CN1673398A - Application of silicon-aluminium alloy in magnesium smelting as reducing agent - Google Patents
Application of silicon-aluminium alloy in magnesium smelting as reducing agent Download PDFInfo
- Publication number
- CN1673398A CN1673398A CN 200410028599 CN200410028599A CN1673398A CN 1673398 A CN1673398 A CN 1673398A CN 200410028599 CN200410028599 CN 200410028599 CN 200410028599 A CN200410028599 A CN 200410028599A CN 1673398 A CN1673398 A CN 1673398A
- Authority
- CN
- China
- Prior art keywords
- silicon
- magnesium
- reducing agent
- reaction
- yield
- 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
Landscapes
- Manufacture And Refinement Of Metals (AREA)
Abstract
The present invention relates to the application of Si-Al alloy as reductant in smelting magnesium. The Si-Al alloy consists of Al 40-70 wt% and Si 25-55 wt% as basic components except impurity and has the added amount of 30-50 wt% of MgO in magnesium material. The present invention substitutes Si-Al alloy for Si-Fe alloy as reductant in smelting magnesium, and can reduce the amount of the reductant, lower reaction temperature, shorten reaction period and raise magnesium yield.
Description
Technical Field
The invention relates to application of silicon-aluminum alloy as a reducing agent in magnesium smelting.
Background
The magnesium metal is widely applied to the fields of aerospace, national defense, automobiles, electronics, metallurgy, chemical industry and the like, the current production method of the magnesium metal mainly comprises an electrolysis method and a Pidgeon method (silicothermic method), the Pidgeon method is adopted to produce the magnesium metal in most areas of China, the Pidgeon method is adopted to produce the magnesium metal by adopting a raw material which is mainly dolomite, and the main component is a compound (MgCO) of magnesium carbonate and calcium carbonate3·CaCO3) The production process includes calcining dolomite into calcined dolomite (MgO.CaO), and mixing calcined dolomite with reductant and fluorite (CaF)2) And after the mixture is ground into powder and pelletized, the powder is placed into a reduction tank with the vacuum degree of 1-15Pa for heating, oxidation-reduction reaction is carried out, Mg in MgO is reduced into crude magnesium by a reducing agent, and the crude magnesium is refined to form high-purity metal magnesium.
In the Pidgeon method production process, a reducing agent is one of main factors determining the energy consumption, yield, production efficiency and production cost of magnesium metal production, currently most enterprises adopt ferrosilicon as the reducing agent, which is changed for decades and is composed of Si (free) and FeSi2、FeSi、Fe3Si2With small amounts of other ferrosilicon compounds, andthe primogenicity is Si (free)>FeSi from high to low2＞FeSi＞Fe3Si2In the actual chemical reaction, mainly plays a role in Si (dissociation), Fe does not basically play a role in reduction, and the ferrosilicon is used as a reducing agent, so that the following main problems exist in the actual production:
1. the energy consumption is high, Fe in the ferrosilicon basically does not participate in reduction, but a large amount of heat is consumed;
2. the yield of magnesium is low, the yield of magnesium produced by Pidgeon process is about 75%, and the rest part of magnesium remains in waste slag;
3. the reaction rate is low, the main reducing agent is Si (free), and the activity of the Si (free) in the nonmetallic reducing agent is poor, so the reaction rate is low and the reaction time is long;
4. the material consumption is high, taking 75# ferrosilicon as an example, nearly 1.13Kg75# ferrosilicon is theoretically consumed for producing 1Kg magnesium, and in the current production cost, the reducing agent accounts for more than 50% of the production cost.
Disclosure of Invention
In order to solve the problems, the invention provides the application of the silicon-aluminum alloy as the reducing agent in magnesium smelting, and the silicon-aluminum alloy (2 Al. Si) is adopted to replace 75# silicon iron as the reducing agent in the magnesium smelting process, so that the using amount of the reducing agent can be reduced, the reaction temperature is reduced, the reaction time is shortened, and the yield of magnesium is improved.
The technical scheme of the invention is as follows:
the application of the silicon-aluminum alloy as a reducing agent in magnesium smelting,
wherein the silicon-aluminum alloy has the basic composition of
Al 40％-70％
Si 55％-25％
The balance of impurities are included in the raw materials,
wherein the dosage of the silicon-aluminum alloy accounts for 30 to 50 percent of the mass of MgO contained in the raw material calcined dolomite,
the reaction temperature is 1000-1300 ℃.
The invention has the beneficial effects that:
1. the consumption of the reducing agent is small, the silicon-aluminum alloy (2 Al-Si) consumed theoretically for producing 1kg of magnesium is about 0.675kg, the consumption of the reducing agent is reduced by 0.455kg compared with the consumption of 75# silicon iron, and the price of the 75# silicon iron and the silicon-aluminum alloy (2 Al-Si) in the current market is basically the same;
2. the reduction temperature is low, magnesium escapes from the material ball in a gaseous state in the production process, and is cooled and crystallized to form solid metal, the boiling point of the magnesium is 1090 ℃, and MgO decomposition, CaO and SO are generated in the actual thermochemical reaction2、Al2O3Etc. there are both endotherms and exotherms in the combination, and the change in the reaction energy (heat) of silicon and aluminum is calculated:
the relationship between free energy and temperature is Δ G1＝441840-249.9T
The initial reaction temperature is T1＝1495.07℃
The relationship between free energy and temperature is Δ G2＝7120967-4516.89T
The initial reaction temperature is T2＝1303.5℃
Temperature difference T2-T1＝1495.07-1303.5＝191.57℃
Theoretically, the initial reaction temperature of aluminum can be reduced by 191.57 ℃ compared with the reaction temperature of aluminum using silicon as a reducing agent, the reduction temperature of aluminum silicon alloy (2 Al. Si) using the reducing agent in actual production can be between 1100 ℃ and 1150 ℃, and the reduction temperature of 75# silicon iron using the reducing agent is usually between 1200 ℃ and 1250 ℃;
3. the reduction time is shortened, the Pidgeon method for producing metal magnesium is completed in a closed system with the pressure below 15Pa, the thermal conductivity coefficient of the silicon-aluminum alloy (2 Al-Si) is higher than that of 75# ferrosilicon, in addition, the activity of aluminum atoms in the silicon-aluminum alloy (2 Al-Si) is much stronger than that of silicon and iron atoms in the ferrosilicon, the chemical reaction rate of aluminum and oxygen is accelerated, the reaction time is correspondingly shortened, and the reaction equilibrium vapor pressure of the silicon-aluminum alloy and the 75# ferrosilicon is calculated:
k＝(P3 Mg/a2 Al)7in the formula: k is an equilibrium constant, PMgEquilibrium vapor pressure (unit: Pa), a for the reaction of magnesiumAlIs the activity of aluminum (a at a reaction temperature of 1200℃)Al＝0.76，aSi0.2) calculated at 1200 ℃: pMg＝25044Pa，PSi4472.4Pa, 1000 ℃: pMg＝5418Pa，PSi＝141.9Pa
The magnesium vapor pressure of the Si-Al alloy reaches 5418Pa at 1000 ℃, the pressure of the Si-Al alloy exceeds the equilibrium vapor pressure 4472.4Pa. of 75# ferrosilicon at 1200 ℃, the pressure of the Si-Al alloy is more than 5 times greater than that of the 75# ferrosilicon at 1200 ℃ (25044/4472.4 is 5.6), the higher the vapor pressure is, the higher the magnesium vapor escape speed is, and experimental tests show that the reduction time of the ferrosilicon is 10-12 hours and the reduction time of the Si-Al alloy (2 Al. Si) is 6-8 hours under the same conditions;
4. the yield is high, although the Pidgeon magnesium smelting process is not complex, the factors influencing the magnesium yield are many, the reducing agent is one of the main factors, and through the test comparison of the silicon-aluminum alloy (2 Al-Si) and 75# ferrosilicon in Pidgeon magnesium smelting, the silicon-aluminum alloy (2 Al-Si) is used as the reducing agent, the yield of magnesium is generally more than 80 percent and can reach more than 90 percent at most, and is about5 percent higher than that of ferrosilicon used as the reducing agent under the same condition.
Detailed Description
Example 1
84Kg of calcined dolomite (39 percent of MgO content) as a raw material, 13Kg of silicon-aluminum alloy containing 55 percent of silicon, 40 percent of aluminum and 5 percent of impurities, which accounts for 39.68 percent of the mass of MgO contained in the calcined dolomite as the raw material, 3Kg of fluorite are mixed, ground, pelletized and then put into a reduction tank with the vacuum degree of 15Pa, the reaction temperature is controlled at 1150 ℃, the reaction time is 8Hr, and the yield of magnesium after the reaction is 74.50 percent.
Example 2
13Kg of Si-Al alloy containing 50% of Si, 45% of Al and 5% of impurities was used under the same conditions as in example 1, and the yield of Mg after the reaction was 86.12%.
Example 3
13Kg of Si-Al alloy containing 45% of Si, 50% of Al and 5% of impurities was used under the same conditions as in example 1, and the yield of Mg after the reaction was 84.21%.
Example 4
13Kg of Si-Al alloy containing 40% of Si, 55% of Al and 5% of impurities was used under the same conditions as in example 1, and the yield of Mg after the reaction was 87.40%.
Example 5
13Kg of Si-Al alloy containing 35% of Si, 60% of Al and 5% of impurities was used under the same conditions as in example 1, and the yield of Mg after the reaction was 89.75%.
Example 6
13Kg of Si-Al alloy containing 30% of Si, 65% of Al and 5% of impurities was used under the same conditions as in example 1, and the yield of Mg after the reaction was 92.02%.
Example 7
13Kg of Si-Al alloy containing 25% of Si, 70% of Al and 5% of impurities was used under the same conditions as in example 1, and the yield of Mg after the reaction was 93.55%.
Example 8
84Kg of calcined dolomite (39 percent of MgO content) as a raw material, 13Kg of silicon-aluminum alloy containing 68 percent of silicon and 32 percent of aluminum accounting for 39.68 percent of the mass of MgO contained in the calcined dolomite as a raw material, 3Kg of fluorite are mixed, ground, pelletized and then put into a reduction tank with the vacuum degree of 15Pa, the reaction temperature is controlled to be 1000 ℃, the reaction time is 8Hr, and the yield of magnesium after the reaction is 73.39 percent.
Example 9
The reaction temperature was controlled to 1050 ℃ and the other conditions were the same as in example 8, whereby the yield of magnesium after the reaction was 79.40%.
Example 10
The reaction temperature was controlled at 1100 deg.C, and the other conditions were the same as in example 8, whereby the yield of magnesium after the reaction was 85.26%.
Example 11
The reaction temperature was controlled to 1150 deg.C, and the yield of magnesium after the reaction was 87.14% under the same conditions as in example 8.
Example 12
The reaction temperature was controlled at 1200 ℃ and the other conditions were the same as in example 8, whereby the yield of magnesium after the reaction was 86.31%.
Example 13
The reaction temperature was controlled to 1250 ℃ and the remaining conditions were the same as in example 8, and the yield of magnesium after the reaction was 78.43%.
Example 14
The reaction temperature was controlled to 1300 ℃ and the other conditions were the same as in example 8, so that the yield of magnesium after the reaction was 70.18%.
Example 15
84Kg of calcined dolomite (39 percent of MgO content) as a raw material, 9.828Kg of silicon-aluminum alloy containing 68 percent of silicon and 32 percent of aluminum accounting for 30 percent of the mass of MgO contained in the calcined dolomite as a raw material, 3Kg of fluorite are mixed, ground, pelletized and then put into a reduction tank with the vacuum degree of 15Pa, the temperature is controlled at 1150 ℃, the reaction time is 8Hr, and the yield of magnesium after the reaction is 63.99 percent.
Example 16
14Kg of Si-Al alloy containing 68% of Si and 32% of Al, which accounted for 42.7% by mass of MgO contained in the calcined dolomite, were taken, the remaining conditions were the same as in example 15, and the yield of Mg after the reaction was 87.32%.
Example 17
16.38Kg of Si-Al alloy containing 68% of Si and 32% of Al, which accounted for 50% by mass of MgO contained in the calcined dolomite, were taken, the remaining conditions were the same as in example 15, and the yield of Mg after the reaction was 88.26%.
Example 18
84Kg of calcined dolomite (39 percent of MgO content) as a raw material, 13Kg of silicon-aluminum alloy containing 68 percent of silicon and 32 percent of aluminum accounting for 39.68 percent of the mass of MgO contained in the calcined dolomite as a raw material, 3Kg of fluorite are mixed, ground, pelletized and then putinto a reduction tank with the vacuum degree of 15Pa, the temperature is controlled at 1150 ℃, the reaction time is 6Hr, and the yield of magnesium after the reaction is 83.19 percent.
Example 19
84Kg of calcined dolomite (39 percent of MgO content) as a raw material, 13Kg of silicon-aluminum alloy containing 68 percent of silicon and 32 percent of aluminum accounting for 39.68 percent of the mass of MgO contained in the calcined dolomite as a raw material, 3Kg of fluorite are mixed, ground, pelletized and then put into a reduction tank with the vacuum degree of 10Pa, the reaction temperature is controlled at 1150 ℃, the reaction time is 8Hr, and the yield of magnesium after the reaction is 90.31 percent.
Example 20
The degree of vacuum in the reduction vessel was 15Pa, and the yield of magnesium after the reaction was 87.14% under the same conditions as in example 19.
Example 21
The degree of vacuum in the reduction vessel was 20Pa, and the yield of magnesium after the reaction was 82.26% under the same conditions as in example 19.
Claims (4)
1. The silicon-aluminum alloy is used as a reducing agent in magnesium smelting.
2. The use of the silicon aluminum alloy of claim 1 as a reducing agent in magnesium smelting, wherein: the silicon-aluminum alloy comprises the following basic components
Al 40％-70％
Si 55％-25％
The balance being impurities.
3. The use of the silicon aluminum alloy of claim 2 as a reducing agent in magnesium smelting, wherein: the dosage of the silicon-aluminum alloy accounts for 30-50% of the mass of MgO contained in the raw material calcined dolomite.
4. The use of the silicon aluminum alloy of claim 3 as a reducing agent in magnesium smelting, wherein: the reaction temperature is 1000-1300 ℃.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN 200410028599 CN1673398A (en) | 2004-03-25 | 2004-03-25 | Application of silicon-aluminium alloy in magnesium smelting as reducing agent |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN 200410028599 CN1673398A (en) | 2004-03-25 | 2004-03-25 | Application of silicon-aluminium alloy in magnesium smelting as reducing agent |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN1673398A true CN1673398A (en) | 2005-09-28 |
Family
ID=35046172
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN 200410028599 Pending CN1673398A (en) | 2004-03-25 | 2004-03-25 | Application of silicon-aluminium alloy in magnesium smelting as reducing agent |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN1673398A (en) |
Cited By (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN101705374A (en) * | 2009-11-06 | 2010-05-12 | 北京大学 | Process for improving production rate of metal magnesium by accelerating reduction |
| CN101113081B (en) * | 2006-07-25 | 2012-07-25 | 贵州世纪天元矿业有限公司 | Method for smelting magnesium by thermal reduction process with co-production of hydraulic gelling material |
| CN112501434A (en) * | 2020-10-19 | 2021-03-16 | 北京中冶设备研究设计总院有限公司 | Liquid magnesium smelting reducing agent and application thereof |
-
2004
- 2004-03-25 CN CN 200410028599 patent/CN1673398A/en active Pending
Cited By (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN101113081B (en) * | 2006-07-25 | 2012-07-25 | 贵州世纪天元矿业有限公司 | Method for smelting magnesium by thermal reduction process with co-production of hydraulic gelling material |
| CN101705374A (en) * | 2009-11-06 | 2010-05-12 | 北京大学 | Process for improving production rate of metal magnesium by accelerating reduction |
| CN112501434A (en) * | 2020-10-19 | 2021-03-16 | 北京中冶设备研究设计总院有限公司 | Liquid magnesium smelting reducing agent and application thereof |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN1056415C (en) | Aluminium-contained premelting slag and preparation method therefor, and molten steel desulfurizer and purifier containing same | |
| CN100398679C (en) | Method of preparing Mg, Sr alloy by vacuum heat reduction | |
| CN1900332A (en) | Method for preparing copper base composite material by chemical precipitation method to obtain composite powder | |
| CN1814835A (en) | Method for producing aluminium-magnesium-scandium intemediate alloy | |
| CN1821429A (en) | Method for producing aluminium enriched slag for extracting aluminium oxide and silicon-iron alloy | |
| CN102560224A (en) | Composite inoculant | |
| CN1081244C (en) | Composite crystal grain fining agent for aluminium and aluminium alloy and preparation process thereof | |
| CN101555554A (en) | Copper smelting agent and manufacture process thereof | |
| CN1673398A (en) | Application of silicon-aluminium alloy in magnesium smelting as reducing agent | |
| CN1619003A (en) | High strength casted aluminium silicon series alloy and its preparation method | |
| WO2011127672A1 (en) | Method for producing metallic magnesium by vacuum reduction | |
| CN1292083C (en) | Method for producing high titanium iron | |
| CN101302576B (en) | Dolomite-based desulfurizer based on in-situ reduction and preparation thereof | |
| CN100389219C (en) | Nickel-silicon-boron intermediate alloy and process for preparing same | |
| CN1209471C (en) | Composite metallurgical refining agent | |
| CN112779432A (en) | Melt purifying agent for vacuum melting of aluminum-magnesium alloy and preparation method thereof | |
| CN100389220C (en) | Method for preparing intermediate alloy of aluminum, silicon and posphor | |
| CN1017809B (en) | Titanium silicon and process thereof | |
| KR101434262B1 (en) | Aluminium alloy and manufacturing method thereof | |
| CN1017811B (en) | Low-aluminium silicon-titanium-iron alloy and its producing process | |
| CN1215086A (en) | Agent for refining and heat-insulating of molten steel surface and its preparation process | |
| CN1189580C (en) | Vanadium-base solid solution hydrogen-storing alloy and its prepn process | |
| CN1664119A (en) | Slag from aluminum smelting for making clean steel and method for preparing same | |
| CN103509957A (en) | Method for producing high ferro-titanium alloy by using titanium slag and titanium concentrate as titanium and iron raw materials | |
| CN102864315B (en) | Vacuum magnesium making method using magnesium-silicon alloy as reducing agent |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| C06 | Publication | ||
| PB01 | Publication | ||
| C02 | Deemed withdrawal of patent application after publication (patent law 2001) | ||
| WD01 | Invention patent application deemed withdrawn after publication |