公开(公告)号：JPS62290891A

公开(公告)日：1987-12-17

申请号：JP13282486

申请日：1986-06-10

Applicant: TOSOH CORP

Inventor： FUKUDA KENICHI ,  MORI TAKASHI ,  KURAUCHI YASUHIRO ,  SUEMATSU TETSUYA

IPC: C08J5/22 ,  B01J47/00 ,  B01J47/12 ,  C08F214/26 ,  C25C7/04

Abstract: PURPOSE:To deposit the metals contained in the metal-contg. waste cyanogen liquid discharged from a plating factory to a cathode to recover said metals and to converting the harmful cyanogen ions to a harmless material by oxidation decomposition by subjecting the above- mentioned waste liquid to an electrolytic treatment in an electrolytic cell where a fluorine contg. anion exchange membrane is used as a diaphragm. CONSTITUTION:The electrolytic cell 1 is divided to a cathode chamber 2 and an anode chamber 4 by the fluorine contg. anion exchange membrane 6 made of the copolymer consisting of the repeating unit expressed by formula [I]. The cathode 3 made of granular or fibrous carbon or the like which is insoluble in aq. KCN soln. and has a large surface area is disposed in the chamber 2 and the anode 5 made of a metal such as Ti, Ta, Zr, Nb, etc., likewise insoluble in the aq. KCN soln. or formed by coating such metal surface with Pt, Ir, Rh, etc., is disposed in the chamber 4. The aq. KON soln. is supplied into the chamber 4 and the waste plating liquid contg. the plating metals and KCN is supplied into the chamber 2. The electrolytic treatment is executed by a DC power source 7. The metallic ions in the waste plating liquid are deposited and recovered on the surface of the cathode 3, and the CN ions migrate from the chamber 2 through the membrane 6 into the chamber 4 and are oxidation-decomposed by the anode 5, by which said ions are converted to harmless material.

公开(公告)号：JPS62260084A

公开(公告)日：1987-11-12

申请号：JP7825586

申请日：1986-04-07

Applicant: TOSOH CORP

Inventor： FUKUDA KENICHI ,  MORI TAKASHI ,  KURAUCHI YASUHIRO ,  SUEMATSU TETSUYA

IPC: C25B1/00

Abstract: PURPOSE:To stably form thick KAu(CN)2 for a long time by using an F-contg. anion exchange membrane of a copolymer consisting of repeating units represented by a prescribed general formula as a diaphragm for electrolysis. CONSTITUTION:A metallic anode 3 contg. gold is placed in the anode chamber 2 of an electrolytic cell 1 provided with a diaphragm 6 and a metallic cathode 5 which is insoluble in an aqueous KCN soln. or the like is placed in the cathode chamber 4. The aqueous KCN soln. or the like is fed and electric current is supplied. An F-contg. anion exchange membrane of a copolymer consisting of repeating units represented by the formula is used as the diaphragm 6. In the formula, X is F or CF3, (l) is 0 or an integer of 1-5, (m) is 0 or 1, (n) is an integer of 1-5, each of (p) and (q) is a positive integer, p/q=2-16, each of R1-R3 is lower alkyl, R4 is H or lower alkyl, Z is a halogen anion and (a) is 2-10. CN ions transferred from the cathode chamber 4 to the anode chamber 2 through the membrane 6 react with gold ions dissolved from the anode 3 and KCN to form KAu(CN)2 in the anode chamber 2. When the concn. of the resulting aqueous KAu(CN)2 soln. is increased to a certain value, the soln. is drawn out of a drawing hole 7 and then Au and an aqueous KCN soln. are newly fed. Thus, KAu(CN)2 can be intermittently formed for a long time.