Method for preparing high-purity sponge zirconium

Abstract

The application provides a preparation method of high-purity sponge zirconium and relates to the field of sponge zirconium preparation. The preparation method comprises the following steps: zircon sand is mixed with coke, petroleum coke, needle coke and pitch coke respectively, and then is loaded into a chlorination furnace in a layered manner from bottom to top; high-temperature chlorine gas is introduced into the bottom of the chlorination furnace to perform a chlorination reaction, so that first crude zirconium tetrachloride gas is obtained; a reduced nickel-based catalyst is added into each loading layer of the chlorination furnace; first cooling is performed to obtain crude zirconium tetrachloride solid, first heating is performed to obtain second crude zirconium tetrachloride gas, purification is performed to obtain refined zirconium tetrachloride gas, and second cooling is performed to obtain refined zirconium tetrachloride solid; second heating is performed on the refined zirconium tetrachloride solid to obtain high-purity zirconium tetrachloride gas; the high-purity zirconium tetrachloride gas is introduced into a reduction furnace containing molten magnesium metal to perform a reduction reaction, so that a mixed product is obtained; and the mixed product is subjected to reduced-pressure distillation to obtain the high-purity sponge zirconium. The preparation method provided in the application has high purity of the obtained sponge zirconium.

Description

TECHNICAL FIELD

[0001] The application relates to the field of sponge zirconium, in particular to a preparation method of high-purity sponge zirconium. BACKGROUND

[0002] Using zircon sand as raw material to react with chlorine to prepare zirconium tetrachloride, and then reducing to obtain sponge zirconium belongs to a common preparation method of sponge zirconium. The chlorination reaction has high energy consumption. In order to reduce the production cost, in the prior art, zircon sand is mixed with a carbonaceous reducing agent, and then reacts with chlorine to reduce the production energy consumption. However, the method has problems such as serious coking of the carbonaceous reducing agent, difficulty in cleaning the reactor, and many impurities in the obtained product, and cannot fundamentally reduce the production cost. In addition, due to the existence of impurities, high-purity sponge zirconium cannot be prepared. SUMMARY

[0003] The purpose of the application is to provide a preparation method of high-purity sponge zirconium to solve the above problems.

[0004] To achieve the above purpose, the application adopts the following technical scheme:

[0005] A preparation method of high-purity sponge zirconium comprises the following steps:

[0006] The zircon sand is mixed with coke, petroleum coke, needle coke and pitch coke respectively, and then is loaded into a chlorination furnace in a direction from bottom to top along the height of the chlorination furnace in a volume ratio of 1:(3-4):(3-4):(2-3) (optionally, the volume ratio can be 1:3:3:2, 1:3.5:3.5:2.5, 1:4:4:3, or any value between 1:(3-4):(3-4):(2-3); the chlorination furnace is subjected to a chlorination reaction by introducing high-temperature chlorine gas from the bottom of the chlorination furnace, to obtain a first crude zirconium tetrachloride gas; in each loading layer of the chlorination furnace, the mass ratio of the zircon sand to the coke is 100:(10-30) (optionally, the mass ratio can be 100:10, 100:20, 100:30, or any value between 100:(10-30); the mass ratio of the zircon sand to the petroleum coke is 100:(20-40) (optionally, the mass ratio can be 100:20, 100:30, 100:40, or any value between 100:(20-40); the mass ratio of the zircon sand to the needle coke is 100:(30-50) (optionally, the mass ratio can be 100:30, 100:40, 100:50, or any value between 100:(30-50); the mass ratio of the zircon sand to the pitch coke is 100:(10-30) (optionally, the mass ratio can be 100:10, 100:20, 100:30, or any value between 100:(10-30); in each loading layer of the chlorination furnace, a reduced nickel-based catalyst corresponding to the total mass of the loading material in the layer is added, which is obtained by mixing macroporous alumina, a nickel salt and a magnesium chloride solution, and then is molded and calcined at 600-1000°C (optionally, the temperature can be 600°C, 700°C, 800°C, 900°C, 1000°C, or any value between 600-1000°C) to obtain the reduced nickel-based catalyst, in which the mass content of nickel oxide is 25%-65% (optionally, the mass content can be 25%, 30%, 35%, 40%, 45%, 50%, 55%, 60%, 65%, or any value between 25%-65%; the content of magnesium oxide is 1-3% (optionally, the content can be 1%, 2%, 3%, or any value between 1-3%);

[0007] The first crude zirconium tetrachloride gas is subjected to first cooling to obtain a crude zirconium tetrachloride solid, which is subjected to first heating to obtain a second crude zirconium tetrachloride gas, which is introduced from the bottom into a purification tower filled with coke, petroleum coke, needle coke, pitch coke and activated carbon, and a refined zirconium tetrachloride gas is output from the top or upper part of the purification tower, which is subjected to second cooling to obtain a refined zirconium tetrachloride solid;

[0008] The refined zirconium tetrachloride solid is subjected to a second heating to obtain high-purity zirconium tetrachloride gas, and the high-purity zirconium tetrachloride gas is introduced into a reduction furnace filled with molten magnesium metal for a reduction reaction to obtain a mixed product;

[0009] Distilling the mixed product under reduced pressure to obtain the high-purity sponge zirconium;

[0010] The temperature of the chlorination reaction is 800-900°C (can be 800°C, 850°C, 900°C or any value between 800-900°C); the temperature of the reduction reaction is 800-900°C (can be 800°C, 850°C, 900°C or any value between 800-900°C), and the pressure is 10-20KPa (can be 10KPa, 15KPa, 20KPa or any value between 10-20KPa); the first The heating temperature, the temperature in the purification tower, and the second heating temperature are each independently 350-400°C (can be 350°C, 360°C, 370°C, 380°C, 390°C, 400°C or any value between 350-400°C); the temperature of the reduced pressure distillation is 950-1000°C (can be 950°C, 960°C, 970°C, 980°C, 990°C, 1000°C or any value between 950-1000°C).

[0011] Preferably, the particle size of the zircon sand is 200-300 mesh; in the chlorination furnace, the particle size of the coke, the petroleum coke, the needle coke, and the pitch coke are each independently 50-200 mesh.

[0012] Optionally, the particle size of the zircon sand can be 200 mesh, 250 mesh, 300 mesh or any value between 200-300 mesh; in the chlorination furnace, the particle size of the coke, the petroleum coke, the needle coke and the pitch coke can each independently be 50 mesh, 100 mesh, 150 mesh, 200 mesh or any value between 50-200 mesh.

[0013] Preferably, in the chlorination furnace, the particle sizes of the coke, the petroleum coke, the needle coke, and the pitch coke increase in sequence.

[0014] Preferably, the temperature of the high-temperature chlorine gas is 600-800°C.

[0015] Optionally, the temperature of the high-temperature chlorine gas may be 600°C, 700°C, 800°C or any value between 600-800°C.

[0016] Preferably, the purification tower is filled with equal volumes of evenly mixed coke, petroleum coke, needle coke, pitch coke and activated carbon.

[0017] Preferably, the particle sizes of the coke, petroleum coke, needle coke, pitch coke and activated carbon loaded in the purification tower are independently 50-100 meshes.

[0018] Optionally, the particle sizes of the coke, petroleum coke, needle coke, pitch coke and activated carbon loaded in the purification tower can independently be 50 mesh, 60 mesh, 70 mesh, 80 mesh, 90 mesh, 100 mesh or any value between 50-100 mesh.

[0019] Preferably, the molar ratio of the high-purity zirconium tetrachloride gas introduced into the reduction furnace to the magnesium metal in the reduction furnace is (1.1-1.3):2.

[0020] Optionally, the molar ratio of the high-purity zirconium tetrachloride gas introduced into the reduction furnace to the magnesium metal in the reduction furnace can be 1.1:2, 1.2:2, 1.3:2 or any value between (1.1-1.3):2.

[0021] Preferably, the vacuum degree of the reduced pressure distillation is 0.5-3Pa.

[0022] Optionally, the vacuum degree of the reduced pressure distillation can be 0.5Pa, 1Pa, 1.5Pa, 2Pa, 2.5Pa, 3Pa or any value between 0.5-3Pa.

[0023] Preferably, the chlorination furnace, the purification tower and the reduction furnace are all purged with nitrogen at 300-500° C. before use.

[0024] Optionally, the temperature of the nitrogen gas may be 300°C, 400°C, 500°C or any value between 300-500°C.

[0025] Preferably, there are multiple reduction furnaces.

[0026] Compared with the prior art, the advantages of this application include:

[0027] The preparation method of high-purity sponge zirconium provided in the present application adopts coke, petroleum coke, needle coke, and pitch coke to be loaded in layers in proportion, and utilizes the performance differences of various carbonaceous reducing agents to alleviate the coking problem; zircon sand is mixed with each carbonaceous reducing agent in proportion before loading, which can ensure the efficiency of the chlorination reaction and the uniformity of the reaction in each layer; adding an appropriate amount of reduced nickel-based catalyst to each of the various reducing agents can, on the one hand, effectively reduce the temperature of the chlorination reaction and reduce energy consumption, and on the other hand, further solve the coking problem, so that the carbonaceous reducing agent remains in a loose state after the chlorination reaction, which is convenient for cleaning the chlorination furnace to quickly carry out the next reaction; on the other hand, while lowering the reaction temperature and avoiding coking, the impurities in the crude zirconium tetrachloride can be reduced; the obtained crude zirconium tetrachloride gas is subjected to a first cooling and a first heating for preliminary purification, and then subjected to a second purification in a purification tower, and then subjected to a third purification through a second cooling and a second heating to obtain high-purity zirconium tetrachloride gas; finally, it is reacted with magnesium metal and subjected to reduced pressure distillation to obtain high-purity sponge zirconium.

[0028] The method for preparing high-purity sponge zirconium provided in this application has relatively low energy consumption and the obtained sponge zirconium has high purity. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] In order to more clearly illustrate the technical solutions of the embodiments of the present application, the following is a brief introduction to the drawings required for use in the embodiments. It should be understood that the following drawings only show certain embodiments of the present application and therefore should not be regarded as limiting the scope of the present application.

[0030] Figure 1 Schematic diagram of the equipment used in the method for preparing high-purity sponge zirconium provided in the embodiment. DETAILED DESCRIPTION

[0031] The embodiments of the present application will be described in detail below in conjunction with specific examples, but it will be understood by those skilled in the art that the following examples are merely illustrative of the present application and should not be considered as limiting the scope of the present application. In the examples, if specific conditions are not specified, the conditions are carried out according to conventional conditions or manufacturer recommendations. The reagents or instruments used are not specified by the manufacturer and are conventional products that can be purchased commercially.

[0032] Example 1

[0033] like Figure 1 As shown, this embodiment provides a method for preparing high-purity sponge zirconium, which specifically includes the following steps:

[0034] 1. Prepare materials;

[0035] Prepare zircon sand with a particle size of 200-300 mesh, coke with a particle size of 50-80 mesh, petroleum coke with a particle size of 80-100 mesh, needle coke with a particle size of 100-150 mesh, pitch coke with a particle size of 150-200 mesh, as well as coke, petroleum coke, needle coke, pitch coke and activated carbon with a particle size of 50-100 mesh;

[0036] 2. Chlorination reaction;

[0037] Zircon sand is mixed with coke, petroleum coke, needle coke, and pitch coke in mass ratios of 100:10, 100:40, 100:30, and 100:30, respectively; and then layered into the chlorination furnace 1 in a volume ratio of 1:3:4:2.5 from bottom to top along the height direction of the chlorination furnace 1; firstly, nitrogen is replaced with 300° C.; and then high-temperature chlorine at 600° C. is introduced from the bottom of the chlorination furnace 1 to carry out a chlorination reaction to obtain a first crude zirconium tetrachloride gas; and the temperature of the chlorination reaction is controlled to be 800-850° C. (the temperature difference in the chlorination furnace 1 cannot exceed 50° C.);

[0038] A reduced nickel-based catalyst is added to each filling layer of the chlorination furnace 1, accounting for 1% of the total mass of the filling material in the corresponding layer. The reduced nickel-based catalyst is obtained by mixing macroporous alumina, nickel salt, and an auxiliary magnesium chloride solution, and then calcining at 1000°C. The reduced nickel-based catalyst has a nickel oxide content of 25% by mass and a magnesium oxide content of 3% by mass. The reduced nickel-based catalyst is in the shape of a clover leaf.

[0039] 3. Cooling purification and adsorption purification;

[0040] The first crude zirconium tetrachloride gas is subjected to a first cooling and exhausting process to obtain a crude zirconium tetrachloride solid, the crude zirconium tetrachloride solid is subjected to a first heating process to obtain a second crude zirconium tetrachloride gas, the second crude zirconium tetrachloride gas is passed from the bottom into a purification tower 2 filled with equal volumes of 50-100 mesh coke, petroleum coke, needle coke, pitch coke and activated carbon, refined zirconium tetrachloride gas is output from the top of the purification tower 2, and the refined zirconium tetrachloride gas is subjected to a second cooling and exhausting process to obtain a refined zirconium tetrachloride solid; the purification tower 2 is replaced with 300° C. nitrogen before use; the first heating temperature is 400° C., and the temperature inside the purification tower 2 is 380° C. (the purification tower 2 is equipped with heating and heat preservation facilities to control the overall temperature difference to no more than 20° C.);

[0041] 4. Reduction reaction;

[0042] The refined zirconium tetrachloride solid is subjected to a second heating to obtain high-purity zirconium tetrachloride gas, which is then introduced into a reduction furnace 3 filled with molten magnesium metal for a reduction reaction to obtain a mixed product. The second heating temperature is 350°C; the reduction reaction temperature is 800°C and the pressure is 10 kPa. The molar ratio of high-purity zirconium tetrachloride gas to magnesium metal is 1.1:2. To ensure the overall stability of the system and facilitate production arrangements, two reduction furnaces 3 are provided.

[0043] 5. Vacuum distillation;

[0044] The mixed product is subjected to reduced pressure distillation in the reduction furnace 3 to obtain high-purity sponge zirconium; the temperature of the reduced pressure distillation is 950° C. and the vacuum degree is 0.5 Pa.

[0045] Example 2

[0046] This embodiment provides a method for preparing high-purity sponge zirconium, which specifically includes the following steps:

[0047] 1. Prepare materials;

[0048] Prepare zircon sand with a particle size of 200-300 mesh, coke with a particle size of 50-80 mesh, petroleum coke with a particle size of 80-100 mesh, needle coke with a particle size of 100-150 mesh, pitch coke with a particle size of 150-200 mesh, as well as coke, petroleum coke, needle coke, pitch coke and activated carbon with a particle size of 50-100 mesh;

[0049] 2. Chlorination reaction;

[0050] Zircon sand is mixed with coke, petroleum coke, needle coke, and pitch coke in mass ratios of 100:30, 100:30, 100:40, and 100:10, and then layered into the chlorination furnace 1 in a volume ratio of 1:4:3.5:2 from bottom to top along the height direction of the chlorination furnace 1. The mixture is first replaced with 500° C. nitrogen gas, and then high-temperature chlorine gas at 800° C. is introduced from the bottom of the chlorination furnace 1 to carry out a chlorination reaction to obtain a first crude zirconium tetrachloride gas. The temperature of the chlorination reaction is controlled to be 850-900° C. (the temperature difference in the chlorination furnace 1 cannot exceed 50° C.);

[0051] A reduced nickel-based catalyst is added to each filling layer of the chlorination furnace 1, accounting for 2% of the total mass of the filling material in the corresponding layer. The reduced nickel-based catalyst is obtained by mixing macroporous alumina, nickel salt, and an auxiliary magnesium chloride solution, and then calcining at 800°C. The reduced nickel-based catalyst has a nickel oxide content of 50% by mass and a magnesium oxide content of 2% by mass. The reduced nickel-based catalyst is spherical.

[0052] 3. Cooling purification and adsorption purification;

[0053] The first crude zirconium tetrachloride gas is subjected to a first cooling and exhausting process to obtain a crude zirconium tetrachloride solid, the crude zirconium tetrachloride solid is subjected to a first heating process to obtain a second crude zirconium tetrachloride gas, the second crude zirconium tetrachloride gas is passed from the bottom into a purification tower 2 filled with equal volumes of 50-100 mesh coke, petroleum coke, needle coke, pitch coke, and activated carbon, refined zirconium tetrachloride gas is output from the top or upper portion of the purification tower 2, the refined zirconium tetrachloride gas is subjected to a second cooling and exhausting process to obtain a refined zirconium tetrachloride solid; the purification tower 2 is replaced with 500° C. nitrogen before use; the first heating temperature is 350° C., and the temperature inside the purification tower 2 is 350° C. (the purification tower 2 is equipped with heating and heat preservation facilities to control the overall temperature difference to no more than 10° C.);

[0054] 4. Reduction reaction;

[0055] The refined zirconium tetrachloride solid is subjected to a second heating to obtain high-purity zirconium tetrachloride gas, which is then introduced into a reduction furnace 3 filled with molten magnesium metal for a reduction reaction to obtain a mixed product. The second heating temperature is 400°C, the reduction reaction temperature is 900°C, and the pressure is 20 kPa. The molar ratio of the high-purity zirconium tetrachloride gas to the magnesium metal is 1.3:2. Two reduction furnaces 3 are provided.

[0056] 5. Vacuum distillation;

[0057] The mixed product is subjected to reduced pressure distillation in the reduction furnace 3 to obtain high-purity sponge zirconium; the temperature of the reduced pressure distillation is 1000° C. and the vacuum degree is 3 Pa.

[0058] Example 3

[0059] This embodiment provides a method for preparing high-purity sponge zirconium, which specifically includes the following steps:

[0060] 1. Prepare materials;

[0061] Prepare zircon sand with a particle size of 200-300 mesh, coke with a particle size of 50-80 mesh, petroleum coke with a particle size of 80-100 mesh, needle coke with a particle size of 100-150 mesh, pitch coke with a particle size of 150-200 mesh, as well as coke, petroleum coke, needle coke, pitch coke and activated carbon with a particle size of 50-100 mesh;

[0062] 2. Chlorination reaction;

[0063] Zircon sand is mixed with coke, petroleum coke, needle coke, and pitch coke in mass ratios of 100:20, 100:20, 100:50, and 100:20, and then loaded into the chlorination furnace 1 in layers along the height direction of the chlorination furnace 1 from bottom to top in a volume ratio of 1:3.5:3.5:3. The mixture is first replaced with nitrogen at 400° C., and then high-temperature chlorine at 700° C. is introduced from the bottom of the chlorination furnace 1 to carry out a chlorination reaction to obtain a first crude zirconium tetrachloride gas. The chlorination reaction temperature is 830-860° C. (the temperature difference in the chlorination furnace 1 cannot exceed 30° C.);

[0064] A reduced nickel-based catalyst is added to each filling layer of the chlorination furnace 1, accounting for 3% of the total mass of the filling material in the corresponding layer. The reduced nickel-based catalyst is obtained by mixing macroporous alumina, nickel salt, and an auxiliary magnesium chloride solution, and then calcining at 600°C. The reduced nickel-based catalyst has a nickel oxide content of 65% by mass and a magnesium oxide content of 1% by mass. The reduced nickel-based catalyst is in the form of a long strip.

[0065] 3. Cooling purification and adsorption purification;

[0066] The first crude zirconium tetrachloride gas is subjected to a first cooling and exhausting process to obtain a crude zirconium tetrachloride solid, the crude zirconium tetrachloride solid is subjected to a first heating process to obtain a second crude zirconium tetrachloride gas, the second crude zirconium tetrachloride gas is passed from the bottom into a purification tower 2 filled with equal volumes of 50-100 mesh coke, petroleum coke, needle coke, pitch coke and activated carbon, refined zirconium tetrachloride gas is output from the top or upper portion of the purification tower 2, the refined zirconium tetrachloride gas is subjected to a second cooling and exhausting process to obtain a refined zirconium tetrachloride solid; the purification tower 2 is replaced with 400° C. nitrogen before use; the first heating temperature is 380° C., and the temperature inside the purification tower 2 is 400° C. (the purification tower 2 is equipped with heating and heat preservation facilities to control the overall temperature difference to no more than 10° C. and the maximum temperature to no more than 400° C.);

[0067] 4. Reduction reaction;

[0068] The refined zirconium tetrachloride solid is subjected to a second heating to obtain high-purity zirconium tetrachloride gas, which is then introduced into a reduction furnace 3 filled with molten magnesium metal for a reduction reaction to obtain a mixed product. The second heating temperature is 370°C, the reduction reaction temperature is 850°C, and the pressure is 15 kPa. The molar ratio of the high-purity zirconium tetrachloride gas to the magnesium metal is 1.2:2. Two reduction furnaces 3 are provided.

[0069] 5. Vacuum distillation;

[0070] The mixed product is subjected to reduced pressure distillation in the reduction furnace 3 to obtain high-purity sponge zirconium; the temperature of the reduced pressure distillation is 980° C. and the vacuum degree is 2 Pa.

[0071] Comparative Example 1

[0072] Different from Example 1, the chlorination furnace 1 was uniformly filled with single zircon sand, petroleum coke (mass ratio 100:40) and the reduced nickel-based catalyst.

[0073] Comparative Example 2

[0074] Different from Example 1, the chlorination furnace 1 was filled with coke of substantially same particle size of 50-100 mesh, petroleum coke, needle coke and pitch coke.

[0075] Comparative Example 3

[0076] Different from Example 1, the reduced nickel-based catalyst was not added.

[0077] Comparative Example 4

[0078] Different from Example 1, the reduced nickel-based catalyst was replaced by pure macroporous alumina.

[0079] Comparative Example 5

[0080] Different from Example 1, the first cooling and exhaust were not performed.

[0081] Comparative Example 6

[0082] Different from Example 1, the purification tower 2 was not passed through, and the second cooling was performed instead of the purification tower 2 after heating at 380°C.

[0083] Comparative Example 7

[0084] Different from Example 1, the second cooling and exhaust were not performed.

[0085] Comparative Example 8

[0086] Different from Example 1, the step 3 was not passed through, and the first crude zirconium tetrachloride gas was directly subjected to the reduction reaction.

[0087] The sponge zirconium products of 100 kg were respectively prepared by the examples and comparative examples, and then the coking conditions of the corresponding chlorination furnace 1 and the contents of C, Cl, Na and Ca in the sponge zirconium products were checked, and the results are shown in Table 1 below:

[0088] Table 1: Coking and impurity content data

[0089]

[0090] From Table 1 above, it can be seen that the mixed use of coke, petroleum coke, needle coke and pitch coke in the chlorination furnace 1, the particle size grading, the use of the reduced nickel-based catalyst can effectively prevent coking. The use of the first cooling, the second cooling, the exhaust and the purification tower can effectively purify the obtained zirconium tetrachloride and ensure the purity of the sponge zirconium.

[0091] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present application, rather than to limit them. Although the present application has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or make equivalent replacements for some or all of the technical features therein. These modifications or replacements do not deviate the essence of the corresponding technical solutions from the scope of the technical solutions of the embodiments of the present application.

Claims

1. A method for preparing high-purity sponge zirconium, characterized in that: include: The zircon sand is mixed with coke, petroleum coke, needle coke and pitch coke respectively, and then loaded into the chlorination furnace in layers along the height direction of the chlorination furnace from bottom to top in a volume ratio of 1: (3-4): (3-4): (2-3), and high-temperature chlorine is introduced from the bottom of the chlorination furnace to carry out chlorination reaction to obtain a first crude zirconium tetrachloride gas; in each loading layer of the chlorination furnace, the mass ratio of the zircon sand to the coke is 100: (10-30), the mass ratio of the zircon sand to the petroleum coke is 100: (20-40), and the mass ratio of the zircon sand to the petroleum coke is 100: (20-40). The mass ratio of the needle coke is 100:(30-50), and the mass ratio of the zircon sand to the pitch coke is 100:(10-30); 1-3% of the total mass of the corresponding layer of filling material is added to each filling layer of the chlorination furnace. The reduced nickel-based catalyst is obtained by mixing macroporous alumina, nickel salt, and an auxiliary magnesium chloride solution, and then calcining at 600°C-1000°C. The reduced nickel-based catalyst has a nickel oxide content of 25%-65% by mass and a magnesium oxide content of 1-3% by mass; The first crude zirconium tetrachloride gas is subjected to a first cooling to obtain a crude zirconium tetrachloride solid, the crude zirconium tetrachloride solid is subjected to a first heating to obtain a second crude zirconium tetrachloride gas, the second crude zirconium tetrachloride gas is passed from the bottom into a purification tower loaded with coke, petroleum coke, needle coke, pitch coke and activated carbon, refined zirconium tetrachloride gas is output from the top or upper part of the purification tower, and the refined zirconium tetrachloride gas is subjected to a second cooling to obtain a refined zirconium tetrachloride solid; The refined zirconium tetrachloride solid is subjected to a second heating to obtain high-purity zirconium tetrachloride gas, and the high-purity zirconium tetrachloride gas is introduced into a reduction furnace filled with molten magnesium metal for a reduction reaction to obtain a mixed product; Distilling the mixed product under reduced pressure to obtain the high-purity zirconium sponge; The temperature of the chlorination reaction is 800-900°C; the temperature of the reduction reaction is 800-900°C, and the pressure is 10-20KPa; the temperature of the first heating, the temperature in the purification tower, and the temperature of the second heating are each independently 350-400°C; the temperature of the reduced pressure distillation is 950-1000°C.

2. The method for preparing high-purity zirconium sponge according to claim 1, wherein The particle size of the zircon sand is 200-300 mesh; in the chlorination furnace, the particle sizes of the coke, the petroleum coke, the needle coke, and the pitch coke are independently 50-200 mesh.

3. The method for preparing high-purity zirconium sponge according to claim 2, characterized in that: In the chlorination furnace, the particle sizes of the coke, the petroleum coke, the needle coke, and the pitch coke increase in sequence.

4. The method for preparing high-purity sponge zirconium according to claim 1, characterized in that: The temperature of the high-temperature chlorine gas is 600-800°C.

5. The method for preparing high-purity zirconium sponge according to claim 1, characterized in that: The purification tower is filled with equal volumes of evenly mixed coke, petroleum coke, needle coke, pitch coke and activated carbon.

6. The method for preparing high-purity zirconium sponge according to claim 5, characterized in that: The particle sizes of the coke, petroleum coke, needle coke, pitch coke and activated carbon loaded in the purification tower are independently 50-100 meshes.

7. The method for preparing high-purity sponge zirconium according to claim 1, characterized in that: The molar ratio of the high-purity zirconium tetrachloride gas introduced into the reduction furnace to the magnesium metal in the reduction furnace is (1.1-1.3):

2.

8. The method for preparing high-purity zirconium sponge according to claim 1, characterized in that: The vacuum degree of the reduced pressure distillation is 0.5-3Pa.

9. The method for preparing high-purity sponge zirconium according to claim 1, characterized in that: The chlorination furnace, the purification tower and the reduction furnace are all purged with nitrogen at 300-500° C. before use.

10. The method for preparing high-purity zirconium sponge according to any one of claims 1 to 9, characterized in that: There are multiple reduction furnaces.

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