USH715H - Recovery of mercury from acid waste residues - Google Patents
Recovery of mercury from acid waste residues Download PDFInfo
- Publication number
- USH715H USH715H US07/019,834 US1983487A USH715H US H715 H USH715 H US H715H US 1983487 A US1983487 A US 1983487A US H715 H USH715 H US H715H
- Authority
- US
- United States
- Prior art keywords
- mercury
- aluminum
- nitric acid
- reaction
- reaction vessel
- 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.)
- Abandoned
Links
- QSHDDOUJBYECFT-UHFFFAOYSA-N mercury Chemical compound [Hg] QSHDDOUJBYECFT-UHFFFAOYSA-N 0.000 title claims abstract description 64
- 229910052753 mercury Inorganic materials 0.000 title claims abstract description 42
- 238000011084 recovery Methods 0.000 title description 9
- 239000002253 acid Substances 0.000 title description 6
- 239000002699 waste material Substances 0.000 title description 3
- XAGFODPZIPBFFR-UHFFFAOYSA-N aluminium Chemical compound [Al] XAGFODPZIPBFFR-UHFFFAOYSA-N 0.000 claims abstract description 28
- GRYLNZFGIOXLOG-UHFFFAOYSA-N Nitric acid Chemical compound O[N+]([O-])=O GRYLNZFGIOXLOG-UHFFFAOYSA-N 0.000 claims abstract description 23
- 229910017604 nitric acid Inorganic materials 0.000 claims abstract description 23
- 238000010791 quenching Methods 0.000 claims abstract description 9
- 230000000171 quenching effect Effects 0.000 claims abstract description 7
- 238000006396 nitration reaction Methods 0.000 claims abstract description 6
- 239000012530 fluid Substances 0.000 claims abstract description 5
- 238000006243 chemical reaction Methods 0.000 claims description 30
- 238000000034 method Methods 0.000 claims description 21
- 229910052782 aluminium Inorganic materials 0.000 claims description 19
- 229940008718 metallic mercury Drugs 0.000 claims description 13
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 claims description 9
- 229910001987 mercury nitrate Inorganic materials 0.000 claims description 8
- DRXYRSRECMWYAV-UHFFFAOYSA-N nitrooxymercury Chemical compound [Hg+].[O-][N+]([O-])=O DRXYRSRECMWYAV-UHFFFAOYSA-N 0.000 claims description 8
- 229910001868 water Inorganic materials 0.000 claims description 7
- 229910052751 metal Inorganic materials 0.000 claims description 5
- 239000002184 metal Substances 0.000 claims description 5
- 239000003758 nuclear fuel Substances 0.000 claims description 5
- 238000005253 cladding Methods 0.000 claims description 4
- 239000003054 catalyst Substances 0.000 claims description 3
- 238000004064 recycling Methods 0.000 claims description 2
- 230000009257 reactivity Effects 0.000 abstract 1
- 239000000243 solution Substances 0.000 description 11
- 239000007788 liquid Substances 0.000 description 7
- 239000000203 mixture Substances 0.000 description 6
- 239000010802 sludge Substances 0.000 description 6
- BQPIGGFYSBELGY-UHFFFAOYSA-N mercury(2+) Chemical compound [Hg+2] BQPIGGFYSBELGY-UHFFFAOYSA-N 0.000 description 5
- QAOWNCQODCNURD-UHFFFAOYSA-N Sulfuric acid Chemical compound OS(O)(=O)=O QAOWNCQODCNURD-UHFFFAOYSA-N 0.000 description 4
- 230000003197 catalytic effect Effects 0.000 description 3
- 238000010790 dilution Methods 0.000 description 3
- 239000012895 dilution Substances 0.000 description 3
- 238000013459 approach Methods 0.000 description 2
- 230000015572 biosynthetic process Effects 0.000 description 2
- 239000004927 clay Substances 0.000 description 2
- 238000001816 cooling Methods 0.000 description 2
- ORMNPSYMZOGSSV-UHFFFAOYSA-N dinitrooxymercury Chemical compound [Hg+2].[O-][N+]([O-])=O.[O-][N+]([O-])=O ORMNPSYMZOGSSV-UHFFFAOYSA-N 0.000 description 2
- 239000012153 distilled water Substances 0.000 description 2
- 150000002500 ions Chemical class 0.000 description 2
- 230000000802 nitrating effect Effects 0.000 description 2
- 230000003647 oxidation Effects 0.000 description 2
- 238000007254 oxidation reaction Methods 0.000 description 2
- 239000000843 powder Substances 0.000 description 2
- 229910000497 Amalgam Inorganic materials 0.000 description 1
- 230000002378 acidificating effect Effects 0.000 description 1
- AZDRQVAHHNSJOQ-UHFFFAOYSA-N alumane Chemical compound [AlH3] AZDRQVAHHNSJOQ-UHFFFAOYSA-N 0.000 description 1
- 230000002596 correlated effect Effects 0.000 description 1
- 239000013078 crystal Substances 0.000 description 1
- 230000006866 deterioration Effects 0.000 description 1
- 238000004090 dissolution Methods 0.000 description 1
- 239000008240 homogeneous mixture Substances 0.000 description 1
- 239000013072 incoming material Substances 0.000 description 1
- 239000006193 liquid solution Substances 0.000 description 1
- 150000002730 mercury Chemical class 0.000 description 1
- 150000002731 mercury compounds Chemical class 0.000 description 1
- 150000002739 metals Chemical class 0.000 description 1
- 238000012544 monitoring process Methods 0.000 description 1
- 238000000926 separation method Methods 0.000 description 1
- 239000007787 solid Substances 0.000 description 1
- 239000012808 vapor phase Substances 0.000 description 1
Images
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
- C22B43/00—Obtaining mercury
-
- G—PHYSICS
- G21—NUCLEAR PHYSICS; NUCLEAR ENGINEERING
- G21C—NUCLEAR REACTORS
- G21C19/00—Arrangements for treating, for handling, or for facilitating the handling of, fuel or other materials which are used within the reactor, e.g. within its pressure vessel
- G21C19/42—Reprocessing of irradiated fuel
- G21C19/44—Reprocessing of irradiated fuel of irradiated solid fuel
-
- 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
- Y02E—REDUCTION OF GREENHOUSE GAS [GHG] EMISSIONS, RELATED TO ENERGY GENERATION, TRANSMISSION OR DISTRIBUTION
- Y02E30/00—Energy generation of nuclear origin
- Y02E30/30—Nuclear fission reactors
-
- 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
-
- 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
- Y02W—CLIMATE CHANGE MITIGATION TECHNOLOGIES RELATED TO WASTEWATER TREATMENT OR WASTE MANAGEMENT
- Y02W30/00—Technologies for solid waste management
- Y02W30/50—Reuse, recycling or recovery technologies
Definitions
- This invention relates in general to processes for recovery of mercury from waste residues, and more particularly to a process for recovering mercury compounds from solutions containing nitric acid.
- Mercury is recovered from process sludge by dissolving the sludge in acid and thereafter adding powdered aluminum. Liquid mercury collects on the bottom of the reaction vessel.
- the invention is used for recycling of aluminum clad nuclear fuel elements.
- Such elements are dissolved in nitric acid using mercury nitrate as a catalyst.
- This mercury may be recovered in metallic form by rapidly quenching the nitric acid reaction prior to or promptly after complete dissolution of the aluminum metal.
- FIG. 1 is a flow chart illustrating the method for recovery of mercury from process sludge.
- FIG. 1 is a flow chart illustrating the method for recovery of mercury from process sludge.
- the incoming material could also be a mercury bearing solution.
- step 1 sludge 10 is added to reaction vessel 20, where it is allowed to react with heated nitric acid. This results in the formation of effluent 30 containing mercury nitrate. Step 1 is not required if the waste fluid or sludge from which mercury is to be recovered already contains nitric acid, as is the case when aluminum clad nuclear fuel elements are being dissolved.
- effluent 30 is placed into contact with aluminum metal in reaction vessel 40.
- This is preferably powdered aluminum. However, it can also be the cladding of a nuclear fuel element.
- nitrated mercury is reduced to mercury metal. Since the rate of nitration of mercury metal in nitric acid is rather slow, relative to the rate of aluminum metal reaction, metallic mercury tends to accumulate in the reaction vessel.
- the nitrating power of the nitric acid solution with respect to metallic mercury is positively correlated with the temperature and with the concentration of the acid.
- step 3 metallic mercury 50 which accumulates as the result of step 2 is continually removed from the bottom of the reaction vessel 40 via drain valve 60.
- the re-nitration of the mercury can be prevented by rapidly reducing the nitrating power of the nitric acid, by means of dilution or reduction in temperature, or by drawing off liquid mercury before it has a chance to react. Dilution, cooling, and mercury removal are all means of quenching the mercury re-nitration reaction.
- the optimum process end time can be detected by observing the size of the accumulated mercury pool, or by observing the concentration of solvated mercury ion in real time, using X-ray fluorescent equipment or an ion electrode.
- Mercury analytical monitoring is set up prior to starting a process so that an entire run may be monitored. The process is allowed to proceed after the addition of aluminum until the mercury ion content of the solution drops to a very low concentration (0.001M or below) and there approaches a steady state. This happens in about an hour if good vessel mixing is provided, and, of course, assuming that only catalytic quantities of mercury nitrate are present. If excess aluminum is present, the nitric acid will be consumed, and this will be the end point.
- Metallic mercury and aluminum can be recovered from the vessel and subjected to physical separation. If excess aluminum is not present, the concentration of mercury ion in solution will thereafter begin to increase at such time as the last of the aluminum is consumed. This is the optimum point to quench the reaction and recover the metallic mercury present.
- a mixture of 100 g. water and 100 g. clay (Peerless #2 AF) was made up in a 400 ml beaker.
- the beaker with the liquid and aluminum powder was placed on a hot plate and heated to about 65° to 70° C. to initiate a reaction.
Landscapes
- Engineering & Computer Science (AREA)
- Physics & Mathematics (AREA)
- Chemical & Material Sciences (AREA)
- Plasma & Fusion (AREA)
- General Engineering & Computer Science (AREA)
- High Energy & Nuclear Physics (AREA)
- Manufacturing & Machinery (AREA)
- Materials Engineering (AREA)
- Mechanical Engineering (AREA)
- Metallurgy (AREA)
- Organic Chemistry (AREA)
- Manufacture And Refinement Of Metals (AREA)
Abstract
Mercury can be recovered from nitric acid-containing fluids by reacting the fluid with aluminum metal to produce mercury metal, and then quenching the reactivity of the nitric acid prior to nitration of the mercury metal.
Description
This invention was made or conceived in the course of or under a contract with the U.S. Department of Energy, under Contract No. DE-AC06-76-FF-02170.
This invention relates in general to processes for recovery of mercury from waste residues, and more particularly to a process for recovering mercury compounds from solutions containing nitric acid.
The prior art discloses numerous methods for recovery or removal of mercury from liquids, but none designed for this application. For example, Townsend U.S. Pat. No. 4,028,236, Gerow U.S. Pat. No. 3,802,910, Nolte U.S. Pat. No. 3,788,842, and Stenger U.S. Pat. No. 3,679,396 disclose various schemes for removal of elemental mercury. These work by means of amalgam formation with another metal.
Some prior art schemes for mercury removal, such as Hack U.S. Pat. No. 3,701,651, Cadmus U.S. Pat. No. 3,764,528 and Knepper U.S. Pat. No. 3,695,838 are restricted to non-acid solutions.
Kinoshita U.S. Pat. No. 4,057,423 teaches a process for removing mercury from sulfuric acid vapors. This process involves contacting acid vapor with metals having a reducing potential greater than that of mercury. The mercury is recovered from vapor phase sulfuric acid rather than from a liquid solution.
Thus, it is the object of this invention to provide an economical means for recovery of mercury from highly acidic sludges and solutions, particularly those which contain nitric acid.
Mercury is recovered from process sludge by dissolving the sludge in acid and thereafter adding powdered aluminum. Liquid mercury collects on the bottom of the reaction vessel.
In one application, the invention is used for recycling of aluminum clad nuclear fuel elements. Such elements are dissolved in nitric acid using mercury nitrate as a catalyst. This mercury may be recovered in metallic form by rapidly quenching the nitric acid reaction prior to or promptly after complete dissolution of the aluminum metal.
FIG. 1 is a flow chart illustrating the method for recovery of mercury from process sludge.
FIG. 1 is a flow chart illustrating the method for recovery of mercury from process sludge. The incoming material could also be a mercury bearing solution.
In step 1, sludge 10 is added to reaction vessel 20, where it is allowed to react with heated nitric acid. This results in the formation of effluent 30 containing mercury nitrate. Step 1 is not required if the waste fluid or sludge from which mercury is to be recovered already contains nitric acid, as is the case when aluminum clad nuclear fuel elements are being dissolved.
In step 2, effluent 30 is placed into contact with aluminum metal in reaction vessel 40. This is preferably powdered aluminum. However, it can also be the cladding of a nuclear fuel element. As the aluminum is oxidized by the nitric acid in effluent 30, nitrated mercury is reduced to mercury metal. Since the rate of nitration of mercury metal in nitric acid is rather slow, relative to the rate of aluminum metal reaction, metallic mercury tends to accumulate in the reaction vessel.
The nitrating power of the nitric acid solution with respect to metallic mercury is positively correlated with the temperature and with the concentration of the acid.
In step 3, metallic mercury 50 which accumulates as the result of step 2 is continually removed from the bottom of the reaction vessel 40 via drain valve 60. Alternatively, when a large pool of mercury has accumulated, the re-nitration of the mercury can be prevented by rapidly reducing the nitrating power of the nitric acid, by means of dilution or reduction in temperature, or by drawing off liquid mercury before it has a chance to react. Dilution, cooling, and mercury removal are all means of quenching the mercury re-nitration reaction.
If the dilution or cooling approach to reaction quenching is to be used, it is important to time the quenching properly. The catalytic oxidation of aluminum by mercuric ion proceeds rapidly, resulting in reduction of mercury ion to metal. The second part of the catalytic cycle, the oxidation of mercury metal to mecuric ion, proceeds comparatively slowly. Therefore, in the mercury recovery process, the bulk of the available mercury is converted from the ionic form to the metal form in a relatively short time. At this point, a steady state is achieved, and a fixed amount of metallic mercury will be present in the reaction vessel. This fixed amount of mercury will remain until such time as the aluminum is dissolved. When the aluminum is dissolved and, therefore, when generation of mercury metal ceases, the size of the mercury pool will begin to decrease as mercury is nitrated back into solution. This is the best time to quench the reaction if it is desired to dissolve a maximum amount of aluminum yet recover a maximum amount of mercury metal.
The optimum process end time can be detected by observing the size of the accumulated mercury pool, or by observing the concentration of solvated mercury ion in real time, using X-ray fluorescent equipment or an ion electrode. Mercury analytical monitoring is set up prior to starting a process so that an entire run may be monitored. The process is allowed to proceed after the addition of aluminum until the mercury ion content of the solution drops to a very low concentration (0.001M or below) and there approaches a steady state. This happens in about an hour if good vessel mixing is provided, and, of course, assuming that only catalytic quantities of mercury nitrate are present. If excess aluminum is present, the nitric acid will be consumed, and this will be the end point. Metallic mercury and aluminum can be recovered from the vessel and subjected to physical separation. If excess aluminum is not present, the concentration of mercury ion in solution will thereafter begin to increase at such time as the last of the aluminum is consumed. This is the optimum point to quench the reaction and recover the metallic mercury present.
Two laboratory scale examples of the process are here presented:
Prodecure:
1. A 100 ml solution of 1M nitric acid was made up in a 250 ml Erlenmeyer flask.
2. A 5 to 10 g. portion of mercuric nitrate crystals was dissolved in the nitric acid.
3. 1 to 2 gm aluminum metal powder was added to the acid solution and stirred to make a homogeneous mixture.
4. The mixture was placed on a hot plate and heated to 60-70 degrees C. This initiated reaction with the aluminum metal.
5. The heat was turned down and the reaction was allowed to proceed for a brief period (10-15 minutes).
6. When a sizeable ball of mercury was observed at the bottom of the reaction flask, the reaction was quenched by addition of cold water.
7. The effluent was removed, and the metallic mercury was recovered from the bottom of the reaction flask. The mercury was removed and rinsed with distilled water. No deterioration was apparent in the mercury after storage for several days in a clean vial.
Procedure:
1. A mixture of 100 g. water and 100 g. clay (Peerless #2 AF) was made up in a 400 ml beaker.
2. A 10 gm portion of mercury nitrate was added and stirred into the clay-water mixture.
3. 5 ml of nitric acid was added to the mixture until the resulting liquid was about 0.5 to 1M in nitric acid.
4. The resulting mixture was then centrifuged to remove the solid clay fraction.
5. 5 g. aluminum metal powder was added to the clear centrifuged liquid.
6. The beaker with the liquid and aluminum powder was placed on a hot plate and heated to about 65° to 70° C. to initiate a reaction.
7. The hot plate was turned off, but the reaction was allowed to continue for about 20 minutes.
8. A large pool of mercury was visible in the bottom of the reaction vessel after 20 minutes. The reaction was immediately quenched with water.
9. The liquid mercury and remaining aluminum was recovered, and the remaining aluminum powder was removed by sluicing with distilled water. A 5 g. pool of mercury was recovered. This was approximately 80% of the mercury in the vessel.
The foregoing is intended to describe the invention. The limits of the invention are to be determined according to the following claims.
Claims (4)
1. In a process wherein a nuclear fuel element, with a cladding comprising aluminum, is subjected to a reaction with a solution comprising water, nitric acid and mercury nitrate in a reaction vessel, and wherein mercury acts as a catalyst, a method for receiving metallic mercury from said solution, comprising the steps of:
first, reacting said cladding to dissolve said aluminum, whereby mercury nitrate is caused to be converted to metallic mercury; and
second, removing said metallic mercury from said reaction vessel prior to re-nitration of said mercury by said nitric acid.
2. The method of claim 1 wherein said quenching step comprises the step of drawing off metallic mercury from said reaction vessel.
3. In a process for recycling nuclear fuel elements possessing a cladding comprising aluminum, wherein the elements are subjected to reaction with a solution comprising nitric acid in a reaction vessel, and wherein mercury acts as a catalyst, a method for recovering the mercury from said solution and said vessel, comprising the steps of:
promptly quenching said reaction after aluminum has been dissolved; and
recovering accumulated metallic mercury from said reaction vessel.
4. A method for recovering metallic mercury from a fluid comprising water, nitric acid and mercury nitrate, contained in a reaction vessel, comprising the steps of: reacting aluminum metal with said fluid, whereby said mercury nitrate is converted to mercury metal; and, removing mercury metal from said reaction vessel prior to nitration of said metal by said nitric acid.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| US07/019,834 USH715H (en) | 1987-02-27 | 1987-02-27 | Recovery of mercury from acid waste residues |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| US07/019,834 USH715H (en) | 1987-02-27 | 1987-02-27 | Recovery of mercury from acid waste residues |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| USH715H true USH715H (en) | 1989-12-05 |
Family
ID=21795280
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| US07/019,834 Abandoned USH715H (en) | 1987-02-27 | 1987-02-27 | Recovery of mercury from acid waste residues |
Country Status (1)
| Country | Link |
|---|---|
| US (1) | USH715H (en) |
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US5364603A (en) * | 1993-08-12 | 1994-11-15 | The United States Of America As Represented By The United States Department Of Energy | Mercury-free dissolution of aluminum-clad fuel in nitric acid |
| US6221128B1 (en) | 1997-06-20 | 2001-04-24 | Brij P. Giri | Recovery and removal of mercury from effluent |
Citations (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US3679396A (en) | 1971-01-14 | 1972-07-25 | Dow Chemical Co | Mercury recovery from sediment |
| US3695838A (en) | 1969-10-31 | 1972-10-03 | Huels Chemische Werke Ag | Process for recovering mercury from waste waters of industrial processes |
| US3701651A (en) | 1970-02-06 | 1972-10-31 | Al Hack & Associates Inc | Process for production of mercury |
| US4599177A (en) | 1982-06-22 | 1986-07-08 | Seitetsu Kagaku Co., Ltd. | Process for removal of mercury from waste water |
-
1987
- 1987-02-27 US US07/019,834 patent/USH715H/en not_active Abandoned
Patent Citations (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US3695838A (en) | 1969-10-31 | 1972-10-03 | Huels Chemische Werke Ag | Process for recovering mercury from waste waters of industrial processes |
| US3701651A (en) | 1970-02-06 | 1972-10-31 | Al Hack & Associates Inc | Process for production of mercury |
| US3679396A (en) | 1971-01-14 | 1972-07-25 | Dow Chemical Co | Mercury recovery from sediment |
| US4599177A (en) | 1982-06-22 | 1986-07-08 | Seitetsu Kagaku Co., Ltd. | Process for removal of mercury from waste water |
Non-Patent Citations (1)
| Title |
|---|
| Bailar, Jr., J. C. et al., Comprehensive Inorganic Chemistry, vol. III, Pergamon Press, 1972, pp. 277, 279-283 and 293-294 and 315-316. |
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US5364603A (en) * | 1993-08-12 | 1994-11-15 | The United States Of America As Represented By The United States Department Of Energy | Mercury-free dissolution of aluminum-clad fuel in nitric acid |
| US6221128B1 (en) | 1997-06-20 | 2001-04-24 | Brij P. Giri | Recovery and removal of mercury from effluent |
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