The method of manufacture of uranium metal from uranium waste and equipment for its implementation

 

(57) Abstract:

The invention relates to the nuclear industry and can find application in the manufacturing of fuel for nuclear power reactors. The technical problem of the invention is a method and equipment to ensure the quality of raw materials uranium-containing waste in a continuous process of manufacturing products of uranium metal, as well as to reduce the cost and environmental hazard production. The method involves the determination of conventional mass fraction U235in the waste uranium recycle in accordance with the empirical formula. Then the waste is dissolved, remove the uranium extraction, receive oxide of uranium, uranium dioxide, tetraploid uranium and uranium metal. Uranium metal rafinuyut. Before refining are adjusting the desired value of the conditional mass fraction U235in a mixture of uranium isotopes in the uranium metal in accordance with the empirical formula. All equipment for nitrous oxide of uranium is associated in a single production line, and equipment for production of uranium tetrafluoride lined forepl is EMPRETEC for the production of fuel for nuclear power reactors.

The problem of recovery of uranium from uranium waste and Uranus return process is of great importance because of the high cost of uranium and as a consequence compact waste uranium metal is returned to the process of melting of uranium. In most cases, the recovery of uranium from waste is hydrometallurgical methods, treatment with acid solutions, adsorption or extraction cleaning and Uranus return to one of the main stages of the process.

The known method fluoride processing of uranium-containing waste, based on the conversion of waste uranium various methods to technical uranium oxides, which ftorida to uranium hexafluoride (see N.P. Galkin, A. A. Mayorov and other Chemistry and technology of fluorine compounds of uranium. M: gosatomizdat, 1961, S. 173-176).

The disadvantage of this method is the large number of operations and cumbersome equipment design, as for each type needs to develop its own technology, which will inevitably lead to a rise in the cost of manufactured products from uranium metal.

There is also known a method and equipment for processing scrap and s waste containing uranium in solution by dissolving nitric acid, purification of uranium by extraction with obtaining pure compounds suitable for use in current production (see A. A. Mayorov, I. B. Braverman. Technology of production of powders of ceramic uranium dioxide. M.: Energoatomizdat, 1985, S. 119-121).

Osnovnym the disadvantage of this method and equipment is that they allow to process certain types of uranium-bearing waste and are not intended to involve all formed during the manufacture of products from uranium waste in the basic process.

An object of the invention is to provide a method and equipment to ensure use as feedstock uranium-containing waste in a continuous process of manufacturing products of uranium metal, as well as to reduce the cost and environmental hazard production.

The problem is solved in that the quality of raw materials used uranium waste, which is processed by known methods by the inclusion of equipment in a continuous single technological cycle of production of products of uranium metal. Ncalc. - estimated conditional mass fraction U235in a mixture of uranium isotopes in the first hinge waste, %;

WITHI5- conditional mass fraction U235in a mixture of uranium isotopes in the first hinge waste, %;

WITHI0- the proportion of the mixture of uranium isotopes in the first hinge waste, %;

WITH20- the proportion of the mixture of uranium isotopes in the second hinge waste, %;

WITH25- conditional mass fraction U235in a mixture of uranium isotopes in the second hinge waste, %;

WITHn5- conditional mass fraction U235in a mixture of uranium isotopes in the n-th sample of the waste, %;

WITHn0- the proportion of the mixture of uranium isotopes in the n-th sample of the waste, %;

mI, m2, mn- weight of waste uranium in the first, second and n-th sample of the waste, respectively, g

and before refining conduct its correlation to the desired values by the formula:

where CTreb.- the desired value of the conditional mass fraction U235in a mixture of uranium isotopes uranium metal, %;

WITH15- conditional mass fraction U235in a mixture of uranium isotopes (high) in the first batch of uranium metal, %;

WITH25- conditional mass fraction U235in cm the first and second batches of uranium metal, respectively, ,

The technical result of the method is achieved to the greatest degree when the following conditions are met:

combustible materials containing uranium waste from the production of uranium metal and metal shavings uranium burn;

nous and Stripping from the production of nitrous oxide, carbon dioxide and uranium tetrafluoride calcined at a temperature of 450-650C;

dissolution of uranium waste is carried out in concentrated nitric acid using deionized water at a temperature of 70-90 C until the concentration of uranium in solution from 150 to 250 g/l;

the annealing ammoniuria carried out at a temperature up to 350C;

the dissolution of uranium dioxide is carried out in concentrated hydrochloric acid using deionized water at temperatures up to 70C;

precipitation of uranium tetrafluoride from a solution spend dosed supply of 40% hydrofluoric acid at a temperature of 50-60C for 2-3 hours;

pre-drying of the uranium tetrafluoride to powder is performed under incandescent lamps with a capacity of 1,000-1,500 kW at a temperature of 40-60C;

final drying and calcination tetrafluoride uranium is carried out in hydrogen furnaces in two stages:

when temperature is in;

during thermal recovery of uranium metal using granular calcium;

machining of uranium metal ingots is carried out with the spindle speed 25-150 min-1and cutting depth up to 3 mm;

etching products from the uranium metal is carried out in nitric acid;

the packaging of uranium metal in plastic bags is carried out in an inert atmosphere using argon and nitrogen.

The technical problem of method and equipment is solved also by the fact that the equipment for production of nitrous oxide, uranium connected in a single continuous production line and consists of a reactor, a solvent, filtering plants, extractor-extractor, furnace annealing, the reactor for the precipitation of ammonium diuranate.

The technical result of the method and equipment according to the invention is achieved when the following conditions are met:

equipment lined with Teflon;

filtration units contain suction filters, made of vinyl plastic;

moving uranium-containing products between technological operations carried out in a nuclear-safe container;

the equipment is manufactured in the venom of the study placed in the following sequence: installation combustion and calcination uranium, the reactor solvent, install filter, extractors-extractor, install filter, furnace annealing, rotating hydrogen furnace, large rotary tube furnace (hereinafter oven BWTP), sliding microwave reactor solvent, filtration installation, hydrogen furnace, installation calliterinae recovery, vacuum refining furnace, the lathe, the pickling bath, the installation package.

This set of features is new and involves an inventive step, because it allows you to use as feedstock uranium waste to produce uranium metal with the desired values of uranium and uranium-235 and consequently reduces the cost of manufacture of products of uranium metal by involving uranium waste in the production cycle of the products. The location of the equipment in a single continuous production line compliance with the specified sequence allows to minimize dusting operations and thereby reduce the environmental hazard of uranium production.

An example of the method.

Process method and equipment for processing uranotaenia of uranium hexafluoride obtaining uranium metal, refining uranium metal, fabrication and control of commodity ingots, packaging ingots.

Preparation of raw materials from uranium waste includes the following:

combustion in furnaces of flammable materials containing uranium waste uranium metal (slag, pieces of uranium metal and so on) and metal shavings uranium;

calcination in an electric furnace at a temperature of 450-650C nous and Stripping from the production of nitrous oxide, carbon dioxide and uranium tetrafluoride;

control of the concentration of uranium and uranium-235 in a prepared party;

determination of the method by the formula (1) conditional mass percentage of uranium-235 in a mixed batch of raw materials;

the formation of parties of the prepared batches of uranium-containing waste for dissolution on the basis of the above calculation to obtain blending with the calculated mass fraction of uranium-235.

Oxide of uranium receive in the model scheme ammoniuria process (HELL-process) by precipitation of ammonium diuranate from nitrate solutions and consists of the following operations:

dissolution in the reactor at t=80 C until the concentration of uranium 150-250 g/l under a CLASS="ptx2">extraction-reextraction with the deposition of crystals of ammonium diuranate in reactors;

filtration of the crystals of ammonium diuranate on the suction filter with the return of mother solutions containing uranium in the reactor dissolution of uranium;

heating up to t=350C crystals of ammonium diuranate in sliding furnaces in pallets of graphite;

control the content of total uranium, uranium-235 and the formation of parties of the feedstock concentrate uranium for the manufacture of uranium dioxide.

All process waste in the form smetak nitrous oxide, Stripping from the production of ammonium diuranate and combustible materials (cloths, filters, rags, etc.,), contaminated with uranium, come back for the surgery feedstock preparation.

The uranium dioxide from nitrous-oxide of uranium is obtained by feeding hydrogen into the rotary kiln with the use of pallets made of graphite.

All process waste in the form smetak uranium dioxide is returned to the operation feedstock preparation.

The uranium hexafluoride is produced from uranium dioxide, which is dissolved in the reactor in hydrochloric acid at t=70C using deionized water, and precipitation of uranium tetrafluoride provide a metered supply of 40% hydrofluoric acid at t waste liquid (mother liquor), containing uranium returned to the site of dissolution.

Pre-drying of the crystals of uranium tetrafluoride to a powder, is carried out at t=40-60C in graphite pallets using incandescent lamps with a capacity of 1000-15000 kW. The use of a graphite trays allows to provide the desired purity of uranium tetrafluoride by impurities of iron, chromium, Nickel, the sum of which should not exceed 0.4% (wt.).

The final drying and calcining is carried out in a hydrogen furnace in two stages: at t=110-S for 1.5-5.5 hours and t to S within 1.0 to 3.5 hours. The consumption of hydrogen is 10-20 l/min

All process waste in the form smetak tetrafluoride uranium is returned to the operation feedstock preparation.

The uranium metal ingots receive calcitonine method of uranium tetrafluoride using granular calcium on the installation calliterinae recovery.

The use of granulated calcium in the form of granules allows to increase the output of uranium metal in suitable reduction due to this amount of uranium in the formed slag from the production of uranium. All process waste in the form of slag from the production of the definition of uranium is carried out in a high-frequency vacuum furnace at temperature up to 1500C for one hour. Before refining define conditional mass percentage of uranium-235 in a mixture of uranium isotopes by the formula (2) in batches of uranium metal to produce metallic uranium with the required value of the conditional mass fraction of uranium-235 in a mixture of uranium isotopes. All process waste from the refining of uranium metal is returned to the operation feedstock preparation.

Preparing ingots in accordance with the normative and technical documentation (NTD) is conducted on a lathe with a spindle speed 25-150 min-1and cutting depth up to 3 mm Metal shavings uranium return to the operation feedstock preparation.

Control commodity ingots of uranium metal impurity and uranium spend spectral method.

Packaging metal ingots after etching in nitric acid, and monitoring for compliance with regard to regulatory technical documentation is carried out in an inert atmosphere in sealed plastic bags, which are placed in a shipping container for shipment to the consumer.

Using the proposed method and equipment will be used as feedstock waste generated in the process of izgotoviteli uranium waste to correct the defect in the production of uranium metal through the use of computational methods in the preparation of uranium wastes for dissolution and before refining to obtain products of uranium with the required values for total uranium and uranium-235 and impurities, and also to reduce as a consequence, the production cycle and reduce the cost of manufacturing products of uranium metal, to create a continuous production line for the manufacture of products of uranium metal with a closed technological cycle of processing generated during this process uranium bearing waste, which will reduce dust-raising operations and reduce the environmental hazards of uranium production.

These benefits will find expression in specific techno-economic indicators in the manufacture of products from uranium metal.

1. The method of manufacture of uranium metal from uranium waste, including the preparation of waste, dissolution, filtration, extraction and reextraction, obtaining nitrous oxide of uranium, uranium dioxide, uranium tetrafluoride and uranium metal, refining, machining and travelinstyle conditional mass fraction U235according to the formula

where CRasch.- estimated conditional mass fraction U235, % in mixture of uranium isotopes;

WITH15- conditional mass fraction U235in a mixture of uranium isotopes in the first hinge waste, %;

WITH10- the proportion of the mixture of uranium isotopes in the first hinge waste, %;

WITH20- the proportion of the mixture of uranium isotopes in the second hinge waste, %;

WITH25- conditional mass fraction U235in a mixture of uranium isotopes in the second hinge waste, %;

WITHn5- conditional mass fraction U235in a mixture of uranium isotopes in the n-th sample of the waste, %;

WITHn0- the proportion of the mixture of uranium isotopes in the n-th sample of the waste, %;

m1, m2, mn- weight of waste uranium in the first, second and n-th sample of the waste, respectively, g

and then, before refining are adjusting the desired value of the conditional mass fraction U235in a mixture of uranium isotopes in the uranium metal, which is determined by the formula

where CTreb.- the desired value of the conditional mass fraction U235in a mixture of uranium isotopes uranium metal, %;

WITH15- conditional mass fraction U235in a mixture of isotope is th mass fraction U235in a mixture of isotopes of uranium of low enrichment in the second game of uranium metal, %;

m1, m2- the weight of the portion of the first and second batches of metallic uranium, respectively, g

2. The method according to p. 1, characterized in that before using uranium wastes as a source of raw materials flammable materials containing uranium waste from the production of uranium metal and metal shavings uranium burn.

3. The method according to p. 1, characterized in that before using uranium wastes as feedstock nous and Stripping from the production of nitrous oxide, carbon dioxide and uranium tetrafluoride calcined at a temperature of 450-650C.

4. The method according to p. 1, characterized in that in the production of nitrous oxide of uranium dissolution of uranium waste is carried out in concentrated nitric acid using deionized water at a temperature of 70-90C. until the concentration of uranium 50-70 g/l and residual acidity in the solution of from 150 to 250 g/l

5. The method according to PP.1 and 4, characterized in that in the production of nitrous oxide uranium calcining ammoniuria carried out at a temperature of 600-650C.

6. The method according to p. 1, characterized in that in the production of uranium tetrafluoride dissolution of curature to 70C.

7. The method according to p. 1, characterized in that the deposition of uranium tetrafluoride from a solution spend dosed supply of 40% hydrofluoric acid at a temperature of 50-60C for 2-3 h

8. The method according to PP.1, 6 and 7, characterized in that the preliminary drying of the uranium tetrafluoride to powder is performed under incandescent lamps with a capacity of 1,000-1,500 kW at a temperature of 40-60C.

9. The method according to PP.1, 6-8, characterized in that the final drying and calcination tetrafluoride uranium is carried out in hydrogen furnaces in two stages: at a temperature of 110-250VC for 1.5 to 5.5 hours; at a temperature up to 550C for 1.0 to 3.5 h with a flow rate of hydrogen 10-20 l/min

10. The method according to PP.1-9, characterized in that during thermal recovery of uranium metal using granular calcium granule size 1-3 mm

11. The method according to PP.1-10, characterized in that the machining of uranium metal ingots is carried out with the spindle speed 25-150 min-1and cutting depth up to 3 mm

12. The method according to PP.1-11, characterized in that the etching products from the uranium metal is carried out in nitric acid followed by rinsing in deionized water.

13. The method according to PP.1-12, characterized in that the packaging out of or nitrogen.

14. Equipment for the manufacture of uranium metal from uranium waste, including incineration and calcination of uranium waste reactors-solvent extractors-extractor, the reactor precipitation of ammonium diuranate, the deposition reactor uranium tetrafluoride, agitators, tanks for fluids, containers, filtration units, oven drying and calcination, hydrogen furnace, installation calliterinae recovery of uranium, vacuum refining furnace, lathe, etching baths, installation, inspection and packing, and equipment for nitrous oxide of uranium consists of a reactor, a solvent, filtering plants, extractor-extractor, reactor precipitation of ammonium diuranate and furnace annealing, connected in a single continuous production line, and equipment receipt tetrafluoride uranium, including the deposition reactor, the stirrer, the vessel for fluids, containers for tetrafluoride, lined with Teflon.

15. Equipment under item 14, characterized in that the filtration units contain suction filters, made of vinyl plastic.

16. Equipment for PP.14 and 15, characterized in that the movement of uranium-containing products between the different themes, it is made in a nuclear-safe geometry.

18. Equipment for PP.14-17, characterized in that the calcination and drying tetrafluoride uranium is carried out in a graphite crucible.

19. Equipment for PP.14 to 18, characterized in that it is placed in the following sequence: installation combustion and calcination recycling of waste uranium, the reactor solvent, install filter, extractors-extractor, the reactor precipitation of ammonium diuranate, the deposition reactor uranium tetrafluoride, containers for solutions, installation of the filter, furnace annealing, rotating hydrogen furnace, a large rotary kiln, roller kiln, reactor-solvent, filtration installation, hydrogen furnace, installation calliterinae recovery, vacuum refining furnace, the lathe, the pickling bath, the installation package.

 

Same patents:

The invention relates to the field of environmental protection against radioactive pollution

The invention relates to the field of waste

The invention relates to the field of processing of liquid radioactive waste

The invention relates to nuclear energy, in particular to the processing technology of ion-exchange resin

The invention relates to a method for dissolving plutonium or plutonium alloy

The invention relates to the field of nuclear energy, and more specifically to the technology of decontamination and disposal of radioactive waste from the activities of nuclear power plants, research institutions, industrial and medical facilities using various radioactive isotopes

The invention relates to nuclear energy, in particular the production of energy, transmutation of radioactive waste, burning weapons-grade plutonium and actinides

The invention relates to the field of recycling of depleted uranium

The invention relates to a method of recycling industrial waste, in particular sludge galvanic Nickel plating, copper plating, chrome plating and mixed sludge

The invention relates to the field of non-ferrous metallurgy, in particular to the design and operation of ore-thermal furnaces with immersion of the electrodes in the melt processed material, and can also be used in ferrous metallurgy and chemical industry

The invention relates to the field of non-ferrous metallurgy, in particular to the design and operation of ore-thermal furnaces with immersion of the electrodes in the melt processed material, and can also be used in ferrous metallurgy and chemical industry

The invention relates to the field of non-ferrous metallurgy, in particular to the design and operation of ore-thermal furnaces with immersion of the electrodes in the melt processed material, and can also be used in ferrous metallurgy and chemical industry

The invention relates to the field of non-ferrous metallurgy, in particular to the design and operation of ore-thermal furnaces with immersion of the electrode in the slag melt, and can also be used in ferrous metallurgy and chemical industry

The invention relates to the field of metallurgy active refractory metals and alloys, including rare earth and actinides, in particular to methods of processing of oil-containing briquettes chips of the above metals and alloys and devices for their implementation

The invention relates to hydrometallurgy of Nickel, in particular to the processing of ferrous Chekov

The invention relates to ferrous metallurgy and is intended for enterprises engaged in the processing of oxidized Nickel ores
The invention relates to ferrous metallurgy and can be used in the processing of foundry waste (crucible residues) production of magnesium alloys

The invention relates to hydrometallurgy uranium and can be used to produce uranium hexafluoride from solutions of different composition using the processes of extraction, Stripping and heat treatment
Up!