阅读说明：本技术 高纯三氧化钼的制备方法 (Preparation method of high-purity molybdenum trioxide ) 是由 车玉思 孙紫昂 陈永强 宋建勋 何季麟 于 2021-08-10 设计创作，主要内容包括：本发明提供了一种高纯三氧化钼的制备方法,涉及金属氧化物制备技术领域,解决了现有技术存在升华法制备高纯三氧化钼升华效率和升华率低、能耗高、品质差的技术问题。该高纯三氧化钼的制备方法包括以下步骤：以工业级氧化钼为原料,将其加热至795℃以上,使氧化钼呈现液态；通过多孔板离心仓的旋转作用将液态氧化钼进行液滴化,和/或雾化；向升华炉炉底输入800-900℃空气或富氧或氧气,与液滴化和/或雾化后的氧化钼与升华炉内逆向接触、混合和反应,将低价氧化钼氧化成高价氧化钼并完成升华；升华氧化钼向上升腾进入冷凝室冷凝,得到高纯三氧化钼。本发明用于提高制备高纯三氧化钼过程中氧化钼的升华效率和升华率,提高高纯氧化钼品质。(The invention provides a preparation method of high-purity molybdenum trioxide, relates to the technical field of metal oxide preparation, and solves the technical problems of low sublimation efficiency and sublimation rate, high energy consumption and poor quality of high-purity molybdenum trioxide prepared by a sublimation method in the prior art. The preparation method of the high-purity molybdenum trioxide comprises the following steps: heating industrial molybdenum oxide serving as a raw material to a temperature of more than 795 ℃ to enable the molybdenum oxide to be in a liquid state; liquid molybdenum oxide is subjected to dropletization and/or atomization through the rotating action of a porous plate centrifugal bin; inputting 800-900 ℃ air or oxygen-enriched or oxygen gas into the bottom of the sublimation furnace, and reversely contacting, mixing and reacting the molybdenum oxide subjected to liquid dropping and/or atomization with the sublimation furnace to oxidize the low-valence molybdenum oxide into high-valence molybdenum oxide and complete sublimation; sublimed molybdenum oxide rises upwards and enters a condensing chamber for condensation to obtain high-purity molybdenum trioxide. The method is used for improving the sublimation efficiency and sublimation rate of the molybdenum oxide in the process of preparing the high-purity molybdenum trioxide and improving the quality of the high-purity molybdenum oxide.)

1. The preparation method of high-purity molybdenum trioxide is characterized by comprising the following steps:

(1) industrial molybdenum oxide is used as a raw material and is heated to the melting point of 795 ℃ or above, so that the molybdenum oxide is completely melted and is in a liquid state;

(2) the liquid molybdenum oxide passes through the porous plate under the rotating action of the porous plate centrifugal bin to realize liquid dripping and/or atomization;

(3) inputting 800-900 ℃ air or oxygen-enriched or oxygen into the bottom of the sublimation furnace, reversely contacting, mixing and oxidizing the molybdenum oxide droplets which are settled downwards under the action of gravity, oxidizing the low-valence molybdenum oxide into high-valence molybdenum oxide and subliming the high-valence molybdenum oxide;

(4) sublimed molybdenum oxide rises upwards and enters a condensation chamber for condensation to obtain high-purity molybdenum trioxide.

2. The method for preparing high-purity molybdenum trioxide of claim 1, wherein a porous plate centrifugal bin is arranged in the sublimation furnace, and in the step (2), liquid molybdenum oxide passes through the porous plate under the rotation action of the porous plate centrifugal bin to realize liquid dripping and/or atomization.

3. The method for preparing high-purity molybdenum trioxide according to claim 2, wherein a rotating mechanism and a rotating shaft are arranged below the sublimation furnace, the porous plate centrifugal bin is connected with the rotating mechanism through the rotating shaft, and the rotating mechanism drives the porous plate centrifugal bin to rotate.

4. The method for preparing high-purity molybdenum trioxide according to claim 2, wherein the pore diameter of the porous plate is less than 20 mm.

5. The method for preparing high-purity molybdenum trioxide as claimed in claim 1, wherein in the step (3), the gas input to the bottom of the sublimation furnace is oxygen-enriched at 800-900 ℃.

6. The method for preparing high-purity molybdenum trioxide according to claim 5, wherein in the step (3), the gas fed to the bottom of the sublimation furnace is oxygen-enriched at 850 ℃.

7. The method for preparing high-purity molybdenum trioxide according to claim 1, wherein in the step (4), impurity elements which are not easy to sublimate in industrial-grade molybdenum oxide are deposited to the bottom of the sublimation furnace under the action of gravity to form waste residues.

8. The method for preparing high-purity molybdenum trioxide of claim 7, wherein the content of molybdenum oxide in the waste residue is less than 15%.

Technical Field

The invention relates to the technical field of metal oxide preparation, in particular to a preparation method of high-purity molybdenum trioxide.

Background

Molybdenum trioxide is an important molybdenum chemical product, and is an indispensable intermediate compound and precursor powder for producing metal molybdenum. In addition, the molybdenum trioxide can be used as a catalyst in the petroleum industry, and can also be used in the fields of enamel glaze pigments, medicines and the like. The nano spherical molybdenum trioxide has high dispersibility and high specific surface area, so that the catalytic performance of the catalyst can be greatly improved, and the nano spherical molybdenum trioxide has a great application prospect in the catalyst industry.

There are various preparation techniques for high-purity molybdenum trioxide, and there are two methods for large-scale application. Firstly, ammonium molybdate is prepared from industrial molybdenum oxide by a wet method, and then high-purity molybdenum trioxide is formed by high-temperature roasting, which is the mainstream method for preparing high-purity molybdenum trioxide at present. Secondly, preparing high-purity molybdenum trioxide by a sublimation method. The process for preparing high-purity molybdenum trioxide by a sublimation method has the advantages of small product granularity, large specific surface area, high activity and the like, and has a promoting effect on reduction of a catalyst and molybdenum powder.

The applicant found that: in the prior art, although the sublimation method for preparing high-purity molybdenum trioxide has the advantages of short flow and direct one-step preparation from industrial molybdenum oxide, the sublimation efficiency is low and generally needs 2-4 h; the sublimation rate is not high, and the sublimation rate is generally 50-60%; the high-purity molybdenum oxide has high impurity content and poor product quality; the sublimation temperature is high, generally 900 ℃ and 1200 ℃, and the energy consumption is high; vacuum or negative pressure is high; the cost advantage is not great, thus the industrial application is greatly influenced. In order to improve the sublimation efficiency and sublimation rate of molybdenum oxide, there are two main methods currently. Firstly, the sublimation temperature and the vacuum degree are further increased. However, low melting point impurities such as lead and zinc have the same sublimation conditions, resulting in high impurity content of the product and affecting the quality of the product. Secondly, increase the sublimed material area, equipment volume increases like this, and the energy consumption increases, and equipment input aggravates.

In summary, the prior art has at least the following technical problems:

the sublimation method for preparing high-purity molybdenum trioxide in the prior art has the advantages of low sublimation efficiency and sublimation rate, high energy consumption and poor quality.

Disclosure of Invention

The invention aims to provide a preparation method of high-purity molybdenum trioxide, which solves the technical problems of low sublimation efficiency and sublimation rate, high energy consumption and poor quality of the high-purity molybdenum trioxide prepared by a sublimation method in the prior art.

In order to achieve the purpose, the invention provides the following technical scheme:

the invention provides a preparation method of high-purity molybdenum trioxide, which comprises the following steps:

(1) industrial molybdenum oxide is used as a raw material and is heated to the melting point of 795 ℃ or above, so that the molybdenum oxide is completely melted and is in a liquid state;

(2) the liquid molybdenum oxide is dripped and/or atomized through the rotating centrifugal action of the porous plate centrifugal bin and the dispersing action of the porous plate;

(3) inputting 800-900 ℃ air or oxygen-enriched or oxygen into the bottom of the sublimation furnace, reversely contacting, mixing and oxidizing the molybdenum oxide droplets which are settled downwards under the action of gravity, oxidizing the low-valence molybdenum oxide into high-valence molybdenum oxide and subliming the high-valence molybdenum oxide;

(4) sublimed molybdenum oxide rises under the action of upward airflow and enters a condensation chamber for condensation, and high-purity molybdenum trioxide is obtained.

In an optional embodiment, a porous plate centrifugal bin is arranged in the sublimation furnace, and in the step (2), the liquid molybdenum oxide passes through the porous plate through the rotating action of the porous plate centrifugal bin to realize the liquid dripping and/or atomization.

In an optional embodiment, a rotating mechanism and a rotating shaft are arranged below the sublimation furnace, the porous plate centrifugal bin is connected with the rotating mechanism through the rotating shaft, and the rotating mechanism drives the porous plate centrifugal bin to rotate.

In alternative embodiments, the aperture of the perforated plate is less than 20 mm.

In an alternative embodiment, in the step (3), the gas input to the bottom of the sublimation furnace is rich in oxygen at 800-.

In an alternative embodiment, in the step (3), the gas fed to the bottom of the sublimation furnace is oxygen-enriched at 850 ℃.

In an optional embodiment, in the step (4), impurity elements which are not easy to sublimate in the industrial-grade molybdenum oxide are deposited to the bottom of the sublimation furnace under the action of gravity to form waste residues.

In an alternative embodiment, the molybdenum oxide content of the slag is less than 15%.

Research on the sublimation phenomenon and process of molybdenum oxide shows that the sublimation efficiency and sublimation rate are positively correlated with temperature, time and a gas-solid/liquid-solid interface, and are not strongly correlated with the thickness of a material layer and the static and dynamic state of the material. Particularly with respect to the gas-solid/liquid-solid interface. That is, when the gas-solid/liquid-solid interface area is increased by 1 time, the sublimation efficiency and sublimation rate are improved by 1 time. Therefore, trying to increase the gas-solid/liquid-solid interfacial area is the main direction to increase sublimation efficiency.

The most effective method for increasing the sublimed gas-solid interface is the fluidized bed technique. However, because the industrial molybdenum oxide contains more impurity elements, the impurity elements easily enter the product along with the sublimation gas flow in the powder fluidization process, and the product quality is reduced. Therefore, a method for improving the efficiency of sublimating molybdenum trioxide by using the fluidized bed technology is not applied.

In view of the linear correlation between the gas-solid/liquid-solid reaction interface and the sublimation efficiency, the fluidized bed technology reinforced gas-solid reaction has the problem of high impurity content. So that the sublimation efficiency of the molybdenum oxide can not meet the requirement of large-scale production all the time. The main problems of the prior art are as follows: the sublimation temperature is high, and is generally between 900 ℃ and 1200 ℃; the impurity element content in the sublimed molybdenum oxide is high; the sublimation efficiency is low, the sublimation time is longer than 2-4h, and the production cost is high; the sublimation rate is low, generally less than 60%; the equipment has large volume so as to increase the gas-solid/gas-liquid reaction interface.

The method utilizes the characteristics of low melting point (795 ℃) and easy sublimation of the molybdenum oxide, and the molten industrial molybdenum oxide is subjected to centrifugal liquid dripping and atomization, so that a gas-liquid interface is remarkably increased, the internal diffusion and sublimation of the molybdenum oxide liquid drop are improved, the sublimation temperature is properly reduced, the temperature range is effectively narrowed, the pollution of volatile impurity elements is favorably controlled, the sublimation efficiency and sublimation rate of the molybdenum oxide are improved, the quality of the sublimed molybdenum oxide is improved, and the green, low-carbon and large-scale preparation of high-purity molybdenum trioxide is promoted.

Based on the technical scheme, the embodiment of the invention can at least produce the following technical effects:

in the prior art, although the sublimation method for preparing high-purity molybdenum trioxide has the advantages of short flow and direct preparation from industrial molybdenum oxide by a one-step method, the sublimation method is low in sublimation efficiency, low in sublimation rate, high in energy consumption, poor in quality and high in cost, so that the industrial application is greatly influenced. In order to improve the sublimation efficiency and sublimation rate of molybdenum oxide, the main current method is to further increase the sublimation temperature and vacuum degree. Therefore, low-melting-point impurity components such as lead, zinc and the like have the same sublimation conditions, so that the impurity content of the product is high, and the quality of the product is influenced.

Compared with the prior art, the preparation method of the high-purity molybdenum trioxide provided by the invention comprises the steps of firstly heating molybdenum oxide to the melting point temperature of 795 ℃ or higher to completely melt the molybdenum oxide to be in a liquid state; the liquid molybdenum oxide is then dropletized and atomized by centrifugation. For example, 1m³The industrial molybdenum oxide melt was placed in a 1 m.times.1 m furnace chamber with a gas-liquid interface of 1m². When the solution was dropletized by centrifugation, it became 1mm³The surface area of the individual droplets is 4.8mm²，1m³The surface area of the molten mass after being converted into liquid drops reaches 480m²The gas-liquid interface will increase 480 times. Then, the molybdenum oxide after being subjected to liquid drop formation or atomization is in reverse contact with a certain amount of high-temperature air/oxygen-enriched air/oxygen at about 850 ℃ input from the furnace bottom under the action of gravity, and is fully mixed, under the suspension state, the low-valence molybdenum oxide is subjected to oxidation reaction to form high-valence molybdenum oxide, and the high-valence molybdenum oxide is sublimated, so that the sublimation rate is improved; finally, sublimed molybdenum oxide has low specific gravity and rises under the action of upward airflow to enter a condensation chamber for condensation, so that high-purity molybdenum trioxide is obtained; and impurity elements which are difficult to sublimate in the industrial molybdenum oxide are deposited at the bottom of the furnace body under the action of gravity. Thereby realizing the sublimation separation of the molybdenum oxide. In the process, the sublimed gas-liquid interface is improved by more than 400 times, and the sublimation rate are improved by more than 400 times, so that the technical problems of low sublimation efficiency and sublimation rate, high energy consumption and poor quality of the high-purity molybdenum trioxide prepared by a sublimation method in the prior art are solved.

Drawings

In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the drawings needed to be used in the description of the embodiments will be briefly introduced below, and it is apparent that the drawings in the following description are only embodiments of the present invention, and it is obvious for those skilled in the art that other drawings can be obtained based on these drawings without inventive efforts.

FIG. 1 is a schematic diagram of a portion of the structure to which the present invention relates;

fig. 2 is a partial schematic view of a multi-well plate centrifuge cartridge according to the present invention.

Reference numerals: 1. a sublimation furnace; 11. a perforated plate centrifugal bin; 2. a rotation mechanism; 3. a rotating shaft.

Detailed Description

In order to make the objects, technical solutions and advantages of the present invention more apparent, the technical solutions of the present invention will be described in detail below. It should be apparent that the described embodiment is only one embodiment of the invention, and not all embodiments. All other embodiments, which can be obtained by a person skilled in the art without any inventive step based on the embodiments of the present invention, are within the scope of the present invention.

The embodiment of the invention provides a preparation method of high-purity molybdenum trioxide.

Example 1:

the technical solution provided by the present invention is explained in more detail with reference to fig. 1 to 2.

As shown in fig. 1 to fig. 2, the method for preparing high-purity molybdenum trioxide provided by the embodiment of the present invention includes the following steps:

(1) industrial molybdenum oxide is used as a raw material and is heated to the melting point of 795 ℃ or above, so that the molybdenum oxide is completely melted and is in a liquid state;

(2) liquid molybdenum oxide passes through the porous plate to realize liquid dripping and/or atomization through the rotating action of the porous plate centrifugal bin 11;

(3) inputting 800-plus 900 ℃ air or oxygen-enriched or oxygen into the bottom of the sublimation furnace 1, making reverse contact with the molybdenum oxide liquid drops which are settled downwards under the action of gravity, fully mixing and carrying out oxidation reaction, oxidizing the low-valence molybdenum oxide in the liquid drops into high-valence molybdenum oxide and subliming;

(4) sublimed molybdenum oxide rises under the action of upward airflow and enters a condensation chamber for condensation, and high-purity molybdenum trioxide is obtained.

In the prior art, although the sublimation method for preparing high-purity molybdenum trioxide has the advantages of short flow and direct one-step preparation from industrial molybdenum oxide, the sublimation efficiency and sublimation rate are low, the energy consumption and quality are poor, and the cost is high, so that the industrial application is greatly influenced. In order to increase the sublimation efficiency and sublimation rate of molybdenum oxide, the main method at present is to further increase the sublimation temperature. Therefore, low-melting-point impurity components such as lead, zinc and the like have the same sublimation conditions, so that the impurity content of the product is high, and the quality of the product is influenced.

Compared with the prior art, the preparation method of the high-purity molybdenum trioxide provided by the invention comprises the steps of firstly heating molybdenum oxide to the melting point temperature of 795 ℃ or higher to completely melt the molybdenum oxide to be in a liquid state; the liquid molybdenum oxide is then dropletized and atomized by spin centrifugation. For example, 1m³The industrial molybdenum oxide melt was placed in a 1m furnace chamber with a gas-liquid interface of 1m². After formation of droplets by centrifugation, 1mm was formed³The surface area of the individual droplets is 4.8mm²，1m³The surface area of the molten mass after being converted into liquid drops reaches 480m²The gas-liquid interface will increase 480 times. Then, the molybdenum oxide after being subjected to liquid drop formation or atomization is in reverse contact with a certain amount of high-temperature air/oxygen-enriched air/oxygen at about 850 ℃ input from the furnace bottom under the action of gravity, and is fully mixed, and in a suspension state, the low-valence molybdenum oxide is oxidized into high-valence molybdenum oxide and is sublimated; finally, sublimed molybdenum oxide has low specific gravity and rises under the action of upward airflow to enter a condensation chamber for condensation, so that high-purity molybdenum trioxide is obtained; and impurity elements which are difficult to sublimate in the industrial molybdenum oxide are deposited at the bottom of the furnace body under the action of gravity. Thereby realizing the sublimation separation of the molybdenum oxide. In the process, due to the improvement of 400 times of the sublimed gas-liquid interface, the sublimation rate and the sublimation rate are improved by more than 400 times, so that the sublimation efficiency and the low sublimation rate of the high-purity molybdenum trioxide prepared by a sublimation method in the prior art are solvedHigh energy consumption and poor quality.

Example 2:

the technical solution provided by the present invention is explained in more detail with reference to fig. 1 to 2.

As shown in fig. 1 to fig. 2, the method for preparing high-purity molybdenum trioxide provided by the embodiment of the present invention includes the following steps:

(1) industrial molybdenum oxide is used as a raw material and is heated to the melting point of 795 ℃ or above, so that the molybdenum oxide is completely melted and is in a liquid state;

(2) liquid molybdenum oxide passes through the porous plate to realize liquid dripping and/or atomization through the rotating action of the porous plate centrifugal bin 11;

(3) inputting 800-900 ℃ air or oxygen-enriched or oxygen into the bottom of the sublimation furnace 1, reversely contacting, mixing and oxidizing the molybdenum oxide droplets which are settled downwards under the action of gravity, oxidizing the low-valence molybdenum oxide into high-valence molybdenum oxide and subliming the high-valence molybdenum oxide;

(4) sublimed molybdenum oxide rises under the action of upward airflow and enters a condensation chamber for condensation, and high-purity molybdenum trioxide is obtained.

In the prior art, although the sublimation method for preparing high-purity molybdenum trioxide has the advantages of short flow and direct one-step preparation from industrial molybdenum oxide, the sublimation efficiency and sublimation rate are low, the energy consumption and quality are poor, and the cost is high, so that the industrial application is greatly influenced. In order to increase the sublimation efficiency and sublimation rate of molybdenum oxide, the main method at present is to further increase the sublimation temperature. Therefore, low-melting-point impurity components such as lead, zinc and the like have the same sublimation conditions, so that the impurity content of the product is high, and the quality of the product is influenced.

Compared with the prior art, the preparation method of the high-purity molybdenum trioxide provided by the invention comprises the steps of firstly heating molybdenum oxide to the melting point temperature of 795 ℃ or higher to completely melt the molybdenum oxide to be in a liquid state; the liquid molybdenum oxide is then dropletized and atomized by spin centrifugation. For example, 1m³The industrial molybdenum oxide melt was placed in a 1m furnace chamber with a gas-liquid interface of 1m². After formation of droplets by centrifugation, 1mm was formed³Of individual droplets, of a watchThe area is 4.8mm²，1m³The surface area of the molten mass after being converted into liquid drops reaches 480m²The gas-liquid interface will increase 480 times. Then, the molybdenum oxide after being subjected to liquid drop formation or atomization is in reverse contact with a certain amount of high-temperature air/oxygen-enriched air/oxygen at about 850 ℃ input from the furnace bottom under the action of gravity, and is fully mixed, and in a suspension state, the low-valence molybdenum oxide is oxidized into high-valence molybdenum oxide and is sublimated; finally, sublimed molybdenum oxide has low specific gravity and rises under the action of upward airflow to enter a condensation chamber for condensation, so that high-purity molybdenum trioxide is obtained; and impurity elements which are difficult to sublimate in the industrial molybdenum oxide are deposited at the bottom of the furnace body under the action of gravity. Thereby realizing the sublimation separation of the molybdenum oxide. In the process, due to the fact that the sublimed gas-liquid interface is improved by more than 400 times, the sublimation rate and the sublimation rate are improved by more than 400 times, and the technical problems that in the prior art, the sublimation efficiency and the sublimation rate of high-purity molybdenum trioxide prepared by a sublimation method are low, the energy consumption is high, and the quality is poor are solved.

As an alternative embodiment, a perforated plate centrifugal bin 11 is arranged in the sublimation furnace 1, and in the step (2), the liquid molybdenum oxide is subjected to liquid dripping and/or atomization through the rotation of the perforated plate centrifugal bin 11; a rotating mechanism 2 and a rotating shaft 3 are arranged below the sublimation furnace 1, the porous plate centrifugal bin 11 is connected with the rotating mechanism 2 through the rotating shaft 3, and the rotating mechanism 2 drives the porous plate centrifugal bin 11 to rotate; the aperture of the perforated plate on the perforated plate centrifugal bin 11 is less than 20 mm; in the step (3), the gas input to the bottom of the sublimation furnace 1 is oxygen-enriched at 850 ℃; in the step (4), impurity elements which are difficult to sublimate in the industrial-grade molybdenum oxide are deposited to the bottom of the sublimation furnace 1 under the action of gravity to form waste residues, and the content of molybdenum oxide in the waste residues is lower than 15%.

The main advantages of the invention are:

1. the sublimation time is short, and is reduced from several hours to several minutes in the traditional sublimation process;

2. the sublimation efficiency is high, and a large amount of molybdenum oxide is instantaneously sublimated;

3. the sublimation energy consumption is low, and is far lower than the conventional sublimation method 900-1200 ℃ at about 850 ℃;

4. the content of impurities is small, and the sublimable impurity elements are few due to low sublimation temperature;

5. the sublimation rate is high, and the highest sublimation rate can reach more than 85 percent;

6. because the low-valence molybdenum oxide is oxidized into high-valence molybdenum oxide again, the content of the molybdenum oxide in the waste residue is lower than 15 percent;

7. can be used for large-scale production.

The above description is only for the specific embodiment of the present invention, but the scope of the present invention is not limited thereto, and any changes or substitutions that can be easily conceived by those skilled in the art within the technical scope of the present invention are included in the scope of the present invention. Therefore, the protection scope of the present invention shall be subject to the protection scope of the appended claims.

In the description of the present invention, it is to be noted that, unless otherwise specified, "a plurality" means two or more; the terms "upper", "lower", "left", "right", "inner", "outer", "front", "rear", "head", "tail", and the like, indicate orientations or positional relationships based on the orientations or positional relationships shown in the drawings, are only for convenience in describing and simplifying the description, and do not indicate or imply that the device or element referred to must have a particular orientation, be constructed in a particular orientation, and be operated, and thus, should not be construed as limiting the invention. Furthermore, the terms "first," "second," "third," and the like are used for descriptive purposes only and are not to be construed as indicating or implying relative importance.

In the description of the present invention, it should also be noted that, unless otherwise explicitly specified or limited, the terms "mounted," "connected," and "connected" are to be construed broadly, e.g., as meaning either a fixed connection, a removable connection, or an integral connection; can be mechanically or electrically connected; may be directly connected or indirectly connected through an intermediate. The specific meaning of the above terms in the present invention can be understood as appropriate to those of ordinary skill in the art.