CN114735708B - Method for preparing silicon with low content of iron, aluminum and calcium - Google Patents
Method for preparing silicon with low content of iron, aluminum and calcium Download PDFInfo
- Publication number
- CN114735708B CN114735708B CN202210463862.2A CN202210463862A CN114735708B CN 114735708 B CN114735708 B CN 114735708B CN 202210463862 A CN202210463862 A CN 202210463862A CN 114735708 B CN114735708 B CN 114735708B
- Authority
- CN
- China
- Prior art keywords
- zinc
- silicon
- iron
- aluminum
- calcium
- 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.)
- Active
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
-
- Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
- Y02P—CLIMATE CHANGE MITIGATION TECHNOLOGIES IN THE PRODUCTION OR PROCESSING OF GOODS
- Y02P10/00—Technologies related to metal processing
- Y02P10/20—Recycling
Abstract
The invention discloses a method for preparing silicon with low iron, aluminum and calcium content, and belongs to the technical field of industrial silicon smelting. The method breaks through the way of obtaining high-quality silicon by controlling the impurity content method in the production raw materials in the prior art, adopts industrial zinc to refine outside a furnace, enables impurities iron, aluminum, calcium and zinc in the industrial silicon to react to form a compound with low melting point, volatilizes the compound by using the high temperature of a silicon melt body to achieve the aim of removing impurities, and enables unverified zinc iron, zinc aluminum and zinc calcium compounds to segregate at a crystal boundary after the silicon is solidified, and then is removed by acid washing after being crushed, and the redundant zinc is changed into gas under the high temperature to be separated under the action of compressed gas; the method can effectively remove the impurities of iron, aluminum and calcium in the silicon melt, does not introduce new impurities, solves the problem of dependence of the existing industrial silicon production on raw materials, has low cost and simple operation, can recycle and reuse redundant zinc, is energy-saving and environment-friendly, and is suitable for industrial mass production.
Description
Technical Field
The invention belongs to the technical field of industrial silicon smelting, and particularly relates to a method for preparing silicon with low iron, aluminum and calcium content.
Background
In the industrial silicon smelting process, the raw materials contain Fe, al, ca, B, P and other impurities, and these impurity elements are reduced together with silicon elements in the silica reduction process and enter the industrial silicon, and are deposited as impurities in the industrial silicon after the condensation of the silicon melt, so that the purity of the industrial silicon is reduced. In order to reduce the content of impurities in the industrial silicon and improve the quality of the industrial silicon, the industrial silicon needs to be subjected to external refining to remove most of the impurities in the industrial silicon. With the progress of technology, the purity requirements of industrial silicon are higher and higher.
At present, the most commonly used impurity removal method in an industrial silicon factory is to perform external refining of industrial silicon in a ladle, and to blow chlorine, nitrogen, oxygen and compressed air or a mixed gas of the above gases into the ladle to perform refining, so as to remove most of the impurities such as Al, ca, B, C, but not remove other impurities such as Fe.
Another common impurity removal method is a slag former refining method, wherein a ladle is added with a combination component of oxides such as calcium oxide, silicon oxide, aluminum oxide, magnesium oxide, calcium fluoride and the like or a mineral raw stone containing the oxides, and the slag former is used for removing part of impurities in silicon, but the removal effect on impurities such as Fe and the like is not ideal, and the separation difficulty of silicon and slag after slag refining greatly influences the silicon yield.
The third common method is a directional solidification method, wherein industrial silicon is poured into a crucible with unidirectional heat radiation, and the industrial silicon is slowly solidified from the bottom upwards to remove metal impurities with larger segregation coefficient in the industrial silicon by utilizing the segregation principle.
Along with the development of modern industry, a plurality of downstream enterprises put forward higher requirements on impurities in refined silicon, especially special grade silicon for silicon steel industry has higher requirements on iron, aluminum and calcium impurities in silicon, but the existing external refining technology cannot effectively separate main metal impurities iron, aluminum and calcium in industrial silicon products, so that the iron, aluminum and calcium impurities become key impurity elements directly influencing the brands of industrial silicon, and the general method adopted for the problem mainly realizes the control of the contents of the impurities iron, aluminum and calcium in the industrial silicon products by controlling production raw materials and smelting processes. However, due to fluctuations in raw material components and furnace conditions, the quality control effect of the industrial silicon product achieved by the method is not stable, and thus the quality of the industrial silicon product is significantly unstable, so that a more economical and effective industrial silicon impurity removal method is needed to be found.
Disclosure of Invention
The invention aims to overcome the defects of the prior art and provides a method for removing iron, aluminum and calcium impurities in industrial silicon melt by external refining, which is simple to operate and low in cost.
The aim of the invention is achieved by the following technical scheme: a method for preparing low-iron aluminum calcium content silicon includes introducing compressed gas into ladle, adding solid zinc into industrial silicon melt to be decontaminated in ladle, maintaining the temperature of silicon melt above 1700 ℃, converting solid zinc into gaseous zinc at high temperature, volatilizing the compound formed by reaction of gaseous zinc and impurities, and allowing redundant gaseous zinc to enter a pipeline under the action of compressed gas to remove impurities in industrial silicon melt.
Further, the compressed gas is compressed argon.
Further, the ventilation pressure of the compressed gas is 0.2-0.3 MPa, the gas flow is 800-1200L/h, and the ventilation time is 20-60 min.
Further, the reaction time of the gaseous zinc and the impurities of iron, aluminum and calcium is 30-60 min.
Further, the mass of the added zinc is 0.15 to 0.3 percent of the mass of the industrial silicon.
Further, the temperature of the industrial silicon melt is 1700 ℃, and a volatilizing method is adopted to remove compounds formed by the reaction of zinc and impurities.
Further, the content of impurity iron in the industrial silicon melt is 200 ppm-350 ppm, the content of impurity aluminum is 150 ppm-220 ppm, and the content of impurity calcium is 100 ppm-150 ppm.
Further, the method comprises the refining step, namely, the non-volatilized impurity compounds are concentrated at the grain boundary after the silicon is solidified, the solidified industrial silicon is crushed, zinc iron, zinc aluminum and zinc calcium alloy at the grain boundary are exposed outside, the crushed industrial silicon material is soaked in an acid solution, and the zinc iron, zinc aluminum and zinc calcium alloy at the grain boundary react with the acid to generate inorganic salt and dissolve out, so that the aim of removing the impurity compounds is fulfilled.
Further, the method also comprises a process of recovering the gaseous zinc in the pipeline in a condensation mode.
The invention has the following advantages: the invention discloses a method for preparing silicon with low iron, aluminum and calcium content, which breaks through the way of obtaining high-quality silicon by controlling the impurity content method in the production raw materials in the prior art, because the solubility of silicon in zinc is very low, the solubility of zinc in silicon is very low, the silicon is basically mutually incompatible at normal temperature, industrial zinc is adopted to refine outside a furnace, impurities iron, aluminum and calcium in the industrial silicon react with zinc to form a compound with low melting point, the compound is volatilized by utilizing the high temperature of a silicon melt to escape to achieve the aim of removing impurities, unvaporized zinc iron, zinc aluminum and zinc calcium compounds are segregated at a crystal boundary after the silicon is solidified, acid washing is adopted to remove after the silicon is crushed, and redundant zinc is changed into gas under the action of compressed gas at high temperature to be separated; the method can effectively remove the impurities of iron, aluminum and calcium in the silicon melt, does not introduce new impurities, solves the problem of dependence of the existing industrial silicon production on raw materials, has low cost and simple operation, can recycle and reuse redundant zinc, is energy-saving and environment-friendly, and is suitable for industrial mass production.
Detailed Description
The invention will be further described with reference to examples, but the scope of the invention is not limited to the following:
example 1: a method for preparing low-iron aluminum calcium content silicon comprises the steps of introducing compressed gas argon into a ladle, wherein the ventilation pressure is 0.2MPa, the gas flow is 800L/h, the ventilation time is 20min, adding zinc into industrial silicon melt to be removed of impurities in the ladle, adding 0.15% of the mass of industrial zinc, reacting for 30min, keeping the temperature of the silicon melt at 1700 ℃, and removing compounds formed by the reaction of the zinc, iron, aluminum and calcium as impurities through volatilization; the non-volatilized compound formed by the reaction of zinc and impurities can segregate at the grain boundary after the solidification of silicon, hydrochloric acid is adopted for washing and removing after the solidification, the purpose of removing impurity iron, aluminum and calcium in industrial silicon melt is achieved, redundant gas zinc enters a pipeline under the action of compressed gas, and the gas zinc in the pipeline is recovered in a condensation mode.
Example 2: a method for preparing low-iron aluminum calcium content silicon comprises the steps of introducing compressed gas argon into a ladle, introducing the pressure of the compressed gas to be 0.3MPa, enabling the gas flow to be 1200L/h, enabling the gas flow to be 60min, adding zinc into industrial silicon melt to be decontaminated in the ladle, adding the mass of the industrial zinc to be 0.3% of the mass of the industrial silicon, reacting for 35min, keeping the temperature of the silicon melt at 1800 ℃, and volatilizing compounds formed by the reaction of the zinc, iron, aluminum and calcium as impurities; the non-volatilized compound formed by the reaction of zinc and impurities can segregate at the grain boundary after the solidification of silicon, and is removed by sulfuric acid washing after crushing, so that the aim of removing iron, aluminum and calcium impurities in industrial silicon melt is fulfilled, redundant gas zinc enters a pipeline under the action of compressed gas, and the gas zinc in the pipeline is recovered by adopting a condensation mode.
Example 3: a method for preparing low-iron aluminum calcium content silicon comprises the steps of introducing compressed gas argon into a ladle, wherein the ventilation pressure is 0.25MPa, the gas flow is 1000L/h, the ventilation time is 30min, adding zinc into industrial silicon melt to be removed of impurities in the ladle, adding 0.2% of the mass of industrial zinc into the industrial silicon melt, reacting for 40min, keeping the temperature of the silicon melt at 2000 ℃, and removing compounds formed by the reaction of the zinc, iron, aluminum and calcium as impurities through volatilization; the non-volatilized compound formed by the reaction of zinc and impurities can segregate at the grain boundary after the solidification of silicon, hydrochloric acid is adopted for washing and removing after the solidification, the purpose of removing impurity iron, aluminum and calcium in industrial silicon melt is achieved, redundant gas zinc enters a pipeline under the action of compressed gas, and the gas zinc in the pipeline is recovered in a condensation mode.
Example 4: a method for preparing low-iron aluminum calcium content silicon comprises the steps of introducing compressed gas argon into a ladle, wherein the ventilation pressure is 0.2MPa, the gas flow is 1100L/h, the ventilation time is 50min, adding zinc into industrial silicon melt to be removed of impurities in the ladle, adding 0.2% of the mass of industrial zinc into the industrial silicon melt, reacting for 60min, keeping the temperature of the silicon melt at 1900 ℃, and removing compounds formed by the reaction of the zinc, iron, aluminum and calcium as impurities through volatilization; the non-volatilized compound formed by the reaction of zinc and impurities can segregate at the grain boundary after the solidification of silicon, and is removed by sulfuric acid washing after crushing, so that the aim of removing iron, aluminum and calcium impurities in industrial silicon melt is fulfilled, redundant gas zinc enters a pipeline under the action of compressed gas, and the gas zinc in the pipeline is recovered by adopting a condensation mode.
The beneficial effects of the invention are illustrated by the following experiments:
experimental example 1:
compressed gas argon is introduced into the ladle, the ventilation pressure is 0.25MPa, the gas flow is 1000L/h, and the ventilation time is 20min. Adding zinc into industrial silicon melt to be decontaminated in a ladle, adding industrial zinc particles with the total mass of 0.1% of the mass of the industrial silicon, adding the industrial zinc at one time, standing for reaction for 30min after adding the industrial zinc, keeping the temperature of the silicon melt at 1800 ℃, and volatilizing compounds formed by the reaction of the zinc and impurities of iron, aluminum and calcium; the non-volatilized compound formed by the reaction of zinc and impurities can segregate at the grain boundary after the solidification of silicon, hydrochloric acid is adopted for washing and removing after the silicon is crushed, the purposes of removing iron, aluminum and calcium of impurities in industrial silicon melt are achieved, redundant gas zinc enters a pipeline under the action of compressed gas, and the gas zinc in the pipeline is recovered in a condensation mode.
The content of impurity iron in the industrial silicon before impurity removal is 330ppm, the content of impurity aluminum is 220ppm, and the content of impurity calcium is 100ppm; the content of impurity iron after refining is 218ppm, the content of impurity aluminum after refining is 102ppm, and the content of impurity calcium after refining is 52ppm.
Experimental example 2:
compressed argon is introduced into the ladle, the ventilation pressure is 0.25MPa, the gas flow is 1000L/h, and the ventilation time is 20min. Adding zinc into industrial silicon melt to be decontaminated in a ladle, gradually adding industrial zinc particles with the total mass of 0.2% of the mass of the industrial silicon in batches, standing for reaction for 30min after adding industrial zinc, keeping the temperature of the silicon melt at 1800 ℃, and volatilizing compounds formed by the reaction of zinc, iron, aluminum and calcium as impurities; the non-volatilized compound formed by the reaction of zinc and impurities can segregate at the grain boundary after the solidification of silicon, hydrochloric acid is adopted for washing and removing after the solidification, the purpose of removing impurity iron, aluminum and calcium in industrial silicon melt is achieved, redundant gas zinc enters a pipeline under the action of compressed gas, and the gas zinc in the pipeline is recovered in a condensation mode.
The content of impurity iron in the industrial silicon before impurity removal is 330ppm, the content of impurity aluminum is 220ppm, and the content of impurity calcium is 100ppm; the content of impurity iron after refining was 176ppm, the content of impurity aluminum after refining was 83ppm, and the content of impurity calcium after refining was 41ppm.
Experimental example 3:
compressed argon is introduced into the ladle, the ventilation pressure is 0.25MPa, the gas flow is 1000L/h, and the ventilation time is 30min. Adding zinc into industrial silicon melt to be removed of impurities in a ladle, gradually adding the zinc into the industrial silicon melt in batches, adding industrial zinc into the industrial silicon melt, and standing for reaction for 30min after adding the industrial zinc, wherein the total mass of the added industrial zinc particles is 0.2% of the mass of the industrial silicon. Maintaining the temperature of the silicon melt at 1800 ℃, and removing compounds formed by the reaction of zinc and impurities of iron, aluminum and calcium through volatilization; the non-volatilized compound formed by the reaction of zinc and impurities can segregate at the grain boundary after the solidification of silicon, hydrochloric acid is adopted for washing and removing after the solidification, the purpose of removing impurity iron, aluminum and calcium in industrial silicon melt is achieved, redundant gas zinc enters a pipeline under the action of compressed gas, and the gas zinc in the pipeline is recovered in a condensation mode.
The content of impurity iron in the industrial silicon before impurity removal is 330ppm, the content of impurity aluminum is 220ppm, and the content of impurity calcium is 100ppm; the content of impurity iron after refining is 153ppm, the content of impurity aluminum after refining is 72ppm, and the content of impurity calcium after refining is 35ppm.
Experimental example 4:
compressed argon is introduced into the ladle, the ventilation pressure is 0.25MPa, the gas flow is 1000L/h, and the ventilation time is 30min. Adding zinc into industrial silicon melt to be decontaminated in a ladle, adding 0.2% of the total mass of industrial zinc particles, gradually adding the zinc in batches, standing for reaction for 60min after adding industrial zinc to keep the temperature of the silicon melt at 1800 ℃, and volatilizing compounds formed by the reaction of the zinc and impurities of iron, aluminum and calcium; the non-volatilized compound formed by the reaction of zinc and impurities can segregate at the grain boundary after the solidification of silicon, hydrochloric acid is adopted for washing and removing after the solidification, the purpose of removing impurity iron, aluminum and calcium in industrial silicon melt is achieved, redundant gas zinc enters a pipeline under the action of compressed gas, and the gas zinc in the pipeline is recovered in a condensation mode.
The content of impurity iron in the industrial silicon before impurity removal is 330ppm, the content of impurity aluminum is 220ppm, and the content of impurity calcium is 100ppm; the content of impurity iron after refining is 145ppm, the content of impurity aluminum after refining is 65ppm, and the content of impurity calcium after refining is 31ppm.
Experimental example 5:
compressed argon is introduced into the ladle, the ventilation pressure is 0.3MPa, the gas flow is 1000L/h, and the ventilation time is 20min. Adding zinc into industrial silicon melt to be decontaminated in a ladle, gradually adding industrial zinc particles with the total mass of 0.2% of the mass of the industrial silicon in batches, standing for reaction for 60min after adding industrial zinc, keeping the temperature of the silicon melt at 1800 ℃, and volatilizing compounds formed by the reaction of zinc, iron, aluminum and calcium as impurities; the non-volatilized compound formed by the reaction of zinc and impurities can segregate at the grain boundary after the solidification of silicon, hydrochloric acid is adopted for washing and removing after the solidification, the purpose of removing impurity iron, aluminum and calcium in industrial silicon melt is achieved, redundant gas zinc enters a pipeline under the action of compressed gas, and the gas zinc in the pipeline is recovered in a condensation mode.
The content of impurity iron in the industrial silicon before impurity removal is 330ppm, the content of impurity aluminum is 220ppm, and the content of impurity calcium is 100ppm; the content of impurity iron after refining is 110ppm, the content of impurity aluminum after refining is 51ppm, and the content of impurity calcium after refining is 20ppm.
Comparative example:
compressed argon is introduced into the ladle, the pressure of the compressed argon is 0.25MPa, the gas flow is 1000L/h, the ventilation time is 20min, and the ladle is kept stand for 30min without adding zinc. The content of impurity iron in the industrial silicon is 330ppm, the content of impurity aluminum is 220ppm, and the content of impurity calcium is 100ppm; the content of impurity iron after refining is 328ppm, the content of impurity aluminum after refining is 120ppm, and the content of impurity calcium after refining is 65ppm. It can be seen that there was substantially no change before and after the reaction.
The foregoing is only a preferred embodiment of the present invention, but the scope of the present invention is not limited thereto, and any person skilled in the art who is skilled in the art to which the present invention pertains will appreciate that the technical scheme and the inventive concept according to the present invention are equally substituted or changed within the scope of the present invention.
Claims (8)
1. A method for preparing low-iron aluminum calcium content silicon is characterized in that compressed gas is introduced into a ladle, solid zinc is added into industrial silicon melt to be decontaminated in the ladle, the temperature of the silicon melt is kept above 1700 ℃, the solid zinc is converted into gaseous zinc at high temperature, compounds formed by the reaction of the gaseous zinc and impurities are removed through volatilization, the non-volatilized impurity compounds after solidification of the silicon are biased to grain boundaries, the solidified industrial silicon is crushed until zinc iron, zinc aluminum and zinc calcium alloy at the grain boundaries are exposed to the outside, the crushed industrial silicon material is soaked in an acid solution, the zinc iron, zinc aluminum and zinc calcium alloy at the grain boundaries react with the acid to generate inorganic salt and dissolve out, the aim of removing the impurity compounds is achieved, and redundant gaseous zinc enters a pipeline under the action of the compressed gas to achieve the aim of removing impurities in the industrial silicon melt.
2. The method of claim 1, wherein the compressed gas is compressed argon.
3. The method for preparing low-iron aluminum calcium content silicon according to claim 1, wherein the ventilation pressure of the compressed gas is 0.2-0.3 MPa, the gas flow rate is 800-1200L/h, and the ventilation time is 20-60 min.
4. The method for preparing the low-iron aluminum calcium content silicon according to claim 1, wherein the reaction time of the gaseous zinc and the impurities of iron, aluminum and calcium is 30-60 min.
5. A method for producing silicon with low iron, aluminum and calcium content according to claim 1 or 4, wherein the mass of added zinc is 0.15-0.3% of the mass of industrial silicon.
6. The method for preparing low-iron aluminum calcium content silicon according to claim 1, wherein the temperature of the industrial silicon melt is 1700 ℃, and a volatilizing method is adopted to remove compounds formed by the reaction of zinc and impurity iron.
7. The method for preparing low-iron aluminum calcium content silicon according to claim 1, wherein the content of impurity iron in the industrial silicon melt is 200ppm to 350ppm, the content of impurity aluminum is 150ppm to 220ppm, and the content of impurity calcium is 100ppm to 150ppm.
8. A method for preparing low iron aluminum calcium silicon according to claim 1, further comprising the step of condensing the gaseous zinc in the pipeline.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202210463862.2A CN114735708B (en) | 2022-04-29 | 2022-04-29 | Method for preparing silicon with low content of iron, aluminum and calcium |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202210463862.2A CN114735708B (en) | 2022-04-29 | 2022-04-29 | Method for preparing silicon with low content of iron, aluminum and calcium |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN114735708A CN114735708A (en) | 2022-07-12 |
| CN114735708B true CN114735708B (en) | 2023-06-02 |
Family
ID=82286072
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN202210463862.2A Active CN114735708B (en) | 2022-04-29 | 2022-04-29 | Method for preparing silicon with low content of iron, aluminum and calcium |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN114735708B (en) |
Citations (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPH08325618A (en) * | 1995-05-26 | 1996-12-10 | Nippon Steel Corp | Method for concentrating zinc component from zinc-containing material by dephosphorization of low-silicon molten iron |
Family Cites Families (7)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| GB755279A (en) * | 1954-05-26 | 1956-08-22 | Union Carbide Ltd | An improved method for decreasing the amount of aluminium and calcium in silicon metal or ferro-silicon alloys |
| EP1550636A4 (en) * | 2002-09-12 | 2012-03-07 | Asahi Glass Co Ltd | Process for producing high-purity silicon and apparatus |
| TW200700316A (en) * | 2005-03-24 | 2007-01-01 | Umicore Nv | Process for the production of si by reduction of sicl4 with liquid zn |
| JP5275110B2 (en) * | 2009-03-30 | 2013-08-28 | コスモ石油株式会社 | Method for producing polycrystalline silicon ingot |
| WO2010148484A1 (en) * | 2009-06-24 | 2010-12-29 | The Governing Council Of The Universtiy Of Toronto | Method of removal of impurities from silicon |
| CN102311121A (en) * | 2011-08-29 | 2012-01-11 | 大连理工大学 | Method for segregation and purification of industrial silicon by alloying |
| CN102583389A (en) * | 2012-03-05 | 2012-07-18 | 昆明理工大学 | Method for purifying industrial silicon through external refining |
-
2022
- 2022-04-29 CN CN202210463862.2A patent/CN114735708B/en active Active
Patent Citations (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPH08325618A (en) * | 1995-05-26 | 1996-12-10 | Nippon Steel Corp | Method for concentrating zinc component from zinc-containing material by dephosphorization of low-silicon molten iron |
Also Published As
| Publication number | Publication date |
|---|---|
| CN114735708A (en) | 2022-07-12 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CA2580398C (en) | Process for the production of ge by reduction of geci4, with liquid metal | |
| CN103952517B (en) | Containing the treatment process of vanadium chromium hot melt and the smelting process of high-chromic vanadium titanium magnet ore concentrate | |
| CN113151685B (en) | Recovery method of ultra-pure copper-manganese target material | |
| ZA200205292B (en) | Process for refining silver bullion with gold separation. | |
| CN101712474B (en) | Method for preparing solar-grade high-purity silicon by dilution purifying technology | |
| CN114735708B (en) | Method for preparing silicon with low content of iron, aluminum and calcium | |
| CN101343694A (en) | Dezincing smelting method for waste mixed aluminum alloy containing zinc | |
| CN109609769B (en) | Process for directly producing anode plate by adopting oxygen-enriched smelting furnace | |
| CN108950143B (en) | Comprehensive utilization method of phosphorus and iron as yellow phosphorus smelting by-product | |
| CN108675306B (en) | Method for efficiently recovering silicon metal in silicon slag | |
| US8187564B2 (en) | Process for producing boron added purified silicon | |
| US6638336B1 (en) | Manufacture of cost-effective titanium powder from magnesium reduced sponge | |
| CN109266863A (en) | A kind of high purity titanium ingot method of purification | |
| CN111041240B (en) | Method for preparing ferrotitanium alloy by using perovskite concentrate as raw material | |
| CN110218836B (en) | Method for dealuminizing and purifying ferrosilicon | |
| CN114890428B (en) | Ternary slag former for external refining of industrial silicon and impurity removing method thereof | |
| CN108441595B (en) | Fluxing agent for quickly melting waste vanadium slag, preparation method and melting method thereof | |
| JP2002534602A (en) | Aluminum production by carbon heating using aluminum scrap as coolant. | |
| CN103966382B (en) | The treatment process of vanadium-bearing hot metal and the smelting process of v-ti magnetite concentrate | |
| CN111348654B (en) | Method for granulating industrial silicon slag by water quenching and separating silicon and slag | |
| CN114735707B (en) | Method for removing phosphorus and boron impurities in industrial silicon melt by external refining | |
| CN114000033B (en) | Smelting method of electrode bar base material and application of electrode bar base material in electroslag remelting G20Cr2Ni4E steel | |
| CN115717199B (en) | Refining method of metallic lithium | |
| CN117385203A (en) | Method for recycling metal beryllium from beryllium-containing waste | |
| CN101863476A (en) | Method for removing boron element from silicon |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| PB01 | Publication | ||
| PB01 | Publication | ||
| SE01 | Entry into force of request for substantive examination | ||
| SE01 | Entry into force of request for substantive examination | ||
| GR01 | Patent grant | ||
| GR01 | Patent grant |