Treatment method of molybdenum-containing substance
阅读说明：本技术 一种含钼的物质的处理方法 (Treatment method of molybdenum-containing substance ) 是由 孙理鑫 牛永生 胡聪伟 窦强 李晴暖 于 2020-07-13 设计创作，主要内容包括：本发明公开了一种含钼的物质的处理方法。本发明公开的处理方法包括以下步骤：在460℃-1000℃下,将含钼的物质和三氟化氮进行反应,得MoF<Sub>6</Sub>,即可；所述的含钼的物质为：(1)含钼化合物；(2)钼单质和含钼化合物；或,(3)物质A和物质B；所述的物质A为钼单质和/或含钼化合物；所述的物质B为核裂变产物和/或熔盐。通过本发明的处理方法,含钼的物质的反应率可达90％-100％,回收率可高达93％-97％。本发明的处理方法工艺简单,流程短,固液废物少。(The invention discloses a method for treating a molybdenum-containing substance. The processing method disclosed by the invention comprises the following steps of: reacting molybdenum-containing substances with nitrogen trifluoride at 460-1000 ℃ to obtain MoF 6 Then, the method is carried out; the molybdenum-containing substances are: (1) a molybdenum-containing compound; (2) elemental molybdenum and molybdenum-containing compounds; or, (3) substance a and substance B; the substance A is a molybdenum simple substance and/or a molybdenum-containing compound; the substance B is a nuclear fission product and/or molten salt. By the treatment method, the reaction rate of the molybdenum-containing substance can reach 90-100%, and the recovery rate can reach 93-97%. The treatment method has the advantages of simple process, short flow and less solid-liquid waste.)
1. A method of treating a molybdenum-containing material, comprising the steps of: reacting molybdenum-containing substances with nitrogen trifluoride at 460-1000 ℃ to obtain MoF6Then, the method is carried out;
the molybdenum-containing substances are: (1) a molybdenum-containing compound; (2) elemental molybdenum and molybdenum-containing compounds; or, (3) substance a and substance B;
the substance A is a molybdenum simple substance and/or a molybdenum-containing compound;
the substance B is molten salt.
2. The method of treating a molybdenum-containing substance according to claim 1,
when the molybdenum-containing substance comprises a molybdenum-containing compound, the molybdenum-containing compound is one or more of molybdenum oxide, molybdenum fluoride and molybdenum chloride;
and/or, when the molybdenum-containing substance comprises a molten salt, the molten salt is a eutectic fluorine salt;
and/or when the molybdenum-containing substance is a substance A and a substance B, the content of molybdenum element in the molybdenum-containing substance is 0.01-30%, wherein the percentage is the mass of the molybdenum element in the molybdenum-containing substance;
and/or when the molybdenum-containing substance is a substance A and a substance B, the mass ratio of the substance A to the substance B is 1:10-1: 1000;
and/or the temperature of the reaction is 500-750 ℃;
and/or the flow of the introduced nitrogen trifluoride is 0.05-0.25L/min;
and/or, the nitrogen trifluoride is introduced in the form of a mixed gas of nitrogen trifluoride and inert gas;
and/or when said MoF6Stopping the reaction when the concentration of (b) is lower than the lower detection limit;
and/or the reaction time is 1-8 h;
and/or after the reaction is finished, further comprising the following steps: purging with inert gas, and vacuumizing;
and/or, said MoF6The recovery method of (1) is a condensation method or an adsorption method.
3. The method of treating a molybdenum-containing substance according to claim 2,
when the molybdenum-containing compound contains molybdenum oxide, the molybdenum oxide is molybdenum trioxide and/or molybdenum dioxide;
and/or, when the molybdenum-containing compound comprises a fluoride of molybdenum, the fluoride of molybdenum is molybdenum trifluoride and/or molybdenum pentafluoride;
and/or, when the molybdenum-containing compound contains a molybdenum chloride, the molybdenum chloride is molybdenum trichloride;
and/or, when the molybdenum-containing substance comprises a molten salt, and the molten salt is a eutectic fluorine salt, the eutectic fluorine salt is KF-ZrF4Eutectic salt, NaF-ZrF4Eutectic salt and LiF-BeF2One or more of a eutectic salt;
and/or when the molybdenum-containing substance is a substance A and a substance B, the content of molybdenum element in the molybdenum-containing substance is 0.1-10%, wherein the percentage is the mass of the molybdenum element in the molybdenum-containing substance;
and/or when the molybdenum-containing substance is a substance A and a substance B, the mass ratio of the substance A to the substance B is 1:30-1: 500;
and/or, when the molybdenum-containing substance does not contain a molten salt, the reaction temperature is 500 ℃ to 600 ℃;
and/or, when the molybdenum-containing substance comprises a molten salt, the temperature of the reaction is 600 ℃ to 750 ℃;
and/or the flow of the introduced nitrogen trifluoride is 0.15-0.25L/min;
and/or, when the nitrogen trifluoride is introduced in the form of a mixed gas of nitrogen trifluoride and an inert gas, the volume fraction of the nitrogen trifluoride in the mixed gas of nitrogen trifluoride and an inert gas is 5% to 50%;
and/or when the nitrogen trifluoride is introduced in the form of a mixed gas of nitrogen trifluoride and inert gas, the introduction flow rate of the mixed gas is 0.2-2L/min;
and/or when the nitrogen trifluoride is introduced in the form of a mixed gas of nitrogen trifluoride and an inert gas, the mixed gas of nitrogen trifluoride and an inert gas is introduced continuously; the continuous feeding time is consistent with the reaction time;
and/or when said MoF6Is lower than the lower detection limit, the lower detection limit is10ppm；
And/or the reaction time is 1-2 h;
and/or the flow rate of the inert gas for purging is 0.3L/min-0.8L/min;
and/or the purging time is 20 min-50 min;
and/or, the purging and the vacuumizing are performed in one cycle, and the cycle time is 4-8 times;
and/or when said MoF6When the recovery mode of the method is a condensation method, the condenser is a multistage condenser;
and/or when said MoF6When the recovery mode is an adsorption method, the adsorbent is one or more of activated alumina, activated carbon and sodium fluoride;
and/or when said MoF6When the recovery method of (2) is an adsorption method, the adsorber is a multistage adsorber.
4. The method of treating a molybdenum-containing substance according to claim 3,
when the molybdenum-containing substance comprises a molten salt, the reaction temperature is 650-750 ℃;
and/or, when the nitrogen trifluoride is introduced in the form of a mixed gas of nitrogen trifluoride and an inert gas, the volume fraction of the nitrogen trifluoride in the mixed gas of nitrogen trifluoride and an inert gas is 10% to 20%;
and/or, when the nitrogen trifluoride is introduced in the form of a mixed gas of nitrogen trifluoride and an inert gas, the introduction flow rate of the mixed gas is 0.5-2L/min, preferably 1-2L/min;
and/or when said MoF6When the recovery mode of the method is a condensation method, the condenser is a two-stage condenser; the first stage condensation temperature may be from-60 ℃ to-40 ℃; the secondary condensation temperature may be from-70 ℃ to-60 ℃;
and/or when said MoF6When the recovery mode is an adsorption method, the adsorber is a two-stage adsorber;
and/or when said MoF6When the recovery method of (1) is an adsorption method, the temperature of the adsorber may be 100 ℃.
5. The method of treating a molybdenum-containing material according to claim 1, wherein the molybdenum-containing material is subjected to a heat-insulating treatment.
6. The method of treating a molybdenum-containing substance according to claim 5,
the temperature of the heat preservation is the same as the temperature of the reaction;
and/or the heat preservation time is 1-30h, 2-24h, preferably 5-24 h.
7. The method of treating a molybdenum-containing substance according to claim 5 or 6,
when the molybdenum-containing substance does not contain molten salt, before the heat preservation, the method further comprises the following steps: pretreating the molybdenum-containing substance;
or, when the molybdenum-containing substance contains molten salt, before the heat preservation, the method further comprises the following steps: pretreating the molybdenum-containing substance.
8. The method of treating a molybdenum-containing substance according to claim 7,
the temperature of the pretreatment is 150-300 ℃;
or the pretreatment time is 1-10 h.
9. The method of treating a molybdenum-containing substance according to claim 8,
the temperature of the pretreatment is 200-250 ℃;
or the pretreatment time is 2-3 h.
10. The method of treating a molybdenum-containing material as claimed in claim 7, further comprising the step of, prior to said pretreatment: removing air and water from the reactor in which the molybdenum-containing material is located.
Technical Field
The invention belongs to the technical field of nuclear energy industry and dry metallurgy, and particularly relates to a method for treating a molybdenum-containing substance.
Background
99Decaying daughter nuclide of Mo99mNuclear and chemical nature of TcIs ideal and is the medical radioactive isotope which is most widely applied in the world at present. At present, the number of the current day,99mo is the most important medical isotope for reactor production, and the global demand is very large.99The Mo preparation method mainly uses pure natural molybdenum or enriched natural molybdenum by reactor thermal neutron irradiation spectrum98MoO3Target production99Mo; irradiation of high enriched uranium or enrichment by reactors235U target of passing235U(n,f)99Mo reaction production99Mo; irradiation of molybdenum or uranium targets with accelerators99Mo or direct production99mTc. In general, reactor production fission99High Mo output and high specific activity, and is still the world at present99The main source of Mo.
Fission of fuel99Production of Mo includes high abundance235Preparation and irradiation of U target, cutting, dissolution and fission of target99Mo extraction and split charging. Fission of fuel99The target used for Mo mainly comprises a uranium aluminum alloy target, a uranium magnesium dispersion target and the like, and the dissolving method of the target can be divided into an alkaline dissolving target and an acidic dissolving target. Production by fission99The first chemical scheme for Mo was developed by Bruk Highun laboratories and employed235Taking a U-Al alloy with 93 percent of U abundance as a target material, and irradiating the target with 6mol/L HNO3The mixture is dissolved and then is added with water,99the separation of Mo adopts alumina chromatographic column chromatography. Due to the fact that99mThe rapid spread and use of Tc in nuclear medicine has greatly increased the use of high purity99Mo requirement, many countries for cracking process production99The Mo technology is extensively and deeply researched, and new processes such as the American Cintichem process, Belgian IRE process, south Africa AEC process and the like are developed and established. However, the above-mentioned process still has the problems of many steps, complicated operation, long separation period, many radioactive wastes, etc.
Disclosure of Invention
The invention aims to solve the technical problem of overcoming the defect that the existing treatment method for the molybdenum-containing substance is single in type, and provides a treatment method for the molybdenum-containing substance. By the treatment method, the reaction rate of the molybdenum-containing substance can reach 90-100%, and the recovery rate can reach 93-97%. The treatment method has the advantages of simple process, short flow and less solid-liquid waste.
The present invention solves the above technical problems by the following technical solutions.
The invention provides a method for treating a molybdenum-containing substance, which comprises the following steps: reacting molybdenum-containing substances with nitrogen trifluoride at 460-1000 ℃ to obtain MoF6Then, the method is carried out;
the molybdenum-containing substances are: (1) a molybdenum-containing compound; (2) elemental molybdenum and molybdenum-containing compounds; or, (3) substance a and substance B;
the substance A is a molybdenum simple substance and/or a molybdenum-containing compound;
the substance B is molten salt.
In certain embodiments of the invention, when the molybdenum-containing material comprises a molybdenum-containing compound, the molybdenum-containing compound can be one or more of an oxide of molybdenum, a fluoride of molybdenum, and a chloride of molybdenum.
The molybdenum oxide can be molybdenum trioxide and/or molybdenum dioxide.
The fluoride of molybdenum can be molybdenum trifluoride and/or molybdenum pentafluoride.
The chloride of the molybdenum can be molybdenum trichloride.
In certain embodiments of the invention, when the molybdenum-containing material comprises a molten salt, the molten salt can be a eutectic fluoride salt.
The co-molten fluoride salt can be a co-molten fluoride salt which is conventional in the field and can also be KF-ZrF4Eutectic salt, NaF-ZrF4Eutectic salt and LiF-BeF2One or more of eutectic salts.
The KF-ZrF4KF and ZrF in eutectic salt4The molar ratio of (a) may be a molar ratio conventional in the art, for example 58: 42. The NaF-ZrF4NaF and ZrF in eutectic salt4The molar ratio of (a) may be a molar ratio conventional in the art, for example 59.5: 40.5. The LiF-BeF2LiF and BeF in eutectic salt2The molar ratio of (a) may be a molar ratio conventional in the art, for example 67: 33.
In certain embodiments of the present invention, when the molybdenum-containing material is material a and material B, the molybdenum element content in the molybdenum-containing material may be a content conventional in the art, and may be 0.01% to 30%, and may also be 0.1% to 10%, such as 0.47%, 1%, 1.25%, 2%, or 3%, wherein the percentage is the mass of the molybdenum element to the mass of the molybdenum-containing material.
In certain embodiments of the present invention, when the molybdenum-containing material is material a and material B, the mass ratio of material a to material B may be 1:10 to 1:1000, or may be 1:30 to 1:500, such as 3:100, 1:100, or 1: 500.
In certain embodiments of the invention, the temperature of the reaction may be from 500 ℃ to 750 ℃, e.g., 500 ℃, 600 ℃, 650 ℃, or 750 ℃.
In certain embodiments of the invention, when the molybdenum-containing material does not comprise a molten salt, the temperature of the reaction may be in the
In certain embodiments of the invention, when the molybdenum-containing material comprises a molten salt, the temperature of the reaction may be in the
In certain embodiments of the invention, the amount of nitrogen trifluoride used is in stoichiometric excess relative to the amount of molybdenum-containing material used. The flow rate of nitrogen trifluoride introduced may be determined by a mass flow meter, and the flow rate of nitrogen trifluoride introduced may be 0.05 to 0.25L/min, for example, 0.05L/min, 0.1L/min, 0.2L/min or 0.25L/min, preferably 0.15 to 0.25L/min.
In certain embodiments of the present invention, the nitrogen trifluoride may be introduced in the form of a mixed gas of nitrogen trifluoride and an inert gas.
The volume fraction of nitrogen trifluoride in the mixed gas of nitrogen trifluoride and inert gas may be 5% to 50%, for example, 5%, 10%, 20% or 50%, preferably 5% to 20%, more preferably 10% to 20%.
The flow rate of the mixed gas of nitrogen trifluoride and inert gas can be determined by a mass flow meter, and the flow rate of the mixed gas can be 0.2-2L/min, such as 0.2L/min, 0.5L/min, 1L/min or 2L/min, preferably 0.5-2L/min, and more preferably 1-2L/min.
The mixed gas of nitrogen trifluoride and inert gas may be introduced continuously.
The continuous feeding time may be the same as the reaction time.
In certain embodiments of the invention, when said MoF is used6When the concentration of (B) is lower than the lower detection limit, the reaction may be stopped.
The lower detection limit is preferably 10 ppm.
The MoF6Can be detected by means conventional in the art, for example by fourier infrared spectroscopy. The reaction time can be 1-8h or 1-2 h.
The stopping of the reaction can be achieved by stopping the introduction of the nitrogen trifluoride.
In some embodiments of the present invention, after the reaction is finished, the method may further comprise the following steps: purging with inert gas, and vacuumizing.
When purging, the flow rate of the inert gas for purging may be 0.3L/min to 0.8L/min, for example 0.6L/min.
The time for the purging may be 20min to 50min, for example 30 min.
The purging and vacuumizing are one cycle, and the number of the cycles can be 4-8, such as 6.
In certain embodiments of the invention, the MoF is6The recovery method of (a) may be a conventional recovery method in the art, and may be a condensation method or an adsorption method.
The condensation method can be carried out by a condenser, which can be a conventional condenser in the field, and can also be a multi-stage condenser, such as a two-stage condenser. The temperature of the condensation may be a temperature conventional in the art, but may be in the range of-70 ℃ to-20 ℃, for example-70 ℃, -60 ℃ or-40 ℃. When a two-stage condenser is used for condensation, the first stage condensation temperature may be from-60 ℃ to-40 ℃, e.g. -40 ℃, and the second stage condensation temperature may be from-70 ℃ to-60 ℃, e.g. -70 ℃ or-60 ℃.
The adsorption method can be used for adsorption by using an adsorber with an adsorbent; wherein, the adsorbent can be one or more of the conventional adsorbents in the field, such as activated alumina, activated carbon and sodium fluoride, and sodium fluoride. The adsorbers may be conventional in the art, or may be multi-stage adsorbers, such as two-stage adsorbers. The temperature of the adsorber may be a temperature conventional in the art, such as 100 ℃.
In certain embodiments of the invention, the molybdenum-containing material may be subjected to a heat-preserving treatment.
The temperature of the incubation may be the same as the temperature of the reaction.
The heat preservation time can be 1-30h, 2-24h, preferably 5-24 h.
In certain embodiments of the present invention, when the molybdenum-containing material does not contain a molten salt, the method may further comprise the following steps before the maintaining step: pretreating the molybdenum-containing substance;
alternatively, when the molybdenum-containing substance contains a molten salt, the method may further comprise, before the maintaining, the steps of: pretreating the molybdenum-containing substance.
The temperature of the pretreatment can be 150-300 ℃, and can also be 200-250 ℃.
The pretreatment time can be 1-10h, preferably 2-3 h.
The pre-treatment may remove free water.
The pretreatment is to place the molybdenum-containing substance at a certain temperature for a certain time.
In some embodiments of the present invention, before the pretreatment, preferably, the method further comprises the following steps: removing air and water from the reactor in which the molybdenum-containing material is located.
The conditions and operations of the reactor for removing the molybdenum-containing material may be those conventional in the art, and inert gas may be used to remove the air and water from the reactor.
In certain embodiments of the present invention, when the molybdenum-containing material comprises elemental molybdenum, the reaction formula of the reaction may be Mo +2NF3→MoF6+N2。
In certain embodiments of the invention, when the molybdenum-containing material comprises molybdenum trifluoride, the reaction may be of the formula 2MoF3+2NF3→2MoF6+N2。
In certain embodiments of the invention, when the molybdenum-containing material comprises molybdenum trichloride, the reaction may be of the formula 2MoCl3+4NF3→2MoF6+2N2+3Cl2。
In certain embodiments of the invention, when the molybdenum-containing material comprises molybdenum dioxide, the reaction formula for the reaction may be MoO2+2NF3→MoF6+N2+O2。
In certain embodiments of the invention, when the molybdenum-containing material comprises molybdenum trioxide, the reaction formula for the reaction can be 2MoO3+4NF3→2MoF6+2N2+3O2。
In the invention, the molybdenum element in the molybdenum simple substance and the molybdenum-containing compound can exist in the form of natural abundance or unnatural abundance. The form in natural abundance is one in which about 14.84% is92Mo, about 9.25% is94Mo, about 15.92% is95Mo, about 16.68% is96Mo, about 9.55% is97Mo, about 24.13% is98Mo, about 9.63% is100And Mo. The non-natural abundance form refers to92Mo、94Mo、95Mo、96Mo、97Mo、98Mo or100The abundance of Mo is greater than its natural abundance, and the forms of unnatural abundance include, but are not limited to92Mo、94Mo、95Mo、96Mo、97Mo、98Mo、99Mo or100Mo。
In the present invention, the inert gas may be an inert gas conventional in the art, such as one, two or three of helium, neon and argon, and further such as argon.
In the present invention, the room temperature is a room temperature well known to those skilled in the art, that is, 5 ℃ to 40 ℃.
On the basis of the common knowledge in the field, the above preferred conditions can be combined randomly to obtain the preferred embodiments of the invention.
The reagents and starting materials used in the present invention are commercially available.
The positive progress effects of the invention are as follows: by the treatment method, the reaction rate of the molybdenum-containing substance can reach 90-100%, and the recovery rate can reach 93-97%. The treatment method has the advantages of simple process, short flow and less solid-liquid waste.
Drawings
FIG. 1 is a schematic view of a process flow for recovering molybdenum by fluorination volatilization using nitrogen trifluoride as a fluorinating agent.
FIG. 2 shows the MoF product in the reactor of example 16The infrared detection spectrum of (1).
Detailed Description
The invention is further illustrated by the following examples, which are not intended to limit the scope of the invention. The experimental methods without specifying specific conditions in the following examples were selected according to the conventional methods and conditions, or according to the commercial instructions.
The molybdenum element in the molybdenum simple substance and the molybdenum-containing compound mentioned in the following examples is present in a natural abundance.
- 上一篇：一种医用注射器针头装配设备
- 下一篇：一种镀锌铜线