JP5651332B2 - Precious metal recovery equipment - Google Patents

Description

【０１２０】
（実験例１１）
実験例１１および後記する実験例１２、１３では、Ａｕ回収工程を繰返し行なったときのチタン製網の影響を調べた。
【０１２１】
上記実験例１において、処理液としてＡｕ含有シアン系メッキ品水洗水３０Ｌを図１に示した貴金属回収装置に充填し、該廃液のＡｕ濃度が１ｍｇ／Ｌになるまで電気分解した後、円筒状回転陰極４に電着したＡｕを回収せずに新たなＡｕ含有シアン系メッキ品水洗水３０Ｌを充填する工程を繰返して３０回行った。当該Ａｕ含有シアン系メッキ品水洗水のＡｕ濃度は９７ｍｇ／Ｌである。円筒状回転陰極４に電着したＡｕが剥離して電解槽１の底に堆積したＡｕ量を測定した。測定結果を下記表２に示す。
【０１２２】
なお、Ａｕ含有シアン系メッキ品水洗水としては、合計で９００Ｌ用いた。該廃液に含まれている総Ａｕ量は８７．３ｇであった。
【０１２３】
下記表２から明らかなように、３０回繰返して電気分解を行った後、円筒状回転陰極４に電着しているＡｕ量は８６．１ｇであり、電解槽の底に堆積したＡｕ量は０．３ｇであった。従って円筒状回転陰極４から剥離したＡｕ率は０．３％であった。
【０１２４】
（実験例１２）
上記実験例１１において、円筒状回転陰極４として表面にチタン製網を設けていない直径１６０ｍｍ、長さ２００ｍｍの円筒状回転陰極４を用いた点以外は、上記実験例１１と同じ条件で処理液を電気分解した。
【０１２５】
下記表２から明らかなように、３０回繰返して電気分解を行った後、円筒状回転陰極４に電着しているＡｕ量は８１．３ｇであり、電解槽の底に堆積したＡｕ量は５．１ｇであった。従って円筒状回転陰極４から剥離したＡｕ率は５．８％であった。
【０１２６】
（実験例１３）
上記実験例１１において、円筒状回転陰極４の表面にチタン製網を巻き付ける際に、チタン製網と円筒状回転陰極の上部複数ヶ所を導線でつなぎ、チタン製網が円筒状回転陰極４の表面に密着しないように、スペーサーを入れて１ｍｍ程度の隙間をあけてから２重となるように巻き付けた円筒状回転陰極４を用いた点以外は、上記実験例１１と同じ条件で処理液を電気分解した。
【０１２７】
下記表２から明らかなように、３０回繰返して電気分解を行った後、円筒状回転陰極４に電着しているＡｕ量は８５．０ｇであり、電解槽の底に堆積したＡｕ量は１．４ｇであった。従って円筒状回転陰極４から剥離したＡｕ率は１．６％であった。
【０１２８】
上記実験例１１〜１３の結果を比べると、円筒状回転陰極４の表面にチタン製網を着接させることで、円筒状回転陰極４への電着性を高めることができ、円筒状回転陰極４の表面からＡｕを剥離させることなく回収できることがわかる。そのため、円筒状回転陰極４の表面から剥れ落ちた貴金属を回収するための特別な機構を別途設ける必要がなくなり、回収装置の省スペース化を実現できる。
【０１２９】
【表２】

【０１３０】
（実験例１４）
実験例１４および後記する実験例１５、１６は、Ａｕ含有王水剥離液の廃液からＡｕを回収したときの回収効率を調べた実験である。
【０１３１】
上記実験例１において、処理液としてＡｕ含有王水剥離液の廃液を用いた点と、電圧を１．０〜２．０Ｖ、電流を２０Ａとして電気分解を行った点以外は、上記実験例１と同じ条件で処理液を電気分解した。当該Ａｕ含有王水剥離液の廃液のＡｕ濃度は８０ｍｇ／Ｌである。電気分解を開始してから数時間経過毎に処理液のＡｕ濃度を測定した結果を下記表３に示す。また、電解時間（ｈｒ）に対する処理液のＡｕ濃度（ｍｇ／Ｌ）の変化を図３に■で示す。
【０１３２】
下記表３から明らかなように、電気分解を６時間行った時点で、処理液のＡｕ濃度は３ｍｇ／Ｌまで低下した。６時間経過する間、円筒状回転陰極４に電着したＡｕが剥離した様子は認められなかった。
【０１３３】
（実験例１５）
上記実験例１４において、円筒状回転陰極４として表面にチタン製網を設けていない直径１６０ｍｍ、長さ２００ｍｍの円筒状回転陰極４を用いた点以外は、上記実験例１４と同じ条件で処理液を電気分解した。電気分解を開始してから数時間経過毎に処理液のＡｕ濃度を測定した結果を下記表３に示す。また、電解時間（ｈｒ）に対する処理液のＡｕ濃度（ｍｇ／Ｌ）の変化を図３に◆で示す。
【０１３４】
下記表３から明らかなように、電気分解を１２時間行った時点で、処理液のＡｕ濃度は１０ｍｇ／Ｌまで低下したが、その後、円筒状回転陰極４に電着したＡｕが剥離して再溶解が起きたため、Ａｕ濃度の上昇が認められた。
【０１３５】
なお、円筒状回転陰極４から剥離したＡｕは、しばらくすると王水に溶解してしまうため、剥離したＡｕ量は測定できなかった。
【０１３６】
（実験例１６）
上記実験例１４において、円筒状回転陰極４の表面にチタン製網を巻き付ける際に、チタン製網と円筒状回転陰極の上部複数ヶ所を導線でつなぎ、チタン製網が円筒状回転陰極４の表面に密着しないように、スペーサーを入れて１ｍｍ程度の隙間をあけてから２重となるように巻き付けた円筒状回転陰極４を用いた点以外は、上記実験例１４と同じ条件で処理液を電気分解した。電気分解を開始してから数時間経過毎に処理液のＡｕ濃度を測定した結果を下記表３に示す。また、電解時間（ｈｒ）に対する処理液のＡｕ濃度（ｍｇ／Ｌ）の変化を図３に▲で示す。
【０１３７】
下記表３から明らかなように、電気分解を３時間行った時点で、円筒状回転陰極４に電着したＡｕが剥離して再溶解が起きた。処理液のＡｕ濃度は、２０ｍｇ／Ｌ前後で推移し、Ａｕ濃度はこれ以上低下しなかった。
【０１３８】
なお、円筒状回転陰極４から剥離したＡｕは、しばらくすると王水に溶解してしまうため、剥離したＡｕ量は測定できなかった。
【０１３９】
実験例１４〜１６の結果をプロットした図３から明らかなように、処理液としてＡｕ含有王水剥離液の廃液を用いた場合であっても、チタン製網を表面に着接させた円筒状回転陰極４を用いることで（図３の■）、電解時間を短くすることができ、Ａｕの回収効率が高くなることが分かる。また、チタン製網を表面に着接させた円筒状回転陰極４を用いることで（図３の■）、処理液のＡｕ濃度を３ｍｇ／Ｌまで低下させることができている。
【０１４０】
【表３】

【０１４１】
（実験例１７）
実験例１７および後記する実験例１８では、Ｐｄ含有廃液からＰｄを回収したときの回収効率を調べた。
【０１４２】
上記実験例１において、処理液としてＰｄ含有廃液（Ｐｄ濃度は１１３ｍｇ／Ｌ、ｐＨ＝８）を用いた点と、電圧を７〜８Ｖとして電気分解を行った点以外は、上記実験例１と同じ条件で処理液を電気分解した。電気分解を開始してから数時間経過毎に処理液のＰｄ濃度を測定した結果を下記表４に示す。
【０１４３】
下記表４から明らかなように、電気分解を６時間行った時点で、処理液のＰｄ濃度は１ｍｇ／Ｌまで低下した。
【０１４４】
（実験例１８）
上記実験例１７において、円筒状回転陰極４として表面にチタン製網を設けていない直径１６０ｍｍ、長さ２００ｍｍの円筒状回転陰極４を用いた点以外は、上記実験例１７と同じ条件で処理液を電気分解した。電気分解を開始してから数時間経過毎に処理液のＰｄ濃度を測定した結果を下記表４に示す。
【０１４５】
下記表４から明らかなように、処理液のＰｄ濃度を１ｍｇ／Ｌにまで低下するには、２７時間必要であった。
【０１４６】
実験例１８の結果と上記実験例１７の結果を比べると、実験例１８の電解時間は約４．５倍に増加しているため、本発明によれば、円筒状回転陰極４の表面にチタン製網を設けて表面積を約３．９倍増加させるだけで、Ｐｄの回収効率を約４．５倍に向上できることがわかる。
【０１４７】
下記表４から明らかなように、Ｐｄ含有廃液からＰｄを回収する場合であっても、円筒状回転陰極４の表面にチタン製網を設けないときよりも、円筒状回転陰極４の表面にチタン製網を設けることによって、電解時間が著しく短くなり、Ｐｄの回収効率が高くなっていることが分かる。
【０１４８】
【表４】

【産業上の利用可能性】
【０１７７】
本発明によれば、貴金属含有溶液から貴金属を電気分解によって回収する際に用いられる装置であって、省スペース化・設備負荷の低減化を実現でき、しかも短時間で貴金属を回収できる回収効率に極めて優れた装置を提供できる。 【Technical field】
  [0001]
  The present inventionYouFrom a solution containing metal by electrolysisYouRecover metalYouThe present invention relates to a metal recovery apparatus.
[Background]
  [0002]
  Some waste liquids (for example, treatment liquids) discharged from factories contain metals such as Au, Ag, Cu, and platinum group elements. These metals are recovered from the waste liquid and recycled. Used. An electrolysis method is known as a method for recovering metal from waste liquid.
  [0003]
  As a metal recovery device using an electrolysis method, for example, in Patent Document 1, a cylindrical inner electrode is provided as a cathode, and an outer electrode is provided around the inner electrode as an anode, and the cathode is configured to be rotatable. In the vicinity of the surface of the cathode on which the metal is deposited, there has been proposed a collection device provided with a plastic collection plate in contact with or close to the metal deposited on the surface of the cathode. According to the method of Patent Document 1, it is described that metal deposited on the cathode surface is scraped off using a plastic recovery plate and deposited below the cathode without being attached to the electrode, and then the metal can be recovered.
  [0004]
  By the way, in order to recover metals from waste liquid industrially, it is desired to increase the recovery efficiency so that the metals can be recovered in as short a time as possible. However, the recovery apparatus disclosed in Patent Document 1 has a poor metal recovery efficiency and takes a long time to recover the metal. Moreover, in the said patent document 1, since the metal electrodeposited on the cathode surface was scraped off using a plastic recovery plate, and the metal was deposited under the cathode and collect | recovered, the collection | recovery apparatus was not able to save space. . Further, depending on the type of waste liquid, the metal deposited under the cathode may be redissolved in the waste liquid, and the metal cannot be sufficiently recovered from the waste liquid.
  [0005]
  As a method for improving the metal recovery efficiency, for example, Patent Document 2 and Patent Document 3 propose a method using a cathode disk.
  [0006]
  Patent Document 2 describes that electrolysis is performed while rotating a disk-shaped cathode, thereby improving the contact efficiency between the cathode and the electrolyte and improving the metal recovery efficiency. In addition, in Patent Document 3, in order to improve the metal recovery efficiency by efficiently stirring the solution in the electrolytic cell, an aspect including a rotation drive mechanism that rotates either the anode or the cathode, A mode in which stirring blades are provided on the anode or the cathode is described.
  [0007]
  However, when the cathode disk is used as in Patent Document 2, it is necessary to excessively increase the number of rotations of the cathode in order to increase the metal recovery efficiency, and there is a problem that the equipment load increases.
  [0008]
  On the other hand, although it is not a technique proposed to increase the metal recovery efficiency, Patent Document 4 includes a pipe-shaped anode and a cylindrical cathode, and is electrically connected to the cathode on the inner periphery of the cathode. There has been proposed a metal recovery device in which a net-like or lath-like cylinder is arranged.
  [0009]
  In the collection device of Patent Document 4, the net-like or lath-like cylinder disposed on the inner periphery of the cathode is formed by the electrodeposition metal and the anode when electrolysis proceeds and the metal electrodeposited on the cathode peels from the cathode. It is arranged to prevent the occurrence of short circuit due to contact. According to FIG. 1 of Patent Document 4, the net-like or lath-like cylinders are arranged with spaces (spaces) without being in close contact with the cathode. Further, a part of the metal electrodeposited on the cathode surface is peeled off from the cathode and deposited below the cathode.
  [0010]
Patent Document 1: Japanese Patent Application Laid-Open No. 61-104096
Patent Document 2: Japanese Patent Laid-Open No. 2006-70364
Patent Document 3: Japanese Patent Application Laid-Open No. 2005-314742
Patent Document 4: Japanese Patent Laid-Open No. 2006-28555
DISCLOSURE OF THE INVENTION
[Problems to be solved by the invention]
  [0011]
  The object of the present invention is from a metal-containing solution.YouThis equipment is used for recovering metals by electrolysis. It can save space and reduce equipment load in a short time.YouAn object of the present invention is to provide an apparatus with extremely high recovery efficiency that can recover metal.
[Means for Solving the Problems]
  [0012]
  According to the present invention, which can solve the above problemsYouWhat is a metal recovery device?YouElectrolyze a metal-containing solutionYouAn apparatus for recovering metal, the apparatus comprising: a columnar or cylindrical rotating cathode that rotates about an axis; and an anode disposed to face the rotating cathode;Titanium net with an average aperture of 0.5 to 3 mm and an average wire diameter of 0.3 to 0.5 mmAnd haveAndOf the rotating cathode facing the anodeFaceThe aboveTitanium meshThe point is that it is covered with.
  [0013]
  Of the present inventionYouIn the metal recovery apparatus, for example, a noble metal can be recovered from a noble metal-containing aqueous solution.
【Effect of the invention】
  [0016]
  According to the present invention, the rotating cathode facing the anodeFace,Titanium net with an average aperture of 0.5 to 3 mm and an average wire diameter of 0.3 to 0.5 mmIt is covered closely withRutaBy adopting a rotating cathodeYouIn addition to the effect of improving the metal recovery efficiency, the following effects are remarkably exhibited.
(1) The surface area of the cathode increases,YouMetal recovery efficiency is dramatically improved.
(2) At the cathodeYouBecause the electrodeposition of metal is improved, it was once deposited on the cathode.YouMetal peeling can be prevented. Therefore, it peeled off from the cathodeYouIt is no longer necessary to provide a special mechanism for collecting metal, and space can be saved in the collection device..
[Brief description of the drawings]
  [0017]
    FIG. 1 shows the first embodiment.YouIt is a schematic explanatory drawing which shows the cross section of a metal collection | recovery apparatus.
    FIG. 2 is a graph showing a change in Au concentration (mg / L) of a treatment solution with respect to electrolysis time (hr).
    FIG. 3 is a graph showing a change in Au concentration (mg / L) of a processing solution with respect to electrolysis time (hr)..
[Explanation of symbols]
  [0018]
1 Electrolysis tank
2 Anode
3 Rotating shaft
4 Cylindrical rotating cathode
5 Motor
6 Circulation tank
7 Pump
8HMade of tonguenetwork
BEST MODE FOR CARRYING OUT THE INVENTION
  [0019]
  The present inventors can realize space saving of the apparatus and reduction of equipment load, andYouWe have intensively studied to provide a recovery device with excellent metal recovery efficiency. As a result, in order to increase the surface area of the rotating cathode, the rotating cathode facing the anodeOn the face,Titanium net with an average aperture of 0.5 to 3 mm and an average wire diameter of 0.3 to 0.5 mmCoveredOverthrowThe electrode is electrodeposited on the rotating cathode.YouThe electrodeposition of the metal was improved, and once electrodeposited on the rotating cathodeYouThe ability to effectively prevent metal stripping,YouThe inventors have found that the metal recovery efficiency is remarkably improved and completed the present invention.
  [0020]
  Hereinafter, for convenience of explanation, it faces the anode.On the face,Titanium net with an average aperture of 0.5 to 3 mm and an average wire diameter of 0.3 to 0.5 mmA recovery device using a rotating cathode coated with “a first embodiment”"WhenSometimes called.
  [0021]
  First embodimentIsThe surface area of the rotating cathode is preferably increased to 3.0 times or more.YouIncreases metal recovery efficiencyTheAlso, YuiAs a result, irregularities occur on the surface of the rotating cathode,YouImproves metal electrodeposition and peel resistanceThe FirstIn one embodiment, the rotating cathodeTitanium mesh"External means" to coating.However, the recovery device of the present inventionthe aboveThe present invention is not limited to the embodiment, and it is of course possible to change the design without departing from the spirit of the present invention.
  [0022]
  First embodiment
  According to this embodimentYouThe metal recovery apparatus includes a columnar or cylindrical rotating cathode that rotates about an axis, an anode disposed to face the rotating cathode,Titanium net with an average aperture of 0.5 to 3 mm and an average wire diameter of 0.3 to 0.5 mmAnd the rotating cathode facing the anodeFaceThe aboveTitanium meshIt is covered with.
  [0023]
  First, the most characteristic feature of this embodiment is “Titanium meshWill be described. Used in this embodimentTitanium meshThe shape of the net (including the grid))soAhRu. The net-like or grid-like form is not particularly limited, and may be a form in which the wires extending in the vertical direction and the horizontal direction intersect, or a form in which the wires extending in the oblique direction with respect to the vertical direction intersect. There may be. The interval between the net-like or lattice-like openings is not particularly limited,Titanium meshMay be configured so that one direction is dense and the other is sparse, and the shape of the opening is rectangular, or the shape of the mesh or lattice-shaped opening is rhombus or You may comprise so that it may become a square. Also, DKispandemetaLeA shape is also used.
  [0024]
  Also,"Titanium meshHave conductivity to the extent that electrolysis is possible, andYouIt must be insoluble so that it does not dissolve in the metal-containing solution (ie, electrolyte) and does not elute during electrolysis..
  [0025]
  the above"Titanium mesh”Is a rotating shadeThe poleThe coated rotating cathode surface is arranged so as to face the anode. aboveTitanium meshThere is no space in the part where the rotating cathode contacts the space as in Patent Document 4 described above. Thus, the rotating cathode surface facing the anodeTitanium mesh surfaceAs a result, the surface of the rotating cathode is uneven, and the surface of the unevenness isYouMetals were electrodeposited and agglomerated together, electrodepositedYouBecause it becomes difficult for the metal to peel from the surface of the rotating cathode,YouThe electrodeposition property of the metal is remarkably improved. Moreover, since the surface area of the rotating cathode is increased by adopting the above configuration, the electrolysis efficiency is improved,YouMetal recovery efficiency is increased.
  [0027]
  the aboveTitanium meshThe average opening is 0.5-3mm,Average wire diameter is 0.3-0.5mmTheThe average isTitanium meshThis is a value obtained by measuring the openings and wire diameters at a plurality of locations and averaging them.
  [0028]
  Titanium meshIf the average opening is less than 0.5 mm, the eyes are clogged too much, and if the average opening exceeds 3 mm, the eyes are too rough, so that the stirring effect of the treatment liquid is reduced, or the area of the rotating cathode Increase the electrolysis efficiencyYouIt is difficult to improve the metal recovery efficiency.
  [0029]
  Titanium meshIf the average wire diameter of the wire constituting the wire is less than 0.3 mm, the wire diameter is too small, and if the average wire diameter exceeds 0.5 mm, the wire diameter is too large, so that the stirring effect of the treatment liquid is reduced, The area of the rotating cathode cannot be increased and the electrolytic efficiency is increased.YouIt is difficult to improve the metal recovery efficiency.
  [0032]
  the aboveTitanium meshIs preferably attached to the surface of the rotating cathode so as to be two to four layers.Titanium meshBy making the number of turns of the double winding or more, the area of the rotating cathode can be sufficiently increased,YouMetal recovery efficiency can be further increased. However,Titanium meshEven if you wrap more than 4 layers,Titanium meshThe effect of dressing is saturatedYouBecause the metal recovery efficiency hardly changes,Titanium meshThe number of windings is preferably quadruple or less.
  [0033]
  Titanium meshThe method of coating the surface of the rotating cathode is not particularly defined.Titanium meshSpot welding at equal intervals and the surface of the rotating cathodeTitanium meshWhat is necessary is just to fix so that a clearance gap does not leave between.
  [0041]
  First embodiment aboveStateThe surface area of the rotating cathode used isTitanium meshCovered bypreviousThe surface area of the rotating cathode is preferably about 3.0 times or more. More preferably, it is 3.3 times or more, and further preferably 3.5 times or more. The surface area of the rotating cathode is preferably as large as possible,Titanium meshIf you wind too much, the rotating cathode becomes too heavy and the rotation is overloaded.RutaTherefore, even if many estimates are made, the upper limit is about 10 times. More preferably, it is 8 times or less, More preferably, it is 6 times or less.
  [0042]
  First embodiment aboveStateThe rotating cathode used is a columnar or cylindrical rotating cathode that rotates about an axis. By using such a rotating cathode, the electrolytic efficiency is improved.YouMetal recovery efficiency is further enhanced. In the present invention, compared with the case where the disk-shaped rotating cathode as in Patent Document 2 and Patent Document 3 is used, the electrolytic solution can be sufficiently stirred at a lower number of revolutions, so that the equipment load can be reduced.
  [0043]
  Here, “columnar” means a solid body or a shape that internally holds a space that does not communicate with the outside, and “tubular” refers to a hollow body that internally possesses a space that communicates with the outside. Means. In the present invention, any aspect is preferably used. The rotating cathode used in the present invention is typically substantially columnar or cylindrical. The cross-sectional shape of the rotating cathode is not limited to a circle, and may be, for example, a “polygonal” form extremely close to a circle. However, if the cross-sectional shape of the rotating cathode is a rectangle (for example, a square), the resistance received from the solution when the cathode is rotated increases, so a load is applied to the power of a motor or the like provided to rotate the cathode. Since it may take too much or the electrolytic solution may scatter, it may be selected appropriately in consideration of equipment load.
  [0044]
  The material of the rotating cathode is conductive enough to be electrolyzed, andYouWhat is necessary is just to be insoluble which does not melt | dissolve in a metal containing solution (namely, electrolyte solution) and does not elute also at the time of electrolysis. Specifically, for example, titanium or stainless steel, or a collection targetYouMetal itself etc. are mentioned.
  [0045]
  The rotating cathode and the anode can be arranged as follows.
  [0046]
  First, when a columnar rotating cathode is used, the anode is disposed outside (outer periphery) of the columnar rotating cathode. The shape of the anode disposed around the columnar rotating cathode is not particularly limited,YouThose usually used for metal recovery devices can be employed. Accordingly, either a plate-like or cylindrical anode can be used. Specifically, a plate-like or cylindrical anode may be disposed so as to surround the periphery (outer periphery) of the columnar rotating cathode. When using a plate-like anode,Titanium meshThe plate-like anode is disposed so as to face the surface of the columnar rotating cathode coated with or the surface of the columnar rotating cathode provided with unevenness. A plurality of such plate-like anodes may be arranged so as to surround the periphery of the columnar rotary cathode.
  [0047]
  On the other hand, when a cylindrical rotating cathode is used, the anode may be disposed outside the cylindrical rotating cathode or may be disposed inside the cylindrical rotating cathode.
  [0048]
  The shape and arrangement method of the anode arranged around (outside / inside) the cylindrical rotating cathode is substantially the same as when the above-described columnar rotating cathode is used.
  [0049]
  In addition, when arrange | positioning an anode inside a cylindrical cathode, in 1st embodiment, it mentioned above.Titanium meshMay be provided on at least the inner surface of the cylindrical rotating cathode, and may be provided on the outer surface of the cylindrical rotating cathode as necessary.. MaThe anode may be arranged near the central axis of the cylindrical rotating cathode, or may be arranged avoiding the vicinity of the central axis of the cylindrical rotating cathode.
  [0050]
  In the present invention, a rotary cathode is used in which a columnar or cylindrical cathode is configured to be rotatable around the axis of the cathode. By performing electrolysis while rotating the cathode, the solution (electrolytic solution) in the electrolytic cell is stirred, so that the contact between the solution and the cathode is effectively performed,YouImproved metal recovery efficiency in a short timeYouMetal can be recovered.
  [0051]
  The rotating cathode can be connected to power such as a motor installed in the apparatus and rotated. The peripheral speed (rotational speed) of the rotating cathode is the size of the electrolytic cell to be used, the amount of solution supplied to the electrolytic cell, or the collection target.YouIt is difficult to define unambiguously because it varies depending on the type of metal.,In general, it is preferable to control the peripheral speed within a range of 0.5 to 1.8 m / sec.
  [0052]
  This is because if the peripheral speed of the cathode is less than 0.5 m / sec, the treatment liquid in the electrolytic cell is not stirred and the treatment liquid stays in the vicinity of the surface of the rotating cathode, and it is difficult to increase the electrolysis efficiency. Therefore, the peripheral speed of the cathode is preferably 0.5 m / sec or more. More preferably, it is 0.7 m / sec or more.
  [0053]
  However, if the peripheral speed of the cathode exceeds 1.8 m / sec, bubbling occurs in the treatment liquid, the electrolysis reaction at the rotating cathode is inhibited, and the electrolysis efficiency is lowered. Further, if the peripheral speed of the cathode is increased too much, the processing solution will be rippled and the processing solution will overflow from the electrolytic cell, resulting in poor safety. Therefore, the peripheral speed of the cathode is preferably 1.8 m / sec or less. More preferably, it is 1.6 m / sec or less, More preferably, it is 1.5 m / sec or less.
  [0054]
  It can be recovered by applying the device of the present invention.RukiExamples of the metal element include Au, Ag, or platinum group elements (Pd, Pt, Ir, Ru, and Rh). In particular, if the recovery device of the present invention is used, an expensive noble metal element such as Au can be recovered in a shorter time and at a lower cost than conventional ones. Therefore, the recovery device of the present invention is a precious metal recovery device from a solution. As extremely useful.
  [0055]
  Used in the present inventionYouThe metal-containing solution isYouAs long as it contains a metal, representative examples thereof include plating waste liquid, photographic development waste liquid, liquid obtained by washing a plated product, and stripping liquid waste liquid.
  [0056]
  Using the above recovery deviceYouElectrolysis conditions for electrolyzing the metal-containing solution are not particularly limited. For example, the voltage may be 1 to 10 V and the current may be about 10 to 25 A.
  [0057]
  ElectrolyzedYouFrom metal-containing solutionsYouAfter electrodepositing the metal on the cathode surface, the cathode is taken out from the recovery device, and this cathode is targeted for recovery.YouImmerse it in a solution in which the metal dissolvesYouWhat is necessary is just to elute and collect | recover metals.
  [0058]
  Next, the present inventionYouThe metal recovery apparatus will be described more specifically with reference to the drawings.
  [0059]
  FIG. 1 shows a first embodiment according to the present invention.YouIt is sectional drawing of a metal collection | recovery apparatus. On the surfaceTitanium mesh8 is a cross-sectional view of a recovery device in which a cylindrical rotating cathode 4 coated so that 8 is in close contact is used, and an anode 2 is disposed so as to surround the outer side of the rotating cathode 4. FIG. In FIG. 1, 1 is an electrolytic cell, 3 is a rotating shaft, 5 is a motor, 6 is a circulation tank, and 7 is a pump. As shown in FIG.YouThe metal recovery apparatus is an embodiment showing an example of the present invention, and is not intended to be limited to this.
  [0060]
  As shown in FIG.YouThe metal recovery apparatus includes a cylindrical rotating cathode 4 that rotates about an axis, and four plate-like anodes 2 that are disposed so as to face the cylindrical rotating cathode 4.TheMade of tongueNet 8And have. At least a part of the surface of the rotating cathode 4 facing the plate-like anode 2 is covered with a titanium mesh 8. Experimental examples 1 to be described later18Then, it experimented using this collection | recovery apparatus.
【Example】
  [0067]
  Hereinafter, the present invention will be described in more detail with reference to experimental examples, but the following experimental examples are not intended to limit the present invention, and may be implemented with appropriate modifications within a range that can meet the purpose described above and below. These are all possible and are within the scope of the present invention.
  [0068]
  (Experimental example 1)
  Experimental Example 1 and Experimental Examples 2 to 10 described later were performed in order to examine the recovery efficiency when Au was recovered from the Au-containing cyan plating product washing water.
  [0069]
  In Experimental Example 1, it is shown in FIG.YouUsing a metal recovery device, Au was recovered as follows.
  [0070]
  A cylindrical rotating cathode 4 is attached to a rotating shaft 3 disposed at the center of the electrolytic cell 1 (capacity is 10 L). The cylindrical rotating cathode 4 operates the motor 5 to operate the rotating shaft 3. It can be rotated in the circumferential direction as the center.
  [0071]
  The cylindrical rotating cathode 4 is made of titanium and has a cylindrical shape with a diameter of 160 mm and a length of 200 mm.Titanium mesh8, a titanium net having an average opening of 1 mm and an average wire diameter of 0.3 mm (20 mesh) is wound twice. The titanium mesh is attached by spot welding so as to be in close contact with the surface of the cylindrical rotating cathode 4.
  [0072]
  When the surface area is calculated without considering the portion where the cylindrical rotating cathode 4 and the titanium mesh contact, the surface area when the titanium mesh is attached to the surface of the cylindrical rotating cathode 4 is titanium. The surface area of the cylindrical rotating cathode 4 not attached to the net increased by about 3.9 times.
  [0073]
  The inner wall surface of the electrolytic cell 1 is provided with a total of four plate-like insoluble anodes (100 mm × 250 mm) on each wall surface.
  [0074]
  The electrolytic bath 1 is filled with 30 L of an Au-containing cyan plating product washing water having an Au concentration of 97 mg / L as the treatment liquid, and the treatment liquid overflowing from the electrolytic tank 1 is stored in the circulation tank 6. The pump 7 was supplied from the circulation tank 6 to the vicinity of the bottom of the electrolytic cell 1 and circulated in the electrolytic cell 1.
  [0075]
  The amount of liquid circulating in the electrolytic cell 1 was 10 L / min, the voltage was 4 to 6 V, the current was 12 A, and the peripheral speed of the cylindrical rotating cathode 4 was 1.0 m / sec (rotation speed 120 rpm). .
  [0076]
  Table 1 shows the results of measuring the Au concentration of the treatment liquid every several hours after the start of electrolysis. Further, the change in Au concentration (mg / L) of the treatment liquid with respect to the electrolysis time (hr) is shown by ▪ in FIG.
  [0077]
  As is apparent from Table 1 below, when the electrolysis was performed for 3 hours, the Au concentration of the treatment liquid decreased to 1 mg / L, and the Au in the treatment liquid was electrodeposited on the surface of the cylindrical rotating cathode 4.
  [0078]
  (Experimental example 2)
  In Experimental Example 2, the influence of the titanium mesh on Au recovery efficiency was examined. Specifically, in Example 1 above, except that the cylindrical rotating cathode 4 having a diameter of 160 mm and a length of 200 mm in which the surface of the cylindrical rotating cathode 4 is not provided with a titanium mesh is used, The treatment solution was electrolyzed under the same conditions. Table 1 shows the results of measuring the Au concentration of the treatment liquid every several hours after the start of electrolysis. Further, the change in Au concentration (mg / L) of the treatment liquid with respect to the electrolysis time (hr) is shown by ♦ in FIG.
  [0079]
  As apparent from Table 1 below, it took 15 hours to reduce the Au concentration of the treatment liquid to 1 mg / L.
  [0080]
  Comparing the results of Experimental Example 2 with the results of Experimental Example 1, the result of Experimental Example 2 shows that the time required to reduce the Au concentration of the treatment liquid to 1 mg / L is about five times. Therefore, it can be seen that the recovery efficiency of Au can be improved by about 5 times only by providing a titanium mesh on the surface of the cylindrical rotating cathode 4 to increase the surface area by about 3.9 times.
  [0081]
  (Experimental example 3)
  In Experimental Example 3, the influence of the peripheral speed of the rotating cathode on the Au recovery efficiency was examined.
  [0082]
  In Experimental Example 2, the treatment liquid was electrolyzed under the same conditions as in Experimental Example 2 except that the peripheral speed of the cylindrical rotating cathode 4 was increased to 2.0 m / sec (rotational speed 240 rpm). Table 1 shows the results of measuring the Au concentration of the treatment liquid every several hours after the start of electrolysis. Further, the change in Au concentration (mg / L) of the treatment liquid with respect to the electrolysis time (hr) is shown by ▲ in FIG.
  [0083]
  As apparent from Table 1 below, it took 12 hours to reduce the Au concentration of the treatment liquid to 1 mg / L.
  [0084]
  Comparing the results of Experimental Example 3 with the results of Experimental Example 2 above, even if the peripheral speed of the cylindrical rotating cathode 4 is doubled, the electrolysis time can be shortened by 3 hours, and the Au recovery efficiency is only about 20%. It did not improve.
  [0085]
  The peripheral speed of the cylindrical rotating cathode 4 is limited to about 2.0 m / sec (rotation speed 240 rpm). If the peripheral speed is increased beyond this, the spilling of the treatment liquid increases, and safe operation cannot be performed.
  [0086]
  As can be seen from FIG. 2, by providing a titanium mesh on the surface of the cylindrical rotating cathode 4 rather than providing a titanium mesh on the surface of the cylindrical rotating cathode 4 (♦ and ▲ in FIG. 2). (■ in FIG. 2), it can be seen that the electrolysis time is remarkably shortened, and the Au recovery efficiency is remarkably improved.
  [0087]
  (Experimental example 4)
  Experimental Example 4 and Experimental Example 5 described later are other experiments in which the influence of the peripheral speed of the rotating cathode on the Au recovery efficiency was examined.
  [0088]
  In the above experimental example 1, the treatment liquid was electrolyzed under the same conditions as in the above experimental example 1 except that the peripheral speed of the cylindrical rotating cathode 4 was reduced to 1/3, 0.3 m / sec (rotation speed 40 rpm). . Table 1 shows the results of measuring the Au concentration of the treatment liquid every several hours after the start of electrolysis.
  [0089]
  As apparent from Table 1 below, it took 6 hours to reduce the Au concentration of the treatment liquid to 1 mg / L.
  [0090]
  Comparing the results of Experimental Example 4 with the results of Experimental Example 1, it was found that if the peripheral speed of the cylindrical rotating cathode 4 is made too small, the electrolysis time becomes longer and the Au recovery efficiency cannot be improved much. . The reason why the recovery efficiency cannot be improved is thought to be due to insufficient stirring of the treatment liquid, and it is considered that the electrolysis reaction has become difficult to proceed.
  [0091]
  (Experimental example 5)
  In Experimental Example 1, the treatment liquid was electrolyzed under the same conditions as in Experimental Example 1 except that the peripheral speed of the cylindrical rotating cathode 4 was increased to 2.0 m / sec (rotational speed 240 rpm). Table 1 shows the results of measuring the Au concentration of the treatment liquid every several hours after the start of electrolysis.
  [0092]
  As apparent from Table 1 below, it took 5 hours to reduce the Au concentration of the treatment liquid to 1 mg / L.
  [0093]
  Comparing the result of Experimental Example 5 with the result of Experimental Example 1, the result of Experimental Example 5 shows that the time required to reduce the Au concentration of the treatment liquid to 1 mg / L is about 1.7 times, and is cylindrical. It has been found that when the peripheral speed of the rotating cathode 4 is too high, the Au recovery efficiency deteriorates. The reason why Au recovery efficiency deteriorated is that the peripheral speed is too high, the bubbling of the processing liquid occurs, and the contact area between the cylindrical rotating cathode 4 and the processing liquid decreases due to the generated bubbles, resulting in an electrolysis reaction. This is thought to be because it became difficult to proceed.
  [0094]
  As is clear from Table 1 below, the Au recovery time becomes longer than the result of Experimental Example 1 and the Au recovery efficiency, regardless of whether the peripheral speed of the cylindrical rotating cathode 4 is too small or too high. It turns out that there is not much improvement.
  [0095]
  (Experimental example 6)
  Experimental Example 6 and Experimental Examples 7 and 8 to be described later are experiments in which the influence of the titanium mesh opening and wire diameter on Au recovery efficiency was examined.
  [0096]
  In Experimental Example 1, the treatment solution was electrolyzed under the same conditions as in Experimental Example 1 except that a mesh having an average opening of 5 mm and an average wire diameter of 1 mm (4 mesh) was used as the titanium mesh. When the surface area is calculated without considering the portion where the cylindrical rotating cathode 4 and the titanium mesh contact, the surface area when the titanium mesh is attached to the surface of the cylindrical rotating cathode 4 is titanium. The increase was about 3.1 times the surface area of the cylindrical rotating cathode 4 not attached to the net.
  [0097]
  Table 1 shows the results of measuring the Au concentration of the treatment liquid every several hours after the start of electrolysis.
  [0098]
  As apparent from Table 1 below, it took 6 hours to reduce the Au concentration of the treatment liquid to 1 mg / L.
  [0099]
  Comparing the results of Experimental Example 6 with the results of Experimental Example 1 described above, it was found that when a mesh with too coarse mesh was used as the titanium mesh, it took time to recover Au and the recovery efficiency of Au was not improved much. It was.
  [0100]
  (Experimental example 7)
  In Experimental Example 1, the treatment liquid was electrolyzed under the same conditions as in Experimental Example 1 except that a mesh having an average opening of 2 mm and an average wire diameter of 0.5 mm (10 mesh) was used as the titanium mesh. did. When the surface area is calculated without considering the portion where the cylindrical rotating cathode 4 and the titanium mesh contact, the surface area when the titanium mesh is attached to the surface of the cylindrical rotating cathode 4 is titanium. The increase was about 3.5 times the surface area of the cylindrical rotating cathode 4 that was not attached to the net.
  [0101]
  Table 1 shows the results of measuring the Au concentration of the treatment liquid every several hours after the start of electrolysis.
  [0102]
  As is apparent from Table 1 below, when the electrolysis was performed for 4 hours, the Au concentration of the treatment liquid decreased to less than 1 mg / L.
  [0103]
  Comparing the results of Experimental Example 7 with the results of Experimental Example 1 above, the time required for the Au concentration of the processing solution to reach about 1 mg / L is almost the same regardless of whether the titanium mesh is 10 mesh or 20 mesh. The efficiency was almost the same.
  [0104]
  (Experimental example 8)
  In Experimental Example 1, the treatment liquid was used under the same conditions as in Experimental Example 1 except that a mesh having an average aperture of 0.3 mm and an average wire diameter of 0.1 mm (60 mesh) was used as the titanium mesh. Electrolyzed. When the surface area is calculated without considering the portion where the cylindrical rotating cathode 4 and the titanium mesh contact, the surface area when the titanium mesh is attached to the surface of the cylindrical rotating cathode 4 is titanium. The increase was about 4.1 times the surface area of the cylindrical rotating cathode 4 not attached to the net.
  [0105]
  Table 1 shows the results of measuring the Au concentration of the treatment liquid every several hours after the start of electrolysis.
  [0106]
  As apparent from Table 1 below, it took 5 hours to reduce the Au concentration of the treatment liquid to 1 mg / L.
  [0107]
  Comparing the results of Experimental Example 8 with the results of Experimental Example 1, it was found that even when a mesh with too fine mesh was used as the titanium mesh, the electrolysis time could not be shortened much and the Au recovery efficiency could not be improved.
  [0108]
  As apparent from Table 1 below, even if the mesh of the titanium mesh is too coarse or too fine, it takes longer to recover Au than the results of Experimental Example 1 and Experimental Example 7, It can be seen that the recovery efficiency of Au has not been improved.
  [0109]
  (Experimental example 9)
  Experimental Example 9 and Experimental Example 10 described later are experiments in which the influence of the number of turns of the titanium net on the Au recovery efficiency was examined.
  [0110]
  In Experimental Example 1, the treatment solution was electrolyzed under the same conditions as in Experimental Example 1 except that the number of turns of the titanium mesh wound around the surface of the cylindrical rotating cathode 4 was single. When the surface area is calculated without considering the portion where the cylindrical rotating cathode 4 and the titanium mesh contact, the surface area when the titanium mesh is attached to the surface of the cylindrical rotating cathode 4 is titanium. The increase was about 2.4 times the surface area of the cylindrical rotating cathode 4 not attached to the net.
  [0111]
  Table 1 shows the results of measuring the Au concentration of the treatment liquid every several hours after the start of electrolysis.
  [0112]
  As apparent from Table 1 below, it took 5 hours to reduce the Au concentration of the treatment liquid to 1 mg / L.
  [0113]
  Comparing the results of Experimental Example 9 with the results of Experimental Example 1 described above, if the number of turns of the titanium mesh wound around the surface of the cylindrical rotating cathode 4 is excessively reduced, it is difficult to sufficiently obtain the effect of winding the titanium mesh. Recognize.
  [0114]
  (Experimental example 10)
  In Experimental Example 1, the treatment solution was electrolyzed under the same conditions as in Experimental Example 1 except that the number of turns of the titanium mesh wound around the surface of the cylindrical rotating cathode 4 was quadrupled. When the surface area is calculated without considering the portion where the cylindrical rotating cathode 4 and the titanium mesh contact, the surface area when the titanium mesh is attached to the surface of the cylindrical rotating cathode 4 is titanium. The increase was about 6.8 times the surface area of the cylindrical rotating cathode 4 not attached to the net.
  [0115]
  Table 1 shows the results of measuring the Au concentration of the treatment liquid every several hours after the start of electrolysis.
  [0116]
  As is clear from Table 1 below, when the electrolysis was performed for 3 hours, the Au concentration of the treatment liquid decreased to 1 mg / L.
  [0117]
  Comparing the results of Experimental Example 10 with the results of Experimental Example 1 shows that the effect of winding the titanium mesh is saturated even if the number of turns of the titanium mesh wound around the surface of the cylindrical rotating cathode 4 is increased excessively.
  [0118]
  As is clear from Table 1 below, if the number of turns of the titanium mesh is reduced too much, the electrolysis time becomes longer than the results of Experimental Example 1 and Experimental Example 10, and it is difficult to improve the Au recovery efficiency. I understand that.
  [0119]
    [Table 1]

  [0120]
  (Experimental example 11)
  In Experimental Example 11 and Experimental Examples 12 and 13 to be described later, the influence of the titanium net when the Au recovery process was repeatedly performed was examined.
  [0121]
  In the above experimental example 1, an Au-containing cyan plating product washing water 30L is shown in FIG.YouAfter filling the metal recovery device and electrolyzing until the Au concentration of the waste liquid reaches 1 mg / L, a new Au-containing cyan-based plating product washing water 30 L without recovering the electrodeposited Au on the cylindrical rotating cathode 4 The process of filling was repeated 30 times. The Au concentration of the Au-containing cyan plating product washing water is 97 mg / L. The amount of Au deposited on the bottom of the electrolytic cell 1 after the electrodeposited Au on the cylindrical rotating cathode 4 was measured. The measurement results are shown in Table 2 below.
  [0122]
  In addition, 900 L was used in total as the Au-containing cyan plating product washing water. The total amount of Au contained in the waste liquid was 87.3 g.
  [0123]
  As is clear from Table 2 below, after 30 times of electrolysis, the amount of Au electrodeposited on the cylindrical rotating cathode 4 is 86.1 g, and the amount of Au deposited on the bottom of the electrolytic cell is It was 0.3 g. Therefore, the rate of Au peeled from the cylindrical rotating cathode 4 was 0.3%.
  [0124]
  (Experimental example 12)
  In the experimental example 11, the treatment liquid was used under the same conditions as in the experimental example 11 except that the cylindrical rotating cathode 4 having a diameter of 160 mm and a length of 200 mm without a titanium mesh on the surface was used as the cylindrical rotating cathode 4. Was electrolyzed.
  [0125]
  As is clear from Table 2 below, after 30 times of electrolysis, the amount of Au electrodeposited on the cylindrical rotating cathode 4 is 81.3 g, and the amount of Au deposited on the bottom of the electrolytic cell is It was 5.1 g. Therefore, the Au ratio peeled from the cylindrical rotating cathode 4 was 5.8%.
  [0126]
  (Experimental example 13)
  In the experimental example 11, when the titanium mesh is wound around the surface of the cylindrical rotating cathode 4, the titanium mesh and the upper portion of the cylindrical rotating cathode are connected by a conductive wire, and the titanium mesh is the surface of the cylindrical rotating cathode 4 In order to prevent the treatment liquid from being discharged under the same conditions as in Experimental Example 11, except that a cylindrical rotating cathode 4 wound with a spacer and a gap of about 1 mm was wound to be doubled. Disassembled.
  [0127]
  As is apparent from Table 2 below, the amount of Au electrodeposited on the cylindrical rotating cathode 4 after 30 times of electrolysis was 85.0 g, and the amount of Au deposited on the bottom of the electrolytic cell was It was 1.4 g. Therefore, the rate of Au peeled from the cylindrical rotating cathode 4 was 1.6%.
  [0128]
  Comparing the results of the above experimental examples 11 to 13, the electrodeposition on the cylindrical rotating cathode 4 can be improved by attaching a titanium mesh to the surface of the cylindrical rotating cathode 4. It can be seen that Au can be recovered from the surface of 4 without peeling off. Therefore, it peeled off from the surface of the cylindrical rotating cathode 4YouThere is no need to provide a special mechanism for recovering the metal, and the space for the recovery device can be saved.
  [0129]
    [Table 2]

  [0130]
  (Experimental example 14)
  Experimental Example 14 and Experimental Examples 15 and 16 to be described later are experiments in which the recovery efficiency when Au was recovered from the waste liquid of the Au-containing aqua repellent liquid was investigated.
  [0131]
  In Example 1 above, except that the waste liquid of Au-containing aqua repellent liquid was used as the treatment liquid, and electrolysis was performed with a voltage of 1.0 to 2.0 V and a current of 20 A, the above Example 1 The treatment liquid was electrolyzed under the same conditions. The Au concentration in the waste liquid of the Au-containing aqua repellent liquid is 80 mg / L. Table 3 below shows the results of measuring the Au concentration of the treatment liquid every several hours after the start of electrolysis. Further, the change in Au concentration (mg / L) of the treatment liquid with respect to the electrolysis time (hr) is shown by ■ in FIG.
  [0132]
  As is clear from Table 3 below, when the electrolysis was performed for 6 hours, the Au concentration of the treatment liquid decreased to 3 mg / L. During the lapse of 6 hours, it was not observed that Au electrodeposited on the cylindrical rotating cathode 4 was peeled off.
  [0133]
  (Experimental example 15)
  In the experimental example 14, the treatment liquid was used under the same conditions as in the experimental example 14 except that the cylindrical rotating cathode 4 having a diameter of 160 mm and a length of 200 mm without a titanium mesh on the surface was used as the cylindrical rotating cathode 4. Was electrolyzed. Table 3 below shows the results of measuring the Au concentration of the treatment liquid every several hours after the start of electrolysis. Further, the change in Au concentration (mg / L) of the treatment liquid with respect to the electrolysis time (hr) is shown by ♦ in FIG.
  [0134]
  As is apparent from Table 3 below, when the electrolysis was performed for 12 hours, the Au concentration of the treatment liquid decreased to 10 mg / L. Thereafter, the electrodeposited Au on the cylindrical rotating cathode 4 was peeled off and re-applied. Since dissolution occurred, an increase in Au concentration was observed.
  [0135]
  In addition, since Au peeled from the cylindrical rotating cathode 4 was dissolved in aqua regia after a while, the amount of peeled Au could not be measured.
  [0136]
  (Experimental example 16)
  In the experimental example 14, when the titanium mesh is wound around the surface of the cylindrical rotating cathode 4, the titanium mesh and the upper part of the cylindrical rotating cathode are connected by a conductive wire, and the titanium mesh is the surface of the cylindrical rotating cathode 4 In order to prevent the treatment liquid from being discharged under the same conditions as in Experimental Example 14, except that the cylindrical rotating cathode 4 wound with a spacer and a gap of about 1 mm was wound twice. Disassembled. Table 3 below shows the results of measuring the Au concentration of the treatment liquid every several hours after the start of electrolysis. Further, the change in Au concentration (mg / L) of the treatment liquid with respect to the electrolysis time (hr) is shown by ▲ in FIG.
  [0137]
  As is apparent from Table 3 below, when the electrolysis was performed for 3 hours, Au electrodeposited on the cylindrical rotating cathode 4 was peeled off and redissolved. The Au concentration of the treatment liquid changed around 20 mg / L, and the Au concentration did not decrease any more.
  [0138]
  In addition, since Au peeled from the cylindrical rotating cathode 4 was dissolved in aqua regia after a while, the amount of peeled Au could not be measured.
  [0139]
  As is apparent from FIG. 3 in which the results of Experimental Examples 14 to 16 are plotted, even when the waste liquid of the Au-containing aqua repellent liquid is used as the processing liquid, a cylindrical shape in which a titanium net is attached to the surface It can be seen that by using the rotating cathode 4 (■ in FIG. 3), the electrolysis time can be shortened and the Au recovery efficiency is increased. Further, by using the cylindrical rotating cathode 4 having a titanium mesh attached to the surface (■ in FIG. 3), the Au concentration of the treatment liquid can be reduced to 3 mg / L.
  [0140]
    [Table 3]

  [0141]
  (Experimental example 17)
  In Experimental Example 17 and Experimental Example 18 described below, the recovery efficiency when Pd was recovered from the Pd-containing waste liquid was examined.
  [0142]
  In the experimental example 1, except that the Pd-containing waste liquid (Pd concentration is 113 mg / L, pH = 8) is used as the treatment liquid and the electrolysis is performed at a voltage of 7 to 8 V, the above experimental example 1 The treatment solution was electrolyzed under the same conditions. Table 4 shows the results of measuring the Pd concentration of the treatment liquid every several hours after the start of electrolysis.
  [0143]
  As is clear from Table 4 below, when the electrolysis was performed for 6 hours, the Pd concentration of the treatment liquid decreased to 1 mg / L.
  [0144]
  (Experiment 18)
  In the experimental example 17, the treatment liquid was used under the same conditions as in the experimental example 17 except that the cylindrical rotating cathode 4 having a diameter of 160 mm and a length of 200 mm without a titanium mesh on the surface was used as the cylindrical rotating cathode 4. Was electrolyzed. Table 4 shows the results of measuring the Pd concentration of the treatment liquid every several hours after the start of electrolysis.
  [0145]
  As apparent from Table 4 below, it took 27 hours to reduce the Pd concentration of the treatment liquid to 1 mg / L.
  [0146]
  Comparing the result of Experimental Example 18 with the result of Experimental Example 17, the electrolysis time of Experimental Example 18 is increased by about 4.5 times. Therefore, according to the present invention, titanium is formed on the surface of the cylindrical rotating cathode 4. It can be seen that the recovery efficiency of Pd can be improved by about 4.5 times simply by providing a net and increasing the surface area by about 3.9 times.
  [0147]
  As is apparent from Table 4 below, even when Pd is recovered from the Pd-containing waste liquid, titanium is formed on the surface of the cylindrical rotating cathode 4 more than when no titanium mesh is provided on the surface of the cylindrical rotating cathode 4. It can be seen that by providing the net, the electrolysis time is remarkably shortened and the recovery efficiency of Pd is increased.
  [0148]
    [Table 4]

[Industrial applicability]
  [0177]
  According to the present invention,YouFrom metal-containing solutionsYouThis equipment is used for recovering metals by electrolysis. It can save space and reduce equipment load in a short time.YouIt is possible to provide an apparatus with extremely high recovery efficiency that can recover metal.

Claims (1)

An apparatus for recovering noble metals by electrolyzing a noble metal-containing solution,
The device
A columnar or cylindrical rotating cathode that rotates about an axis; and
An anode disposed to face the rotating cathode;
Average mesh opening is 0.5 to 3 mm, average wire diameter has a titanium network 0.3 to 0.5 mm, and
A surface of the rotating cathode facing the anode is covered with the titanium mesh, and a noble metal recovery device.

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