CN115491527B - Pretreatment method of uranium-containing waste residues and recycling method of uranium - Google Patents
Pretreatment method of uranium-containing waste residues and recycling method of uranium Download PDFInfo
- Publication number
- CN115491527B CN115491527B CN202210965153.4A CN202210965153A CN115491527B CN 115491527 B CN115491527 B CN 115491527B CN 202210965153 A CN202210965153 A CN 202210965153A CN 115491527 B CN115491527 B CN 115491527B
- Authority
- CN
- China
- Prior art keywords
- uranium
- leaching
- containing waste
- acid
- waste residue
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Active
Links
Classifications
-
- C—CHEMISTRY; METALLURGY
- C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
- C22B—PRODUCTION AND REFINING OF METALS; PRETREATMENT OF RAW MATERIALS
- C22B60/00—Obtaining metals of atomic number 87 or higher, i.e. radioactive metals
- C22B60/02—Obtaining thorium, uranium, or other actinides
- C22B60/0204—Obtaining thorium, uranium, or other actinides obtaining uranium
- C22B60/0208—Obtaining thorium, uranium, or other actinides obtaining uranium preliminary treatment of ores or scrap
-
- C—CHEMISTRY; METALLURGY
- C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
- C22B—PRODUCTION AND REFINING OF METALS; PRETREATMENT OF RAW MATERIALS
- C22B1/00—Preliminary treatment of ores or scrap
- C22B1/02—Roasting processes
- C22B1/08—Chloridising roasting
-
- C—CHEMISTRY; METALLURGY
- C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
- C22B—PRODUCTION AND REFINING OF METALS; PRETREATMENT OF RAW MATERIALS
- C22B60/00—Obtaining metals of atomic number 87 or higher, i.e. radioactive metals
- C22B60/02—Obtaining thorium, uranium, or other actinides
- C22B60/0204—Obtaining thorium, uranium, or other actinides obtaining uranium
- C22B60/0213—Obtaining thorium, uranium, or other actinides obtaining uranium by dry processes
-
- C—CHEMISTRY; METALLURGY
- C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
- C22B—PRODUCTION AND REFINING OF METALS; PRETREATMENT OF RAW MATERIALS
- C22B60/00—Obtaining metals of atomic number 87 or higher, i.e. radioactive metals
- C22B60/02—Obtaining thorium, uranium, or other actinides
- C22B60/0204—Obtaining thorium, uranium, or other actinides obtaining uranium
- C22B60/0217—Obtaining thorium, uranium, or other actinides obtaining uranium by wet processes
- C22B60/0221—Obtaining thorium, uranium, or other actinides obtaining uranium by wet processes by leaching
- C22B60/0226—Obtaining thorium, uranium, or other actinides obtaining uranium by wet processes by leaching using acidic solutions or liquors
- C22B60/023—Obtaining thorium, uranium, or other actinides obtaining uranium by wet processes by leaching using acidic solutions or liquors halogenated ion as active agent
-
- C—CHEMISTRY; METALLURGY
- C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
- C22B—PRODUCTION AND REFINING OF METALS; PRETREATMENT OF RAW MATERIALS
- C22B60/00—Obtaining metals of atomic number 87 or higher, i.e. radioactive metals
- C22B60/02—Obtaining thorium, uranium, or other actinides
- C22B60/0204—Obtaining thorium, uranium, or other actinides obtaining uranium
- C22B60/0217—Obtaining thorium, uranium, or other actinides obtaining uranium by wet processes
- C22B60/0221—Obtaining thorium, uranium, or other actinides obtaining uranium by wet processes by leaching
- C22B60/0226—Obtaining thorium, uranium, or other actinides obtaining uranium by wet processes by leaching using acidic solutions or liquors
- C22B60/0234—Obtaining thorium, uranium, or other actinides obtaining uranium by wet processes by leaching using acidic solutions or liquors sulfurated ion as active agent
-
- C—CHEMISTRY; METALLURGY
- C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
- C22B—PRODUCTION AND REFINING OF METALS; PRETREATMENT OF RAW MATERIALS
- C22B60/00—Obtaining metals of atomic number 87 or higher, i.e. radioactive metals
- C22B60/02—Obtaining thorium, uranium, or other actinides
- C22B60/0204—Obtaining thorium, uranium, or other actinides obtaining uranium
- C22B60/0217—Obtaining thorium, uranium, or other actinides obtaining uranium by wet processes
- C22B60/0221—Obtaining thorium, uranium, or other actinides obtaining uranium by wet processes by leaching
- C22B60/0226—Obtaining thorium, uranium, or other actinides obtaining uranium by wet processes by leaching using acidic solutions or liquors
- C22B60/0239—Obtaining thorium, uranium, or other actinides obtaining uranium by wet processes by leaching using acidic solutions or liquors nitric acid containing ion as active agent
-
- C—CHEMISTRY; METALLURGY
- C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
- C22B—PRODUCTION AND REFINING OF METALS; PRETREATMENT OF RAW MATERIALS
- C22B7/00—Working up raw materials other than ores, e.g. scrap, to produce non-ferrous metals and compounds thereof; Methods of a general interest or applied to the winning of more than two metals
- C22B7/006—Wet processes
- C22B7/007—Wet processes by acid leaching
-
- Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
- Y02P—CLIMATE CHANGE MITIGATION TECHNOLOGIES IN THE PRODUCTION OR PROCESSING OF GOODS
- Y02P10/00—Technologies related to metal processing
- Y02P10/20—Recycling
Abstract
The invention provides a pretreatment method of uranium-containing waste residues and a recycling method of uranium, and relates to the technical field of resource utilization. The uranium component in the uranium-containing waste residue is wrapped, so that the uranium leaching rate of the conventional acid leaching treatment method is low, and the method uses sodium chloride as a chlorinating agent, and carries out low-temperature chlorination roasting at 150-500 ℃, so that the aggregation structure of the uranium-containing waste residue can be effectively destroyed, and the uranium-containing waste residue is decomposed into small particles; the chloridizing roasting has high selectivity and can convert part of Fe and Al components in uranium-containing waste residue into FeCl 3 、AlCl 3 Further causes the destruction of the uranium-containing waste residue structure, so that the uranium component is further exposed. Meanwhile, feOCl generated in the chloridizing roasting process has a catalytic effect on the uranium leaching process, so that the uranium leaching effect is further enhanced, and the subsequent uranium leaching effect of strong acid leaching is further remarkably improved.
Description
Technical Field
The invention relates to the technical field of resource utilization, in particular to a pretreatment method of uranium-containing waste residues and a recycling method of uranium.
Background
Uranium resources are important strategic resources related to national security, and are basic guarantees of nuclear big national status of China. Uranium is widely used in the fields of scientific research, industry, national defense, and the like. Along with the great improvement of the production capacity of uranium mining and smelting in China, the storage of radioactive uranium-containing waste residues generated in the production process is increased, and the process technology research on the secondary recycling of uranium resources in the residues is very necessary because the uranium content in the residues is still higher.
In recent years, many scholars have made diligent research into the treatment of uranium-containing waste residues to recover uranium resources. For example, as Zhao Zhi et al (Zhao Zhi, li Jiang, sun Zhanxue, wang Xuegang, shi Weijun. Uranium slag acid-mixed curing acidsDegree contrast test [ J]The non-ferrous metal (smelting part), 2013 (03): 32-34.) takes the unloading slag of the microbial column leaching test as raw material, uses acid liquor of 100, 150 and 200g/L to carry out acid mixing curing, carries out spraying with the daily spraying amount of 5-10% for 20 hours after curing and column loading, and respectively has the accumulated leaching rate of 222%, 28.1% and 338% of uranium after 38 days of spraying, and the leaching rate of 29.55%, 32.96% and 40.03% of slag by weight. Liao Bingyou et al (Liao Bingyou, wang Xuegang, liu Chao, xu Subei, wang Tingjian, liu Hongwei, long Jie, wang Shijun. Influence of microwave chloridizing roasting on leaching of low grade uranium ores [ J)]Nonferrous metals (smelting section), 2021 (08): 106-110.) in comparison with different chlorinating agents (CaCl) 2 、FeCl 3 ) The influence of microwave roasting pretreatment on low-grade uranium ore leaching, wherein CaCl 2 The leaching rate of roasted uranium is low, and the main reason is CaCl 2 Sintering phenomenon occurs when high-temperature roasting, and CaSiO is generated by generating' silicon-calcium reaction 3 The method has the advantages that the mineral is wrapped, the uranium leaching rate is reduced, the surface structure of the ore is damaged by the introduction of ferric chloride to loosen the ore, the exposure area of the uranium mineral is increased, and meanwhile, the layered substance catalytic chemical reaction is generated, so that the uranium leaching rate is further improved, the uranium leaching rate of low-grade uranium mineral can be improved by microwave chlorination roasting, and the highest uranium leaching rate is 85.15%. However, the above treatment methods generally have a problem of low uranium leaching rate.
Disclosure of Invention
In view of the above, the invention aims to provide a pretreatment method of uranium-containing waste residues and a recycling method of uranium, and the pretreatment method provided by the invention can remarkably improve the leaching rate of uranium, and the leaching rate of uranium is up to 96% after subsequent acid leaching treatment.
In order to achieve the above object, the present invention provides the following technical solutions:
the invention provides a uranium-containing waste residue pretreatment method, which comprises the following steps:
mixing uranium-containing waste residues with sodium chloride, and performing chloridizing roasting to obtain roasted uranium waste residues; the temperature of the chloridizing roasting is 150-500 ℃.
Preferably, the mass of the sodium chloride is 10-50% of the mass of the uranium-containing waste residue.
Preferably, the heat preservation time of the chloridizing roasting is 0.5-3 h.
Preferably, the grain size of uranium-containing waste residues is less than 1mm.
The invention provides a method for recycling uranium in uranium-containing waste residues, which comprises the following steps:
mixing the roasted uranium waste residue obtained by the pretreatment method in the technical scheme with strong acid, and carrying out acid leaching to obtain the recycled uranium material.
Preferably, the strong acid comprises at least one of nitric acid, sulfuric acid and hydrochloric acid.
Preferably, the ratio of the mass of the roasted uranium waste residue to the mass of the strong acid is 1g:0.02 to 0.04mol.
Preferably, the temperature of the acid leaching is 50-100 ℃ and the time is 120-150 min.
Preferably, after the acid leaching, the method further comprises: carrying out solid-liquid separation on the acid leaching slurry obtained by acid leaching to obtain a liquid component and a solid component; pickling the solid component to obtain pickling solution; and combining the pickling solution with the liquid component, concentrating and drying to obtain the recycled uranium material.
Preferably, the acid washing is performed using an aqueous solution of a strong acid having a pH of 2 to 4.
The invention provides a uranium-containing waste residue pretreatment method, which comprises the following steps: mixing uranium-containing waste residues with sodium chloride, and performing chloridizing roasting to obtain roasted uranium waste residues; the temperature of the chloridizing roasting is 150-500 ℃. The uranium component in the uranium-containing waste residue is wrapped, so that the conventional acid leaching treatment method has low uranium leaching rate and too low chloridizing roasting temperature, so that the damage degree of the structure of the uranium-containing waste residue is low, and the uranium leaching effect is poor; the over-high chloridizing roasting temperature can sinter sodium chloride and uranium-containing waste residues, so that uranium components in the sodium chloride and the uranium-containing waste residues are wrapped, and recycling of uranium is not facilitated. The invention uses sodium chloride as chlorinating agent, and carries out low-temperature chlorination roasting at 150-500 ℃, which can effectively destroy the aggregation structure of uranium-containing waste residue, so that uranium is released from the coating layer (aggregation structure and flocculate formed by impurity iron, aluminum, etc.), and the uranium is decomposedForming small particles; and the chloridizing roasting has high selectivity, and other metal components and oxides (such as Fe 2 O 3 With SiO 2 ) Effectively separate and chloridize to convert part of Fe and Al components into FeCl 3 、AlCl 3 The uranium-containing waste residue structure is further damaged, so that uranium components are further exposed, and the uranium leaching effect of subsequent acid leaching is remarkably improved. Meanwhile, in the chloridizing roasting process, fe 2 O 3 FeCl produced 3 FeOCl is generated in the chemical vapor migration process, and has a catalytic effect on the uranium leaching process, so that the uranium leaching effect is further enhanced, and the uranium leaching rate of the subsequent strong acid leaching is further remarkably improved. In addition, the invention uses sodium chloride low-temperature chloridizing roasting to pretreat, has low energy consumption and low cost, and the generated chlorine and hydrogen chloride gas are easy to control, thus being suitable for industrial production.
The invention provides a method for recycling uranium in uranium-containing waste residues, which comprises the following steps: mixing the roasted uranium waste residue obtained by the pretreatment method in the technical scheme with strong acid, and carrying out acid leaching to obtain the recycled uranium material. The agglomeration structure of the roasted uranium waste residue adopted by the invention is destroyed, and the roasted uranium waste residue has FeOCl components, and FeOCl has a catalytic effect on the acid leaching process of uranium, so that uranium is easy to leach in the acid leaching process, and the uranium leaching rate is high.
As shown in the test results of the examples, the uranium-containing waste residue is pretreated by the pretreatment method provided by the invention, and then subjected to acid leaching by strong acid, and the uranium leaching rate is as high as 96%.
Drawings
FIG. 1 is a process flow diagram for uranium recovery;
FIG. 2 is a graph showing the effect of chloridizing roasting temperature on uranium leaching;
FIG. 3 is a graph showing the effect of sodium chloride addition on uranium leaching;
FIG. 4 is a graph showing the effect of chloridizing roasting time on uranium leaching;
FIG. 5 is an SEM-EDS analysis chart of uranium hydrometallurgy process waste slag powder, prepared roasted uranium waste slag and recycled uranium material adopted in example 19, wherein (a) and (c) are SEM charts of uranium hydrometallurgy process waste slag powder, (b) are SEM charts of roasted uranium waste slag, (d) are SEM charts of recycled uranium material, (c 1) are EDS charts of uranium hydrometallurgy process waste slag powder, and (d 1) are EDS charts of recycled uranium material;
FIG. 6 is an XRD spectrum of uranium hydrometallurgy process slag powder, prepared roasted uranium slag and recycled uranium material used in example 19;
fig. 7 is a diagram showing the main element contents of the uranium hydrometallurgy process waste slag powder, the prepared roasted uranium waste slag and the recycled uranium material adopted in example 19.
Detailed Description
The invention provides a pretreatment method of uranium-containing waste residues, which comprises the following steps:
mixing uranium-containing waste residues with sodium chloride, and performing chloridizing roasting to obtain roasted uranium waste residues; the temperature of the chloridizing roasting is 150-500 ℃.
In the present invention, all raw material components are commercially available products well known to those skilled in the art unless specified otherwise.
The invention mixes uranium-containing waste residue with sodium chloride, and carries out chloridizing roasting to obtain roasted uranium waste residue.
In the invention, the uranium-containing waste residue comprises uranium hydrometallurgy process waste residue; the source of the uranium hydrometallurgy process waste residues is not particularly limited, and the uranium hydrometallurgy process waste residues well known to those skilled in the art are adopted. In a specific embodiment of the invention, the uranium hydrometallurgy process waste residue is preferably mixed waste residue generated by mixing and standing residues left by new line extraction in the production and processing processes of a uranium hydrometallurgy enterprise and waste water in a system and then passing through a plate frame, and the main components are shown in table 1:
TABLE 1 content of major Components of uranium hydrometallurgy Process slag (wt%)
As can be seen from Table 1, in addition to the higher content of uranium component in the uranium hydrometallurgy process waste residue, the content of oxide formed by other elements such as silicon, phosphorus, iron, zirconium and the like is also relatively higherIn (3) SiO without acid consumption 2 26.42% of Al consuming acid 2 O 3 CaO and Fe 2 O 3 The content is relatively low, and the ZrO content is up to 15.26% 2 Is an amphoteric oxide which can be eutectic-melted with alkali or dissolved in concentrated sulfuric acid and hydrofluoric acid, and can be kept in a relatively stable state in a nitric acid leaching system of ores.
In the present invention, the uranium-containing waste residue is preferably subjected to pretreatment before use, and the pretreatment preferably includes: and (3) sequentially carrying out coarse screening, mixing, drying, crushing and screening on the uranium-containing waste residues. In the present invention, the purpose of the coarse screen is to remove non-slag impurities such as branches and leaves. In the present invention, the mixing is preferably a reverse mixing, and the number of times of the reverse mixing is preferably 4 to 5 times, more preferably 5 times. In the present invention, the drying temperature is preferably 60 to 105 ℃, more preferably 60 to 80 ℃; the invention has no special limit to the drying time, and the drying is carried out until the weight is constant; the drying is preferably carried out in an electrothermal forced air drying oven. In the present invention, the drying step further includes cooling to room temperature, and the cooling method is not particularly limited, and a cooling method well known to those skilled in the art, such as natural cooling, may be adopted. The crushing mode and the sieving are not particularly limited, and the crushing mode and the sieving which are well known to the person skilled in the art are adopted until the particle size of the obtained uranium-containing waste slag powder is less than 1mm, more preferably less than 500 mu m; the screened oversize preferably resumes the crushing.
In the present invention, the mass of sodium chloride is preferably 10 to 50%,15 to 40%, more preferably 20 to 30%, and most preferably 25% of the mass of uranium-containing waste residues.
The invention is not particularly limited to the mixing, and the uranium-containing waste residue and sodium chloride can be uniformly mixed by a method well known to those skilled in the art.
In the present invention, the temperature of the chloridizing roasting is 150 to 500 ℃, preferably 200 to 500 ℃, more preferably 200 to 400 ℃; the temperature rising speed from the room temperature to the chloridizing roasting temperature is preferably 10-12 ℃/min, more preferably 10-11 ℃/min; the heat preservation time of the chloridizing roasting is preferably 0.5-3 h, more preferably 0.5-2.5 h, and more preferably 1-2 h; too long chloridizing roasting can harden part of the uranium-containing waste residue components, so that subsequent uranium leaching is difficult to complete, and the energy consumption and the cost are high. In the present invention, the chloridizing calcination is preferably performed under vacuum.
In the invention, uranium in uranium-containing waste residue is wrapped by impurity components formed by flocculating matters such as iron, aluminum and the like, so that the uranium leaching rate of a conventional acid leaching treatment method is low; and the chloridizing roasting has high selectivity, and other metal components and oxides (such as Fe 2 O 3 With SiO 2 ) Effectively separate and chloridize to convert part of Fe and Al components into FeCl 3 、AlCl 3 Further causing the damage of uranium-containing waste residue structure. Moreover, during chloridizing roasting, fe 2 O 3 FeCl produced 3 FeOCl is generated in the chemical vapor migration process, and has a catalytic effect on the uranium leaching process, so that the uranium leaching effect is further enhanced, and the subsequent uranium leaching effect of strong acid leaching is further remarkably improved.
In the invention, the main components of the chloridized roasting product comprise FeOCl and FeCl 3 、AlCl 3 、Al 2 O 3 、SiO 2 、P 2 O 5 、Fe 2 O 3 、ZrO 2 、CaO、TiO 2 、SO 3 And U.
After the chlorination roasting is completed, the method preferably further comprises the step of cooling the obtained chlorination roasting product to room temperature to obtain roasted uranium waste residues. The cooling mode is not particularly limited, and a cooling mode well known to those skilled in the art, such as natural cooling, may be adopted.
The invention also provides a recycling method of uranium in uranium-containing waste residues, which comprises the following steps:
mixing the roasted uranium waste residue obtained by the pretreatment method in the technical scheme with strong acid, and carrying out acid leaching to obtain the recycled uranium material.
In the present invention, the strong acid preferably includes at least one of nitric acid, sulfuric acid and hydrochloric acid, more preferably nitric acid; the strong acid is preferably used in the form of an aqueous solution of a strong acid, and the concentration of the aqueous solution of a strong acid is preferably 7 to 8mol, more preferably 7.4 to 7.8mol/L. In the present invention, the ratio of the mass of the roasted uranium waste residue to the amount of the acid substance is preferably 1g:0.02 to 0.04mol, more preferably 1g:0.02 to 0.03mol.
In the present invention, the temperature of the acid leaching is preferably 50 to 100 ℃, more preferably 60 to 90 ℃, still more preferably 80 to 85 ℃; the acid leaching time is preferably 120 to 150min, more preferably 120 to 140min. In the present invention, the acid leaching is preferably performed under stirring conditions, and the stirring speed is preferably 200 to 400rpm, more preferably 200 to 300rpm.
After the acid leaching, the invention preferably further comprises: carrying out solid-liquid separation on the acid leaching slurry obtained by acid leaching to obtain a liquid component and a solid component; pickling the solid component to obtain pickling solution; and combining the pickling solution with the liquid component, concentrating and drying to obtain the recycled uranium material. The solid-liquid separation method is not particularly limited, and a solid-liquid separation method well known to those skilled in the art may be employed, and specifically, for example, centrifugal separation, the conditions of which are not particularly limited, and the liquid component and the solid component may be separated. In the present invention, the acid washing is preferably performed using an aqueous acid solution having a pH of preferably 2 to 4, more preferably 2 to 3; the aqueous acid solution preferably includes an aqueous nitric acid solution, an aqueous hydrochloric acid solution, or an aqueous sulfuric acid solution, more preferably an aqueous nitric acid solution; the acid for pickling is preferably the same as the acid for pickling so as to avoid the introduction of different acid groups, and when nitric acid is used as the acid for pickling and pickling, the obtained recycled uranium material can be directly recycled to the uranium hydrometallurgical purification process. The concentration of the present invention is not particularly limited, and may be performed by any concentration means known to those skilled in the art. In the present invention, the drying temperature is preferably 60 to 105 ℃, more preferably 60 to 80 ℃; the invention has no special limit to the drying time, and the drying is carried out until the weight is constant; the drying is preferably carried out in an electrothermal forced air drying oven.
In the present invention, the chemical composition of the recycled uranium material is preferably UO 3 R x Wherein R is the acid radical ion of strong acid for acid leaching, and x satisfies UO 3 R x The valence of (2) is 0.
The technical solutions of the present invention will be clearly and completely described in the following in connection with the embodiments of the present invention. It will be apparent that the described embodiments are only some, but not all, embodiments of the invention. All other embodiments, which can be made by those skilled in the art based on the embodiments of the invention without making any inventive effort, are intended to be within the scope of the invention.
Reagents used in examples and comparative examples: the main components of uranium hydrometallurgy process waste residues are shown in table 1; sodium chloride (NaCl) and nitric acid (HNO) 3 ) All are analytically pure, purchased from national pharmaceutical chemicals, inc., and all the water is deionized water. The apparatus used for chloridizing roasting in examples and comparative examples was a KSX-6-14Q vacuum atmosphere tube furnace, and a quartz boat was used as a container.
Example 1
The uranium is recovered by adopting the process flow diagram shown in fig. 1, and the specific steps are as follows:
(1) Pretreatment: coarse screening is carried out on uranium hydrometallurgy process waste residues to remove impurities such as branches and leaves, the mixture is piled up and mixed for 5 times, the mixture is placed in an electrothermal blowing drying oven at 60 ℃ for drying to constant weight, the mixture is naturally cooled to room temperature and then taken out, the mixture is ground and then passes through a 100-mesh sieve, the upper part of the sieve is continuously ground, the undersize part is uranium hydrometallurgy process waste residue powder (-100 meshes, namely the particle size is less than 150 mu m), and the mixture is placed in a sample bag for sealing and storage.
(2) Chloridizing roasting pretreatment: 10g of uranium hydrometallurgy process waste slag powder and 0.5g of NaCl are fully and evenly mixed, placed in a quartz boat, placed in a vacuum atmosphere tube furnace, heated to 200 ℃ at a programmed heating speed of 10 ℃/min, subjected to thermal insulation chlorination roasting for 2h, cooled to room temperature and taken out to obtain roasted uranium waste slag (9.684 g).
(3) Acid leaching: and (3) fully stirring and mixing the roasted uranium waste residue obtained in the step (2) with 40mL of nitric acid aqueous solution with the concentration of 7.4mol/L, placing the mixture in a constant-temperature magnetic stirrer with the temperature of 80 ℃, and carrying out acid leaching for 2h at the rotating speed of 200rpm to obtain acid leaching slurry.
(4) Post-treatment: centrifuging the acid leaching slurry by using a table type centrifuge to obtain clarified leaching liquid and solid components, transferring the leaching liquid to a 200mL measuring cylinder, rinsing and shaking the solid components at the bottom of the centrifuge tube by using a nitric acid aqueous solution with the pH value of 25 mLpH=2, centrifuging, pouring the obtained pickling liquid into the measuring cylinder, repeating the pickling operation for 3 times to obtain the pickling liquid and leaching slag, measuring the volume, sampling and analyzing the uranium concentration, concentrating, and drying in an electrothermal blowing drying box at the temperature of 60 ℃ to constant weight to obtain the recycled uranium material. Transferring the rest leaching residues into a porcelain plate, placing in an electrothermal blowing constant-temperature drying oven at 80 ℃ for drying, weighing, grinding with a mortar, loading into a sample bag and labeling, and sampling and analyzing the uranium content in the leaching residues.
Uranium leaching rate (η) =m i /m 0 ×100％，
Wherein m is i For recycling the quality of uranium element in uranium material, the unit is g;
m 0 the unit is g, which is the mass of uranium element in uranium-containing waste residue;
uranium leaching rate data are the average of three replicates.
Examples 2 to 19
Uranium materials were recovered from uranium hydrometallurgy process waste residues in the same manner as in example 1, and the chloridizing roasting conditions and uranium leaching rates in examples 2 to 19 are shown in table 2, and the other conditions are the same as in example 1.
Comparative examples 1 to 17
Uranium materials were recovered from uranium hydrometallurgy process waste residues in the same manner as in example 1, and chloridizing roasting and uranium leaching rates of comparative examples 1 to 18 are shown in table 2, except that the conditions were the same as in example 1.
Examples 1 to 19 and comparative examples 1 to 2 show the uranium leaching rates as shown in fig. 2 to 4, wherein fig. 2 shows the effect of chloridizing roasting temperature on uranium leaching effect, fig. 3 shows the effect of sodium chloride addition on uranium leaching effect, and fig. 4 shows the effect of chloridizing roasting time on uranium leaching effect.
TABLE 1 Chlorination and uranium Leaching Rate results for examples 1-19 and comparative examples 1-17
(1) The chlorination roasting process involves complex physical and chemical phase changes, not limited to only chemical reactions between solids and solids, and between solids and gases. Temperature is one of the most important factors, and plays a critical role in both chemical reactions and chemical reaction processes. As can be seen from table 2 and fig. 2, as the chloridizing roasting temperature changes, the uranium leaching rate of the uranium hydrometallurgy process waste residue shows a regular change of rising and then falling with the rising of the temperature. When the chloridizing roasting temperature is increased from 100 ℃ to 200 ℃, the uranium leaching rate is increased from 76.45% to 94.45%; when the temperature is continuously increased to 600 ℃, the leaching rate is reduced by 23.12% compared with 200 ℃, so that the chloridizing roasting temperature is the optimal condition at 200 ℃. Compared with the traditional acid leaching method (without chloridizing roasting), the temperature is increased by chloridizing roasting treatment, which is beneficial to chemical reaction, but also easy to generate other side effects. The excessive chloridizing roasting temperature can sinter sodium chloride and uranium hydrometallurgy process waste residues, so that uranium components in the sodium chloride and the uranium hydrometallurgy process waste residues are wrapped, and recycling of uranium is not facilitated. This demonstrates that increasing the chloridizing roasting temperature promotes leaching, but that too high a temperature can inhibit leaching.
(2) As can be seen from table 2 and fig. 3, as the amount of sodium chloride added increases, the uranium leaching rate shows a change rule of increasing and then decreasing. When the adding amount of sodium chloride is 20%, the highest value of uranium leaching rate is 95.97%; when the adding amount of sodium chloride is low, the reaction of sodium chloride and uranium hydrometallurgy process waste residues is incomplete, and the leaching effect of uranium is affected. The comprehensive test result shows that the chlorination addition amount is 20%Optimum conditions. It can also be seen from this that the oxide chlorination reaction proceeds not only in relation to temperature, but also in relation to the partial pressure of chlorine and oxygen in the oxidation system. Selective chlorination roasting to convert a portion of the metal oxide to chloride during the chlorination roasting can be achieved by controlling the ratio of the added chloride. In the whole test process, along with the gradual increase of the addition amount of sodium chloride, the structure of uranium hydrometallurgy process waste residues is mainly destroyed in the initial reaction stage, and the specific surface area and the porosity of the uranium hydrometallurgy process waste residues are increased, so that dissociation of uranium is promoted. However, with the increase of the sodium chloride consumption, the sodium chloride can react with SiO in uranium hydrometallurgy process waste residues in the chloridizing roasting process 2 、Al 2 O 3 The equal oxide reacts to generate hydrogen chloride gas (the reaction is shown in the formula (1) and the formula (2)), and the hydrogen chloride gas reacts with metal elements such as aluminum, iron, zirconium and the like in uranium hydrometallurgy process waste residues to form FeCl 2 、AlCl 3 Unstable chemical components, such as hydrogen, are easily reduced into metal particles in the reaction and are adsorbed on the surface of uranium hydrometallurgy process waste residues, so that secondary package is formed on the uranium components. While the addition of chlorinating agents may promote the reaction to form new silicate components, which are also good adsorbents for uranium. Therefore, the proper sodium chloride addition can effectively promote the dissociation of uranium.
NaCl+SiO 2 +H 2 O→Na 2 SiO 3 +2HCl type (1)
NaCl+Al 2 O 3 +H 2 O→Na 2 Al 2 O 4 +2HCl formula (2).
(3) The chloridizing roasting time is an important influencing factor of the chemical reaction. As can be seen from table 2 and fig. 4, the influence of the chloridizing roasting time on the uranium leaching rate is relatively obvious, and the uranium leaching rate generally changes in a stepwise increasing manner as the chloridizing roasting time increases. Under the condition that other conditions are unchanged, the chlorination roasting time is prolonged, the more thorough the chemical reaction is performed, the more favorable the waste residue structure of the uranium hydrometallurgy process is further decomposed, and the exposure area of uranium components is further increased; otherwise, insufficient chloridizing roasting time can lead to incomplete physicochemical reaction of uranium hydrometallurgy process waste residues, and an ideal leaching effect is difficult to achieve. Because the uranium hydrometallurgy process waste residue components are complex, when the chloridizing roasting time is 120min, the uranium leaching rate reaches a peak value 95.97%; when the chloridizing roasting time reaches 150min, the uranium leaching rate is 95.21%, but the uranium leaching rate is reduced. The complexity of chemical reaction of uranium hydrometallurgy process waste residues is further illustrated, and side reaction can be generated in the long-term chlorination roasting time [19], so that the leaching effect of uranium is affected; the chlorination roasting time is short, the reaction is insufficient, and the leaching of uranium is also not facilitated. In conclusion, the chloridizing roasting time is 120min optimally.
(4) The specific surface area is an indispensable consideration condition of the chemical reaction process, the finer the granularity of the waste residue of the uranium hydrometallurgy process is, the better the uranium leaching effect is, and when the granularity reaches-74 mu m, the highest uranium leaching rate reaches 95.97 percent. Along with the continuous decrease of the granularity of the uranium hydrometallurgy process waste residue, under the condition of sufficient chloridizing roasting time, the structure of the uranium hydrometallurgy process waste residue gradually becomes loose, so that the exposure of uranium components is increased, the specific surface area is increased, and the reaction is more and more complete; whereas the smaller the specific surface area, the less uranium components are exposed and the less pronounced the leaching effect. Therefore, the influence of the granularity of the uranium hydrometallurgy process waste residue on the uranium leaching rate is obvious, and the granularity of the uranium hydrometallurgy process waste residue in chloridizing roasting is the best of-74 mu m.
Comparative example 18
Uranium materials are recovered from uranium hydrometallurgy process waste residues according to the method of example 1, differing from example 1 only in that: and (3) chloridizing roasting in the step (2) is not carried out. The uranium leaching effects of example 1 and comparative example 18 are shown in table 3.
Table 3 uranium leaching effects of example 1 and comparative example 18
As shown in Table 3, the uranium grade of the uranium hydrometallurgy process waste residue is up to 12.00%, the leaching rate is 76.45% by adopting a conventional acid method, the uranium grade of the leaching residue is 4.11%, and a large amount of uranium remains in the leaching residue after acid leaching. After chloridizing roasting treatment is carried out by adding sodium chloride, the uranium leaching rate of uranium hydrometallurgy process waste residue is up to 95.97%, and the uranium grade of leaching residue is reduced to 0.91%. The uranium leaching effect of uranium hydrometallurgy process waste residues is obviously improved after chloridizing roasting pretreatment by using sodium chloride.
Test case
Analysis of sodium chloride low-temperature chloridizing roasting nitric acid leaching action mechanism
(1) Macroscopic phase structure analysis
The high uranium-containing waste residue is treated by the sodium chloride low-temperature chloridizing roasting nitric acid leaching process, the uranium leaching rate is up to 95.97%, and the efficient recovery of uranium resources is realized. To understand the change law of the chlorination roasting and the leaching before and after the leaching in more detail, the waste slag powder (particle size-74 μm) of the uranium hydrometallurgy process used in example 19, and the obtained roasted uranium waste slag and recycled uranium material were analyzed by using a scanning electron microscope (SEM-EDS) and X-ray diffraction (XRD), and the results are shown in fig. 5 and 6.
Fig. 5 is an SEM-EDS analysis diagram of uranium hydrometallurgy process slag powder, roasted uranium slag and recycled uranium material, wherein (a) and (c) are SEM diagrams of uranium hydrometallurgy process slag powder, (b) are SEM diagrams of roasted uranium slag, (d) are SEM diagrams of recycled uranium material, (c 1) are EDS diagrams of uranium hydrometallurgy process slag powder, and (d 1) are EDS diagrams of recycled uranium material. As can be seen from fig. 5 (a) and (b), the uranium hydrometallurgy process waste slag powder has a relatively complete structure and is aggregated into clusters, and exists in a large particle wrapping form, which is not beneficial to the full progress of chemical reaction in the leaching process, not only increases the acid consumption required by leaching, but also is a main reason for low uranium leaching rate; the surface structure of large particles of the roasted uranium waste residue after chloridizing roasting by adding sodium chloride becomes loose, gaps and cracks are increased, the specific surface area of the uranium hydrometallurgy process waste residue is increased, uranium components are further exposed, and the leaching effect of uranium is obviously improved; the chloridized roasting has proved to have a remarkable effect on uranium dissociation. As can be seen from (c), (c 1), (d) and (d 1) in fig. 5, the uranium hydrometallurgy process waste slag powder has obvious uranium characteristic peaks, and the uranium characteristic peaks of the recycled uranium material after chloridizing roasting and acid leaching treatment tend to be horizontal. The method provided by the invention has the advantages that most uranium is dissolved in the strong acid solution (pickle liquor), and the method provided by the invention has a remarkable extraction effect on uranium components of uranium hydrometallurgy process waste residues.
(2) Microscopic chemical mechanism analysis
Chloridizing roasting is highly selective and can be accomplished under relatively mild conditions compared to other methods (oxidation or reduction processes) based on high chemical activity on metal components. And HCl and Cl in the selection of chlorinating agent 2 Can easily react with iron and aluminum elements in uranium-containing waste residues to form ferric chloride, aluminum chloride and other components, however, the solid chlorinating agent has better effect on the aspects of high corrosiveness and difficult control, such as CaCl 2 And NaCl, etc., while CaCl 2 Is more suitable for high temperature and NaCl is more suitable for medium and low temperature chloridizing roasting.
XRD analysis was performed on the raw material uranium hydrometallurgy process waste slag powder (original sample) adopted in example 19, and the obtained roasted uranium waste slag (chloridized roasting sample) and recycled uranium material (leaching sample), and the leaching mechanism was explored by performing ICP analysis on the contents of main elements of aluminum, silicon, iron and uranium, and the results are shown in FIG. 6 and FIG. 7.
Fig. 6 is an XRD spectrum of uranium hydrometallurgy process waste slag powder, roasted uranium waste slag and recycled uranium material, and it can be seen from fig. 6 that the characteristic peak of uranium content of 12.00% in the raw uranium hydrometallurgy process waste slag is not prominent, whereas the characteristic peak of uranium hydrometallurgy process waste slag after chlorination roasting is prominent, so that it can be judged that the reason for causing the insignificant leaching effect of the uranium hydrometallurgy process waste slag is due to encapsulation of uranium components.
Fig. 7 is a diagram of main element contents of uranium hydrometallurgy process waste slag powder, roasted uranium waste slag and recycled uranium material, and as can be seen from fig. 7, enrichment of silicon and phosphorus in main components in the uranium hydrometallurgy process waste slag occurs, and target element uranium is greatly reduced after treatment, but iron element is also reduced. The waste residue in the comprehensive process flow is formed by mixing the residue left by new line extraction with the residue left by the standing of the wastewater in the system, and a flocculating agent and a binder which are required to be added in the standing process for removing insoluble substances in the solution all contain iron components, so that the uranium is wrapped by the iron components in the waste residue of the uranium hydrometallurgy process.
The low-temperature chloridizing roasting of sodium chloride is characterized in that the waste of uranium hydrometallurgy process can be effectively destroyed at low temperatureThe agglomerated structure of the slag is decomposed into small particles; and chloridizing roasting has high selectivity, other metal components and oxides such as Fe 2 O 3 With SiO 2 Effective separation; with the progress of chloridizing roasting, complex metal components are converted into FeCl by chloridizing such as partial iron and aluminum components 3 、AlCl 3 And the like, the damage of the uranium hydrometallurgy process waste residue structure can be further caused. And since the chloridizing roasting is carried out in a relatively closed tube furnace, feCl therein 3 And Fe (Fe) 2 O 3 FeOCl is generated in the chemical vapor migration process, the reaction is shown in the formula (3), and meanwhile, the FeOCl has a catalytic effect on the uranium leaching process, so that the uranium leaching effect is further enhanced. UO during the subsequent nitric acid leaching process 3 Then reacts with nitric acid to convert into UO 3 (NO 3 ) 2 The main chemical reaction is shown as formula (4):
FeCl 3 +Fe 2 O 3 3FeOCl (3)
UO 3 +2HNO 3 →UO 3 (NO 3 ) 2 +H 2 O formula (4).
In summary, 1) the uranium content in the uranium hydrometallurgy process waste residue is 12.00%, under the optimized conditions of 20% of sodium chloride addition, 200 ℃ of chloridizing roasting temperature and 2 hours of chloridizing roasting time, the uranium leaching rate reaches 95.97%, and is improved by 19.52% compared with 76.45% of the traditional acid leaching process. 2) The uranium components in the uranium hydrometallurgy process waste residues are wrapped, so that the conventional acid leaching rate is low, and the low-temperature chlorination roasting is utilized to change the material structure of the iron and aluminum components wrapping the uranium in the uranium hydrometallurgy process waste residues, so that the uranium components are further exposed, and the leaching effect is greatly improved. 3) Along with the great improvement of the production capacity of uranium mining and smelting in China, the stock of uranium-containing waste residues generated in the production process is increased, and the technological research on the secondary recycling of uranium resources in the uranium-containing waste residues is very necessary because the uranium content in the uranium-containing waste residues is still higher. The method for recycling uranium resources by utilizing the low-temperature chloridizing roasting nitric acid leaching method of sodium chloride has the advantages of low energy consumption, considerable effect and economy, and the generated chlorine and hydrogen chloride gas are easy to control, so that a powerful basis can be provided for recycling the radioactive waste residue uranium resources.
The foregoing is merely a preferred embodiment of the present invention and it should be noted that modifications and adaptations to those skilled in the art may be made without departing from the principles of the present invention, which are intended to be comprehended within the scope of the present invention.
Claims (7)
1. A uranium-containing waste residue pretreatment method comprises the following steps:
mixing uranium-containing waste residues with sodium chloride, and performing chloridizing roasting to obtain roasted uranium waste residues; the temperature of chloridizing roasting is 150-500 ℃;
the mass of the sodium chloride is 10-50% of the mass of uranium-containing waste residue;
the heat preservation time of the chloridizing roasting is 0.5-3 h;
the grain diameter of the uranium-containing waste residue is less than 1mm.
2. The method for recycling uranium in uranium-containing waste residues is characterized by comprising the following steps of:
mixing the roasted uranium waste residue obtained by the pretreatment method of claim 1 with strong acid, and carrying out acid leaching to obtain the recycled uranium material.
3. The recovery method of claim 2, wherein the strong acid comprises at least one of nitric acid, sulfuric acid, and hydrochloric acid.
4. A recycling method according to claim 2 or 3, characterized in that the ratio of the mass of the roasted uranium waste residue to the mass of the substance of the strong acid is 1g:0.02 to 0.04mol.
5. The recovery method according to claim 2, wherein the acid leaching is performed at a temperature of 50 to 100 ℃ for 120 to 150 minutes.
6. The recovery method according to claim 2 or 5, characterized in that after the acid leaching, further comprising: carrying out solid-liquid separation on the acid leaching slurry obtained by acid leaching to obtain a liquid component and a solid component; pickling the solid component to obtain pickling solution; and combining the pickling solution with the liquid component, concentrating and drying to obtain the recycled uranium material.
7. The method according to claim 6, wherein the acid washing is performed using a strong acid aqueous solution having a pH of 2 to 4.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202210965153.4A CN115491527B (en) | 2022-08-12 | 2022-08-12 | Pretreatment method of uranium-containing waste residues and recycling method of uranium |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202210965153.4A CN115491527B (en) | 2022-08-12 | 2022-08-12 | Pretreatment method of uranium-containing waste residues and recycling method of uranium |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN115491527A CN115491527A (en) | 2022-12-20 |
| CN115491527B true CN115491527B (en) | 2023-07-28 |
Family
ID=84467270
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN202210965153.4A Active CN115491527B (en) | 2022-08-12 | 2022-08-12 | Pretreatment method of uranium-containing waste residues and recycling method of uranium |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN115491527B (en) |
Families Citing this family (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN116024443B (en) * | 2023-03-30 | 2023-06-20 | 湖南东方钪业股份有限公司 | Recovery method of scandium metal |
Citations (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| GB865095A (en) * | 1957-05-03 | 1961-04-12 | Atomic Energy Commission | Uranium recovery process |
| AU3061100A (en) * | 1999-01-15 | 2000-08-01 | British Nuclear Fuels Plc | Improvements in and relating to processing materials |
| CN113699392A (en) * | 2020-12-17 | 2021-11-26 | 核工业北京化工冶金研究院 | Method for improving leaching rate of acid leaching uranium |
| CN114182115A (en) * | 2021-10-25 | 2022-03-15 | 南华大学 | Leaching method of uranium-containing difficult-leaching alkaline residues |
-
2022
- 2022-08-12 CN CN202210965153.4A patent/CN115491527B/en active Active
Patent Citations (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| GB865095A (en) * | 1957-05-03 | 1961-04-12 | Atomic Energy Commission | Uranium recovery process |
| AU3061100A (en) * | 1999-01-15 | 2000-08-01 | British Nuclear Fuels Plc | Improvements in and relating to processing materials |
| CN113699392A (en) * | 2020-12-17 | 2021-11-26 | 核工业北京化工冶金研究院 | Method for improving leaching rate of acid leaching uranium |
| CN114182115A (en) * | 2021-10-25 | 2022-03-15 | 南华大学 | Leaching method of uranium-containing difficult-leaching alkaline residues |
Non-Patent Citations (1)
| Title |
|---|
| 含铀难浸碱渣加温加压强化浸出试验研究;周龙等;矿冶工程;第42卷(第3期);96-99 * |
Also Published As
| Publication number | Publication date |
|---|---|
| CN115491527A (en) | 2022-12-20 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| Lu et al. | Recovery of gallium from Bayer red mud through acidic-leaching-ion-exchange process under normal atmospheric pressure | |
| JP4332591B2 (en) | Method for recovering silica and then alumina from coal ash | |
| Yu et al. | A low-emission strategy to recover lead compound products directly from spent lead-acid battery paste: Key issue of impurities removal | |
| CA3008040C (en) | Rare earth ore processing methods by acid mixing, sulphating and decomposing | |
| Yang et al. | A closed-circuit cycle process for recovery of carbon and valuable components from spent carbon cathode by hydrothermal acid-leaching method | |
| CN104372173B (en) | A kind of method being enriched with platinum from fluorine-containing inefficacy platinum catalyst | |
| CN110564970A (en) | Process method for recovering potassium, sodium and zinc from blast furnace cloth bag ash | |
| Ubaldini et al. | Removal of iron from quartz sands: A study by column leaching using a complete factorial design | |
| CN109957657B (en) | Method for simultaneously recycling iron, sodium and aluminum from red mud | |
| CN115491527B (en) | Pretreatment method of uranium-containing waste residues and recycling method of uranium | |
| CN103866142A (en) | Method of recycling molybdenum and rhenium from molybdenum concentrate by hydrometallurgy | |
| Tang et al. | A cleaner process for lead recovery from lead-containing hazardous solid waste and zinc leaching residue via reducing-matting smelting | |
| Kang et al. | Leaching of gallium from corundum flue dust using mixed acid solution | |
| Zheng et al. | Removal of magnesium and calcium from electric furnace titanium slag by H3PO4 oxidation roasting–leaching process | |
| Wang et al. | Recovery of lead and silver from zinc acid-leaching residue via a sulfation roasting and oxygen-rich chlorination leaching method | |
| CN105861838A (en) | Method for enriching platinum from fluorine-containing failure platinum catalyst | |
| Xian et al. | Extraction of molybdenum and nickel from roasted Ni–Mo ore by hydrochloric acid leaching, sulphation roasting and water leaching | |
| Li et al. | Selective separation of aluminum, silicon, and titanium from red mud using oxalic acid leaching, iron precipitation and pH adjustments with calcium carbonate | |
| CN104004917B (en) | From the useless composition brass earth of positive pole, reclaim the method for terne metal | |
| CN1361295A (en) | Direct zinc sulfide concentrate leaching-out process with coupled synergic leaching-out and solvent extraction and separation | |
| EP4265756A2 (en) | Process for recovering materials from bauxite residue, microwave reactor for heating mining products and method for heating a mining product | |
| CN111573725B (en) | Method for extracting titanium dioxide from titanium-containing blast furnace slag to prepare titanium dioxide | |
| Qu et al. | Effective recovery of Ti as anatase nanoparticles from waste red mud via a coupled leaching and boiling route | |
| JP2665437B2 (en) | Purification method of silicon metal | |
| He et al. | Study on the mechanism and kinetics of sulfuric acid leaching scandium from rich scandium anatase |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| PB01 | Publication | ||
| PB01 | Publication | ||
| SE01 | Entry into force of request for substantive examination | ||
| SE01 | Entry into force of request for substantive examination | ||
| GR01 | Patent grant | ||
| GR01 | Patent grant |