WO2011153683A1

WO2011153683A1 - Method for producing metallic magnesium by vacuum circulating silicothermic process and apparatus thereof

Info

Publication number: WO2011153683A1
Application number: PCT/CN2010/073643
Authority: WO
Inventors: 牛强; 储少军
Original assignee: Niu Qiang; Chu Shaojun
Priority date: 2010-06-07
Filing date: 2010-06-07
Publication date: 2011-12-15
Also published as: CN101999005A; CN101999005B; US20120198968A1

Abstract

A method for producing metallic magnesium by vacuum circulating silicothermic process and apparatus thereof. The method comprises the following steps: passing molten ferrosilicon (109) of 1350～1600℃ and magnesium ore powder containing magnesia blended therein through a vacuum container (104) with a vacuum of 350～10000Pa periodically in a manner of circulating flow, and collecting liquid magnesium (201), i.e. the magnesium vapor released upon condensing. The apparatus comprises a heating container (101) and a vacuum container (104) connected with an elevating dip pipe (102) and a falling dip pipe (103) whose lower ends immersed into the molten ferrosilicon (109) in the heating container (101). An inert gas blowing device is inserted into the elevating dip pipe (102) wall. The method and apparatus thereof can improve productivity.

Description

Method and device for preparing metal magnesium by vacuum circulating silicon thermal method

The invention relates to a method and a device for smelting magnesium, in particular to a method and a device for vacuum smelting silicon thermal magnesium smelting. Background technique

Magnesium and magnesium alloys have the advantages of light weight, high specific strength, good thermal conductivity, easy recovery, and low environmental pollution. They have important application value in the fields of automobile manufacturing, machinery and electronics, aerospace, defense and military industries. Known as "green materials in the 21st century."

There are generally two processes for the industrial production of magnesium metal: one type of book is electrolytic method; the other type is vacuum heat reduction method, which generally uses ferrosilicon as a reducing agent, which is generally used for the heating cycle reduction process outside the horizontal tank. Pi Jiangfa.

Electrolytic magnesium smelting has gradually given way to the Pijiang Law in recent years due to the inevitable environmental problems caused by the generation of chlorine.

China's primary magnesium production has accounted for about 80% of the world's share, almost all using Pijiang Fasheng, the so-called Pijiang method, is a refined magnesium method developed by the famous Canadian metallurgist LM Pidgeon in 1942, and named after him The process is still in use and there is no fundamental improvement. The process is shown in Figure 1. The silicon-containing silicon containing 75% silicon ferrite and the magnesia-containing calcined white powder are mixed into a solid phase contact method, placed in a horizontal tank made of heat-resistant steel, and the outside of the tank is heated by flame to promote horizontal The material in the tank is subjected to a chemical reaction, and the reaction temperature of the material is about 1150 to 1250 ° C, and the degree of vacuum is generally less than 20 Pa. The existing Pijiang method magnesium smelting has the following disadvantages:

1. The reactant ferrosilicon and calcined white are chemically reacted in solid phase contact mode, and the reaction rate is slow. The typical reaction process has a reduction reaction period of 10 to 12 hours, and the efficiency is low;

2. External heating by flame, heat is gradually transferred from the outside of the reactor to the inside, the cycle is long, the heat energy loss is large, the heat energy utilization rate is low, and the professional analysis considers the heat utilization rate of the typical process. Only about 20%;

3. Due to the external heating method, the reactor volume is limited. The typical inner diameter of the horizontal tank is less than 400 mm. The amount of primary charge is small. The single magnesium can only produce 20~30 kg of raw magnesium at a time. It has a large area and is difficult to manage on site. Large, difficult to achieve large-scale production and mechanized operations;

4. Using silicon-containing element 75% ferrosilicon as reducing agent, the general consumption of magnesium ferrosilicon is 1.05~120 tons, that is, silicon waste is 45~100%, and all iron elements are wasted;

5. The reduced magnesium vapor is directly condensed into solid crystalline magnesium under high vacuum without the convenience of flow, and it is difficult to collect and release.

6. The horizontal tank is generally made of expensive heat-resistant steel containing nickel and chromium, which is fast in consumption and high in cost;

7. The smoke and dust are seriously polluted, the working environment is bad, and the negative impact on the surrounding ecological environment is large;

8. It requires manual loading, slag removal, and cleaning of crystalline magnesium, which is labor intensive.

A batch of invention and utility model patented technologies that have been authorized and disclosed have proposed an improved method for the above-mentioned shortcomings of the Pijiang process of smelting magnesium, mainly by heating the electric energy of the flame energy to clean energy. The specific heat source has the resistance sheet heating and the charge resistance. Heating, induction heating, etc., another improvement is the external heating to internal heating.

Since the above invention and utility model patents do not relate to the solid form of the ferrosilicon of the reactant, the efficiency of the reduction reaction of magnesium is not substantially improved.

For this reason, a process for internal heat magnesium smelting has been proposed. For example, Chinese Patent No. 95100495.6 discloses an internal heat magnesium smelting technique in which calcined dolomite, aluminum bauxite, and silicon iron containing more than 75% of silicon are charged into an electric furnace. Under the vacuum condition of O.OlPa, the slag resistance heats up, and the silicon thermal reduction magnesium oxide refines magnesium.

However, the only 95100495.6 "electric furnace hot charge silicon thermal reduction vacuum magnesium smelting new process" which may involve liquid reaction is only after the solid charge is charged, and the charge will be molten as the temperature rises. The stage is still the solid phase contact method. However, the reaction system described in this patent cannot recover magnesium vapor in the form of liquid magnesium due to high vacuum, which causes the magnesium vapor to directly condense into solid crystalline magnesium, which blocks the vacuum system. In addition, the process cannot achieve continuous production.

Summary of the invention The invention aims at a disadvantage of the prior art, and discloses a novel vacuum circulation molten silicon thermal method for smelting magnesium and a device thereof.

It is an object of the present invention to provide a method and apparatus for achieving continuous or semi-continuous production of magnesium metal, thereby improving magnesium production efficiency;

Another object of the present invention is to shorten the metal magnesium reduction cycle and increase the productivity of magnesium metal;

Yet another object of the present invention is to improve thermal energy utilization;

Still another object of the present invention is to eliminate the use of a reduction tank made of heat resistant steel; yet another object of the present invention is to achieve a reduction in the inner diameter of the reduction tank and to achieve a reactor size reduction;

Still another object of the present invention is to make full use of both silicon and iron elements in ferrosilicon, and to realize the comprehensive utilization of silicon and iron by continuously producing and producing an alloy containing silicon and iron as a by-product;

Still another object of the present invention is to condense and collect the obtained magnesium vapor in a liquid state, which is easy to control the flow direction of the magnesium product, and is convenient for collecting and releasing the magnesium product;

Still another object of the present invention is to reduce smoke pollution and contribute to environmental protection.

The method of vacuum circulating molten silicon thermal magnesium smelting according to the present invention comprises the following steps: First, the ferrosilicon is heated to a molten state in a heating vessel, and the temperature is maintained at 1350 to 1600. C ;

In the second step, the molten liquid ferrosilicon and the magnesium oxide powder containing magnesium oxide mixed therein are periodically flowed through a vacuum container separated from the heating container by a circular flow, and the degree of vacuum is 350 to 10000 Pa. Magnesium oxide in the powder is reduced by silicon in the above molten liquid ferrosilicon to form magnesium vapor;

In the third step, the magnesium vapor obtained in the second step is condensed into a liquid state and collected.

In the second step of the method for smelting magnesium according to the present invention, the molten liquid ferrosilicon forms a circular flow under the action of vacuum suction and a driving force for charging the inert gas to be thermally expanded, and periodically passes through the vacuum vessel.

In the second step of the method for smelting magnesium according to the present invention, the magnesium ore powder is sprayed into the annular flow of molten liquid ferrosilicon, and flows along with the molten liquid ferrosilicon, when in a vacuum vessel, with silicon. The molten iron reacts chemically to form magnesium vapor and rises above the vacuum vessel.

In the third step of the method for smelting magnesium according to the present invention, the magnesium vapor is cooled to a temperature of 650 ° C to 700 ° C and trapped by liquid magnesium droplets, thereby being condensed into liquid magnesium and collected.

In the method of smelting magnesium according to the present invention, the mass percentage of silicon in the molten liquid ferrosilicon in the heating vessel is more than 30% and less than 65%. During the magnesium smelting process, a solid or molten ferrosilicon alloy or industrial silicon having a silicon content higher than that of the molten liquid ferrosilicon in the heating vessel is periodically added to the heating vessel to supplement the consumed silicon element and increase the ferrosilicon in the heating vessel. The amount of silicon is such that the magnesium smelting process continues.

In the method for smelting magnesium according to the present invention, after the magnesium smelting process is stopped, one or more of industrial silicon, industrial pure iron, and iron alloy are added to the molten liquid ferrosilicon in the heating vessel to adjust the molten liquid silicon. The chemical composition of iron produces an alloy containing at least two elements, silicon and iron, as a by-product of magnesium smelting.

In the method of smelting magnesium according to the present invention, the liquid waste is periodically discharged from the heating vessel during the magnesium smelting process.

The present invention also provides an apparatus for vacuum circulating molten silicon thermal magnesium smelting, comprising a heating vessel in which molten liquid ferrosilicon is contained;

a vacuum vessel, the lower port of the impregnating pipe connected to the lower end thereof is inserted below the liquid silicon iron surface of the heating vessel;

An air blowing device is in communication with the impregnation line and is capable of blowing an inert gas into the impregnation pipe.

In the magnesium smelting apparatus of the present invention, the vacuum vessel is disposed above the heating vessel, the impregnation pipe is located at a lower side of the vacuum vessel, and is in communication with the vacuum vessel, and the impregnation pipe is inserted into the heating vessel Wherein, when the lower port of the impregnating pipe is submerged below the liquid level in the heating vessel, the internal space of the vacuum vessel and its impregnated pipe is isolated from the atmosphere to form a closed space, and vacuum evacuation is performed. The lower portion becomes a vacuum container, and the liquid substance in the heating container is sucked up into the impregnation pipe and the vacuum container.

In the apparatus for smelting magnesium according to the present invention, the impregnation pipe has at least two manifolds, and the mouthpiece of the air blowing device is below or lateral to the first manifold, and an inert gas can be blown into the first manifold. Lifting the ferrosilicon in the first manifold to the vacuum vessel and from the second manifold Drop and return to the heating vessel.

In the magnesium smelting apparatus of the present invention, the vacuum vessel is provided with a condenser, the condenser is connected to the vacuum vessel, and the vacuuming device vacuums the vacuum vessel through the condenser to cool the magnesium vapor into a liquid state and It falls into the liquid magnesium storage device below the condenser.

In the magnesium smelting apparatus of the present invention, the impregnating pipe has three manifolds, wherein one of the manifolds is filled with argon gas, so that the ferrosilicon liquid rises in the manifold to the vacuum vessel, and from the other two The manifolds are lowered and returned to the heating vessel.

In the magnesium smelting apparatus of the present invention, the magnesium vapor collecting device is provided with a cooling member and a magnesium liquid spraying member for cooling the collected magnesium vapor and collecting the collected magnesium liquid by spraying the magnesium liquid. The magnesium vapor condenses to form liquid magnesium.

In the magnesium smelting apparatus of the present invention, the vacuum vessel side wall is provided with at least one plasma heater, and the plasma heater can heat the substance inside the vacuum vessel.

In the method and apparatus for vacuum circulating molten silicon thermal magnesium smelting according to the present invention, the reaction chamber (vacuum container) is creatively distinguished from the reactant storage chamber (heating container), and only a vacuum environment is formed in the reaction chamber. The chemical reaction of silicon-reduced magnesium oxide occurs in a vacuum environment, and at the same time, the reactant storage chamber becomes a container for replenishing the raw material and removing the waste residue - the liquid or solid ferrosilicon or industrial silicon is exchanged into the reactant storage chamber, and the supplement is consumed by the reduction process. The silicon element, while eliminating the silica-containing slag formed by the reduction process, allows the magnesium smelting process to proceed continuously without damaging the vacuum environment.

After the vacuum is formed, the inert gas is rapidly expanded at a high temperature by blowing an inert gas such as argon into the immersion tube, and the suction of the liquid material by the vacuum is applied to cause the liquid reactant to rise into the vacuum reaction in the immersion tube. The chamber then descends from the other dip tube under the action of gravity, thereby forming a circular flow between the vacuum reaction chamber and the reactant storage chamber, continuously drawing the molten liquid ferrosilicon and magnesium ore powder which has not undergone the reduction reaction into the vacuum The reaction chamber undergoes a chemical reaction.

It is well known that the rule of pyrometallurgical chemical reaction is that the chemical reaction rate of solids and solids is much slower, and the reaction involving liquids is much faster. Therefore, the present invention uses liquid ferrosilicon as a reducing agent, and the chemical reaction directly participates in the liquid phase. If there is a rapid and intense flow mixing of the liquid reactants, the boundary area of the chemical reaction will be greatly increased, resulting in a reaction rate that is quieter than the liquid. The state has accelerated a lot. Thus, the circulation of the molten liquid ferrosilicon greatly increases the reaction rate and improves the production efficiency of the magnesium smelting process. Therefore, the present invention can use a lower silicon content of ferrosilicon as a reducing agent, for example, by using 75 ferrosilicon and 45 ferrosilicon or pure iron to prepare silicon ferrite containing 30% to 65% of silicon, which expands the application of the reducing agent. range.

In the process of reducing magnesium oxide by ferrosilicon alloy, with the consumption of silicon element, the content of silicon in ferrosilicon is gradually reduced, so that the rate of reduction is also lowered. The present invention continuously adds a high silicon content silicon-containing substance (such as high-grade silicon). Iron, industrial silicon, etc., so that the chemical reaction rate is always maintained at a high level, and continuous production is achieved.

At the end of the magnesium smelting process, a certain amount of ferrosilicon remains, and an alloy such as ferrosilicon, industrial pure iron, silicon-aluminum-iron, industrial silicon is added to adjust the composition of the residual ferrosilicon as a by-product of magnesium smelting. This link takes full advantage of the remaining silicon and iron.

In the reduction process of magnesium smelting, increasing the vacuum is conducive to the reduction of magnesium vapor, but too high vacuum easily condenses the magnesium vapor into powdery solid raw magnesium, clogging the vacuum pipeline, damaging the equipment and destroying the continuity of production. The combination of higher temperature and lower vacuum used in the reduction process of the present invention is advantageous for both the rapid reduction of magnesium vapor and the collection of magnesium vapor in a liquid state. At the same time, the spray of liquid magnesium is used to capture the magnesium vapor, which improves the recovery rate of magnesium.

The magnesium smelting method and apparatus of the present invention internally heats the ferrosilicon liquid through an induction coil and a plasma heating gun, thereby reducing heat energy consumption and improving energy use efficiency. DRAWINGS

Figure 1 is a flow chart of the Pijiang process magnesium smelting process.

2 is a schematic flow chart of a method for vacuum-smelting silicon thermal magnesium smelting according to the present invention. 3 is a schematic view showing the structure of a vacuum circulating molten silicon thermal magnesium smelting according to the present invention. Figure 4 is a schematic view of the vacuum circulation state of the present invention.

Figures 2, 3, 4:

101—— induction heating furnace

102—rise dip tube

103—Down dip tube

104—vacuum reaction chamber Induction coil

Refractory layer

Induction heating furnace tilting mechanism Induction heating furnace lifting mechanism Melting ferrosilicon

Argon blow tube

Upper feed room

Lower feed room

Upper feed chamber wide door lower feed chamber wide door powder delivery pipe plasma heater slag tank

Dipping pipe flange Vacuum chamber upper sealing flange Liquid metal magnesium Liquid magnesium storage tank

Magnesium liquid riser wide door Magnesium liquid riser Liquid magnesium storage tank valve Condenser

Magnesium liquid quantitative lifting pump Dust removal vacuum system connecting pipe Vacuum connecting pipe valve Magnesium liquid spray port Magnesium droplet

Condenser valve liquid magnesium storage tank drain 302——heating the surface of ferrosilicon in the heating vessel

303—— Flow direction of ferrosilicon water

The detailed description of the present invention will be further described in conjunction with the accompanying drawings, in which FIG.

The method and equipment for vacuum-circulating molten silicon thermal magnesium smelting according to the present invention are a ferrosilicon ferrite as a reducing agent, which is periodically passed through a high-temperature vacuum vessel and reduced therein. Magnesium oxide powder, thereby extracting magnesium metal vapor.

As shown in FIG. 2, the method for vacuum-circulating molten silicon thermal magnesium smelting according to the present invention comprises the following steps:

Step 501, heating the ferrosilicon to a molten state in a heating vessel.

In the step, the heating container may be an induction furnace, and an induction coil is arranged around the induction furnace, and the temperature of the silicon iron in the heating furnace is maintained at 1350 to 1600 ° C after being powered.

Step 502, the molten liquid ferrosilicon and the magnesium ore containing magnesium oxide are periodically flowed through a vacuum vessel separated from the heating vessel, and the magnesium oxide in the magnesium ore powder is in the molten liquid ferrosilicon. The silicon is reduced to form magnesium vapor.

The two dip tubes are raised and lowered in the lower part of the vacuum vessel, and the nozzles of the two dip tubes are immersed in the surface of the ferrosilicon water in the heating furnace. When the vacuum vessel is evacuated to 350 Pa to 100000 Pa, the ferrosilicon liquid is pumped under vacuum suction into the two dip tubes and continues to rise from the two dip tubes into the vacuum vessel. Continuously charging the rising impregnation pipe with an inert gas (such as argon gas) can increase the rise of the ferrosilicon water in the rising dip tube, and the gushing flow enters the vacuum vessel, and then descends from the descending dip tube under the action of gravity. Returning to the heating vessel, a self-rising dip tube is formed into the vacuum vessel, returning from the vacuum vessel to the descending dip tube to the heating vessel, and then rising from the heating vessel to the annular flow of the rising dip tube.

During the circulation of the ferrosilicon liquid, the magnesium ore powder is sprayed into the ferrosilicon solution by using an inert gas as a carrier gas, mixed with the ferrosilicon solution, and then entangled by the ferrosilicon solution. The position at which the magnesium ore fines are sprayed may be in the ferrosilicon liquid in the vacuum vessel, in the ferrosilicon liquid in the heating vessel, or in the rising dip tube or the descending dip tube. When the ferrosilicon and magnesium ore powder are in a vacuum container, The reduction reaction produces a magnesium vapor which escapes to the space above the vacuum vessel and is vacuumed away from the vacuum vessel.

After the silicon is reduced to magnesium oxide, it is oxidized to silica, and combined with calcium oxide, aluminum oxide, magnesium oxide and the like in the magnesium ore powder to form a liquid slag, which is mixed with the ferrosilicon liquid to continue the circulation. When the circulation speed is low, the liquid slag floats above the ferrosilicon liquid in the heating vessel, and the slag can be periodically discharged outside the heating vessel by the action of labor, machinery or air flow.

The content of silicon in the molten liquid ferrosilicon in the heating vessel needs to be greater than 30%; adding solid or molten ferrosilicon containing 75% of silicon and industrial silicon to the heating vessel, supplementing the consumed silicon element, and increasing the silicon in the heating vessel The iron content of iron makes the magnesium smelting process continuous.

When the magnesium smelting process is terminated, stopped or suspended, the composition of the residual ferrosilicon can be adjusted to make it suitable for the ferrosilicon product, and then the condensed ingot, such as 45 ferrosilicon, silico-alumina, etc. Magnesium by-product. Then, molten silicon containing 30 to 65% of ferrosilicon is added to the heating vessel to carry out continuous magnesium smelting.

Step 503, the magnesium vapor obtained in the condensation step 502 is in a liquid state and collected.

In this step, the magnesium vapor generated in the above step 502 is cooled to a temperature of 650 700 ° C and trapped by liquid magnesium droplets, and condensed into liquid magnesium to be collected.

In the method of vacuum circulating molten silicon thermal magnesium smelting according to the present invention, liquid ferrosilicon is used as a reducing agent, so that a liquid phase directly participates in the chemical reaction, and the liquid reaction phase undergoes a vigorous annular flow, thereby greatly improving the reaction efficiency. . The continuous smelting process can be carried out continuously or semi-continuously by continuously replenishing the high silicon reducing agent. In addition, the final residual ferrosilicon is adjusted to its constituents by the addition of an alloy containing a higher silicon content, such as 45 ferrosilicon or aluminosilicate.

The invention also provides a vacuum circulation molten silicon thermal magnesium smelting device, as shown in FIG. 3, comprising:

Heating the vessel 101, wherein the molten liquid ferrosilicon is contained therein;

The lower container port of the vacuum container 104, the lower end of which is submerged below the liquid silicon iron surface of the heating container 101;

An air blowing device 110 is in communication with the impregnation line and is capable of blowing an inert gas into the impregnation pipe.

Wherein the vacuum vessel 104 is disposed above the heating vessel 101, the dip tube The tract is located on the lower side of the vacuum vessel 104 and is in communication with the vacuum vessel 104. The immersion tube is inserted into the heating vessel 101, and is sealed with the ferronickel 109 in the heating vessel 101 by the vacuum vessel 104. Isolated, forming a closed space. The outer casing of the vacuum vessel 104 is a steel shell, a lining heat insulation layer and a refractory layer; the heat insulation layer is a asbestos board, a paraffin stone or a cupric oxide hollow sphere; the refractory layer comprises a high alumina, corundum, Carbonaceous, silicon carbide refractory. On the side wall of the vacuum vessel 104, at least one plasma heater 116 is also provided for heating the contents of the vacuum vessel 104 to maintain the reaction temperature. In the present invention, two plasma heaters 116 are symmetrically disposed on the side wall of the vacuum vessel 104.

The heating vessel 101 includes a vessel having a refractory layer 106 and an induction coil 105 disposed on a periphery of the refractory layer 106. After the induction coil 105 is energized, the ferrosilicon 109 having a silicon content of 30% to 65% in the heating container 101 can be heated to 1350 to 1600 ° C to make the ferrosilicon molten, and the input energy is maintained during the magnesium smelting process. The temperature. In the upper portion of the heating vessel 101, on the side of the descending dip tube 103, a slag bath 117 is provided for periodically discharging the liquid slag after the reaction. In order to facilitate the lifting and pouring of the heating container 101, the present invention further provides a tilting device 107 and a lifting device 108, wherein the tilting device 107 is connected to the heating container 101 for adjusting the tilting angle of the heating container for the final The pouring of the residual ferrosilicon liquid is carried out; the lifting device 108 is connected to the heating vessel 101 for adjusting the height of the heating vessel 101.

The molten liquid ferrosilicon in the heating vessel 101 is from the outside. As shown in FIG. 3, the lifting mechanism 108 is initially activated to lower the heating vessel 101, inject the ferrosilicon solution, or place the solid ferrosilicon therein. The induction coil 105 is energized to melt the solid ferrosilicon. In the continuous magnesium smelting process, liquid or solid ferrosilicon is added from the vicinity of the side wall of the heating vessel 101 to replenish the consumed silicon element.

The magnesium ore fines are supplied as a powder delivery pipe 115, which can communicate with the heating vessel 101, or can communicate with the vacuum vessel 104, and can also communicate with the rising dip pipe 102 or the descending dip pipe 103. The powder conveying pipe 115 conveys the magnesium oxide powder containing the inert gas as a carrier gas. Specifically, the powder conveying pipe 115 is connected to an argon gas supply device and a powder supply device, and the powder supply device is disposed at the front end of the argon gas supply device, and when the argon gas is introduced, the powder supply is supplied. The magnesium ore powder supplied from the apparatus is blown into the heating device 101. Still as shown in FIG. 3, the powder supply device The arrangement includes at least one feed chamber, and a valve is disposed between the feed chamber and the powder delivery tube 115. In the present invention, two upper and lower feed chambers are used, as shown in Fig. 3, respectively, an upper feed chamber 111 and a lower feed chamber 112, and an upper feed is provided between the upper feed chamber 111 and the lower feed chamber 112. The material valve 113 is provided with a lower feed valve 114 between the lower feed chamber and the powder delivery pipe 115. This solid feed device prevents air from entering the vacuum system.

The vacuum vessel 104 is disposed above the heating vessel 101. The vacuum vessel 104 has a vacuum of 350 Pa to 1000 Pa, and the impregnation pipe is located below the vacuum vessel 104 and inserted into the heating vessel 101, and the impregnation pipe is The vacuum vessel 104 is sealed by the liquid material in the heating vessel to form a closed space that is isolated from the atmosphere. The impregnation pipe has at least two manifolds, that is, a rising dip pipe 102 and a descending dip pipe 103; or, the impregnation pipe has three manifolds, one of which is provided with an inert gas, and the other two are connected The molten liquid ferrosilicon 109 in the vacuum vessel 104 is returned. As shown in FIG. 3, the nozzles of the rising dip tube 102 and the descending dip tube 103 are both below the liquid silicon iron level contained in the heating vessel 101, and the lower or side of the rising dip tube 102 The blow port of the air blowing device 110 is connected, and the air blowing device 110 can blow an inert gas (for example, argon gas) into the rising immersion pipe 102, and the descending immersing pipe 103 returns the molten liquid silicon iron 109 in the vacuum container 104. During the production process, the lower dip tube 102 and the lower nozzle of the descending dip tube 103 are under the surface of the molten liquid ferrosilicon water in the heating vessel 101, and at the same time, argon gas is introduced into the rising dip tube 102, and the argon gas is thermally expanded. Under the vacuum and the vacuum suction of the system, the molten ferrosilicon water 109 enters the vacuum vessel 104 through the rising dip tube 102, and is returned from the descending dip tube 103 to the heating vessel 101. 4 is a schematic view of the vacuum circulation state, and 303 is a flow direction of liquid ferrosilicon. As shown in FIG. 4, there is a molten silicon iron surface 301 in the vacuum reaction chamber 104 and a molten silicon iron surface 302 in the induction heating furnace. The height difference is that the molten silicon iron surface 302 in the heating vessel 101 is also called a free liquid surface, and the height difference between 301 and 302 can reach 2 meters or more.

The rising dip tube 102 and the descending dip tube 103 are respectively composed of two parts connected up and down, the upper part is integrally connected with the vacuum reactor 104, and the lower part is connected to the upper part through the flange 118, so that the lower parts of the two dip tubes can be easily replaced. The top of the vacuum vessel 104 has an opening that is openly connected to the line with the sealing flange 119 to facilitate opening the sealing flange 119 to preheat or repair the interior of the vacuum vessel. During the residence of the vacuum vessel 104, the ferrosilicon water 109 reduces magnesium oxide in the magnesium ore powder to form magnesium vapor under high temperature vacuum conditions.

A magnesium vapor collection device is disposed on the vacuum vessel 104. The magnesium vapor collection device may be disposed in at least two. Specifically, the magnesium vapor collection device includes a magnesium magnesium storage tank 202 and a magnesium liquid riser that communicates with the liquid magnesium storage tank 202. 204. A magnesium liquid quantitative lift pump 207 disposed on the pipeline of the magnesium liquid riser 204, a magnesium liquid spray port 210 at the outlet of the magnesium liquid riser 204, and a condenser 206. The condenser 206 is connected to the vacuum container 104. The vacuum apparatus evacuates the vacuum vessel 104 through a condenser 206 to pass magnesium vapor through the condenser 206. Specifically, as shown in FIG. 3, the top of the vacuum vessel 104 is provided with a condenser 206 communicating therewith, and the liquid magnesium storage tank 202 is disposed directly below the condenser 206. The condenser 206 is used to cool the magnesium vapor generated in the vacuum vessel 104. The condenser 206 and the liquid magnesium storage tank 202 are generally disposed beside the vacuum vessel 104 and communicate with the vacuum vessel 104. The liquid magnesium storage tank 202 is disposed directly below the condenser 206 to ensure that the magnesium vapor condenses into droplets that fall into the liquid magnesium storage tank 202.

The condenser 206 is connected to a vacuuming device to effect vacuuming of the vacuum vessel 104 through the condenser 206. As shown in Fig. 3, a dust removal vacuum system connection pipe 208 is connected above the condenser 206, and a vacuum connection pipe valve 209 is provided at the communication of the dust removal vacuum system connection pipe 208 and the condenser 206. Vacuuming of the vacuum vessel 104 is accomplished by opening and closing the vacuum connection tube valve 209.

As shown in FIG. 3, the condenser 206 can employ a water cooling system and is directly above the liquid magnesium storage tank 202. A magnesium liquid riser valve 203 is provided at a communication point between the magnesium liquid riser 204 and the liquid magnesium storage tank 202. With the above structural design, after the magnesium liquid riser valve 203 is opened and the magnesium liquid quantitative lift pump 207 is turned on, the liquid magnesium 201 in the liquid magnesium storage tank 202 can be guided to be ejected from the magnesium liquid spray port 210, due to the condenser. 206 is connected to the vacuum vessel 104. The condenser 206 is filled with magnesium vapor. The temperature of the magnesium vapor is absorbed by the water cooling device and the temperature is lowered to 650 to 700 ° C. When the magnesium liquid droplet 211 ejected from the magnesium liquid shower port 210 falls into the In the case of the condenser 206, the magnesium vapor therein is trapped and falls into the liquid magnesium storage tank 202 in the form of droplets. The liquid magnesium storage tank 202 is provided with a liquid magnesium storage tank drain port 213 for releasing the produced liquid magnesium.

A condenser valve 212 may be provided at the communication of the condenser 206 with the vacuum vessel 104. A valve 205 may be disposed at a top end of the liquid magnesium storage tank 202.

The smelting process of the apparatus for vacuum smelting silicon thermal magnesium smelting according to the present invention is as follows: a molten liquid ferrosilicon having a temperature of 1350 ° C to 1600 ° C and a silicon content of 30% to 65% is placed in a heating In the container 101, an induction coil 105 is arranged on the periphery of the heating container 101, and the ferrosilicon 109 in the furnace is heated after being energized to maintain the temperature of the silicon iron in the heating furnace at 1350 ° C to 1600 ° C. The height of the heating vessel 101 is raised by the lifting mechanism 108. When the liquid surface of the molten ferrosilicon 109 in the heating vessel 101 is immersed in the lower ports of the two dip tubes 102 and 103, the vacuum vessel 104 is sealed from the atmosphere and sealed to the vacuum. The vessel 104 is evacuated to 350 Pa to 1000 Pa while argon gas is blown into the rising dip tube 102. The liquid ferrosilicon water 109 rises from the rising dip tube 102 into the vacuum vessel 104 under the double action of vacuum pumping force and argon gas expansion rising force, then flows down from the descending dip tube 103, returns to the heating vessel 101, and thus reciprocates to form a circular flow. . During the residence of the vacuum vessel 104, the ferrosilicon water 109 reacts with the magnesium ore powder of the same vacuum vessel 104 under high temperature vacuum conditions to generate magnesium vapor, which escapes to the space above the vacuum vessel 104 and is vacuum pumped. In the condenser 206, the ambient condensing device absorbs heat and cools down. At a temperature of 650 to 700 ° C, the magnesium vapor is trapped by the liquid magnesium droplets 211 ejected from the magnesium liquid shower port 210 to become liquid magnesium. It is lowered into the liquid magnesium storage tank 202 below. When the silicon concentration of the liquid ferrosilicon 109 is lowered, a portion of the ferrosilicon 75 is replenished, so that the magnesium sintering process is continuously performed. When the magnesium smelting process is completed, the vacuum is stopped, and the liquid magnesium 201 in the liquid magnesium storage tank 202 is the original magnesium product, and the residual liquid ferrosilicon 109 in the heating vessel 101 is adjusted to meet the requirements by adding an alloy such as ferrosilicon. Then, the elevating mechanism 108 and the tilting mechanism 107 are activated to lower and tilt the heating vessel 101, and the residual ferrosilicon water flows out and condenses into a ferrosilicon product as a magnesium sinter by-product. The liquid slag is periodically discharged from the slag bath 117 throughout the process.

The present invention will be described below with a specific example. To facilitate the order of presentation, the numbers are specifically 601, 602, etc.:

601 - Prepare a medium frequency induction furnace with a power of 8000 kW as the heating vessel 101. The inner chamber of the heating vessel is in the shape of a large round table with a diameter of 100 cm, a taper of 0.4 (a height of 1 cm along the vertical height, and an increase of 0.4 cm in the inner diameter of the furnace). 2t silicon-containing silicon 75% and 4t silicon-containing 45% ferrosilicon were added and melted in the heating vessel 101 to prepare 6t silicon-containing 55% silicon iron liquid, and the temperature was maintained at 1550 °C. 602 - Heated to 1000 ° C with a natural gas flame inside the vacuum vessel 104 and the upper and lower dip tubes 102 and 103. The vacuum vessel 104 has a diameter of 70 cm and a height of 450 cm. The upper and lower dip tubes 102 and 103 have an inner diameter of 15 cm and a length of 130 cm. A silicon carbide refractory material is used.

603 - Prepare 13 tons of magnesium ore fines containing magnesium oxide. Where the MgO content is 80%,

The CaO content is 10%, the A1 ₂ 0 ₃ content is 10%, and the particle size is 0.01~2 mm. It was stored in the upper feed chamber 111 and the temperature was maintained at 800 °C.

604 - Another 4000 kg of silicon-iron containing 75% of silicon is melted in an induction furnace.

605 - Open the vacuum connection pipe valve 209 and the liquid magnesium storage tank valve 205, close the magnesium liquid riser valve 203 and the condenser valve 212, and pour 500 kg of molten magnesium metal into the liquid magnesium storage tank 202 at a temperature of 700 ° C. . The liquid magnesium tank valve 205 is then closed and the condenser valve is opened 212

606—— The temperature in the vacuum reaction chamber 104 reaches 1000 °C, and the natural gas is heated to remove the flame.

The lower ends of the two dip tubes 102 and 103 are sealed with a metal sheath, and the vacuum reaction chamber 104 and the upper and lower dip tubes 102, 103 are evacuated by a vacuum pump system via a dedusting vacuum system connection pipe 208.

607 - When the pressure in the vacuum reaction chamber 104 reaches 1000OOpa, the induction heating furnace 101 is slowly raised by the induction heating furnace lifting mechanism 108, so that the lower ends of the upper and lower dip tubes 102 and 103 are immersed 65 cm below the silicon iron liquid level 302.

608—— With the melting of the upper and lower dip tubes 102 and 103 port seal iron, ferrosilicon

109 is vacuumed into the upper and lower dip tubes 102, 103 and the vacuum reaction chamber 104. The vacuum is continued until the pressure in the vacuum reaction chamber 104 reaches 800 Pa, and the pressure is maintained.

609 - argon gas is introduced into the argon blowing pipe 110 at a flow rate of 120 NL / min, and the argon gas enters the rising immersion pipe 102 and is heated by the ferrosilicon liquid to a high temperature to expand, and the driving silicon iron liquid rises in the rising immersion pipe 102. It enters the vacuum reaction chamber 104, then descends along the descending dip tube 103, and flows back into the induction heating furnace 101 to form a circulation.

610 - Cooling water is introduced into the condenser 206, and the flow rate of the cooling water is 50 kg/s. Keep cold The condenser temperature is 650 °C

611 - Open the magnesium storage tank valve 205 and the magnesium liquid riser valve 203, start the magnesium liquid lift pump 207, and form a spray at a rate of 30 kg of magnesium per minute.

612 - closing the lower feed chamber valve 114, opening the upper feed chamber valve 113, so that the magnesium ore powder in the upper feed chamber 111 enters the lower feed chamber 112, then closes the upper feed chamber valve 113, and opens the lower feed chamber Valve 114

613——Injecting the magnesium ore powder into the ferrosilicon 109 of the induction heating furnace 101 through the powder delivery pipe 115 with argon as the carrier gas, the injection rate is 30 kg/min, and the carrier gas flow rate is 120 NL/min. Continuous blowing for 60 minutes.

614 - Stop spraying magnesium powder while stopping the carrier gas input.

615 - Increase the argon rate in the argon blow tube 110 to 170 NL/min for 10 minutes.

616 - Reduce the argon rate in the argon blow tube 110 to 50 NL/min for 10 minutes.

617 - The slag layer above the ferrosilicon 109 in the induction furnace 104 is removed from the slag bath 117.

618——Close the magnesium liquid quantitative lift pump 207, close the liquid magnesium storage tank valve 205 and the magnesium liquid lift pipe valve 203

619——Open the liquid magnesium storage tank drain port 213 to release part of the liquid metal magnesium 201, and the flowing magnesium liquid is used for refining, alloying or ingot casting.

620——Close the liquid magnesium tank drain 213.

621——Injecting 75% of the silicon-containing silicon containing molten silicon into the induction heating furnace 101 from another induction furnace, and adding 600 kg.

622 - Repeat the operation of 612 620.

623 - The molten silicon furnace 101 was again charged with 600 kg of molten silicon-containing 75% silicon iron.

624 - Repeat the operation of 612 620.

625 - Again into the vacuum furnace 101, melted silicon-containing 75% silicon iron solution 600 kg.

626 - Repeat the operation of 612 620.

627 - again into the vacuum furnace 101 into the molten silicon-containing 75% silicon iron solution 600 kg.

628 - Repeat the operation of 612 620.

629 - Once again into the vacuum furnace 101, melted silicon-containing 75% silicon iron solution 600 kg.

630 - Repeat the operation of 612 620.

631 - The molten silicon furnace 101 was again charged with 600 kg of molten silicon-containing 75% silicon iron.

632 - Repeat the operation of 612 620.

633 - Stop vacuuming, close condenser valve 212 and vacuum connection valve 209.

634 - argon gas is continuously blown from the argon blow pipe 110 for 10 minutes, and the flow rate is increased to

150 NL/min.

635 - The induction heating furnace lifting mechanism 108 is operated to slowly lower the induction heating furnace 101 until the ports of the upper and lower dip tubes 102 and 103 are completely separated from the ferrosilicon liquid 109.

636 - Open the liquid magnesium storage tank drain 213 and release all the magnesium liquid 201 for refining, alloying or ingot casting.

637——Sampling and analysis of the silicon content of 109 in the ferrosilicon water in the induction heating furnace 101,

320 kg of silicon-containing 75% ferrosilicon makes the silicon-containing liquid 109 in the induction heating furnace 101 have a silicon content of 45%.

638—— Remove the powder conveying pipe 115 with argon as the carrier gas, operate the induction heating furnace tilting mechanism 107, invert the induction heating furnace 101, pour out the residual ferrosilicon water 109, ingot, and condense. In actual production, the high-temperature slag that is periodically discharged is heated to heat the magnesium ore powder to be added to the ferrosilicon liquid to realize energy recovery and utilization. To facilitate the next operation, a portion of the magnesium solution is retained in the magnesium storage tank.

In this example, a total of 5170 kg of magnesium was obtained. A total of 5,920 kilograms of silicon iron containing 75% silicon is consumed, 4000 kilograms of silicon iron containing 45% silicon is consumed, and 6245 kilograms of silicon iron containing 45% silicon is obtained as a by-product. Then the consumption of silicon in tons of magnesium is 663 kg, and the consumption of iron is 47 kg. In comparison, the Pijiang method smelting magnesium, tons of magnesium consumes 1.2 tons of ferrosilicon, that is, tons of magnesium consumes 900 kilograms of silicon, 300 kilograms of iron. In the above embodiment of the invention, the consumption per ton of magnesium and silicon is reduced by 26% and the consumption of iron is reduced by 84%.

After measurement, in this example, the energy consumption per ton of magnesium is 9200kwh, while the energy consumption per ton of magnesium in the reduction of the Pijiang process magnesium smelting is 14400~18000kwh, so the energy consumption per ton of magnesium is reduced by 36%~49%.

The reduction smelting process of the present invention does not use a reduction tank made of expensive heat-resistant steel, and the consumption of heat-resistant steel material is eliminated.

The reduced magnesium smelting process of the present invention can achieve continuous production by continuously injecting magnesium oxide ore powder, periodically discharging slag and blending high silicon ferrosilicon.

The process and equipment of the present invention are suitable for large-scale, easy to realize mechanization, automation, reduce labor intensity, and achieve accurate quantitative operation. The invention adopts vacuum circulation, the liquid silicon iron water and the magnesium oxide powder are thoroughly mixed and stirred, the reaction boundary area is greatly increased, and the production efficiency is greatly improved, which is the development direction of the modern metallurgical industry technology.

Although the embodiments of the present invention have been disclosed as above, they are not limited to the applications listed in the specification and the embodiments, and are fully applicable to various fields suitable for the present invention, and are easily accessible to those skilled in the art. The present invention is not limited to the specific details and the illustrated and described embodiments herein, without departing from the scope of the appended claims.

Claims

PCT10101 Quanhe Li Request

A method of vacuum circulating molten silicon thermal magnesium smelting, characterized in that: the first step comprises: heating the ferrosilicon to a molten state in a heating vessel to maintain a temperature of 1350 to 1600 ° ;; In the second step, the molten liquid ferrosilicon and the magnesium ore powder mixed with the magnesium oxide are periodically flowed through the vacuum vessel separated from the heating vessel in a circular flow manner, and the degree of vacuum is maintained between 350 Pa and 1000 Pa, The mineral powder is reduced by the above molten liquid ferrosilicon to form magnesium vapor; in the third step, the magnesium vapor obtained in the second step is condensed into a liquid state and collected.

2. The method of smelting magnesium according to claim 1, wherein in the second step, the molten liquid ferrosilicon forms a ring under the action of a vacuum pumping action and a driving force for charging the inert gas to be thermally expanded. Flow, periodically through the vacuum vessel.

3. The method of smelting magnesium according to claim 1, wherein in the second step, the magnesium ore powder is sprayed into the annular flow of molten liquid ferrosilicon, and flows along with the molten liquid ferrosilicon. When in a vacuum vessel, it chemically reacts with the ferrosilicon to form magnesium vapor and rises above the vacuum vessel.

The method for smelting magnesium according to claim 1, wherein in the third step, the magnesium vapor is cooled to 650 ° C to 700 ° C and is captured by liquid magnesium droplets sprayed. The collection is condensed into liquid magnesium and collected.

5. The method of smelting magnesium according to claim 1, wherein the mass percentage of silicon in the molten ferrosilicon in the heating vessel is greater than 30% and less than 65%, and during the magnesium smelting process, periodically The heating vessel is filled with a solid or molten ferrosilicon alloy having a silicon-containing mass percentage higher than that of the molten ferrosilicon in the heating vessel or directly adding industrial silicon.

6. The method of smelting magnesium according to claim 1, wherein one of industrial silicon, industrial pure iron, and iron alloy is added to the molten liquid ferrosilicon in the heating vessel after the magnesium smelting process is terminated. Several, to adjust the chemical composition of molten liquid ferrosilicon, to produce an alloy containing at least two elements of silicon and iron as a by-product of magnesium.

The method of smelting magnesium according to claim 1, wherein the liquid waste is periodically discharged from the heating vessel during the magnesium smelting process.

8. A vacuum circulating molten silicon thermal magnesium smelting apparatus, comprising: a heating vessel in which molten liquid ferrosilicon is contained;

a vacuum vessel, the lower port of the impregnating pipe communicated at the lower end thereof is inserted below the liquid silicon iron surface of the heating vessel; the air blowing device is in communication with the impregnation pipe and is capable of blowing inertness into the impregnation pipe gas.

9. The magnesium smelting apparatus according to claim 8, wherein the vacuum vessel is disposed above the heating vessel, the impregnation conduit is located on a lower side of the vacuum vessel, and is in communication with the vacuum vessel, the impregnation a pipe is inserted into the heating vessel, and when the lower port of the impregnating pipe is submerged below the liquid level in the heating vessel, the internal space of the vacuum vessel and the impregnated pipe is isolated from the atmosphere to form a closed The space becomes a vacuum vessel under vacuum pumping, and the liquid substance in the heating vessel is sucked up into the impregnation pipe and the vacuum vessel.

10. The magnesium smelting apparatus according to claim 8, wherein the impregnating duct has at least two manifolds, and the blowing port of the air blowing device is below or lateral to the first manifold, and is capable of being first An inert gas is blown into the manifold to cause the ferrosilicon to rise into the vacuum vessel in the first manifold, and descend from the second manifold to be returned to the heating vessel.

11. The magnesium smelting apparatus according to claim 8, wherein: said vacuum container A condenser is provided, the condenser being in communication with the vacuum vessel, the vacuuming apparatus vacuuming the vacuum vessel through a condenser, cooling the magnesium vapor to a liquid state and falling into a liquid magnesium storage device below the condenser.

12. The apparatus for smelting magnesium according to claim 8, wherein the impregnation pipe has three manifolds, wherein one of the manifolds is filled with argon gas, so that the ferrosilicon liquid rises in the manifold to the The vacuum vessel is lowered from the other two manifolds and returned to the heating vessel.

13. The apparatus for smelting magnesium according to claim 11, wherein said condenser is provided with a cooling member and a magnesium liquid spray member for cooling magnesium vapor passing through the condenser and spraying the molten magnesium The passed magnesium vapor is condensed to form liquid magnesium and collected.

14. The magnesium smelting apparatus according to claim 8, wherein the vacuum vessel side wall is provided with at least one plasma heater, and the plasma heater heats the interior of the vacuum vessel.