JPS61223139A - Method for removing tellurium - Google Patents

Abstract

PURPOSE:To remove easily and effectively Te from an acidic aqueous soln. contg. copper and/or arsenic as well as Te even in case of a high concn. of Te by adding copper to the soln. in the presence of a reducing agent. CONSTITUTION:When Te is removed from an acidic aqueous soln. contg. copper and/or arsenic as well as Te such as a copper electrolytic soln. or a soln. obtd. by the oxidation leaching of anode sludge, solid copper and/or deposited copper is added to the soln. in the presence of a reducing agent by an amount >=4 times the amount (gram ion) of the dissolved Te to remove the Te as a Cu-Te compound. The preferred reducing agent is gaseous SO2 and granular, wiry or powdery copper of <=about 10mm diameter and/or length is used as the solid copper.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for removing tellurium dissolved in an acidic aqueous solution containing copper and/or arsenic, for example, in a narrow sense, tellurium dissolved in a solution handled in a copper smelting process. .

Conventionally, in copper electrolysis processes, for example, most of the tellurium contained in the anode is mixed into the anode mud. When oxidized leaching is performed to remove copper and/or arsenic from this anode mud, one of the tellurium
0-15% is leached.

Also, depending on one condition, tellurium may be leached even in the case of copper electrolysis as described above.

However, there is no technology that is generally considered effective for removing tellurium from these liquids, and it is mostly ignored or only slightly removed by adding copper powder, electrowinning, etc. .

In the case of the acid aqueous solution containing copper and/or arsenic, the effect of adding copper powder alone is extremely small, and electrowinning not only has a poor removal effect but also removes a large amount of copper and arsenic. Since arsenic is also precipitated, the processing cost increases, which is not preferable.

Therefore, as a result of intensive research, the present inventors have made the following invention.

. A method for telling fortune-telling The present invention is based on the present invention, in which tellurium in an acidic aqueous solution containing copper and/or arsenic is at least four times the amount of dissolved tellurium gram ions.
Add solid copper in the presence of a reducing agent.

And/or relates to a method of removing tellurium as a compound with copper using precipitated copper.

In a preferred embodiment, a method for removing tellurium is provided in which the reducing agent is sulfur dioxide gas.

Yet another embodiment provides a method for removing tellurium in which the solid copper is in the form of granules, lines, or powder having a diameter and/or length of 1101I or less.

Month 11i Todorojun] Chapter 1 - The present invention will be described in detail below.

The solution to be treated in the present invention is an acidic aqueous solution containing copper and/or arsenic, and examples thereof include a copper electrolyte and a leachate obtained by oxidizing and leaching anode mud.

It has long been known that tellurium in an acidic aqueous solution can be removed as a compound such as copper litelluride by adding copper.

However, this effect is almost ineffective in solutions in which various ionic species are dissolved, such as a copper electrolyte.

As a result of various studies, the inventors of the present invention found that the cause of the problem was copper ions, arsenic ions, and even monovalent arsenic ions, and then devised a method to effectively remove tellurium even under conditions where copper and arsenic ions are present. I found it.

That is, copper is the substance that reduces tellurium and further removes it as a precipitate, but in order to make this reaction possible, it is essential to add a reducing agent.

The amount of copper added needs to be four times or more the amount of gram ions of tellurium. The finer the shape of the copper, the less the need for it, and the diameter and/or length of the copper is preferably 10 mm or less.

Further, when using an autoclave or the like, it is also possible to use hydrogen, and when copper powder is precipitated using hydrogen, addition of copper can be omitted.

Reducing agents include sulfur dioxide gas, sodium sulfite, and sodium thiosulfate. Any of these can be used, but if an increase in sodium ions in the liquid is not desired, sulfur dioxide gas is preferable.The amount of these reducing agents to be used is affected by the concentration of acid, arsenic ions, and copper ions, so it cannot be determined However, it is essential that an excess of reducing agent be present in the solution when removing tellurium. Moreover, when arsenic is monovalent, it is preferable to reduce it to trivalent arsenic in advance.

A higher temperature is preferable, but 1 normal operating temperature (50 to 6
0°C) is also sufficient.

The reaction time varies depending on the concentrations of copper, arsenic, tellurium and acid, but 2 hours or more is sufficient.

By implementing the present invention as described above, the following effects can be obtained.

(1) Even if the solution contains copper and/or arsenic and is high in tellurium, tellurium can be easily removed.

(2) According to the present invention, tellurium can be easily removed even if the slime in copper electrolysis contains a high amount of tellurium, and a preferable treatment can be performed.

・ (a) Te (VI) and Cu (n) are each 0.55
g/l and an aqueous solution containing 40 g/l, (b) further As(V
), (0) or As(II) (Log/l) was added to each aqueous solution IQ, and 200 mesh or less of copper powder was added to each solution, which was 8 times the gram ion amount of tellurium.
The mixture was stirred in a glass reaction container while being kept at 60°C.

The gas phase atmosphere was SO□ gas. Although the concentration of sulfuric acid in the liquid was in the range of 100 to 200 g/l, the influence was small.

The results are shown in Table 2, and it can be seen that the addition of a reducing agent is very effective.

Put the solution (b) shown in Example 1 into an autoclave,
The hydrogen partial pressure was maintained at 150°C to be 8XIO''Pa, and the reaction was carried out for 1 hour.As a result, the tellurium in the liquid was 0.0
The ratio was less than 0.01 g/1, and a mixture of copper telluride and copper powder was obtained.

(d) Te (■) in an aqueous solution containing 200 g/l of sulfuric acid.
(e) plus Cu (■)
40 g/l of (f) and As(■) added to L
Each of the aqueous solutions IQ and IQ added was placed in a glass reaction container, kept at 60°C, and copper powder of 200 mesh or less was added in an amount 8 times the amount of gram ions of tellurium, and stirred under a nitrogen atmosphere. Show the results.

Table 1 In the case of tellurium only (d), tellurium can be quickly removed by adding copper powder, but if copper ions or arsenic ions are present (e) or (f) it becomes extremely difficult to remove tellurium. I understand.

Claims (3)

[Claims] (1) Tellurium in an acidic aqueous solution containing copper and or arsenic,
It is characterized by adding solid copper in the presence of a reducing agent and/or using precipitated copper to remove tellurium as a compound with copper at least four times the amount of dissolved tellurium gram ions. How to remove tellurium. (2) The method for removing tellurium according to claim 1, wherein the reducing agent is sulfur dioxide gas. (3) The method for removing tellurium according to claim 1, wherein the solid copper is in the form of particles, lines, or powder with a diameter and/or length of 10 mm or less.