JPH04154924A - Method for recovering platinum group element from nuclear fuel reprocessing waste - Google Patents
Method for recovering platinum group element from nuclear fuel reprocessing wasteInfo
- Publication number
- JPH04154924A JPH04154924A JP2273355A JP27335590A JPH04154924A JP H04154924 A JPH04154924 A JP H04154924A JP 2273355 A JP2273355 A JP 2273355A JP 27335590 A JP27335590 A JP 27335590A JP H04154924 A JPH04154924 A JP H04154924A
- Authority
- JP
- Japan
- Prior art keywords
- insoluble residue
- nuclear fuel
- platinum group
- recovered
- fuel reprocessing
- 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
- 238000000034 method Methods 0.000 title claims abstract description 27
- 238000012958 reprocessing Methods 0.000 title claims abstract description 21
- 239000003758 nuclear fuel Substances 0.000 title claims abstract description 20
- BASFCYQUMIYNBI-UHFFFAOYSA-N platinum Chemical group [Pt] BASFCYQUMIYNBI-UHFFFAOYSA-N 0.000 title claims abstract description 20
- 239000002699 waste material Substances 0.000 title claims description 7
- 229910052707 ruthenium Inorganic materials 0.000 claims abstract description 27
- 229910052750 molybdenum Inorganic materials 0.000 claims abstract description 26
- 239000001301 oxygen Substances 0.000 claims abstract description 19
- 229910052760 oxygen Inorganic materials 0.000 claims abstract description 19
- QVGXLLKOCUKJST-UHFFFAOYSA-N atomic oxygen Chemical compound [O] QVGXLLKOCUKJST-UHFFFAOYSA-N 0.000 claims abstract description 18
- 229910052763 palladium Inorganic materials 0.000 claims abstract description 18
- 238000001704 evaporation Methods 0.000 claims abstract description 5
- 230000001590 oxidative effect Effects 0.000 claims abstract description 5
- KDLHZDBZIXYQEI-UHFFFAOYSA-N Palladium Chemical compound [Pd] KDLHZDBZIXYQEI-UHFFFAOYSA-N 0.000 claims description 35
- ZOKXTWBITQBERF-UHFFFAOYSA-N Molybdenum Chemical compound [Mo] ZOKXTWBITQBERF-UHFFFAOYSA-N 0.000 claims description 25
- 239000002893 slag Substances 0.000 claims description 24
- KJTLSVCANCCWHF-UHFFFAOYSA-N Ruthenium Chemical compound [Ru] KJTLSVCANCCWHF-UHFFFAOYSA-N 0.000 claims description 23
- 239000011733 molybdenum Substances 0.000 claims description 22
- 239000010948 rhodium Substances 0.000 claims description 20
- 229910052703 rhodium Inorganic materials 0.000 claims description 18
- MHOVAHRLVXNVSD-UHFFFAOYSA-N rhodium atom Chemical compound [Rh] MHOVAHRLVXNVSD-UHFFFAOYSA-N 0.000 claims description 18
- 239000012298 atmosphere Substances 0.000 claims description 13
- 229910052751 metal Inorganic materials 0.000 claims description 8
- 239000002184 metal Substances 0.000 claims description 7
- 238000000926 separation method Methods 0.000 claims description 7
- 238000010438 heat treatment Methods 0.000 claims description 4
- 230000003647 oxidation Effects 0.000 abstract description 10
- 238000007254 oxidation reaction Methods 0.000 abstract description 10
- 239000007789 gas Substances 0.000 abstract description 8
- 238000011084 recovery Methods 0.000 abstract description 6
- 230000008020 evaporation Effects 0.000 abstract description 2
- 239000000203 mixture Substances 0.000 description 10
- 239000003795 chemical substances by application Substances 0.000 description 8
- 239000000470 constituent Substances 0.000 description 8
- 239000002927 high level radioactive waste Substances 0.000 description 6
- 239000002994 raw material Substances 0.000 description 5
- 238000005253 cladding Methods 0.000 description 4
- 239000000446 fuel Substances 0.000 description 4
- WABPQHHGFIMREM-UHFFFAOYSA-N lead(0) Chemical compound [Pb] WABPQHHGFIMREM-UHFFFAOYSA-N 0.000 description 4
- 239000000843 powder Substances 0.000 description 4
- 239000002915 spent fuel radioactive waste Substances 0.000 description 4
- 238000006243 chemical reaction Methods 0.000 description 3
- 238000000605 extraction Methods 0.000 description 3
- 230000004992 fission Effects 0.000 description 3
- 239000007788 liquid Substances 0.000 description 3
- 150000002739 metals Chemical class 0.000 description 3
- 229910000476 molybdenum oxide Inorganic materials 0.000 description 3
- PQQKPALAQIIWST-UHFFFAOYSA-N oxomolybdenum Chemical compound [Mo]=O PQQKPALAQIIWST-UHFFFAOYSA-N 0.000 description 3
- 229910001925 ruthenium oxide Inorganic materials 0.000 description 3
- WOCIAKWEIIZHES-UHFFFAOYSA-N ruthenium(iv) oxide Chemical compound O=[Ru]=O WOCIAKWEIIZHES-UHFFFAOYSA-N 0.000 description 3
- 230000007704 transition Effects 0.000 description 3
- 229910052778 Plutonium Inorganic materials 0.000 description 2
- 239000002253 acid Substances 0.000 description 2
- 239000005388 borosilicate glass Substances 0.000 description 2
- 229910052804 chromium Inorganic materials 0.000 description 2
- 238000010586 diagram Methods 0.000 description 2
- 238000004090 dissolution Methods 0.000 description 2
- 238000005538 encapsulation Methods 0.000 description 2
- 239000011521 glass Substances 0.000 description 2
- 229910052742 iron Inorganic materials 0.000 description 2
- 239000000463 material Substances 0.000 description 2
- OYEHPCDNVJXUIW-UHFFFAOYSA-N plutonium atom Chemical compound [Pu] OYEHPCDNVJXUIW-UHFFFAOYSA-N 0.000 description 2
- 239000010802 sludge Substances 0.000 description 2
- 239000000126 substance Substances 0.000 description 2
- 229910052713 technetium Inorganic materials 0.000 description 2
- GKLVYJBZJHMRIY-UHFFFAOYSA-N technetium atom Chemical compound [Tc] GKLVYJBZJHMRIY-UHFFFAOYSA-N 0.000 description 2
- 238000004017 vitrification Methods 0.000 description 2
- 239000002912 waste gas Substances 0.000 description 2
- 229910052726 zirconium Inorganic materials 0.000 description 2
- MYMOFIZGZYHOMD-UHFFFAOYSA-N Dioxygen Chemical compound O=O MYMOFIZGZYHOMD-UHFFFAOYSA-N 0.000 description 1
- 229910052770 Uranium Inorganic materials 0.000 description 1
- 239000000956 alloy Substances 0.000 description 1
- 229910045601 alloy Inorganic materials 0.000 description 1
- 230000015572 biosynthetic process Effects 0.000 description 1
- 238000007664 blowing Methods 0.000 description 1
- 230000015556 catabolic process Effects 0.000 description 1
- 238000005260 corrosion Methods 0.000 description 1
- 230000007797 corrosion Effects 0.000 description 1
- 230000000694 effects Effects 0.000 description 1
- 239000010419 fine particle Substances 0.000 description 1
- 238000005755 formation reaction Methods 0.000 description 1
- 238000004519 manufacturing process Methods 0.000 description 1
- 239000011159 matrix material Substances 0.000 description 1
- 238000002844 melting Methods 0.000 description 1
- 230000008018 melting Effects 0.000 description 1
- 150000002926 oxygen Chemical class 0.000 description 1
- -1 platinum group metals Chemical class 0.000 description 1
- 229910001924 platinum group oxide Inorganic materials 0.000 description 1
- 238000012545 processing Methods 0.000 description 1
- 230000002285 radioactive effect Effects 0.000 description 1
- 239000012857 radioactive material Substances 0.000 description 1
- 229920006395 saturated elastomer Polymers 0.000 description 1
- 238000003860 storage Methods 0.000 description 1
- JFALSRSLKYAFGM-UHFFFAOYSA-N uranium(0) Chemical compound [U] JFALSRSLKYAFGM-UHFFFAOYSA-N 0.000 description 1
- 238000001771 vacuum deposition Methods 0.000 description 1
- 238000007738 vacuum evaporation Methods 0.000 description 1
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 description 1
Classifications
-
- 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
Landscapes
- Inorganic Compounds Of Heavy Metals (AREA)
- Manufacture And Refinement Of Metals (AREA)
Abstract
Description
【発明の詳細な説明】
[産業上の利用分野]
本発明は核燃料再処理廃棄物からの白金族元素の回収法
に関する。DETAILED DESCRIPTION OF THE INVENTION [Industrial Field of Application] The present invention relates to a method for recovering platinum group elements from nuclear fuel reprocessing waste.
[従来の技術]
核燃料再処理プラントでは、原子炉から発生する使用済
核燃料を化学処理することにより使用済核燃料中に含ま
れる核燃料物質と熱核反応により生じる核分裂生成物と
を分離する。前者は核燃料として原子炉て再利用される
。後者は半減期の長い放射性同位元素を含み、その放射
能も非常に高い。そのため長期間生物圏と隔離する必要
があり、このためガラス固化/耐食性容器への密封が行
われ、一定期間貯蔵した後深地層中に処分される計画が
ある。しかし、これら核分裂生成物中には白金族に属す
る金属元素及び化学的に類似した性質を有する元素群が
含まれる。その元素としては、モリブデン、テクネチウ
ム、ルテニウl\、ロジウム、パラジウムが挙げられる
。これらの元素群は、再処理の酸溶解工程において余り
溶解せず、微粒子状で存在し、各再処理工程を経て高レ
ベル廃液貯蔵タンク等の底部にスラッジ状態で蓄積され
る。[Prior Art] In a nuclear fuel reprocessing plant, spent nuclear fuel generated from a nuclear reactor is chemically treated to separate nuclear fuel materials contained in the spent nuclear fuel from fission products produced by thermonuclear reactions. The former is reused as nuclear fuel in nuclear reactors. The latter contains radioactive isotopes with long half-lives, and their radioactivity is also very high. Therefore, it is necessary to isolate it from the biosphere for a long period of time, and there are plans to vitrify it and seal it in a corrosion-resistant container, store it for a certain period of time, and then dispose of it in deep geological formations. However, these fission products include metallic elements belonging to the platinum group and a group of elements having chemically similar properties. Examples of the elements include molybdenum, technetium, ruthenium, rhodium, and palladium. These element groups do not dissolve much in the acid dissolution step of reprocessing and exist in the form of fine particles, and are accumulated in the form of sludge at the bottom of high-level waste liquid storage tanks and the like after each reprocessing step.
更に、これらの元素群に加えて燃料被覆管剪断層、燃料
被覆管外表面に付着していた水垢なども酸溶解工程で余
り溶解せずにスラッジ成分に入ってくる。それらは総称
して不溶性残渣と呼ばれている。Furthermore, in addition to these elements, water scales attached to the fuel cladding shear layer, the outer surface of the fuel cladding, and the like also enter the sludge component without being significantly dissolved in the acid dissolution process. They are collectively called insoluble residues.
この不溶性残渣はその後のガラス固化によっても硼珪酸
ガラスマトリックスに均質な相として取り込まれ難く、
高レベルガラス固化体の放射性物質包蔵特性に著しい悪
影響を与える。This insoluble residue is difficult to incorporate into the borosilicate glass matrix as a homogeneous phase even during subsequent vitrification.
This has a significant negative impact on the radioactive material encapsulation properties of high-level vitrified materials.
[発明が解決しようとする課題]
白金族元素(ルテニウム、ロジウム、パラジウム)は我
が国に殆ど産出せず、世界的にみても資源が乏しく、産
出国も偏在しており、極めて高価な金属となっている。[Problem to be solved by the invention] Platinum group elements (ruthenium, rhodium, and palladium) are hardly produced in Japan, and resources are scarce even in the world, and producing countries are unevenly distributed, making them extremely expensive metals. ing.
一方、使用済核燃料中には、ウラン、プルトニウ゛ムな
どの核分裂により生成する白金族元素が相当量台まれて
おり、もし、その全量が回収されれば我が国消費量全体
の数十%以上にも相当するものとなり準国産資源として
利用していくことができる。On the other hand, spent nuclear fuel contains a considerable amount of platinum group elements produced through nuclear fission, such as uranium and plutonium, and if all of this was recovered, it would account for more than several tens of percent of Japan's total consumption. It can be used as a quasi-domestic resource.
現在、核燃料再処理で発生する高レベル廃棄物(不溶性
残渣)中に含まれる白金族の存在形態は天然鉱石中のそ
れとは異なっており、モリブデン、テクネチウム、パラ
ジウム、ロジウムを主成分とする合金を形成していると
考えられている。これら各元素を分離、抽出し回収する
方法は未だ開発されていない。Currently, the existence form of platinum group metals contained in high-level waste (insoluble residue) generated in nuclear fuel reprocessing is different from that in natural ores, and alloys mainly composed of molybdenum, technetium, palladium, and rhodium are It is thought that it is forming. A method for separating, extracting, and recovering these elements has not yet been developed.
従って、本発明の目的は核燃料再処理で発生する不溶性
残渣から白金族元素を分離・回収する方法を提供するこ
とにある。Therefore, an object of the present invention is to provide a method for separating and recovering platinum group elements from insoluble residues generated during nuclear fuel reprocessing.
[課題を解決するための手段]
即ち、本発明は核燃料再処理で発生する不溶性残渣を1
〜200 ppmの酸素を含む気流中で1000〜12
00℃の温度で選択酸化してモリブデンを分離する工程
;次に、空気雰囲気あるいは酸素雰囲気中1000〜1
200℃の温度で更に酸化を行いルテニウムを分離する
工程;及び前記両工程によりモリブデン及びルテニウム
を分離した不溶性残渣を10弓トール以下の真空中11
00〜1200°Cの温度で処理してパラジウムを蒸発
分離する工程を含んでなることを特徴とする核燃料再処
理廃棄物からの白金族元素の回収法に係る。[Means for solving the problem] That is, the present invention reduces the amount of insoluble residue generated during nuclear fuel reprocessing to 1
1000-12 in an air stream containing ~200 ppm oxygen
Step of separating molybdenum by selective oxidation at a temperature of 00°C; Next, 1000 to 1
A step of further oxidizing at a temperature of 200° C. to separate ruthenium; and a step of separating the insoluble residue from which molybdenum and ruthenium were separated in the above two steps in a vacuum of 10 torr or less.
The present invention relates to a method for recovering platinum group elements from nuclear fuel reprocessing waste, which comprises a step of evaporating and separating palladium by treatment at a temperature of 00 to 1200°C.
更に、本発明は核燃料再処理で発生する不溶性残渣を金
属鉛中に1100〜1200℃の温度で抽出すると共に
その後の分離1駆で用いるスラグ相を形成させる工程;
前記工程で得られた金属鉛−スラグ相の系を、1100
〜1200℃の温度に加熱しながら溶融鉛にエアを吹き
込みモリブデンとルテニウムの酸化物を形成せしめる工
程;及びこれらの酸化物をスラグ相に移行することによ
り、鉛中にパラジウムとロジウムを回収する分離工程を
含んでなることを特徴とする核燃料再処理廃棄物からの
白金族元素の回収法に係る。Further, the present invention includes a step of extracting insoluble residue generated in nuclear fuel reprocessing into metallic lead at a temperature of 1100 to 1200°C and forming a slag phase for use in the subsequent separation step;
The metallic lead-slag phase system obtained in the above step was heated to 1100
A process of blowing air into molten lead while heating it to a temperature of ~1200°C to form oxides of molybdenum and ruthenium; and a separation process of recovering palladium and rhodium from the lead by transferring these oxides to the slag phase. The present invention relates to a method for recovering platinum group elements from nuclear fuel reprocessing waste, which comprises a process.
[作 用]
本発明方法で原料となる使用済燃料の再処理で発生する
不溶性残渣の総量は処理対象とする燃料の燃焼度などに
より異なるが、燃料単位トン当たりおよそ2〜6kft
であり、その組成内訳は次の通りである。[Function] The total amount of insoluble residue generated in the reprocessing of spent fuel as a raw material in the method of the present invention varies depending on the burnup of the fuel to be processed, but is approximately 2 to 6 kft per unit ton of fuel.
The composition breakdown is as follows.
超ウラン元素:0.8〜3.7重量%
白金族元素(Moも含めて)=70〜90重量%被覆管
剪断屑など(Zr、Fe、Cr): 2.5〜14重量
%
また、白金族元素(Moも含めて)の各元素側の構成割
合は次のようになる。Transuranium elements: 0.8 to 3.7% by weight Platinum group elements (including Mo) = 70 to 90% by weight Cladding tube sheared waste, etc. (Zr, Fe, Cr): 2.5 to 14% by weight, The composition ratio of each element of the platinum group elements (including Mo) is as follows.
Mo:IC1−55重量%
Ru:30〜50重量%
Rh:1〜20重量%
Pd: 5〜10重量%
Tc:2〜20重量%
本発明による白金族元素の分離・回収方法は、(1)l
化蒸発分離法及び真空蒸発分離法を使用して行うもの、
及び(2)鉗抽出法と金属とのなじみの少ない酸化物の
スラグ相への移行を利用して行うものである。Mo: IC1-55% by weight Ru: 30-50% by weight Rh: 1-20% by weight Pd: 5-10% by weight Tc: 2-20% by weight The method for separating and recovering platinum group elements according to the present invention includes (1) )l
those performed using the evaporation separation method and the vacuum evaporation separation method;
and (2) utilizing the force extraction method and the transition of oxides that are less compatible with metals into a slag phase.
回収法]
まず、上述のような組成を有する不溶性残渣が高レベル
廃液から捕集され、レトルI・内に挿入される。100
0〜1200℃のi黒度て゛1〜2001’1ll11
程度の酸素を含む気流中て、不溶性残渣を加熱、酸化さ
せる。この処理により主としてモリブデン元素が不溶性
残渣から選択的に酸化蒸発する。Collection Method] First, an insoluble residue having the composition as described above is collected from a high-level waste liquid and inserted into a retort I. 100
0~1200℃ i blackness 1~2001'1ll11
The insoluble residue is heated and oxidized in an air stream containing a certain amount of oxygen. This treatment selectively oxidizes and evaporates mainly the molybdenum element from the insoluble residue.
酸化により生成、蒸発するモリブデン酸化物は冷却器で
析出させ回収される。更に、同一温度すなわち1000
〜1200°Cて気流中の酸素ポテンシャルを上げて酸
化蒸発を行い(大気中あるいは酸素雰囲気中)、ルテニ
ウム元素をモリブデンと同様に酸化蒸発する。ルテニウ
ム酸化物を冷却器に回収する。Molybdenum oxide produced and vaporized by oxidation is precipitated and recovered in a cooler. Furthermore, at the same temperature, i.e. 1000
The ruthenium element is oxidized and evaporated in the same manner as molybdenum by increasing the oxygen potential in the air stream at ~1200°C (in the air or in an oxygen atmosphere). Collect the ruthenium oxide in a cooler.
上記処理を行った不溶性残渣中には主にパラジウムとロ
ジウムの元素が酸化されずに残る。この残りの不溶性残
渣中にはロジウムが主として存在する。In the insoluble residue after the above treatment, mainly palladium and rhodium elements remain without being oxidized. Rhodium is mainly present in this remaining insoluble residue.
以下に酸化蒸発法及び真空蒸発法の原理を説明する。な
お、第1図に不溶性残渣構成元素の酸化物に対する酸素
分圧と温度の関係を示す。また、揮発性酸化物の蒸気圧
を次に示す。The principles of the oxidation evaporation method and the vacuum evaporation method will be explained below. Note that FIG. 1 shows the relationship between oxygen partial pressure and temperature for oxides of insoluble residue constituent elements. In addition, the vapor pressure of volatile oxides is shown below.
揮発性酸化物
他主L 流気■
MOO310,1mmHg(800℃)760mmHg
(1155℃)
Rub< 183mmHg (〜100℃)第
1図から分かるように、例えば1100℃の温度におい
てt ppmの濃度の酸素を含む雰囲気に相当する酸素
分圧ではモリブデン元素が選択的に酸化される。また、
生成するモリブデン酸化物の蒸気圧は1気圧に近く、不
溶性残渣から蒸発、分離する。一方、この酸素分圧では
不溶性残渣のその他の構成元素は酸化を受けないため、
気流雰囲気の酸素分圧を上げることにより(大気あるい
は純酸素雰囲気)再び第1図から明らかなようにルテニ
ウム元素が選択的に酸化される。ルテニウム酸化物の回
収はモリブデンと同様冷却器により行われる。Volatile oxides and other main L Flow ■ MOO310, 1mmHg (800℃) 760mmHg
(1155°C) Rub < 183mmHg (~100°C) As can be seen from Figure 1, for example, at a temperature of 1100°C, molybdenum element is selectively oxidized at an oxygen partial pressure corresponding to an atmosphere containing oxygen at a concentration of t ppm. Ru. Also,
The vapor pressure of the generated molybdenum oxide is close to 1 atm, and it is evaporated and separated from the insoluble residue. On the other hand, other constituent elements of the insoluble residue do not undergo oxidation at this oxygen partial pressure.
By increasing the oxygen partial pressure in the airflow atmosphere (air or pure oxygen atmosphere), the ruthenium element is again selectively oxidized, as is clear from FIG. Ruthenium oxide is recovered using a cooler, similar to molybdenum.
上記の処理により不溶性残渣からはモリブデンとルテニ
ウムが分離 回収される。不溶性残渣中にはパラジウム
とロジウムが残る。この2つの元素の中て1100℃で
のパラジウム元素の蒸気圧が第2図に示すように高く、
真空中例えば10−3トール以下の減圧下で1100〜
1200℃の温度で加熱することによりパラジウム元素
を選択的に蒸発分離することが可能てあり、最終的にロ
ジウム元素が単独で残ることになる。Through the above treatment, molybdenum and ruthenium are separated and recovered from the insoluble residue. Palladium and rhodium remain in the insoluble residue. Of these two elements, palladium has the highest vapor pressure at 1100°C, as shown in Figure 2.
in vacuum, e.g. 1100 ~ under reduced pressure of 10-3 torr or less
By heating at a temperature of 1200°C, it is possible to selectively evaporate and separate the palladium element, and ultimately the rhodium element remains alone.
回収法2
まず、上述のような組成を有する不溶性残渣が高レベル
廃液から捕集されてpb粉末(白金族元素抽出剤)並び
にスラグ形成剤と混合した後、電気炉内に挿入される。Recovery Method 2 First, the insoluble residue having the composition as described above is collected from the high-level waste liquid, mixed with PB powder (platinum group element extractant) and slag forming agent, and then inserted into an electric furnace.
1100〜1200℃の温度でこの不溶性残渣とスラグ
形成剤の混合物を溶融し、不溶性残渣を鉛に抽出すると
共にスラグを形成する。抽出にPl)粉末を用いたのは
、白金族元素がpbに選択的に抽出されること、また、
スラグ形成剤として硼珪酸ガラスを用いたのは、このガ
ラスの融点が比較的低いこと並びに高レベル廃棄物ガラ
ス固化体にも用いられており、包蔵性に優れている等を
考慮したことによる。スラグ形成剤の組成は次の範囲の
ものを用いる。This mixture of insoluble residue and slag forming agent is melted at a temperature of 1100-1200°C to extract the insoluble residue into lead and form a slag. The reason why Pl) powder was used for extraction is that platinum group elements are selectively extracted by PB, and
The reason why borosilicate glass was used as the slag forming agent was because this glass has a relatively low melting point, is also used in high-level waste vitrification, and has excellent encapsulation properties. The composition of the slag forming agent used is within the following range.
スラグ組成
5102:45〜50重量%
B2O2:10〜20重量%
AN203:5〜10重量%
その他微量酸化物の合計二〜10重量%また、不溶性残
渣、pb粉末、スラグ形成剤の混合比はpb粉末の量は
溶融状態のpbへ移行する成分が飽和状態にならないよ
うな旦とする必要があり、従って、原料となる不溶性残
渣の成分組成等に依存して決定されるものである。また
、不溶性残渣とスラグ形成剤の混合比は重量比で1・2
〜3程度とする。生成した不溶性残渣を含む鉛−スラグ
系を、更に、1100〜1200°Cて加熱し、溶融鉛
にエアを吹き込み、モリブデンとルテニウムを選択的に
酸化させ酸化物を形成させる。Slag composition 5102: 45-50% by weight B2O2: 10-20% by weight AN203: 5-10% by weight Total of other trace oxides 2-10% by weight Also, the mixing ratio of insoluble residue, PB powder, and slag forming agent is PB The amount of powder needs to be such that the components transferred to the molten Pb do not reach a saturated state, and therefore, it is determined depending on the component composition of the insoluble residue used as the raw material. In addition, the mixing ratio of the insoluble residue and the slag forming agent is 1.2 by weight.
- About 3. The lead-slag system containing the produced insoluble residue is further heated to 1100-1200°C, and air is blown into the molten lead to selectively oxidize molybdenum and ruthenium to form oxides.
モリブデン及びルテニウムの酸化物生成の反応式の一例
を次に示す。An example of a reaction formula for producing oxides of molybdenum and ruthenium is shown below.
酸化物生成の反応式
%式%
生じたこれらの酸化物はスラグ相へ移行する。上記処理
を行った金属鉛中には主にパラジウムとロジウムの元素
が酸化されずに残る。Reaction formula for oxide production % Formula % These oxides produced transition to the slag phase. Mainly palladium and rhodium elements remain in the metal lead subjected to the above treatment without being oxidized.
以下に本発明の原理を記載する。第3図に不溶性残渣構
成元素の酸化物に対する酸素分圧と温度との関係を示す
。The principle of the present invention will be described below. FIG. 3 shows the relationship between oxygen partial pressure and temperature for oxides of insoluble residue constituent elements.
第3図から分かるように、例えば1100℃の温度にお
いてエアの雰囲気ではモリブデン及びルテニウム元素が
選択的に酸化される。この際、超ウラン元素(プルトニ
ウム等)、被覆管剪断層など(Zr、 Fe、 Cr)
も酸化物になる傾向が強く、生成した酸化物は同様にス
ラグ相に移行する。MO酸化物は揮発性が強いので一部
気相へ移行する。As can be seen from FIG. 3, molybdenum and ruthenium elements are selectively oxidized in an air atmosphere at a temperature of, for example, 1100°C. At this time, transuranic elements (plutonium, etc.), cladding shear layers, etc. (Zr, Fe, Cr)
also has a strong tendency to become oxides, and the oxides produced similarly transition to the slag phase. Since MO oxide is highly volatile, a portion of it moves into the gas phase.
それはRu酸化物も同様である。一方、当該雰囲気では
不溶性残渣のその他の構成元素ツマラジウムとロジウム
は酸化を受けないため、溶融鉛中に残る。The same applies to Ru oxide. On the other hand, in this atmosphere, the other constituent elements of the insoluble residue, thumaladium and rhodium, do not undergo oxidation and therefore remain in the molten lead.
上記の処理により不溶性残渣からはモリブデンとルテニ
ウムが酸化物として分離され、スラグ相に移行する。鉛
抽出した不溶性残渣中には主としてパラジウムとロジウ
ムが残る。 −[実 施 例]
実施例1
本発明の回収法1の1実施態様を第4図のフローシート
に従って説明する。Through the above treatment, molybdenum and ruthenium are separated from the insoluble residue as oxides and transferred to a slag phase. Mainly palladium and rhodium remain in the insoluble residue after lead extraction. - [Example] Example 1 One embodiment of the recovery method 1 of the present invention will be described according to the flow sheet of FIG. 4.
核燃料再処理工程から回収された不溶性残渣(1)[こ
こでは、Mo −Ru −P d −Rbの組成が20
=60 : 10 : 10(原子%)の模擬試料を用
いた]を回転レトルト(2)に装荷する。Arガス(3
)を11/分の流速で流しながら、温度を1100℃に
上げ不溶性残渣中のモリブデン元素を選択酸化させる。Insoluble residue (1) recovered from nuclear fuel reprocessing process [here, the composition of Mo-Ru-Pd-Rb is 20
=60:10:10 (atomic %) using a simulated sample] is loaded into the rotating retort (2). Ar gas (3
) at a flow rate of 11/min, the temperature is raised to 1100°C to selectively oxidize the molybdenum element in the insoluble residue.
酸化が均一に行われるように回転レトルトを用いた。ま
た、Arガスを雰囲気として用いたのは、通常、Arガ
ス中に1ppI11程度の酸素が含まれ1100℃の温
度条件でモリブデンを選択的に酸化させるに適していた
からである。この処理により生成するモリブデン酸化物
は蒸気圧が高く、気流と共に搬送され冷却器(4)内で
冷却、凝縮し回収された。モリブデンの分離を終了した
後、雰囲気の酸素濃度を上げて[この場合、大気雰囲気
(3)とした]1100℃て加熱を継続した。この温度
・雰囲気条件ではルテニウム元素が選択的に酸化され、
生成するルテニウム酸化物も揮発性に富むことからモリ
ブデンと同様冷却器により回収された。A rotating retort was used to ensure uniform oxidation. Further, Ar gas was used as the atmosphere because Ar gas usually contains about 1 ppI11 of oxygen and was suitable for selectively oxidizing molybdenum at a temperature of 1100°C. The molybdenum oxide produced by this treatment had a high vapor pressure, and was transported along with the air flow, cooled and condensed in the cooler (4), and recovered. After the separation of molybdenum was completed, the oxygen concentration of the atmosphere was increased (in this case, atmospheric atmosphere (3)) and heating was continued at 1100°C. Under these temperature and atmospheric conditions, the ruthenium element is selectively oxidized,
Since the ruthenium oxide produced is also highly volatile, it was recovered using a cooler like molybdenum.
廃ガスはスクラバー(5)を通して排気した。The waste gas was exhausted through a scrubber (5).
これらの工程でモリブデンとルテニウムが分離・回収さ
れた。Arガス雰囲気中の処理でモリブデンが100%
除去されるが、この際10%程度のルテニウムも酸化に
より分離される。大気雰囲気中では、残ったルテニウム
元素が100%酸化し、蒸発、分離した。Molybdenum and ruthenium were separated and recovered through these steps. 100% molybdenum by treatment in Ar gas atmosphere
At this time, about 10% of ruthenium is also separated by oxidation. In the air atmosphere, the remaining ruthenium element was 100% oxidized, evaporated, and separated.
次に、モリブデンとルテニウムを除去した不溶性残渣を
真空炉(6)に装荷し、1100℃で加熱しパラジウム
元素を蒸発、分離し冷却器で回収した。真空炉内には不
溶性残渣の構成元素であるロジウムが残った。Next, the insoluble residue from which molybdenum and ruthenium had been removed was loaded into a vacuum furnace (6) and heated at 1100° C. to evaporate and separate the palladium element, which was recovered in a cooler. Rhodium, a constituent element of the insoluble residue, remained in the vacuum furnace.
実施例2
本発明の回収法2の1実施態様を第5図に従って説明す
る。Example 2 An embodiment of recovery method 2 of the present invention will be described with reference to FIG.
核燃料再処理工程から回収された不溶性残渣(11)[
ここでは、Mo−Ru−Pd−Rhの組成が20:60
:10:10(原子%)の模擬試料を用いた]、鉛粉末
及びスラグ形成剤を重量比で1:10:2の割合で混合
した原料を電気炉(12)に装荷する。温度を1100
℃に上げ原料を溶融し金属鉛相(13)とスラグ相(1
4)とを形成せしめる。この操作により、不溶性残渣は
鉛中に回収された。Insoluble residue recovered from nuclear fuel reprocessing process (11) [
Here, the composition of Mo-Ru-Pd-Rh is 20:60.
:10:10 (atom %) was used], a raw material prepared by mixing lead powder and a slag forming agent in a weight ratio of 1:10:2 is loaded into an electric furnace (12). temperature 1100
℃ and melt the raw material to form a metallic lead phase (13) and a slag phase (1
4). By this operation, the insoluble residue was recovered in lead.
スラグ相(14)は鉛相(13)の上部に形成された。A slag phase (14) was formed on top of the lead phase (13).
この操作により、不溶性残渣は鉛中に回収された。By this operation, the insoluble residue was recovered in lead.
この操作を終了した後、更に、1100℃で加熱を継続
しながら、溶融鉛にゆっくりとエア(1))を吹き込む
。鉛の酸化による損失を少なくするためにエアの吹き込
みはゆっくりとする必要がある。After completing this operation, air (1)) is slowly blown into the molten lead while continuing to heat it at 1100°C. Air must be blown slowly to reduce loss due to lead oxidation.
この操作で、主として鉛中のモリブデンとルテニウムが
酸化すると共にこれらの酸化物がカラス相ヘ取り込まれ
ることが確認された。この際、少量の鉛が酸化され、ス
ラグ相へ移行した。廃ガスはコールドトラップ(15)
及びスクラバー(16)を通し排気しな。また、鉛中に
はパラジウムとロジウムが金属状態て残った。It was confirmed that this operation mainly oxidized molybdenum and ruthenium in lead, and that these oxides were incorporated into the glass phase. At this time, a small amount of lead was oxidized and transferred to the slag phase. Cold trap for waste gas (15)
and exhaust through the scrubber (16). Additionally, palladium and rhodium remained in the lead as metals.
[発明の効果]
本発明により核燃料再処理プラン1へて発生ずる高レベ
ル廃棄物(不溶性残渣)より、回収法1ではルテニウム
、ロジウム、パラジウムの白金族元素を効率的に分離・
回収することができる。また、回収法2ては不溶性残渣
より(ルテニウム十ロジウム)と(パラジウム士ロジウ
ム)の組み合わせで白金族元素を分離することがてきる
。比較的高価な後者のロジウムとパラジウムを金属状態
で鉛相に分離・回収することができる。[Effect of the invention] According to the present invention, from the high-level waste (insoluble residue) generated in nuclear fuel reprocessing plan 1, recovery method 1 can efficiently separate and remove platinum group elements such as ruthenium, rhodium, and palladium.
It can be recovered. In recovery method 2, platinum group elements can be separated from the insoluble residue by a combination of (ruthenium and rhodium) and (palladium and rhodium). Rhodium and palladium, which are relatively expensive, can be separated and recovered in their metallic state into a lead phase.
比較的簡単な装置で処理可能なこと、また、高レベルで
あるため実際の処理はコンクリート製のセル内で行われ
るがセルでは薬品の使用が制限されており他に薬品を用
いない本発明はその点からも有利である。It can be processed with relatively simple equipment, and since the level is high, the actual processing is carried out in a concrete cell, but the use of chemicals is restricted in the cell, so the present invention does not use any other chemicals. It is also advantageous from that point of view.
第1図は不溶性残渣構成元素の酸化物の酸素分圧と温度
との関係を示すグラフであり、第2図は不溶性残渣構成
元素の蒸気圧と温度の関係を示ず図であり、第3図は本
発明方法の1実施態様を示すフローシートであり、第4
図は不溶性残渣構成元素の酸化物の酸素分圧と温度の関
係を示す図であり、第5図は本発明方法の他の実施態様
を示す図である。図中、1・・・不溶性残渣、2・・・
レトルト、3・・・Arガス、酸素あるいは大気、4・
・・冷却器、5・・・スクラバー、6・・・真空炉、7
・・・分離白金族元素(金属Ru、Pct)、8・・・
白金族酸化物(Ru、Mo)、11・・・不溶性残渣+
鉛粉末+スラグ形成剤(原料)、12・・・電気炉、1
3・・・鉛(不溶性残渣を含む)、14・・・スラグ相
(Mo、Ru酸化物が移行)、15・・・コールドトラ
ップ、16・・・スクラバー、17・・・エア。
特許出願人 三菱原子カニ業株式会社
手続補正書(方式)
平成3年2月13日FIG. 1 is a graph showing the relationship between the oxygen partial pressure and temperature of the oxide of the insoluble residue constituent elements, FIG. 2 is a graph showing the relationship between the vapor pressure and temperature of the insoluble residue constituent elements, and FIG. The figure is a flow sheet showing one embodiment of the method of the present invention, and the fourth
The figure is a diagram showing the relationship between the oxygen partial pressure of the oxide of the insoluble residue constituent element and temperature, and FIG. 5 is a diagram showing another embodiment of the method of the present invention. In the figure, 1... insoluble residue, 2...
Retort, 3...Ar gas, oxygen or atmosphere, 4.
...Cooler, 5...Scrubber, 6...Vacuum furnace, 7
...Separated platinum group elements (metal Ru, Pct), 8...
Platinum group oxide (Ru, Mo), 11... insoluble residue +
Lead powder + slag forming agent (raw material), 12... electric furnace, 1
3... Lead (including insoluble residue), 14... Slag phase (Mo and Ru oxides migrate), 15... Cold trap, 16... Scrubber, 17... Air. Patent applicant: Mitsubishi Atomic Crab Industry Co., Ltd. Procedural amendment (method) February 13, 1991
Claims (1)
pmの酸素を含む気流中で1000〜1200℃の温度
で選択酸化してモリブデンを分離する工程;次に、空気
雰囲気あるいは酸素雰囲気中1000〜1200℃の温
度で更に酸化を行いルテニウムを分離する工程;及び前
記両工程によりモリブデン及びルテニウムを分離した不
溶性残渣を10^−^3トール以下の真空中1100〜
1200℃の温度で処理してパラジウムを蒸発分離する
工程を含んでなることを特徴とする核燃料再処理廃棄物
からの白金族元素の回収法。 2、核燃料再処理で発生する不溶性残渣を金属鉛中に1
100〜1200℃の温度で抽出すると共にその後の分
離工程で用いるスラグ相を形成させる工程;前記工程で
得られた金属鉛−スラグ相の系を、1100〜1200
℃の温度に加熱しながら溶融鉛にエアを吹き込みモリブ
デンとルテニウムの酸化物を形成せしめる工程;及びこ
れらの酸化物をスラグ相に移行することにより、鉛中に
パラジウムとロジウムを回収する分離工程を含んでなる
ことを特徴とする核燃料再処理廃棄物からの白金族元素
の回収法。[Claims] 1. Insoluble residue generated in nuclear fuel reprocessing from 1 to 200p
A process of selectively oxidizing molybdenum at a temperature of 1000 to 1200°C in an air flow containing pm of oxygen; a process of further oxidizing at a temperature of 1000 to 1200°C in an air or oxygen atmosphere to separate ruthenium. ; and the insoluble residue from which molybdenum and ruthenium were separated in both of the above steps in a vacuum of 10^-^3 torr or less at 1100 ~
A method for recovering platinum group elements from nuclear fuel reprocessing waste, comprising a step of evaporating and separating palladium by treatment at a temperature of 1200°C. 2. Insoluble residues generated during nuclear fuel reprocessing are mixed into metal lead.
A step of extracting at a temperature of 100 to 1200°C and forming a slag phase for use in the subsequent separation step;
A step in which air is blown into molten lead while heating it to a temperature of °C to form oxides of molybdenum and ruthenium; and a separation step in which palladium and rhodium are recovered from the lead by transferring these oxides to the slag phase. A method for recovering platinum group elements from nuclear fuel reprocessing waste, comprising:
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JP2273355A JPH04154924A (en) | 1990-10-15 | 1990-10-15 | Method for recovering platinum group element from nuclear fuel reprocessing waste |
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Application Number | Priority Date | Filing Date | Title |
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JP2273355A JPH04154924A (en) | 1990-10-15 | 1990-10-15 | Method for recovering platinum group element from nuclear fuel reprocessing waste |
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Publication Number | Publication Date |
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JPH04154924A true JPH04154924A (en) | 1992-05-27 |
Family
ID=17526746
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JP (1) | JPH04154924A (en) |
Cited By (1)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
JP2005201765A (en) * | 2004-01-15 | 2005-07-28 | Central Res Inst Of Electric Power Ind | Nuclear species separation method for solid state fission product content |
-
1990
- 1990-10-15 JP JP2273355A patent/JPH04154924A/en active Pending
Cited By (1)
Publication number | Priority date | Publication date | Assignee | Title |
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JP2005201765A (en) * | 2004-01-15 | 2005-07-28 | Central Res Inst Of Electric Power Ind | Nuclear species separation method for solid state fission product content |
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