阅读说明：本技术 金属镁的生产方法 (Method for producing metal magnesium ) 是由 李凤善 黄忠源 梁文玉 张富信 刘猛 张�杰 徐子涵 陈欣舒 于 2020-12-30 设计创作，主要内容包括：本发明提供一种金属镁的生产方法,包括如下步骤：将高温熔融态的镍铁渣加入到真空反应容器中,并对真空反应容器进行抽真空处理；向抽真空处理后的真空反应容器中喷入还原剂粉末；对喷入还原剂粉末的真空反应容器进行加热处理,使镍铁渣与还原剂粉末发生充分还原反应,得到低硅位SiFe和高品位的含镁渣；向充分还原反应后的真空反应容器中加入稀渣剂,得到含有氧化镁的液态稀渣；向加入稀渣剂后的真空反应容器中加入硅铁,对真空反应容器内产生的单质镁进行净化回收处理,得到金属镁。利用本发明能够解决现有技术中,从镍铁渣中提取金属镁的过程中反应效率低、成本高、对镍铁渣的利用量有限等问题。(The invention provides a method for producing metal magnesium, which comprises the following steps: adding the ferronickel slag in a high-temperature molten state into a vacuum reaction container, and vacuumizing the vacuum reaction container; spraying reducing agent powder into the vacuum reaction container after vacuum-pumping treatment; heating the vacuum reaction container sprayed with the reducing agent powder to ensure that the ferronickel slag and the reducing agent powder are subjected to full reduction reaction to obtain low-silicon-level SiFe and high-grade magnesium-containing slag; adding a slag diluting agent into the vacuum reaction container after the full reduction reaction to obtain liquid slag containing magnesium oxide; and adding ferrosilicon into the vacuum reaction container after the slag diluent is added, and purifying and recycling the simple substance magnesium generated in the vacuum reaction container to obtain the metal magnesium. The method can solve the problems of low reaction efficiency, high cost, limited utilization amount of the ferronickel slag and the like in the process of extracting the metal magnesium from the ferronickel slag in the prior art.)

1. A method for producing magnesium metal, characterized in that the method comprises the following steps:

adding the ferronickel slag in a high-temperature molten state into a vacuum reaction container, and vacuumizing the vacuum reaction container to maintain the internal pressure of the vacuum reaction container at 5000-10000 Pa;

spraying reducing agent powder into the vacuum reaction container by using inert gas as a carrier through a spraying device; wherein the amount of effective reducing components in the reducing agent powder is 1-1.1 times of the molar equivalent of the sum of iron and silicon in the ferronickel slag; the pressure of inert gas in the vacuum reduction reaction container is 1500Pa-3000 Pa;

heating the vacuum reaction container sprayed with the reducing agent powder to maintain the temperature in the vacuum reaction container at 1550 +/-50 ℃, and preserving the temperature for 30-50 min to ensure that the ferronickel slag and the reducing agent powder are subjected to full reduction reaction to obtain low-silicon-level SiFe and high-grade magnesium-containing slag; wherein, in the low silicon SiFe, the Si content is 30-55%; in the high-grade magnesium-containing slag, the MgO content is 30-50%;

adding a slag diluent into the vacuum reaction container after the full reduction reaction, and diluting the high-grade magnesium-containing slag to obtain liquid slag containing magnesium oxide;

adding ferrosilicon into the vacuum reaction container after the slag diluent is added, heating and vacuumizing the vacuum reduction reaction container, and purifying and recycling the simple substance magnesium generated in the vacuum reaction container through a purifying device when the internal pressure of the vacuum reaction container is 1000Pa +/-100 Pa and the temperature is 1450-1600 ℃ to obtain the metal magnesium.

2. The method for producing metallic magnesium according to claim 1, wherein the temperature of the ferronickel slag in a high-temperature molten state is 1450 ℃ to 1500 ℃.

3. The method for producing metallic magnesium according to claim 1, wherein the reducing agent powder is carbon powder; wherein the carbon powder is bituminous coal carbon powder or semi-coke carbon powder.

4. The method for producing metallic magnesium according to claim 1, wherein in the process of heating the vacuum reaction vessel into which the reducing agent powder is injected to maintain the temperature in the vacuum reaction vessel at 1550 ℃ ± 50 ℃ and maintaining the temperature for 30min to 50min to cause the nickel iron slag and the reducing agent powder to undergo a sufficient reduction reaction to obtain a magnesium oxide-containing high viscosity slag,

the reduction reaction occurring within the vacuum reaction vessel comprises:

SiO₂(l)+5C(s)+Fe₂O₃(l)＝2SiFe(l)+5CO(g)。

5. the method for producing metallic magnesium according to claim 1, wherein the amount of the slag thinner added is 3-9% of the mass of the ferronickel slag.

6. The method for producing metallic magnesium according to claim 1, wherein the slag thinning agent is CaF₂Any one or at least two of KF and NaF are mixed according to any proportion.

Technical Field

The invention belongs to the technical field of comprehensive utilization of metallurgical waste residues, and particularly relates to a production method of magnesium metal.

Background

The ferronickel slag is liquid or solid waste slag discharged in the ferronickel smelting process, about 6 tons of slag are generated when 1 ton of ferronickel is produced, with the gradual expansion of ferronickel alloy smelting scale in China, the annual discharge amount of the ferronickel slag exceeds 3000 ten thousand tons, and the ferronickel slag becomes the fourth large smelting slag after the ferronickel slag, the steel slag and the red mud. Compared with other metallurgical slag, the valuable metal of the ferronickel slag is difficult to recover, the slag discharge amount is large, and the problem of metallurgical waste slag treatment is gradually solved. At present, the development of ferronickel slag disposal and utilization technology is relatively lagged, the comprehensive utilization rate of ferronickel slag in China is less than 10%, a large-scale absorption way is lacked, and stacking or landfill treatment is mainly adopted, so that not only is a large amount of land occupied, but also soil and environment are polluted, and serious challenges are brought to the sustainable development of ferronickel smelting. In order to reduce the harm caused by the ferronickel slag and improve the reutilization of secondary resources and explore a green development process for the ferronickel smelting industry, the comprehensive utilization research of the ferronickel slag needs to be enhanced.

At present, aiming at the characteristic that water-quenched ferronickel slag contains certain pozzolanic activity, the ferronickel slag can partially replace blast furnace slag, slag and the like to be used for preparing cement and concrete or used as concrete aggregate, and can also be used for preparing building materials such as slag fiber and microcrystalline glass by referring to a method for comprehensively utilizing blast furnace slag, slag and fly ash, but most of the ferronickel slag is in the laboratory research stage. The magnesia content of the cement raw material is required to be lower than 6 percent, and the magnesia content of the nickel-iron slag is generally higher than 25 percent. More importantly, the amount of the ferronickel slag processed and utilized by the method for manufacturing the microcrystalline glass, the inorganic polymer and the like is very small compared with the output of the ferronickel slag which is so large in China, and the ferronickel slag has no large-scale absorbability. And the elements such as Fe, Mg, Si, Al and the like cannot be comprehensively utilized, so that a great deal of waste of resources is caused. The main reason for restricting the wide application of the nickel-iron slag in these fields is the high magnesium content in the nickel-iron slag.

Patent CN107513621B discloses a method for enriching magnesium from ferronickel slag, which includes two schemes. The first scheme is as follows: taking molten ferronickel slag as a raw material, controlling the temperature of the molten ferronickel slag at 1500-600 ℃, then preserving the heat for at least 5min, and cooling; obtaining the rich magnesium slag and the poor magnesium slag. The second scheme is as follows: taking the cooled ferronickel slag as a raw material, heating the cooled ferronickel slag to be molten, cooling to 1500-600 ℃, preserving heat for at least 5min, and cooling; obtaining the rich magnesium slag and the poor magnesium slag. The method has simple process and low cost, is beneficial to the enrichment of valuable element magnesium in the ferronickel slag, enables the large-scale utilization of the ferronickel metallurgical slag to be possible, and has considerable social and economic benefits.

Patent CN108048667A discloses a method for recovering magnesium metal from high-magnesium ferronickel slag. The method mainly comprises the steps of taking high-magnesium nickel iron slag in a high-temperature molten state as a raw material, firstly adding solid carbon into equipment with a magnetic field, then adding magnesium-containing nickel iron slag into the equipment, vacuumizing until the pressure in a furnace is 5500Pa, and reacting to obtain simple substance magnesium. The invention has simple process and high utilization rate of energy and resources.

In the thesis of 'analysis of a process for smelting ferronickel-magnesium metal by a laterite-nickel ore pyrogenic process' for improving a Magnetium smelting process, ferrosilicon smelting reduction is carried out on ferronickel slag to obtain magnesium metal, and primary energy consumption, carbon emission and technical and economic indexes of the traditional magnesium smelting process and the production of magnesium by using the laterite-nickel ore hot-melt slag are comparatively analyzed to find that the production cost of the magnesium metal in the process is lower than that in the traditional process, and the process has good economic benefit. However, the article only theoretically analyzes the new process flow and does not carry out experimental verification.

The processes or methods described in the above patents or papers all perform certain research on magnesium extraction from the ferronickel slag, and realize utilization of the ferronickel slag to a certain extent, but most of the processes or methods are in a theoretical stage, and the reaction efficiency is not high, and the utilization amount of the ferronickel slag is very limited, so that elements such as Fe, Mg, Si, Al and the like and heat energy of high-temperature molten ferronickel slag cannot be comprehensively utilized, and a great deal of waste heat and resources are wasted.

Disclosure of Invention

In view of the above problems, the present invention aims to provide a method for producing magnesium metal, so as to solve the problems in the prior art that the reaction efficiency is low, the utilization amount of the ferronickel slag is limited, the elements such as Fe, Mg, Si, and Al and the heat energy of the high-temperature molten ferronickel slag cannot be comprehensively utilized, and a large amount of resources are wasted in the process of extracting magnesium metal from the ferronickel slag.

The invention provides a method for producing metal magnesium, which comprises the following steps:

adding the ferronickel slag in a high-temperature molten state into a vacuum reaction container, and vacuumizing the vacuum reaction container to maintain the internal pressure of the vacuum reaction container at 5000-10000 Pa;

spraying reducing agent powder into the vacuum reaction container by using inert gas as a carrier through a spraying device; wherein the amount of effective reducing components in the reducing agent powder is 1-1.1 times of the molar equivalent of the sum of iron and silicon in the ferronickel slag; the pressure of inert gas in the vacuum reduction reaction container is 1500Pa-3000 Pa;

heating the vacuum reaction container sprayed with the reducing agent powder to maintain the temperature in the vacuum reaction container at 1550 +/-50 ℃, and preserving the temperature for 30-50 min to ensure that the ferronickel slag and the reducing agent powder are subjected to full reduction reaction to obtain low-silicon-level SiFe and high-grade magnesium-containing slag; wherein, in the low silicon SiFe, the Si content is 30-55%; in the high-grade magnesium-containing slag, the MgO content is 30-50%;

adding a slag diluent into the vacuum reaction container after the full reduction reaction, and diluting the high-grade magnesium-containing slag to obtain liquid slag containing magnesium oxide;

adding ferrosilicon into the vacuum reaction container after the slag diluent is added, heating and vacuumizing the vacuum reduction reaction container, and purifying and recycling the simple substance magnesium generated in the vacuum reaction container through a purifying device when the internal pressure of the vacuum reaction container is 1000Pa +/-100 Pa and the temperature is 1450-1600 ℃ to obtain the metal magnesium.

In addition, the preferable scheme is that the temperature of the nickel-iron slag in a high-temperature molten state is 1450-1500 ℃.

In addition, preferably, the reducing agent powder is carbon powder; wherein the carbon powder is bituminous coal carbon powder or semi-coke carbon powder.

In addition, the preferable scheme is that in the process of heating the vacuum reaction container sprayed with the reducing agent powder to maintain the temperature in the vacuum reaction container at 1550 +/-50 ℃, preserving the temperature for 30-50 min to ensure that the nickel-iron slag and the reducing agent powder are subjected to full reduction reaction to obtain the magnesium oxide-containing high-viscosity slag,

the reduction reaction occurring within the vacuum reaction vessel comprises:

SiO₂(l)+5C(s)+Fe₂O₃(l)＝2SiFe(l)+5CO(g)。

in addition, the preferable scheme is that the addition amount of the slag diluting agent is 3-9% of the mass of the nickel-iron slag.

In addition, preferably, the slag thinning agent is CaF₂Any one or at least two of KF and NaF are mixed according to any proportion.

According to the technical scheme, the magnesium extracting reduction is carried out twice on the reducing agent powder and the ferrosilicon, the ferrosilicon and the magnesium-rich slag are obtained by carrying out low-vacuum thermal reduction on the high-temperature molten ferronickel slag, and a small amount of ferrosilicon is added on the basis to reduce the magnesium-rich slag to obtain the magnesium metal; the invention can be matched with a ferronickel furnace to consume 100% of liquid ferronickel slag, eliminates the harm of the ferronickel slag to the environment, is beneficial to the sustainable development of ferronickel production enterprises, fully utilizes the heat of the high-temperature ferronickel slag, reduces the energy consumption of reduction heating, and can effectively reduce the cost of magnesium smelting.

To the accomplishment of the foregoing and related ends, one or more aspects of the invention comprise the features hereinafter fully described. The following description and the annexed drawings set forth in detail certain illustrative aspects of the invention. These aspects are indicative, however, of but a few of the various ways in which the principles of the invention may be employed. Further, the present invention is intended to include all such aspects and their equivalents.

Drawings

Other objects and results of the present invention will become more apparent and more readily appreciated as the same becomes better understood by reference to the following description taken in conjunction with the accompanying drawings. In the drawings:

fig. 1 is a flow chart of a method for producing metallic magnesium according to an embodiment of the present invention.

The same reference numbers in all figures indicate similar or corresponding features or functions.

Detailed Description

In the following description, for purposes of explanation, numerous specific details are set forth in order to provide a thorough understanding of one or more embodiments. It may be evident, however, that such embodiment(s) may be practiced without these specific details.

Aiming at the problems that in the prior art, the reaction efficiency is low, the utilization amount of the ferronickel slag is limited, elements such as Fe, Mg, Si and Al and the heat energy of high-temperature molten ferronickel slag cannot be comprehensively utilized, and a large amount of resources are wasted, and the like in the process of extracting the magnesium metal from the ferronickel slag, a production method of the magnesium metal is provided.

Specific embodiments of the present invention will be described in detail below with reference to the accompanying drawings.

In order to explain the method for producing magnesium metal provided by the present invention, fig. 1 shows the flow of the method for producing magnesium metal of the embodiment of the present invention.

As shown in FIG. 1, the method for producing magnesium metal provided by the invention comprises the following steps:

s1, adding the ferronickel slag in a high-temperature molten state into a vacuum reaction container, and vacuumizing the vacuum reaction container to maintain the internal pressure of the vacuum reaction container at 5000-10000 Pa.

Specifically, the ferronickel slag in a high-temperature molten state is added into a vacuum reaction container through a feeding hopper and other devices, and the vacuum reaction container added with the ferronickel slag in the high-temperature molten state is vacuumized, so that the internal pressure of the vacuum reaction container is maintained at 5000Pa-10000 Pa.

Wherein the temperature of the nickel-iron slag in a high-temperature molten state is 1450-1500 ℃. The temperature is close to the temperature just generated by the ferronickel slag, and the temperature of the ferronickel slag in a high-temperature molten state can be fully utilized when the ferronickel slag is subsequently reduced, so that the reduction heating energy consumption is reduced, and the cost is reduced.

S2, spraying reducing agent powder into the vacuum reaction container by using inert gas as a carrier through a spraying device; wherein the amount of effective reducing components in the reducing agent powder is 1-1.1 times of the molar equivalent of the sum of iron and silicon in the ferronickel slag; the pressure of inert gas in the vacuum reduction reaction vessel is 1500Pa-3000 Pa.

Specifically, the reducing agent powder is sprayed into the vacuum reaction container to be reacted by using the inert gas as a carrier through the spraying device, so that the reducing agent powder is more fully contacted with the ferronickel slag, and the subsequent reduction reaction is facilitated.

Wherein, in the process of spraying the reducing agent powder into the vacuum reaction container by using inert gas as a carrier through the spraying device,

spraying reducing agent powder into a reaction ladle of a vacuum reaction container by using inert gas as a carrier through a spraying device; wherein the vacuum reaction container comprises a vacuum tank and a reaction ladle arranged in the vacuum tank; a molten pool is arranged at the bottom of the reaction ladle; a splash-proof cover is arranged at the top of the reaction ladle, a socket is arranged on the splash-proof cover, and a molten pool is arranged at the bottom of the reaction ladle; the top of the vacuum tank is provided with a vacuum cover, and the vacuum cover is provided with an opening; an opening is disposed below the socket. The vacuum reaction container is convenient to carry out vacuum treatment through the vacuum tank, and the reducing agent powder is convenient to spray into the reaction ladle through the socket on the splash-proof cover and the opening on the vacuum cover.

S3, heating the vacuum reaction container sprayed with the reducing agent powder to maintain the temperature in the vacuum reaction container at 1550 +/-50 ℃, and preserving the temperature for 30-50 min to ensure that the ferronickel slag and the reducing agent powder are subjected to full reduction reaction to obtain low-silicon-level SiFe and high-grade magnesium-containing slag; wherein, in the low silicon SiFe, the Si content is 30-55%; in the high-grade magnesium-containing slag, the MgO content is 30-50%;

specifically, the vacuum degree and the temperature can just control the iron and the silicon in the ferronickel slag to be fully reduced, but the aluminum and the magnesium do not react. Preserving heat for 30-50 min to make it generate sufficient reduction reaction, and the heating method can be selected to be electrified and heated.

Wherein, in the process of heating the vacuum reaction container sprayed with the reducing agent powder to maintain the temperature in the vacuum reaction container at 1550 +/-50 ℃, preserving the temperature for 30-50 min to ensure that the ferronickel slag and the reducing agent powder generate full reduction reaction to obtain low-silicon SiFe and high-grade magnesium-containing slag,

a spraying device penetrates through an opening of a vacuum cover and a socket of a splash-proof cover to be inserted into a reaction ladle, reducing agent powder is sprayed into the reaction ladle, a molten pool at the bottom of the reaction ladle is heated, the temperature in the molten pool is maintained at 1550 +/-50 ℃, the temperature is kept for 30-50 min, nickel-iron slag and the reducing agent powder are subjected to full reduction reaction, and low-silicon-level SiFe and high-grade magnesium-containing slag are obtained.

Wherein, the spraying device is a spray gun, and the spray gun is inserted into the vacuum reaction vessel through the opening of the vacuum cover and the socket of the splash-proof cover. The spray gun is a common spray device, and other spray devices may be selected for replacement, and are not particularly limited herein.

Wherein the reducing agent powder is carbon powder; wherein the carbon powder is bituminous coal carbon powder or semi-coke carbon powder. The carbon powder can better utilize the heat of the nickel-iron slag.

Wherein, in the process of heating the vacuum reaction container sprayed with the reducing agent powder to maintain the temperature in the vacuum reaction container at 1550 +/-50 ℃, preserving the temperature for 30-50 min to ensure that the ferronickel slag and the reducing agent powder have full reduction reaction to obtain the high-viscosity slag containing magnesium oxide,

the reduction reaction that takes place in the vacuum reaction vessel includes:

SiO₂(l)+5C(s)+Fe₂O₃(l) 2sife (l) +5co (g). And S4, adding a slag diluting agent into the vacuum reaction container after the full reduction reaction, and diluting the high-viscosity slag containing the magnesium oxide to obtain liquid slag containing the magnesium oxide.

Specifically, a proper amount of slag diluting agent is added into the vacuum reaction container through a feeding device, so that the high-viscosity slag with high magnesium oxide is converted into liquid slag acceptable for industrial production.

Wherein, the addition amount of the slag thinning agent is 3 to 9 percent of the mass of the nickel-iron slag.

Wherein the slag thinning agent is CaF₂Any one or at least two of KF and NaF are mixed according to any proportion.

S5, adding ferrosilicon into the vacuum reaction container added with the slag diluent, heating and vacuumizing the vacuum reduction reaction container, and purifying and recycling the simple substance magnesium generated in the vacuum reaction container through a purifying device when the internal pressure of the vacuum reaction container is 1000Pa +/-100 Pa and the temperature is 1450-1600 ℃ to obtain the metal magnesium.

Specifically, the ferrosilicon is 75 percent (the silicon accounts for 75 percent) and can further reduce the liquid slag, thereby being beneficial to the extraction of magnesium metal. Heating and vacuumizing, reducing high-grade magnesium-containing slag by a ferrosilicon liquid to generate simple substance magnesium when the pressure in a vacuum reaction container is 1000Pa +/-100 Pa and the temperature is 1450-.

The method can adopt a periodic reduction mode of a vacuum reaction container for production, namely, the consumption of Mg in the nickel-iron slag is reduced continuously in the continuous reduction process, and the reaction is stopped when the Mg is reduced to less than or equal to 5 percent. And replacing the new ferronickel slag liquid to start the reduction process of a new period again. The invention can also adopt the production of double vacuum reaction vessels in an alternative semi-continuous reduction mode, namely, two identical vacuum reaction vessels are adopted to connect the collecting pipeline in parallel on the same liquid collecting and collecting purification system and the exhaust system through the switching valve, and when one vacuum reaction vessel is in the first step, the SiO is reduced by carbon heat₂In the state, the discharged CO product gas enters a gas chamber for collection, the other vacuum reaction container is in a state of reducing magnesium oxide by ferrosilicon in the second step, and the product magnesium steam is switched to a collection and purification system to collect metal magnesium and byproduct metal.

According to the production method of the magnesium metal, provided by the invention, the ferrosilicon is subjected to low-vacuum thermal reduction and high-temperature melting of the ferronickel slag through two magnesium extraction reductions of the reducing agent powder and the ferrosilicon to obtain ferrosilicon and magnesium-rich slag, and a small amount of ferrosilicon is added to reduce the magnesium-rich slag to obtain the magnesium metal, so that the abundant heat energy of the ferronickel slag can be effectively utilized, and various elements Si, Fe, Mg and the like in the ferronickel slag can be comprehensively utilized to generate good economic benefits; the invention can be matched with a ferronickel furnace to consume 100% of liquid ferronickel slag, eliminates the harm of the ferronickel slag to the environment, is beneficial to the sustainable development of ferronickel production enterprises, fully utilizes the heat of the high-temperature ferronickel slag, reduces the energy consumption of reduction heating, and can effectively reduce the cost of magnesium smelting.

The production method of magnesium metal proposed according to the present invention is described above by way of example with reference to the accompanying drawings. However, it will be appreciated by those skilled in the art that various modifications may be made to the method for producing magnesium metal as set forth in the foregoing description without departing from the scope of the invention. Therefore, the scope of the present invention should be determined by the contents of the appended claims.