and (3) removing metal impurities by acid washing: putting the silicon powder material obtained in the step (1) into HCl solution for acid washing, adjusting the rotating speed to 130-;
(3) oxidation refining dephosphorization: adding the silicon powder raw material in the step (2) into a smelting furnace for melting, heating and preserving heat, adding a slagging agent A, and then adding gas-phase SiO2And O2The mixed gas A is kept warm for 2 to 2.5 hours to ensure that phosphorus is volatilized after being oxidized, slag extraction treatment is carried out after phosphorus is removed, and H is introduced into the smelting furnace after slag extraction2Reduction of excess SiO2Is discharged out ofAfter tail gas is exhausted, pouring the mixed solution into a crucible for directional solidification so as to remove residual phosphorus in the solution, and cooling the solution to room temperature after evaporation to obtain a phosphorus and silicon removing raw material for later use;
(4) removing boron by an improved heat exchange method: melting the phosphorus and silicon removing raw material in the step (3) in a reaction kettle, vacuumizing to 1-2KPa, heating, preserving heat, adding a slagging agent B into the silicon melt in sequence, and introducing H2Removing boron in the solution after 3.5-4h of slagging and gas reaction of the mixed gas B and water vapor, carrying out slag extraction treatment after boron removal, and cooling the solution to room temperature after evaporation to obtain a silicon primary product for later use;
(5) reduction and purification: and (4) mixing the silicon primary product in the step (4) with a reducing agent, so that the silicon primary product is reduced to generate simple substance silicon, and obtaining the product.
Wherein, the weight percentage of the HCl solution in the step (2) is 18-20 wt%, and the mass ratio of the silicon powder to the HCl solution is 4: 1; gas phase SiO in step (3)2And O2In the volume ratio of 3:2, H in the step (4)2And steam in a volume ratio of 2: 1; in the step (3), the temperature is raised to 2000-2(ii) a The slag former A in the step (3) comprises the following components in percentage by mass: CaCO340％、CaF230 percent of MgO and 30 percent of slag former A, wherein the addition amount of the slag former A is 4-6 percent of the mass of the silicon powder raw material; in the step (4), the temperature is raised to 2200-; the slag former B in the step (4) comprises the following components in percentage by mass: CaCO350％、CaF238 percent and 12 percent of MgO, and the addition amount of the slag former B is 3 to 4 percent of the mass of the phosphorus and silicon removing raw material; in the step (5), the reducing agent is formed by mixing petroleum coke, graphite and carbon black in a mass ratio of 1:1:2, the content of C in the reducing agent is more than 99%, and the addition amount of the reducing agent is 1-1.1 times of the mass of the primary silicon product.
Example 2:
a preparation process of low-boron-phosphorus high-purity silicon comprises the following steps:
(1) preparing raw materials: putting the industrial silicon raw material into a sand mill for grinding treatment, and grinding until the industrial silicon raw material is sieved by a 200-mesh sieve to obtain silicon powder for later use;
(2) and (3) removing metal impurities by acid washing: putting the silicon powder material obtained in the step (1) into HCl solution for acid washing, adjusting the rotating speed to 130-;
(3) oxidation refining dephosphorization: adding the silicon powder raw material in the step (2) into a smelting furnace for melting, heating and preserving heat, adding a slagging agent A, and then adding gas-phase SiO2And O2The mixed gas A is kept warm for 2 to 2.5 hours to ensure that phosphorus is volatilized after being oxidized, slag extraction treatment is carried out after phosphorus is removed, and H is introduced into the smelting furnace after slag extraction2Reduction of excess SiO2After the tail gas is discharged, pouring the mixed solution into a crucible for directional solidification so as to remove the residual phosphorus in the solution, and after evaporation, cooling the solution to room temperature to obtain a phosphorus and silicon removing raw material for later use;
(4) removing boron by an improved heat exchange method: melting the phosphorus and silicon removing raw material in the step (3) in a reaction kettle, vacuumizing to 1-2KPa, heating, preserving heat, adding a slagging agent B into the silicon melt in sequence, and introducing H2Removing boron in the solution after 3.5-4h of slagging and gas reaction of the mixed gas B and water vapor, carrying out slag extraction treatment after boron removal, and cooling the solution to room temperature after evaporation to obtain a silicon primary product for later use;
(5) reduction and purification: and (4) mixing the silicon primary product in the step (4) with a reducing agent, so that the silicon primary product is reduced to generate simple substance silicon, and obtaining the product.
Wherein, the weight percentage of the HCl solution in the step (2) is 18-20 wt%, and the mass ratio of the silicon powder to the HCl solution is 4: 1; gas phase SiO in step (3)2And O2In the volume ratio of 3:2, H in the step (4)2And steam in a volume ratio of 2: 1; in the step (3), the temperature is raised to 2000-2(ii) a The slag former A in the step (3) comprises the following components in percentage by mass: CaCO345％、CaF230 percent of MgO and 25 percent of slag former A, wherein the addition amount of the slag former A is 4 to 6 percent of the mass of the silicon powder raw material; in the step (4), the temperature is raised to 2200-; the slag former B in the step (4) comprises the following components in percentage by mass: CaCO355％、CaF235 percent of MgO and 10 percent of slag former B, and the addition amount of the slag former B is 3 to 4 percent of the mass of the phosphorus and silicon removing raw material; in the step (5), the reducing agent is formed by mixing petroleum coke, graphite and carbon black in a mass ratio of 1:1:2, the content of C in the reducing agent is more than 99%, and the addition amount of the reducing agent is 1-1.1 times of the mass of the primary silicon product.
Example 3:
a preparation process of low-boron-phosphorus high-purity silicon comprises the following steps:
(1) preparing raw materials: putting the industrial silicon raw material into a sand mill for grinding treatment, and grinding until the industrial silicon raw material is sieved by a 200-mesh sieve to obtain silicon powder for later use;
(2) and (3) removing metal impurities by acid washing: putting the silicon powder material obtained in the step (1) into HCl solution for acid washing, adjusting the rotating speed to 130-;
(3) oxidation refining dephosphorization: adding the silicon powder raw material in the step (2) into a smelting furnace for melting, heating and preserving heat, adding a slagging agent A, and then adding gas-phase SiO2And O2The mixed gas A is kept warm for 2 to 2.5 hours to ensure that phosphorus is volatilized after being oxidized, slag extraction treatment is carried out after phosphorus is removed, and H is introduced into the smelting furnace after slag extraction2Reduction of excess SiO2After the tail gas is discharged, pouring the mixed solution into a crucible for directional solidification so as to remove the residual phosphorus in the solution, and after evaporation, cooling the solution to room temperature to obtain a phosphorus and silicon removing raw material for later use;
(4) removing boron by an improved heat exchange method: melting the phosphorus and silicon removing raw material in the step (3) in a reaction kettle, vacuumizing to 1-2KPa, heating, preserving heat, adding a slagging agent B into the silicon melt in sequence, and introducing H2Mixed gas B with water vapor, passing through 3.5Removing boron in the solution after slagging and gas reaction for-4 h, carrying out slag extraction treatment after boron removal, and cooling the solution to room temperature after evaporation to obtain a silicon primary product for later use;
(5) reduction and purification: and (4) mixing the silicon primary product in the step (4) with a reducing agent, so that the silicon primary product is reduced to generate simple substance silicon, and obtaining the product.
Wherein, the weight percentage of the HCl solution in the step (2) is 18-20 wt%, and the mass ratio of the silicon powder to the HCl solution is 4: 1; gas phase SiO in step (3)2And O2In the volume ratio of 3:2, H in the step (4)2And steam in a volume ratio of 2: 1; in the step (3), the temperature is raised to 2000-2(ii) a The slag former A in the step (3) comprises the following components in percentage by mass: CaCO350％、CaF230 percent of MgO and 20 percent of slag former A, wherein the addition amount of the slag former A is 4 to 6 percent of the mass of the silicon powder raw material; in the step (4), the temperature is raised to 2200-; the slag former B in the step (4) comprises the following components in percentage by mass: CaCO360％、CaF232 percent of MgO, 8 percent of MgO, and the addition amount of the slag former B is 3 to 4 percent of the mass of the phosphorus and silicon removing raw material; in the step (5), the reducing agent is formed by mixing petroleum coke, graphite and carbon black in a mass ratio of 1:1:2, the content of C in the reducing agent is more than 99%, and the addition amount of the reducing agent is 1-1.1 times of the mass of the primary silicon product.
It is noted that, herein, relational terms such as first and second, and the like may be used solely to distinguish one entity or action from another entity or action without necessarily requiring or implying any actual such relationship or order between such entities or actions. Also, the terms "comprises," "comprising," or any other variation thereof, are intended to cover a non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements does not include only those elements but may include other elements not expressly listed or inherent to such process, method, article, or apparatus. Without further limitation, an element defined by the phrase "comprising an … …" does not exclude the presence of other identical elements in a process, method, article, or apparatus that comprises the element.
The above examples are only intended to illustrate the technical solution of the present invention, but not to limit it; although the present invention has been described in detail with reference to the foregoing embodiments, it will be understood by those of ordinary skill in the art that: the technical solutions described in the foregoing embodiments may still be modified, or some technical features may be equivalently replaced; and such modifications or substitutions do not depart from the spirit and scope of the corresponding technical solutions of the embodiments of the present invention.
Claims (8)
1. A preparation process of low-boron-phosphorus high-purity silicon is characterized by comprising the following steps:
(1) preparing raw materials: putting the industrial silicon raw material into a sand mill for grinding treatment, and grinding until the industrial silicon raw material is sieved by a 200-mesh sieve to obtain silicon powder for later use;
(2) and (3) removing metal impurities by acid washing: putting the silicon powder material obtained in the step (1) into HCl solution for acid washing, adjusting the rotating speed to 130-;
(3) oxidation refining dephosphorization: adding the silicon powder raw material in the step (2) into a smelting furnace for melting, heating and preserving heat, adding a slagging agent A, and then adding gas-phase SiO2And O2The mixed gas A is kept warm for 2 to 2.5 hours to ensure that phosphorus is volatilized after being oxidized, slag extraction treatment is carried out after phosphorus is removed, and H is introduced into the smelting furnace after slag extraction2Reduction of excess SiO2After the tail gas is discharged, pouring the mixed solution into a crucible for directional solidification so as to remove the residual phosphorus in the solution, and after evaporation, cooling the solution to room temperature to obtain a phosphorus and silicon removing raw material for later use;
(4) removing boron by an improved heat exchange method: the phosphorus and silicon removing raw material in the step (3) is put into a reaction kettle for melting, the reaction kettle is vacuumized to 1-2KPa, and the silicon melt is heated and kept warmAdding slag former B and then H2Removing boron in the solution after 3.5-4h of slagging and gas reaction of the mixed gas B and water vapor, carrying out slag extraction treatment after boron removal, and cooling the solution to room temperature after evaporation to obtain a silicon primary product for later use;
(5) reduction and purification: and (4) mixing the silicon primary product in the step (4) with a reducing agent, so that the silicon primary product is reduced to generate simple substance silicon, and obtaining the product.
2. The process for preparing high-purity silicon with low boron and phosphorus content as claimed in claim 1, wherein: the weight percentage of the HCl solution in the step (2) is 18-20 wt%, and the mass ratio of the silicon powder to the HCl solution is 4: 1.
3. The process for preparing high-purity silicon with low boron and phosphorus content as claimed in claim 1, wherein: gas phase SiO in step (3)2And O2In the volume ratio of 3:2, H in the step (4)2And water vapor in a volume ratio of 2: 1.
4. The process for preparing high-purity silicon with low boron and phosphorus content as claimed in claim 1, wherein: in the step (3), the temperature is raised to 2000-2。
5. The process for preparing high-purity silicon with low boron and phosphorus content as claimed in claim 1, wherein: the slag former A in the step (3) comprises the following components in percentage by mass: CaCO340-50％、CaF225-35 percent of MgO and 20-30 percent of slag former A, and the addition amount of the slag former A is 4-6 percent of the mass of the silicon powder material.
6. The process for preparing high-purity silicon with low boron and phosphorus content as claimed in claim 1, wherein: in the step (4), the temperature is raised to 2200-.
7. A low boron phosphorus alloy according to claim 1The preparation process of the high-purity silicon is characterized by comprising the following steps: the slag former B in the step (4) comprises the following components in percentage by mass: CaCO350-60％、CaF230-40 percent of MgO and 8-12 percent of MgO, and the addition amount of the slag former B is 3-4 percent of the mass of the phosphorus and silicon removing raw material.
8. The process for preparing high-purity silicon with low boron and phosphorus content as claimed in claim 1, wherein: in the step (5), the reducing agent is formed by mixing petroleum coke, graphite and carbon black in a mass ratio of 1:1:2, the content of C in the reducing agent is more than 99%, and the addition amount of the reducing agent is 1-1.1 times of the mass of the primary silicon product.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201811088653.4A CN110902684A (en) | 2018-09-18 | 2018-09-18 | Preparation process of low-boron-phosphorus high-purity silicon |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201811088653.4A CN110902684A (en) | 2018-09-18 | 2018-09-18 | Preparation process of low-boron-phosphorus high-purity silicon |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN110902684A true CN110902684A (en) | 2020-03-24 |
Family
ID=69812832
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN201811088653.4A Pending CN110902684A (en) | 2018-09-18 | 2018-09-18 | Preparation process of low-boron-phosphorus high-purity silicon |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN110902684A (en) |
-
2018
- 2018-09-18 CN CN201811088653.4A patent/CN110902684A/en active Pending
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CA1133681A (en) | Process for purifying silicon, and the silicon so produced | |
| CN101555015B (en) | Purifying method and device for removing boron from polysilicon | |
| CN102229430B (en) | Technical method for preparing solar energy polycrystalline silicon by using metallurgical method | |
| CN101353167A (en) | Preparation of hyperpure metallurgy silicon | |
| Lynch | Winning the global race for solar silicon | |
| CN101555013A (en) | Refining method of industrial silicon | |
| CN106185948B (en) | A kind of industrial silicon slag making dephosphorization process | |
| CN101362600B (en) | Method for removing boron from polysilicon by wet metallargy | |
| CN102807220B (en) | Silicon purification method | |
| WO2012000428A1 (en) | Method for preparing high purity silicon | |
| CN104058405B (en) | A kind of remove foreign matter of phosphor and the method for boron in metallic silicon | |
| CN107313063A (en) | 5N high purity tellurium smelting processes | |
| CN110194456B (en) | Method for smelting metal silicon by using waste silicon sludge | |
| CN102260909A (en) | Method for purifying silicon | |
| CN103570023B (en) | Slag-making and boron-removing method for industrial silicon | |
| CN103693648B (en) | A kind of method strengthening the removal of impurities of industrial silicon wet chemistry | |
| CN110156023B (en) | Environment-friendly method for smelting high-purity silicon | |
| JP2005255417A (en) | Method for purifying silicon | |
| CN102154566B (en) | Method for preparing high-manganese-content manganese-aluminum masteralloy by taking pyrolusite as raw material | |
| CN110902684A (en) | Preparation process of low-boron-phosphorus high-purity silicon | |
| CN108950143B (en) | Comprehensive utilization method of phosphorus and iron as yellow phosphorus smelting by-product | |
| CN110273075A (en) | The method for preparing high-silicon aluminium-silicon alloy using metal alum recovery crystalline silicon cutting waste material | |
| CN102774840B (en) | Technique for purifying industrial silicon by metallurgical method | |
| CN102020278A (en) | Method for removing impurity phosphorus in silicon | |
| KR101180353B1 (en) | Refining method of Phosphorus and other impurities from MG-Si by acid leaching |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| PB01 | Publication | ||
| PB01 | Publication | ||
| WD01 | Invention patent application deemed withdrawn after publication |
Application publication date: 20200324 |
|
| WD01 | Invention patent application deemed withdrawn after publication |