CN118164537A - Technological process for preparing uranium oxide by direct hydrogen reduction of uranyl carbonate - Google Patents
Technological process for preparing uranium oxide by direct hydrogen reduction of uranyl carbonate Download PDFInfo
- Publication number
- CN118164537A CN118164537A CN202211583795.4A CN202211583795A CN118164537A CN 118164537 A CN118164537 A CN 118164537A CN 202211583795 A CN202211583795 A CN 202211583795A CN 118164537 A CN118164537 A CN 118164537A
- Authority
- CN
- China
- Prior art keywords
- liquid
- hydrogen
- reaction
- reactor
- uranium
- 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.)
- Pending
Links
- 239000001257 hydrogen Substances 0.000 title claims abstract description 61
- 229910052739 hydrogen Inorganic materials 0.000 title claims abstract description 61
- UFHFLCQGNIYNRP-UHFFFAOYSA-N Hydrogen Chemical compound [H][H] UFHFLCQGNIYNRP-UHFFFAOYSA-N 0.000 title claims abstract description 55
- WZECUPJJEIXUKY-UHFFFAOYSA-N [O-2].[O-2].[O-2].[U+6] Chemical compound [O-2].[O-2].[O-2].[U+6] WZECUPJJEIXUKY-UHFFFAOYSA-N 0.000 title claims abstract description 25
- 229910000439 uranium oxide Inorganic materials 0.000 title claims abstract description 25
- DSERHVOICOPXEJ-UHFFFAOYSA-L uranyl carbonate Chemical compound [U+2].[O-]C([O-])=O DSERHVOICOPXEJ-UHFFFAOYSA-L 0.000 title claims abstract description 19
- 230000009467 reduction Effects 0.000 title claims description 11
- 238000004519 manufacturing process Methods 0.000 title description 10
- 239000007788 liquid Substances 0.000 claims abstract description 86
- 238000000034 method Methods 0.000 claims abstract description 39
- 239000012295 chemical reaction liquid Substances 0.000 claims abstract description 38
- 239000007787 solid Substances 0.000 claims abstract description 33
- 239000000047 product Substances 0.000 claims abstract description 30
- 238000005984 hydrogenation reaction Methods 0.000 claims abstract description 26
- 239000002245 particle Substances 0.000 claims abstract description 25
- 239000006228 supernatant Substances 0.000 claims abstract description 21
- 239000003054 catalyst Substances 0.000 claims abstract description 20
- FCTBKIHDJGHPPO-UHFFFAOYSA-N uranium dioxide Inorganic materials O=[U]=O FCTBKIHDJGHPPO-UHFFFAOYSA-N 0.000 claims abstract description 14
- 239000002994 raw material Substances 0.000 claims abstract description 13
- 238000000926 separation method Methods 0.000 claims abstract description 12
- 230000009471 action Effects 0.000 claims abstract description 11
- 238000002386 leaching Methods 0.000 claims abstract description 11
- OOAWCECZEHPMBX-UHFFFAOYSA-N oxygen(2-);uranium(4+) Chemical compound [O-2].[O-2].[U+4] OOAWCECZEHPMBX-UHFFFAOYSA-N 0.000 claims abstract description 11
- 238000001035 drying Methods 0.000 claims abstract description 6
- 150000002431 hydrogen Chemical class 0.000 claims abstract description 6
- 238000009826 distribution Methods 0.000 claims abstract description 5
- 238000001914 filtration Methods 0.000 claims abstract description 5
- 229910052770 Uranium Inorganic materials 0.000 claims description 44
- JFALSRSLKYAFGM-UHFFFAOYSA-N uranium(0) Chemical compound [U] JFALSRSLKYAFGM-UHFFFAOYSA-N 0.000 claims description 44
- 239000000243 solution Substances 0.000 claims description 25
- 230000008569 process Effects 0.000 claims description 22
- 238000001556 precipitation Methods 0.000 claims description 16
- PXHVJJICTQNCMI-UHFFFAOYSA-N Nickel Chemical compound [Ni] PXHVJJICTQNCMI-UHFFFAOYSA-N 0.000 claims description 15
- 239000007789 gas Substances 0.000 claims description 14
- 239000007791 liquid phase Substances 0.000 claims description 11
- IJGRMHOSHXDMSA-UHFFFAOYSA-N Atomic nitrogen Chemical compound N#N IJGRMHOSHXDMSA-UHFFFAOYSA-N 0.000 claims description 10
- 239000000919 ceramic Substances 0.000 claims description 7
- 229910052759 nickel Inorganic materials 0.000 claims description 7
- 239000012071 phase Substances 0.000 claims description 6
- 238000007599 discharging Methods 0.000 claims description 5
- 239000000463 material Substances 0.000 claims description 5
- 229910052751 metal Inorganic materials 0.000 claims description 5
- 239000002184 metal Substances 0.000 claims description 5
- 229910052757 nitrogen Inorganic materials 0.000 claims description 5
- 238000004062 sedimentation Methods 0.000 claims description 5
- BASFCYQUMIYNBI-UHFFFAOYSA-N platinum Substances [Pt] BASFCYQUMIYNBI-UHFFFAOYSA-N 0.000 claims description 4
- 238000006555 catalytic reaction Methods 0.000 claims description 3
- 230000005484 gravity Effects 0.000 claims description 3
- 229910000510 noble metal Inorganic materials 0.000 claims description 3
- 229910052697 platinum Inorganic materials 0.000 claims description 3
- 238000004064 recycling Methods 0.000 claims description 3
- 239000008247 solid mixture Substances 0.000 claims description 3
- 238000005485 electric heating Methods 0.000 claims description 2
- 238000010438 heat treatment Methods 0.000 claims description 2
- 238000010926 purge Methods 0.000 claims description 2
- 229910001220 stainless steel Inorganic materials 0.000 claims description 2
- 239000010935 stainless steel Substances 0.000 claims description 2
- XEEYBQQBJWHFJM-UHFFFAOYSA-N Iron Chemical compound [Fe] XEEYBQQBJWHFJM-UHFFFAOYSA-N 0.000 claims 4
- 230000018044 dehydration Effects 0.000 claims 1
- 238000006297 dehydration reaction Methods 0.000 claims 1
- 239000012527 feed solution Substances 0.000 claims 1
- 229910052742 iron Inorganic materials 0.000 claims 1
- 229910052707 ruthenium Inorganic materials 0.000 claims 1
- 238000006243 chemical reaction Methods 0.000 abstract description 32
- 230000001376 precipitating effect Effects 0.000 abstract description 3
- 238000011065 in-situ storage Methods 0.000 abstract description 2
- 238000002156 mixing Methods 0.000 abstract 2
- 239000013049 sediment Substances 0.000 abstract 1
- DGAQECJNVWCQMB-PUAWFVPOSA-M Ilexoside XXIX Chemical compound C[C@@H]1CC[C@@]2(CC[C@@]3(C(=CC[C@H]4[C@]3(CC[C@@H]5[C@@]4(CC[C@@H](C5(C)C)OS(=O)(=O)[O-])C)C)[C@@H]2[C@]1(C)O)C)C(=O)O[C@H]6[C@@H]([C@H]([C@@H]([C@H](O6)CO)O)O)O.[Na+] DGAQECJNVWCQMB-PUAWFVPOSA-M 0.000 description 11
- 239000011734 sodium Substances 0.000 description 11
- 229910052708 sodium Inorganic materials 0.000 description 11
- 238000006722 reduction reaction Methods 0.000 description 9
- HEMHJVSKTPXQMS-UHFFFAOYSA-M Sodium hydroxide Chemical compound [OH-].[Na+] HEMHJVSKTPXQMS-UHFFFAOYSA-M 0.000 description 6
- QGZKDVFQNNGYKY-UHFFFAOYSA-N Ammonia Chemical compound N QGZKDVFQNNGYKY-UHFFFAOYSA-N 0.000 description 5
- 230000008901 benefit Effects 0.000 description 5
- 239000000446 fuel Substances 0.000 description 5
- CURLTUGMZLYLDI-UHFFFAOYSA-N Carbon dioxide Chemical compound O=C=O CURLTUGMZLYLDI-UHFFFAOYSA-N 0.000 description 4
- OAKJQQAXSVQMHS-UHFFFAOYSA-N Hydrazine Chemical compound NN OAKJQQAXSVQMHS-UHFFFAOYSA-N 0.000 description 4
- 239000007790 solid phase Substances 0.000 description 4
- 229910021529 ammonia Inorganic materials 0.000 description 3
- -1 ammonia cation Chemical class 0.000 description 3
- 238000009903 catalytic hydrogenation reaction Methods 0.000 description 3
- 238000010531 catalytic reduction reaction Methods 0.000 description 3
- 239000012530 fluid Substances 0.000 description 3
- 238000006460 hydrolysis reaction Methods 0.000 description 3
- 239000002244 precipitate Substances 0.000 description 3
- 230000002285 radioactive effect Effects 0.000 description 3
- 239000002354 radioactive wastewater Substances 0.000 description 3
- 239000012265 solid product Substances 0.000 description 3
- 239000000126 substance Substances 0.000 description 3
- 239000002351 wastewater Substances 0.000 description 3
- CDBYLPFSWZWCQE-UHFFFAOYSA-L Sodium Carbonate Chemical compound [Na+].[Na+].[O-]C([O-])=O CDBYLPFSWZWCQE-UHFFFAOYSA-L 0.000 description 2
- 239000003638 chemical reducing agent Substances 0.000 description 2
- 125000004122 cyclic group Chemical group 0.000 description 2
- ZAASRHQPRFFWCS-UHFFFAOYSA-P diazanium;oxygen(2-);uranium Chemical compound [NH4+].[NH4+].[O-2].[O-2].[O-2].[O-2].[O-2].[O-2].[O-2].[U].[U] ZAASRHQPRFFWCS-UHFFFAOYSA-P 0.000 description 2
- 238000005516 engineering process Methods 0.000 description 2
- 230000007062 hydrolysis Effects 0.000 description 2
- 239000000203 mixture Substances 0.000 description 2
- 238000000746 purification Methods 0.000 description 2
- 239000011347 resin Substances 0.000 description 2
- 229920005989 resin Polymers 0.000 description 2
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 description 2
- OKTJSMMVPCPJKN-UHFFFAOYSA-N Carbon Chemical compound [C] OKTJSMMVPCPJKN-UHFFFAOYSA-N 0.000 description 1
- GRYLNZFGIOXLOG-UHFFFAOYSA-N Nitric acid Chemical compound O[N+]([O-])=O GRYLNZFGIOXLOG-UHFFFAOYSA-N 0.000 description 1
- 238000004458 analytical method Methods 0.000 description 1
- 239000007864 aqueous solution Substances 0.000 description 1
- QVGXLLKOCUKJST-UHFFFAOYSA-N atomic oxygen Chemical compound [O] QVGXLLKOCUKJST-UHFFFAOYSA-N 0.000 description 1
- 229910052799 carbon Inorganic materials 0.000 description 1
- 239000001569 carbon dioxide Substances 0.000 description 1
- 229910002092 carbon dioxide Inorganic materials 0.000 description 1
- 230000008859 change Effects 0.000 description 1
- 239000003153 chemical reaction reagent Substances 0.000 description 1
- 230000010485 coping Effects 0.000 description 1
- 230000007547 defect Effects 0.000 description 1
- 230000008021 deposition Effects 0.000 description 1
- 238000000151 deposition Methods 0.000 description 1
- 238000010586 diagram Methods 0.000 description 1
- WYICGPHECJFCBA-UHFFFAOYSA-N dioxouranium(2+) Chemical compound O=[U+2]=O WYICGPHECJFCBA-UHFFFAOYSA-N 0.000 description 1
- 238000004090 dissolution Methods 0.000 description 1
- 230000005611 electricity Effects 0.000 description 1
- 239000003480 eluent Substances 0.000 description 1
- 238000005265 energy consumption Methods 0.000 description 1
- 238000004880 explosion Methods 0.000 description 1
- 239000002360 explosive Substances 0.000 description 1
- 238000001125 extrusion Methods 0.000 description 1
- 238000003682 fluorination reaction Methods 0.000 description 1
- 239000012535 impurity Substances 0.000 description 1
- 229910052500 inorganic mineral Inorganic materials 0.000 description 1
- 229910052741 iridium Inorganic materials 0.000 description 1
- 239000011707 mineral Substances 0.000 description 1
- 229910017604 nitric acid Inorganic materials 0.000 description 1
- 239000003758 nuclear fuel Substances 0.000 description 1
- 230000001590 oxidative effect Effects 0.000 description 1
- 239000001301 oxygen Substances 0.000 description 1
- 229910052760 oxygen Inorganic materials 0.000 description 1
- 238000007747 plating Methods 0.000 description 1
- 238000002360 preparation method Methods 0.000 description 1
- 238000011160 research Methods 0.000 description 1
- 238000007790 scraping Methods 0.000 description 1
- 229910000029 sodium carbonate Inorganic materials 0.000 description 1
- 229910001415 sodium ion Inorganic materials 0.000 description 1
- 238000001179 sorption measurement Methods 0.000 description 1
- 230000008961 swelling Effects 0.000 description 1
- 231100000167 toxic agent Toxicity 0.000 description 1
- 239000003440 toxic substance Substances 0.000 description 1
- SANRKQGLYCLAFE-UHFFFAOYSA-H uranium hexafluoride Chemical compound F[U](F)(F)(F)(F)F SANRKQGLYCLAFE-UHFFFAOYSA-H 0.000 description 1
Landscapes
- Inorganic Compounds Of Heavy Metals (AREA)
Abstract
The invention discloses a method for preparing high-purity uranium dioxide solid by directly hydrogenating and reducing in-situ leaching uranyl carbonate leacheate. Mixing the enriched leaching solution with the circulating liquid of the reaction, then entering a pre-hydrogenation reaction kettle, dissolving a certain amount of hydrogen into the reaction liquid under the action of 1-10.0 Mpa hydrogen pressure, carrying out heat exchange and steam preheating with the precipitated product liquid, entering a reactor containing a catalyst and uranium oxide particles from the bottom through a distribution plate, carrying out reaction under the action of the catalyst or the uranium oxide product particles and the hydrogen, leading the precipitated reaction liquid to carry small particle products out of the reactor through the top end of the reactor, precipitating in a settling tank, leading supernatant liquid out of a reaction system after filtering and heat exchange of the raw material liquid to enter a leaching solution system for circulation, leading uranium dioxide solid generated by the reaction out of the system through the bottom of the reactor, filtering and drying the solid after separation of the sediment, mixing the liquid with the enriched raw material liquid, and then entering the pre-hydrogenation reaction kettle for circulation.
Description
Technical Field
The invention relates to a technological process for preparing uranium oxide solid particles by uranyl carbonate hydrogenation reduction, in particular to a technological process for preparing uranyl carbonate by pre-hydrogenation liquid phase catalytic reduction.
Background
The nuclear energy has the characteristics of cleanness, low carbon, safety, reliability, low cost and the like, so that a set of sustainable atomic nuclear energy utilization technical route is developed through the innovation of nuclear energy science and technology, and the nuclear energy has important significance in protecting environment and coping with climate change.
The production process of nuclear fuel is that uranium is leached from ore, uranium-containing oxide solid is prepared after concentration and precipitation, and nuclear pure grade uranium hexafluoride fuel product is finally prepared through processes of purification, impurity removal, hydrofluorination, fluorination and the like. At present, an advanced technology of in-situ leaching of CO 2+O2 is adopted in uranium ore resource exploitation in China, after the extracted liquid is enriched by separation resin, the extracted liquid is leached by carbonic acid solution to form uranyl carbonate solution with uranium content of 10-50g/L, sodium hydroxide is added for precipitation, sodium diuranate products (commonly called yellow cakes) are generated, and the precipitated supernatant liquid has to be managed as radioactive wastewater. In order to prepare high-purity fuel uranium and sodium diuranate products, sodium ions are required to be extracted and separated through nitric acid dissolution, ammonium diuranate solids are prepared through ammonia precipitation and purification, and then fuel-grade uranium oxide solids are obtained through roasting. The process has the defects of long process flow, high uranium-containing radioactive wastewater discharge (more than 50 tons of wastewater is estimated to be discharged for a short time) in the process, high fuel cost and the like. Therefore, in order to solve the problems of high emission of uranium-containing radioactive wastewater, low uranium content of sodium diuranate products and high cost of long production process in the uranium fuel production process in China, a novel uranium product production process is needed, and a high-purity uranium oxide product which can be used for preparing fuel uranium can be directly obtained.
Two types of methods for preparing uranium-containing solids by precipitation of sodium uranyl carbonate are used for generating sodium or ammonia cation-containing precipitates by using alkaline substances, and the sodium uranyl carbonate is used after roasting and drying; the other is to reduce the valence state of the reduced uranium from hexavalent to tetravalent, and hydrolyze the uranium at a pH value of more than 7 and a temperature of more than 90 ℃ to directly generate uranium oxide solid. The liquid phase reduction hexavalent uranium reducing agent capable of being subjected to liquid phase reduction under the condition of proper temperature comprises hydrazine and hydrogen, wherein the hydrazine is a highly toxic substance, the treatment difficulty of ammonium ions as a reduced product is high, and the hydrogen reduction has the advantage of low price and water as a product, so that the use of hydrogen as the reducing agent is an ideal choice. However, hydrogen is a flammable and explosive gas, and is rarely used in the radionuclear industry, and its safety is critical to the process.
The uranium has a relatively large molecular weight, even if the uranium content is 50g/L, and its molar concentration is 0.2mol/L, if the reaction proceeds according to the following formula:
na 4[UO2(CO3)3]+H2＝UO2 (precipitate) +2NaHCO 3+Na2CO3
One mole of uranyl ion has a chemical reaction equivalent of 1 mole of hydrogen, so the 1L solution consumes only 0.2 mole of hydrogen. When the temperature of the hydrogen is 90 ℃, the pressure is 3.0-4.0 Mpa, about 0.1mol of hydrogen can be dissolved in each L of aqueous solution, if we pass through the product clear liquid after the cyclic precipitation, the uranium concentration is reduced to below 25g/L, the dissolved concentration of the hydrogen just meets the requirement of stoichiometric ratio, and the excessive hydrogen is adjusted to a proper value by increasing the amount of the clear liquid after the cyclic precipitation, thereby realizing the purpose of uranium reduction.
Through the theoretical analysis and a large amount of experimental researches, a novel technological process for preparing uranium dioxide solid particles by pre-hydrogenation catalytic reduction of sodium uranyl carbonate is developed. In the process, hydrogen required in the reaction process enters a reaction liquid and a circulating liquid with a certain proportion in a pre-hydrogenation mode, and catalytic hydrogenation reduction is carried out in a fixed bed reactor fixed with a mesh-based or honeycomb ceramic-based catalyst to prepare solid uranium oxide. The greatest advantage of this process is that, since the hydrogen is dissolved in the reaction liquid by means of prehydrogenation, a single-phase flow reactor is present in the reactor, which avoids the risks of swelling and explosion due to the high temperature of the gas, the violent reaction, even when operating at high pressure. By the implementation of the process, the effective uranium content in the ton of products can be increased from 73% to 88%, the recycling of the precipitation liquid is realized, and compared with the traditional method for precipitating the ton of uranium products by sodium hydroxide, the waste water is reduced by about 50 tons.
Disclosure of Invention
The invention provides a process for directly preparing a high-purity uranium oxide product by reducing uranyl carbonate solution through catalytic hydrogenation, which is mainly characterized in that the safety of liquid phase hydrogenation reduction in the field of radioactive chemical industry is solved by utilizing circulating clear liquid and reaction liquid for pre-hydrogenation.
In order to achieve the above purpose, the invention provides a process flow for preparing uranium oxide by direct hydrogen reduction of uranyl carbonate, which comprises the steps that a certain amount of reaction liquid is metered by a metering pump P-1 and then mixed with a reaction liquid circulating liquid by a P-2 pump to enter a pre-hydrogenation reaction kettle (the flow ratio is 1:1-1:10), part of hydrogen is dissolved in a liquid phase under the action of high-pressure hydrogen of 1-10.0 Mpa, the mixture is metered by a pump P-3 and then enters a heat exchanger H-1 to exchange heat with product liquid to be preheated, then enters a heat exchanger H-2 to be preheated to 90-150 ℃ by using electricity or steam, then enters the reactor R-1 from the bottom of the reactor after being distributed by a distribution plate, and then reacts with hydrogen to generate solid uranium dioxide particles under the catalysis of nickel mesh catalyst and generated uranium oxide solid particles, small particles flow upwards along with the liquid to overflow to enter a top V-4 liquid phase tank to be precipitated, the supernatant is filtered by a filter and then enters the H-1 heat exchanger to enter a pre-heat exchanger to enter a V-7 to be subjected to leaching kettle, the supernatant is separated into a solid phase to be separated by the supernatant, and then enters a solid phase system to be separated by the supernatant to be dried, and then enters a solid phase system to be separated into the supernatant and the supernatant, and the supernatant is discharged to be separated by the supernatant phase. Under the action of gravity, the produced and long uranium dioxide solid particles leave from the bottom of the reactor and enter a liquid-solid separation tank V-5 to be mixed with the solid of V-4 and then enter a V-6 gas replacement kettle, after dissolved hydrogen is replaced by nitrogen, the liquid-solid mixture enters a sedimentation separation tank V-3, all supernatant fluid enters a V-2 to be recycled, and solid products from V-3 and V-8 enter a drying box D-1 to be dried after being dehydrated and filtered together to form uranium oxide solid products.
The reaction equation of the process is as follows:
[ UO 2(CO3)3]4-+H2＝UO2 (precipitate) +2HCO 3 -+CO3 2-
The reaction process mainly comprises the steps of using a fixed net base and a honeycomb catalyst to catalyze and dissolve hydrogen, reducing hexavalent uranyl carbonate ions by dissociated hydrogen ions to generate tetravalent uranium, carrying out hydrolysis in a high-temperature water solution, precipitating, discharging a solid uranium oxide product from the reactor after passing through the bottom of the reactor, and preparing uranium oxide solid after precipitation, filtration and drying.
Wherein the raw material liquid comprises sodium uranyl carbonate solution with uranium content of 1-100g/L and pH value of 7-11. Increasing the uranium content in the raw material liquid increases the reaction load, resulting in an increase in the uranium content of the outlet reaction completion liquid; lowering the pH reduces the rate of reaction hydrolysis.
The circulation ratio of the reaction liquid to the circulating product liquid is 1:1-1:10, the solubility of hydrogen can be increased by increasing the circulation ratio, the reaction rate is improved, but the load of the reactor is increased by increasing the circulation ratio, the preheating energy consumption is increased, and the production and operation cost of uranium products per ton is increased.
Wherein the reactor R-1 is internally fixed with one or two of a net-based or honeycomb ceramic-based monolithic catalyst, wherein the net-based can be nickel net or noble metal plated with noble metal such as Pt, ru, pb or Ir, and the honeycomb ceramic-based catalyst can be a prefabricated honeycomb ceramic immersed catalyst or a deposition, precipitation and extrusion catalyst. The operating temperature is 90-150 ℃ (preferably 100-120 ℃), and the operating pressure is 1.0-10.0 Mpa (gauge pressure) (preferably 2.0-8.0 Mpa); increasing the reaction temperature can increase the hydrogenation and hydrolysis reaction rate, but the reaction temperature is too high, and the produced uranium dioxide solid is easy to structure on the surface of the catalyst; increasing the pressure can increase the reaction rate, but too high a pressure increases the cost of the reactor and pump.
The uranium oxide in the mineral layer is converted into uranyl carbonate solution by carbon dioxide and high-pressure oxygen under the drive of pressure, and then is brought onto the ground along with fluid, and the carbonic acid eluent with uranium content of 1-50g/L is obtained through resin adsorption, separation and concentration. The enriched leaching solution and the reacted circulating solution are mixed and then enter a pre-hydrogenation reaction kettle, a certain amount of hydrogen is dissolved in the reaction solution under the action of 1-10.0 Mpa hydrogen pressure, the reaction solution exchanges heat with precipitated product solution and is preheated to 90-150 ℃, the reaction solution enters a reactor containing a catalyst and uranium oxide particles from the bottom through a distribution plate, the reaction solution reacts under the action of the catalyst or the uranium oxide product particles and the hydrogen, the precipitated reaction solution carries small particle products to leave the reactor through the top end of the reactor, after being precipitated in a settling tank, supernatant fluid is filtered and the raw material solution exchanges heat and then leaves a reaction system to enter a leaching solution system for circulation, uranium dioxide solid generated by the reaction leaves the system through the bottom of the reactor, the solid is filtered and dried after being separated through the settling, the liquid is mixed with the enriched raw material solution and enters the pre-hydrogenation reaction kettle for circulation. The process has the advantages that the safety problem of hydrogen-related reaction in the radioactive raw material liquid is solved by circulating the enriched reaction liquid and the precipitation liquid for pre-hydrogenation, all equipment is in liquid phase single-phase operation except for the pre-hydrogenation reaction kettle in the whole process, so that the safety operation of higher pressure is facilitated, and the reaction efficiency is improved. In the optimal embodiment, the hydrogen pressure is 8.0Mpa, the mass ratio of the reaction liquid to the circulating liquid is 1:3, the operating temperature of the reactor is 110 ℃, and the uranium content of the outlet liquid of the reaction liquid containing 30g/L of uranium is less than or equal to 35mg/L under the action of a nickel catalyst screen.
Compared with the prior art, the invention has the substantial characteristics that:
1. compared with the existing sodium diuranate (yellow cake) process in China, the uranium content of the process can reach 88%, and the discharge amount of waste water can be reduced by more than 50 tons per ton of uranium products;
2. Compared with the foreign ammonia precipitation preparation U 3O8, the method does not need a roasting process, and has the advantages of short process flow and low cost;
3. Compared with the method for preparing U 3O8 by oxidizing the bottom with H 2O2, the method has the advantages that the cost of the adopted hydrogen is far lower than that of H 2O2, and the consumption of chemical reagents is low;
4. Compared with the existing hydrogenation heterogeneous catalytic reduction process, the method avoids the use of gas-phase hydrogen in the reactor and solves the problem of safety of hydrogen used in the radioactive chemical industry.
Drawings
FIG. 1 is a process flow diagram of the present invention; wherein: p-1 reaction liquid metering pump; p-2 circulating liquid metering pump;
P-3 a raw material liquid metering pump; v-1, pre-hydrogenation reaction kettle; v-2 circulating liquid buffer tank; a settling separation tank at the bottom of the V-3 reactor; a liquid outlet tank at the top of the V-4 reactor; v-5, discharging a material tank from the bottom of the reaction liquid; v-6 gas replacement kettle; the hydrogen at the top of the V-7 reaction solution is replaced by a kettle; a V-8 reactor top discharge sedimentation tank; a reactor (R-1); f-1 filtering; d-1 a dryer; a first heat exchanger (H-1); a second heat exchanger (H-2).
Detailed Description
The device comprises a pre-hydrogenation reaction kettle, a catalytic hydrogenation reaction kettle, a top and bottom outlet liquid tank, a top and bottom normal pressure liquid dissolved hydrogen replacement kettle, a top and bottom product liquid precipitation tank, a circulating liquid buffer tank, a solid phase product filter, a drying box and the like.
After being metered by a reaction liquid metering pump P-1, a certain uranium-containing reaction liquid is metered by a circulation liquid metering pump P-2 and then mixed with the circulation liquid to enter a pre-hydrogenation reaction kettle V-1 (the flow volume ratio of the reaction liquid to the circulation liquid is 1:1-1:10), hydrogen from a hydrogen source is introduced into the pre-hydrogenation reaction kettle, part of the hydrogen is dissolved into liquid phase materials in the pre-hydrogenation reaction kettle under the action of high-pressure hydrogen of 1-10.0 Mpa, the liquid phase materials in the pre-hydrogenation reaction kettle are metered by a raw material liquid metering pump P-3 and then enter a first heat exchanger H-1 to be preheated by heat exchange with product liquid, then enter a second heat exchanger H-2 to be preheated to 90-150 ℃ by electric heating or steam heating and then enter the reactor R-1 from the bottom of the reactor, the mixture is distributed by a distribution plate and then reacts with hydrogen under the combined catalysis of a nickel screen catalyst and generated uranium oxide solid particles to generate solid uranium dioxide particles, the small particles overflow from the top end of a reactor (R-1) along with liquid to enter a reactor top outlet liquid tank V-4 for precipitation, supernatant liquid in the reactor top outlet liquid tank V-4 is filtered by a filter and then leaves the reactor top outlet liquid tank V-4 to enter a first heat exchanger H-1 for preheating reaction liquid, then enters a reaction liquid top hydrogen replacement kettle V-7, unreacted residual hydrogen is replaced by introducing nitrogen into the lower part or the bottom of the reaction liquid top hydrogen replacement kettle (V-7) and then is emptied,
The liquid in the hydrogen replacement kettle (V-7) at the top of the reaction liquid is further settled and separated in a discharging settling tank V-8 at the top of the reactor, part of supernatant liquid enters a circulating liquid buffer tank (V-2) to be recycled as circulating liquid, and part of supernatant liquid leaves the device or system and returns to enter a uranium leaching liquid leaching concentration system to be recycled, and the solid obtained by precipitation enters a filter F-1 to be separated in solid-liquid separation and then is dried by a dryer D-1 to form a uranium oxide product. Under the action of gravity, the produced and long uranium dioxide solid particles leave from the bottom of the reactor R-1 and enter a reaction liquid bottom discharge tank V-5, are mixed with solids which leave from the bottom of a reactor top discharge tank V-4 and enter the reaction liquid bottom discharge tank V-5, leave from the bottom of the reaction liquid bottom discharge tank (V-5) and enter a gas replacement kettle V-6, after dissolved hydrogen is replaced by introducing nitrogen into the lower part or the bottom of the gas replacement kettle (V-6), the liquid-solid mixture in the gas replacement kettle (V-6) enters a reactor bottom sedimentation separation tank V-3, all supernatant in the reactor bottom sedimentation separation tank (V-3) enters a circulating liquid buffer tank V-2 to be recycled as circulating liquid, and the precipitated solids enter a filter (F-1) to be dehydrated and filtered and then are dried by a dryer (D-1) to form uranium oxide solid products.
Wherein the raw material liquid comprises uranyl carbonate solution with uranium content of 1-100 g/L and pH value of 7-11.
Wherein the reactor (R-1) is a fixed bed in which a metal mesh-based or honeycomb ceramic-based catalyst is fixed and in which a liquid single-phase flow is carried out, and the operation temperature is 90-150 ℃; the flow rate of the reaction liquid is 50kg/h, the flow rate of the circulating liquid is 50-500 kg/h (the optimal flow rate is 150-300 kg/h), and the hydrogen pressure is 1-10.0 Mpa (the optimal flow rate is 2.0-8.0 Mpa).
Wherein the filter (F-1) can be one or more of a plate-frame filter, a rotary filter or a scraping filter.
The filter in the liquid outlet tank (V-4) at the top end of the reactor is a granular stainless steel metal sintered filter with the diameter less than or equal to 5 microns.
The top of the hydrogen replacement kettle (V-7) at the top of the gas replacement kettle V-6 and the top of the reaction liquid are respectively provided with a purge gas outlet with a valve. A liquid outlet with a valve is arranged at the bottom of the circulating liquid buffer tank V-2.
Example 1
The treatment capacity of the reaction solution is 62.5kg/h, the raw material solution is uranium content 30g/L sodium uranyl carbonate solution, the PH value is 10.0, and the flow rate of the circulating solution is 125kg/h; the reactor uses nickel screen with the wire diameter of 0.5mm and the mesh of 10 meshes as a catalyst, and the running temperature is 90 ℃; the hydrogen pressure in the pre-hydrogenation reaction kettle is 3.0MPa; the uranium content of the outlet reaction completed liquid was 50mg/L, and the average particle diameter was 25. Mu.m.
Example 2
The same as in example 1, except that the concentration of the sodium uranyl carbonate raw material liquid was 100g/L, the uranium content of the outlet reaction completion liquid was 102mg/L, and the average particle diameter was 42.5. Mu.m, was different from example 1 (the rest of the procedure was the same).
Example 3
The difference from example 1 was that the pressure of hydrogen gas was 8.0MPa (the rest of the procedure was the same as in example 1), the uranium content of the outlet reaction-completed liquid was 10mg/L, and the average grain diameter was 45. Mu.m.
Example 4
The same as in example 1, except that (the rest of the procedure was the same as that of example 1) the flow rate of the circulating liquid was 312.5kg/h; the uranium content of the outlet reaction completed liquid was 5mg/L, and the average particle diameter was 15. Mu.m.
Example 5
The same as in example 1, except that (the rest of the procedure is the same as that of example 1) a nickel mesh platinum plating catalyst was used; the uranium content of the outlet reaction completed liquid was 15mg/L, and the average particle diameter was 30. Mu.m.
Example 6
The difference from example 1 was that (the rest of the procedure was the same as in example 1) the temperature of the reactor was 120℃and the uranium content of the outlet reaction-completed liquid was 30mg/L and the average particle diameter was 105. Mu.m.
Claims (8)
1. A method for preparing uranium oxide by direct hydrogen reduction of uranyl carbonate,
After a certain uranium content of reaction liquid is metered by a reaction liquid metering pump (P-1), the reaction liquid and circulating liquid are metered by a circulating liquid metering pump (P-2) and then mixed into a pre-hydrogenation reaction kettle (V-1) (wherein the flow volume ratio of the reaction liquid to the circulating liquid is 1:1-1:10), hydrogen from a hydrogen source is introduced into the pre-hydrogenation reaction kettle, part of hydrogen is dissolved into liquid phase materials in the pre-hydrogenation reaction kettle under the action of high-pressure hydrogen of 1-10.0 Mpa, the liquid phase materials in the pre-hydrogenation reaction kettle are metered by a raw material liquid metering pump (P-3) and then enter a first heat exchanger (H-1) to exchange heat with product liquid for preheating, enters a second heat exchanger (H-2), is preheated to 90-150 ℃ by using electric heating or steam heating, enters a reactor (R-1) from the bottom of the reactor, is distributed by a distribution plate, reacts with hydrogen under the combined catalysis of a nickel screen catalyst and generated uranium oxide solid particles to generate solid uranium dioxide particles, small particles flow upwards along with liquid, overflow from the top end of the reactor (R-1) and enter a reactor top outlet tank (V-4) for precipitation, supernatant liquid in the reactor top outlet tank (V-4) is filtered by a filter and enters a first heat exchanger (H-1) heat exchanger for preheating reaction liquid, enters a reaction liquid top hydrogen replacement kettle (V-7), introducing nitrogen into the lower part or the bottom of a reaction liquid top hydrogen replacement kettle (V-7) to replace unreacted residual hydrogen, then emptying, further settling and separating liquid in the reaction liquid top hydrogen replacement kettle (V-7) in a reactor top discharging sedimentation tank (V-8), enabling a supernatant liquid part to enter a circulating liquid buffer tank (V-2) to be used as circulating liquid for recycling, enabling a part of supernatant liquid part to leave a device or a system, enabling solid obtained by precipitation to enter a filter (F-1) to be subjected to solid-liquid separation, and drying by a dryer (D-1) to form uranium oxide products;
Under the action of gravity, the produced and long uranium dioxide solid particles leave from the bottom of the reactor (R-1) and enter a reaction liquid bottom discharge tank (V-5), are mixed with the solid which leaves from the bottom of a reactor top discharge tank (V-4) and enters the reaction liquid bottom discharge tank (V-5), leave from the bottom of the reaction liquid bottom discharge tank (V-5) and enter a gas replacement kettle (V-6), after dissolved hydrogen is replaced by introducing nitrogen into the lower part or the bottom of the gas replacement kettle (V-6), the liquid-solid mixture in the gas replacement kettle (V-6) enters a settling separation tank (V-3) at the bottom of the reactor, and the supernatant in the settling separation tank (V-3) is completely recycled as circulating liquid in a circulating liquid buffer tank (V-2), and the precipitated solid enters a filter (F-1) for dehydration and filtration and is dried by a dryer (D-1) to form a uranium oxide product.
2. The process according to claim 1, wherein the feed solution comprises uranyl carbonate solution having a uranium content of 1 to 100g/L and a PH of 7 to 11.
3. The process according to claim 1, wherein the reactor (R-1) is a fixed bed of liquid single-phase flow with internally fixed metal mesh-based or honeycomb ceramic-based catalyst, operating at a temperature of 90-150 ℃; the flow rate of the reaction liquid is 50-100kg/h, the flow rate of the circulating liquid is 50-500 kg/h (the optimal flow rate is 150-300 kg/h), and the hydrogen pressure is 1-10.0 Mpa (the optimal pressure is 2.0-8.0 Mpa).
4. A process according to claim 1 or 3, wherein the catalyst is composed of one or more of nickel mesh, iron mesh, or metal mesh wire or monolithic honeycomb ceramic catalyst coated with one or more noble metals of Pt, pb or Ru on the surface.
5. The method according to claim 1, wherein the filter (F-1) may be one or several of a plate and frame filter, a rotary filter or a doctor blade filter.
6. The method according to claim 1, wherein the filter in the reactor top outlet tank (V-4) is a particulate stainless steel sintered metal filter having a filterable diameter of 5 μm or less.
7. The method according to claim 1, wherein the top of the gas replacement vessel (V-6) and the top of the reaction liquid hydrogen replacement vessel (V-7) are respectively provided with purge gas discharge ports with valves.
8. The method according to claim 1,
Part of supernatant liquid in a discharging settling tank (V-8) at the top of the reactor leaves the device or the system and returns to the uranium leaching liquid leaching and concentrating system for recycling.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202211583795.4A CN118164537A (en) | 2022-12-09 | 2022-12-09 | Technological process for preparing uranium oxide by direct hydrogen reduction of uranyl carbonate |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202211583795.4A CN118164537A (en) | 2022-12-09 | 2022-12-09 | Technological process for preparing uranium oxide by direct hydrogen reduction of uranyl carbonate |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN118164537A true CN118164537A (en) | 2024-06-11 |
Family
ID=91357433
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN202211583795.4A Pending CN118164537A (en) | 2022-12-09 | 2022-12-09 | Technological process for preparing uranium oxide by direct hydrogen reduction of uranyl carbonate |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN118164537A (en) |
-
2022
- 2022-12-09 CN CN202211583795.4A patent/CN118164537A/en active Pending
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| RU2580575C1 (en) | METHOD FOR COMPLEX EXTRACTION OF METALLIC COBALT, RUTHENIUM AND ALUMINIUM FROM SPENT CATALYST Сo-Ru/Al2O3 FOR FISCHER-TROPSCH SYNTHESIS | |
| CN110668483A (en) | Method for preparing aluminum fluoride by electrolyzing aluminum carbon slag | |
| CN111333046B (en) | Resource recovery method and system for waste lithium iron phosphate anode based on hydrochloric acid circulation | |
| CN105695751A (en) | Purification process of manganese anode slime | |
| CN114934195A (en) | Lithium salt recovery method and recovery equipment for aluminum electrolysis waste | |
| CN115161475B (en) | Lithium iron phosphate powder lithium extraction leaching kettle and continuous extraction method | |
| CN103834805A (en) | Method of leaching divalent cobalt from cobalt copper bidery metal | |
| CN118164537A (en) | Technological process for preparing uranium oxide by direct hydrogen reduction of uranyl carbonate | |
| CN113526558B (en) | Method for preparing uranium nitrate by reducing uranyl nitrate through catalytic hydrogenation | |
| CN112029998B (en) | Method for recovering platinum group metal from granular waste catalyst by combination of dissolution, absorption and desorption | |
| CN105776270B (en) | The preparation method of nano-aluminum hydroxide in a kind of pelite | |
| CN103352124A (en) | Method for separating and recovering V and Cr from V-Cr waste material | |
| CN118162065A (en) | Method for preparing uranium oxide by catalytic hydrogenation of sodium uranyl carbonate | |
| Alfredson | Australian experience in the production of yellow cake and uranium fluorides | |
| CN219274041U (en) | Harmless environment-friendly disposal device for waste nickel catalyst | |
| CN205999031U (en) | The production system of nanometer class molybdenum disulfide | |
| CN110129549A (en) | A kind of useless tungsten processing method and processing unit | |
| CN206570129U (en) | Nickel-containing waste water processing system | |
| CN115786719B (en) | Method for efficiently dissociating nickel metallurgical waste residues and improving resource recovery efficiency | |
| CN217839084U (en) | System for recovering metal palladium from waste palladium-carbon catalyst | |
| CN110016553B (en) | Hot-pressing oxidation leaching system and process | |
| CN111547754B (en) | Method for converting regenerated cryolite into aluminum fluoride | |
| CN215593152U (en) | Platinum, aluminium recovery unit in platinum aluminium base catalyst | |
| CN109052458A (en) | The preparation process of four basic lead sulphate crystal seed of nanoscale is prepared using waste lead accumulator | |
| CN116143143B (en) | Method and device for recycling waste salt and waste sulfuric acid in BDO production |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| PB01 | Publication | ||
| SE01 | Entry into force of request for substantive examination |