JPS59157294A - Method for removing bismuth from copper electrolytic solution - Google Patents

Abstract

PURPOSE:To remove bismuth efficiently and selectively from a copper electrolytic soln. contg. bismuth without exerting unfavorable influence on the soln. by bringing the soln. into contact with an anion exchange resin. CONSTITUTION:A copper electrolytic soln. contg. at least bismuth and having deteriorated performance after use in the manufacture of high purity arsenious acid or the like is brought into contact with an anion exchange resin at ordinary temp. or an elevated temp. The anion exchange resin includes a strongly basic anion exchange styrene resin represented by the expression. The resin having adsorbed bismuth is brought into contact with hydrochloric acid or sodium hydroxide to elute the bismuth and to regenerate the resin. By this method bismuth can be removed efficiently and selectively from the copper electrolytic soln.

Description

DETAILED DESCRIPTION OF THE INVENTION Bismuth, along with arsenic, antimony, and tin, is an impurity that severely reduces the electrical conductivity of copper. Therefore, the bismuth accumulated in the copper electrolyte must be removed. Conventionally known methods for removing bismuth include the steel removal electrolytic method in which copper is electrolytically deposited using an insoluble anode, and the sulfur precipitation method using a sulfurizing agent. Alternatively, there are hydrolysis methods and solvent extraction methods that precipitate by adding alkali.0 However, among these conventional methods, copper removal electrolysis, sulfurization precipitation, and hydrolysis methods remove most of the copper.

Arsenic and antimony precipitate together with bismuth.

From this precipitate, copper = 1-arsenic, bismuth.

Separating and recovering antimony is expensive and difficult. Therefore, it was necessary to develop a method for selectively removing only bismuth from the copper electrolyte. Particularly in recent years, as high-purity arsenic acid has been produced using copper electrolyte as a raw material, it has become increasingly important to establish a method for selectively removing bismuth.

In order to achieve this objective, the present inventors have repeatedly examined and researched and clarified the advantages and disadvantages of various methods. First, regarding the solvent extraction method, since bismuth is a metal element, @
It is collected by an ion exchanger, but the liquid must be in the pH range. Copper electrolyte is originally a solution containing about 200 f/ of free sulfuric acid, so if this liquid is changed to the pH range, it will not only become useless as an electrolyte, but also be used as a medium when eliminating free acid. This method cannot be adopted because it has the drawbacks of consumption of abrasive powder and precipitation of copper or other metal elements.

There is also a method in the prior art for selectively extracting bismuth from the copper electrolyte itself, which contains a large amount of free acid, using a reagent other than the cationic exchange system, that is, an alkyl phosphoric acid such as tributyl phosphoric acid or an alkyl amine such as trioctylamine.・However, in the solvent extraction method, the organic solvent used does not mix with the copper electrolyte, causing problems such as deterioration of the electrodeposited surface of electrolytic copper. 〇Other copper electrolyte purification methods include activated carbon and There is also a way to make contact. JP-A-57-1
According to No. 55399, antimony in a copper electrolyte is removed at a very high rate according to this method. However, as can be seen from the description in JP-A-Sho, the bismuth removal rate is low in the activated carbon method. Furthermore.

The activated carbon method has the disadvantage that organic substances in the liquid are adsorbed and removed indiscriminately. As is well known, glue is used in metal electrolytes mainly for the purpose of smoothing the electrodeposited surface.

Organic additives such as gelatin, thiourea, higher alcohols, saccharin, or sugars are added, but when activated carbon comes into contact with the electrolyte, these useful additives are adsorbed and removed by the activated carbon. However, there is a serious drawback in that unless a large amount of additive is supplied to the electrolytic solution, the state of electrodeposition deteriorates considerably.

As a method for overcoming the above-mentioned drawbacks, the present inventors have come up with the present invention based on the second idea that bismuth can be selectively removed very well by a method of bringing an anion exchange resin into contact with a copper electrolyte. .

The copper electrolyte contains copper and sulfuric acid, and contains the aforementioned impurities such as arsenic and antimony, as well as nickel and lead. It may contain zinc, tin, alkali metals, alkaline earth metals, or other impurities. Since the actual property is adsorption by an anion exchange resin, it is necessary that the liquid to be treated be acidic.

There is no problem since the copper electrolyte always contains free sulfuric acid of 50 f/ or more. The anion exchange resin and the copper electrolyte may be brought into contact with each other by stirring the solution and the resin in a tank, or by passing the copper electrolyte through a resin-filled column. The liquid temperature at the time of contact may be at room temperature or in a heated state. Since the copper electrolyte is usually heated to about 60℃, it is fine if it is brought into contact with the resin as is.The resin that has adsorbed bismuth is brought into contact with hydrochloric acid or an aqueous solution of caustic soda to elute the bismuth and regenerate it. .

The type and type of anion exchange resin used in the present invention is not particularly limited; however, strongly basic anion exchange resins, that is, those having quaternary ammonium as an exchange group are preferable. Examples of trade names for such strongly basic anion exchange resins include IMnberli
te IRA-400, 1)owez-11Ice A
There are c1dite FF and Zeo Rex SB, but as a result of the experiments conducted by the present inventors, it has been confirmed that the styrene-based strong basic compound having the structural formula (1) or (2) below is particularly suitable. It is an anion exchange resin.

, (1) -cH-r4-cH-a2-cm
-Example of product name D Engineering A Engineering ON SA 20A Examples are shown below.

Example resin = D Engineering A Engineering ON SA 20A Copper electrolyte: Free sulfuric acid 196 f/l, Ou 46.5 P
/lNi 7.8 f/l, As 4.9 f/l,
BiO, 32f/l.

51) 0.4 ay7 Contact method: 4 t of electrolyte and resin in the proportions shown in the table below were placed in a beaker and stirred for 1 hour while being maintained at 60° C. with a heater.

Results: Table 1 shows the amount of resin in relation to the liquid and the amount of contact with the solution.Table 1: Test results.EffectsBismuth can be selectively removed without any negative effect on the copper electrolyte.

Electrolytic copper with extremely low bismuth content can be produced. Alternatively, a copper anode with a high bismuth content can be electrolyzed without deteriorating the quality of produced electrolytic copper.

By selectively removing bismuth from the copper electrolytic waste solution in advance, the bismuth content in the electrolytically precipitated steel precipitated in the decoppering electrolytic process becomes extremely small, so when recovering arsenic or copper from the electrolytically precipitated steel, , has the advantage of containing less bismuth.

During the selective removal of bismuth, a side effect is that some antimony is removed from the copper electrolyte.

It goes without saying that the method of the present invention can selectively adsorb bismuth from an acidic aqueous solution of sulfuric acid other than a copper electrolyte, but also mineral acids other than sulfuric acid, such as bismuth from an acidic aqueous solution of hydrochloric acid.

Selective adsorption can be achieved by the method of the present invention.

Patent applicant: Japan Mining Co., Ltd. Agent: Patent attorney (7569) Keishi Namikawa

Claims (1)

[Claims] A method for removing bismuth from a copper electrolyte, the method comprising contacting a copper electrolyte containing at least bismuth as an impurity with an anion exchange resin.