Unitika Ltd.

Doryokuro Kakunenryo Kaihatsu Jigyodan

Hideto Obara

Tadaya Ishibashi

Hiroshi Kano

Masanori Sasaki

Shintaro Yamashita

Satoshi Taue

Keiichiro Otomura

Kozo Kondo

Shozo Tomoshige

Soichiro Yano

In an electrolyzer provided according to this invention, the polarity of electrodes is periodically inverted at very short intervals. This has the effect of allowing gases to be generated uniformly all over the surface of each electrode in the form of extremely small bubbles instead of being formed in specific positions in the form of large bubbles as is the case with a conventional electrolyzer in which a direct current is allowed to flow without changing the flow direction. Thus the surfaces of electrodes are prevented from being covered with bubbles, and the flow of liquids along the surfaces of electrodes is not disturbed by the bubbles any more.

Electrolyzer and a method of operating the same

A method for the operation of electrolytic baths whereby a charged, dissociative metal cationic solute which dissolves in a solution such as treatment used for a metal surface acid-washing, is separated and migrated through the diaphragm of an ion-selective separatory membrane. The cathode chamber solution contains as the electrolyte maintaining the basic electrical conductivity, a salt containing ammonium and at least one of sodium or potassium ions as the cation, and a salt containing a chloric ion or both a chloric ion and a sulfuric ion, but no nitric ion, as the anions. Furthermore, as the regulator which maintains the alkalinity in response to the progress of the electrolysis process, the cathode chamber solution contains at least one of an ammonium salt, a carbonate or a carboxylate. By this, metal oxide particles or metal particles are separated and produced in the circulated cathode chamber solution.

Method for the operation of electrolytic baths to produce Fe.sub.3

The present invention relates to the method of treating the salt bath liquid. In the surface treatment of the steel material by the use of the high-temperature salt bath mainly comprising sodium hydroxide and sodium nitrate, the salt ingredients contained in the washings generated are separated to be recovered and the metal salts contained are separated in the form of the insoluble salts. The salts contained in the nitrate radical-containing liquid system are recovered as the free acids again, the alkalies being recovered, and the reagents contained in the overflow from the salt-washing tank being recovered. The anode chamber liquid generated in the recoverying operation of the reagents is returned to the washing tank again to increase the concentration of the salts. The anode chamber liquid is poured into the pickling tank to reduce the oxidizing soluble metal salts contained in the washings by iron within the pickling tank, whereby the oxidizing soluble metal salts are insolubilized. The mixture liquid of the overflows from the respective tanks and the washing water for removing the foreign matters in the salt bath is mixed with the nitric acid-containing liquid for pickling the steel material and then sodium hydroxide is supplied to alkalize. Thus, the dissolved metal compounds in the liquids, which have been used for the treatment, are separated into the insoluble solid metal hydroxides and the liquid of the soluble salts without mixing the insoluble alkalies.

Method of treating salt bath liquid

An apparatus and method for purifying metal ion-containing bath liquids used for metal surface cleaning. The method comprises circulating two kinds of bath liquids (11A, 11B) through a plurality of electrolytic cells (1), each composed of an anode (2) and a cathode (4) separated by two ion-selective permeable diaphragms (6, 7), in such a way as to introduce the bath liquid into the intermediate compartment (8), electrophoresing metal ions contained in the bath liquids (11A, 11B ) into the cathode compartment (5) of each electrolytic cell (1), simultaneously circulating the catholyte (14) through the cathode compartment (5) of the electrolytic cell (1), thereby forming and coagulating easily magnetizable metal particles and hardly magnetizable metal particles in the catholyte (14), and separating the coagulation using a magnetic separator (17).

Apparatus and method for purifying bath liquids

The present invention relates to an electrolyzer for treating an object liquid. A cylindrical anode plate is formed as an outer wall of said electrolyzer and a cylindrical cathode plate is coaxially arranged at a position close to an inner surface of said anode plate. An ion exchange membrane is coaxially arranged between both electrodes to form an isolating chamber for a selective electrophoretic separation and removal and a concentration. A liquid, which has been subjected to an aimed treatment in said isolating chamber, is uniformly flown out from a whole circumference through a circumferential passage provided in an upper portion of an electrode portion. Thus, anions, which have acted upon metal cations, are dissociated in said isolating chamber to selectively separate merely cations. In addition, an improvement of the anode brought into contact with said object liquid in durability, a simplification of electrode surfaces in repair and processing, a uniformation of a current density, a handling of the liquid under the conditions corresponding to an operating object of the electrolyzer and the like can be achieved.

Electrolyzer and method of operating same

The present invention provides a process for producing a uranium oxide by dissolving a yellow cake in sulfuric acid or hydrochloric acid, bringing the obtained solution into contact with a chelating resin of diaminocarboxylic acid type and subjecting the product to neutralizing precipitation followed by heat treatment. By the contact of the solution with the chelating resin, iron, copper, molybdenum and vanadium among the metallic impurities are removed and in the subsequent neutralizing precipitation step, other metallic impurities such as aluminum, calcium, magnesium, sodium and potassium are removed. This process can easily produce uranium oxide having a high purity using a simple apparatus.

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Uji, Japan

Hideto Obara