JP3784940B2

JP3784940B2 - Method for removing arsenic in copper electrolyte

Info

Publication number: JP3784940B2
Application number: JP27824197A
Authority: JP
Inventors: 和彦元場; 康勝佐々木
Original assignee: Nippon Mining and Metals Co Ltd
Current assignee: Nippon Mining Holdings Inc
Priority date: 1997-09-25
Filing date: 1997-09-25
Publication date: 2006-06-14
Anticipated expiration: 2017-09-25
Also published as: JPH1190413A

Description

【０００１】
【発明の属する技術分野】
本発明は、銅電解液中のひ素の除去方法に関するものであり、より詳しく述べるならば銅製錬等におけるＡｓ含有電解液等からＡｓを除去する際の処理液量を少なくする方法に関するものである。
【０００２】
【従来の技術】
銅電解処理後の銅電解液は、一般にＣｕ４０〜５０ｇ／Ｌ、Ａｓ１〜２０ｇ／Ｌ、遊離（ｆ）硫酸１５０〜２００ｇ／Ｌを含有している。この電解液からひ素を除去し、再度電解に戻す場合、例えばＡｓを５ｇ／Ｌ以下に維持することが電気銅の品質などの面から必要になる。ここで、浄液中のＡｓ濃度を５ｇ／Ｌ（５×１０^-3Ｔ／ｍ³ ）、アノードからのＡｓ溶出量を１０Ｔ／月、Ａｓの浄液効率を７０％とすると、電解液の一部約２９００ｍ³ ／月（≒１０（Ｔ／月）／５×１０^-3（Ｔ／ｍ³ ）×０．７０）を抜き出し、この２９００ｍ³ ／月について浄液を施することが必要になる。
【０００３】
また銅電解液はさらに１〜２０ｇ／Ｌ程度のＮｉを含有することもあるが、この銅電解液から上記のように抜き出された２９００ｍ³ ／月全量あるいはその一部についてＮｉを除去する浄液を行っていた。
【０００４】
【発明が解決しようとする課題】
従来法では十分に浄液するためには上記例で説明したように電解液をそのまま抜き出しており、このために浄液水量が例えば２９００ｍ³ ／月と多くなっているので、本発明は浄液水量を大幅に低減することができる銅電解液中のひ素の除去方法を提供することを目的とする。
【０００５】
【課題を解決するための手段】
本発明は、ひ素を含有する銅電解液と、例えば特開昭５８−６４１８０号に記載された下記アミノポリアルコール基を有する樹脂などのひ素吸着用キレート樹脂を接触させ、吸着後液をひ素吸着用キレート樹脂から排出した後、ひ素吸着後のキレート樹脂を水洗することなく酸液で溶離を施し、溶離初期の溶離後液を浄液することを特徴とする銅電解液中のひ素の除去方法を提供するものである。なお式中Ｒはアルキル基（Ｃ_n Ｈ_2n+1）である。
以下、本発明を詳細に説明する。
【０００６】
【化１】

【０００７】
キレート樹脂などで不純物を除去する場合、通常は吸着終了後樹脂塔内に残留した処理液を溶離液と混ざらないように、エアーパージしさらに水洗して塔内から排除する。しかしながら、本発明者らの実験によると、ひ素吸着用キレート樹脂は水洗時に吸着した砒素の一部が溶離し、残留液との分離ができないことが判明した。水洗時に溶離する砒素量は種々工夫をしても全吸着砒素量の３０％を下回ることはできなかった。
一方現状ではニッケルの除去は銅など他のイオンを除いた後あるいは同時にしかできないため、除去すべきニッケル量を含んだ電解液分はどうしても系外に排出する必要があった。そこで吸着後水洗工程なしで溶離し、溶離初期の樹脂塔内に残留した電解液と一部溶離して濃度が上昇した砒素を分離せずに、そのまま通常の浄液工程に送ることにより、浄液量を大幅に削減できるとともに、砒素を効率よく除くことができる本発明方法に至った。
【０００８】
溶離に使用する溶離液は温水あるいは適量の酸、好ましくは３０〜５０ｇ／Ｌの濃度の硫酸あるいは塩酸を含有する酸液であればよいが、上記のように溶離後期の溶離後液（以下「溶離後期液」と略称する）はＡｓ濃度が低くかつ適量の酸を含有するので、これを必要により酸を補加して、溶離に再使用すると、処理液総量の増大を抑えることができる。この溶離液の好ましい濃度はＡｓが０．１ｇ／Ｌ未満、遊離硫酸が３０〜５０ｇ／Ｌ未満である。
【０００９】
溶離後期液は、キレート樹脂の能力を高いレベルに維持するためには、硫化処理によりひ素及び銅を除去し、その後脱硫を施した溶離後液を繰返し溶離に使用することが好ましい。ここで硫化処理は硫化水素、ＮａＨＳなどにより行う。この処理後、主として銅、ひ素、ニッケルなどを含有する沈殿物を固液分離により分離する。ろ液は溶存Ｈ₂ Ｓを含有するために、硫酸銅溶液などにより脱硫する。また、溶離後期後は消石灰などで中和し、再利用することもできるが、この場合は添加する硫酸量が増加する欠点がある。
【００１０】
溶離初期の溶離後液（以下「溶離初期液」と略称する）は上述のように比較的Ｃｕ及びＡｓ濃度が高い。この溶離初期液は通例により脱砒電解、硫化及び溶媒抽出などを施し、処理後の硫酸液は電解に戻す。
【００１１】
銅電解液に含有されるＮｉは溶離初期液及び溶離後期液中に移行し、上述のように回収されるが、Ｎｉは砒素吸着用キレート樹脂に吸着されないのでほとんどは吸着後液中に残留する。
ここで、アノードからのＡｓ溶出量／（電解液中のＡｓ許容濃度×浄液でのＡｓ除去率）をＡｓ基準浄液量（Ｃｌ_AS）と表しアノードからのＮｉ溶出量／（電解液中のＮｉ許容濃度×浄液でのＮｉ除去率）をＮｉ基準浄液量（Ｃｌ_Ni）と表すと、Ｃｌ_AS＞Ｃｌ_Niの条件が充たされる場合に浄液量を減らす効果がある。
【００１２】
溶離液を硫化後循環させ溶離を繰り返し行い、また吸着を繰り返して行うと、樹脂塔内の樹脂が全体として残存する溶存Ｈ₂ Ｓにより黒く変色する場合がある。そこで、変色した樹脂を、Ｈ₂ ＳＯ₄ ，ＨＣｌ，ＨＮＯ₃ ，ＮａＯＨ，ＮＨ₃ などで再生し、その後樹脂を分析した。その結果を次の表に示す。
【００１３】
【表１】

【００１４】
この結果より、酸、特に硝酸が再生剤として有効であることが分かる。
また硝酸を用いて再生すると、樹脂の色が黒色から元のベージュ色に戻る。これは樹脂中に蓄積していた硫化銅が硝酸溶液中に溶解し、硫化銅が分解して黒色から元のベージュ色に戻ったと考えられる。
以下、実施例により本発明を詳しく説明する。
【００１５】
【実施例】
図１の▲１▼に成分濃度及び量を示す銅電解液１０００ｃｃをキレート樹脂（製品名：ミヨ油脂Ｂ−１、量１００ｃｃ，吸着能力Ａｓ２０ｇ／Ｒ）により吸着処理したところ、▲２▼に成分濃度及び量を示す吸着後液９２０ｃｃが得られ、砒素が２ｇ樹脂に吸着された。この状態で樹脂を水洗すると砒素が溶離してしまうが、水洗をしないで、直ちに遊離硫酸濃度が３０ｇ／Ｌである溶離液２００ｃｃ（▲３▼）で溶離を行った。なお、この溶離液は後述のように循環液である。
【００１６】
溶離の結果、成分濃度及び量を▲４▼に示す溶離初期液と同じく▲５▼に示す溶離後期液が得られた。これらの液の合計量は２８０ｃｃ（Ａｓ量＝２ｇ）であり、上述の従来法では同じ量のＡｓを処理するための液量が４００ｃｃであったので、処理液量が３０％少なくなった。
一方、溶離後期液▲５▼には２．４ｇのＮａＨＳを添加して硫化を行い、次に固液分離により成分濃度及び量を▲６▼に示す硫化物７ｇを生成した。硫化物を分離した分離後液は▲７▼に示すように硫酸水溶液であるが、微量のＨ₂ Ｓを含有するために脱硫化水素を行い、残留Ｈ₂ Ｓを吸着させた後、水５４ｃｃ及び硫酸２．４ｇを補加した溶離液▲３▼とした。
【００１７】
脱硫処理、ダミー樹脂を通さないで吸着及び溶離を１２回繰り返したとことろキレート樹脂が黒変し、またＡｓ吸着効率の低下が目立ったので、樹脂１５ｃｃ当り３ＮＨＮＯ₃ 水溶液１５０ｃｃで再生したところ樹脂は元の色に戻った。
【００１８】
【発明の効果】
以上説明したように本発明によると、銅電解液中のＡｓを除去する際の処理水量を少なくして処理コストを低減することができる。また溶離初期液及び溶離後期液中のＡｓ濃度は銅電解液よりも高濃度となるために、ひ素除去コストが安くなる。
また溶離液を繰り返し使用すると（請求項２、３）、セミクローズド処理系統となり、一層のコスト低減を図ることができる。
最後にキレート樹脂の再生（請求項４）によって、キレート樹脂を長期に使用すると樹脂原単位も低く押さえることができる。
【図面の簡単な説明】
【図１】本発明の一実施例に係る処理フローチャートである。[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a method for removing arsenic in a copper electrolyte, and more specifically, relates to a method for reducing the amount of treatment liquid when removing As from an As-containing electrolyte in copper smelting or the like. .
[0002]
[Prior art]
The copper electrolytic solution after the copper electrolytic treatment generally contains Cu 40 to 50 g / L, As 1 to 20 g / L, and free (f) sulfuric acid 150 to 200 g / L. When removing arsenic from this electrolytic solution and returning to electrolysis again, for example, it is necessary to maintain As at 5 g / L or less from the viewpoint of the quality of electrolytic copper. Here, when the As concentration in the purified liquid is 5 g / L (5 × 10 ⁻³ T / m ³ ), the As elution amount from the anode is 10 T / month, and the As purified liquid efficiency is 70%, Some 2900 m ³ / month (≈10 (T / month) / 5 × 10 ⁻³ (T / m ³ ) × 0.70) must be extracted and purified at 2900 m ³ / month Become.
[0003]
Further, the copper electrolyte may further contain about 1 to 20 g / L of Ni. However, the total amount of 2900 m ³ / month extracted as described above or a part thereof may be removed from the copper electrolyte. The liquid was gone.
[0004]
[Problems to be solved by the invention]
In the conventional method, in order to sufficiently purify the liquid, as described in the above example, the electrolytic solution is extracted as it is. For this reason, the amount of purified water is increased to, for example, 2900 m ³ / month. An object of the present invention is to provide a method for removing arsenic in a copper electrolyte that can greatly reduce the amount of water.
[0005]
[Means for Solving the Problems]
In the present invention, a copper electrolyte containing arsenic is brought into contact with a chelating resin for arsenic adsorption such as a resin having the following aminopolyalcohol group described in JP-A-58-64180, and the adsorbed solution is adsorbed to arsenic. A method for removing arsenic from a copper electrolyte characterized by elution with an acid solution without rinsing the chelate resin after arsenic adsorption after draining from the chelate resin, and purifying the solution after elution at the initial stage of elution Is to provide. In the formula, R is an alkyl group (C _n H _{2n + 1} ).
Hereinafter, the present invention will be described in detail.
[0006]
[Chemical 1]

[0007]
When removing impurities with a chelate resin or the like, usually, the treatment liquid remaining in the resin tower after completion of adsorption is purged with air and further washed with water so as not to be mixed with the eluent. However, according to experiments by the present inventors, it was found that a part of arsenic adsorbed during washing with water is eluted from the arsenic adsorption chelating resin and cannot be separated from the residual liquid. The amount of arsenic eluted at the time of washing with water could not fall below 30% of the total amount of adsorbed arsenic even if various measures were taken.
On the other hand, at present, nickel can be removed only after removing other ions such as copper or at the same time. Therefore, it is necessary to discharge the electrolytic solution containing the amount of nickel to be removed out of the system. Therefore, after the adsorption, elution is performed without a water washing step, and the electrolyte remaining in the resin tower at the beginning of the elution is partly eluted and arsenic whose concentration has been increased is not separated and sent to the normal purification step as it is. The present invention has led to the method of the present invention that can greatly reduce the amount of liquid and efficiently remove arsenic.
[0008]
The eluent used for the elution may be warm water or an acid solution containing an appropriate amount of acid, preferably sulfuric acid or hydrochloric acid having a concentration of 30 to 50 g / L. Since the As concentration is low and contains an appropriate amount of acid, an increase in the total amount of the processing solution can be suppressed by supplementing the acid if necessary and reusing it for elution. Preferred concentrations of this eluent are As less than 0.1 g / L and free sulfuric acid less than 30-50 g / L.
[0009]
In order to maintain the ability of the chelating resin at a high level, it is preferable that the elution late solution after removing arsenic and copper by sulfidation and then desulfurizing is used repeatedly for elution in order to maintain the ability of the chelate resin at a high level. Here, the sulfurating treatment is performed with hydrogen sulfide, NaHS or the like. After this treatment, a precipitate mainly containing copper, arsenic, nickel and the like is separated by solid-liquid separation. Since the filtrate contains dissolved H ₂ S, it is desulfurized with a copper sulfate solution or the like. In addition, it can be neutralized with slaked lime after the latter stage of elution and reused, but in this case, there is a drawback that the amount of sulfuric acid to be added increases.
[0010]
As described above, the post-elution solution at the beginning of elution (hereinafter abbreviated as “elution initial solution”) has a relatively high Cu and As concentration. This elution initial solution is usually subjected to dearsenic electrolysis, sulfurization and solvent extraction, and the treated sulfuric acid solution is returned to electrolysis.
[0011]
Ni contained in the copper electrolyte moves into the initial elution liquid and the late elution liquid, and is recovered as described above. However, since Ni is not adsorbed by the chelating resin for arsenic adsorption, most of it remains in the post-adsorption liquid. .
Here, the amount of As eluted from the anode / (As permissible concentration in electrolyte solution × As removal rate in the purified solution) is expressed as an As reference solution amount (Cl _AS ), and the amount of Ni eluted from the anode / (in the electrolyte solution) If the Ni permissible concentration x Ni removal rate in the purified liquid is expressed as the Ni reference purified liquid amount (Cl _Ni ), there is an effect of reducing the purified liquid amount when the condition of Cl _AS > Cl _Ni is satisfied.
[0012]
If the eluent is circulated after sulfurization and elution is repeated, and adsorption is repeated, the resin in the resin tower may turn black due to the dissolved H ₂ S remaining as a whole. Therefore, the discolored resin was regenerated with H ₂ SO ₄ , HCl, HNO ₃ , NaOH, NH _{3 and the} like, and then the resin was analyzed. The results are shown in the following table.
[0013]
[Table 1]

[0014]
From this result, it can be seen that acid, particularly nitric acid is effective as a regenerant.
Also, when regenerated with nitric acid, the color of the resin returns from black to the original beige color. This is considered that the copper sulfide accumulated in the resin was dissolved in the nitric acid solution, and the copper sulfide was decomposed to return from black to the original beige color.
Hereinafter, the present invention will be described in detail by way of examples.
[0015]
【Example】
In Fig. 1 (1), 1000 cc of copper electrolyte showing the component concentration and amount was adsorbed with chelate resin (product name: Millo oil B-1, amount 100 cc, adsorption capacity As20 g / R). 920 cc of post-adsorption liquid indicating the concentration and amount was obtained, and arsenic was adsorbed on 2 g resin. When the resin was washed with water in this state, arsenic was eluted, but immediately with no elution, elution was carried out with 200 cc (3) of an eluent having a free sulfuric acid concentration of 30 g / L. This eluent is a circulating liquid as will be described later.
[0016]
As a result of elution, an elution late solution shown in (5) was obtained in the same manner as the elution initial solution shown in (4). The total amount of these liquids was 280 cc (As amount = 2 g). Since the amount of liquid for treating the same amount of As was 400 cc in the above-described conventional method, the amount of the treatment liquid was reduced by 30%.
On the other hand, 2.4 g of NaHS was added to the late elution solution (5) to perform sulfidation, and then 7 g of sulfide having the component concentration and amount shown in (6) was produced by solid-liquid separation. The separated solution after separating the sulfide is an aqueous sulfuric acid solution as shown in (7). However, since it contains a trace amount of H ₂ S, desulfurized hydrogen is used to adsorb the residual H ₂ S, and then 54 cc of water is added. And eluent (3) supplemented with 2.4 g of sulfuric acid.
[0017]
After desulfurization treatment, adsorption and elution were repeated 12 times without passing through the dummy resin, the chelate resin turned black, and the decrease in As adsorption efficiency was noticeable. When regenerated with 150 cc of ₃ NHNO ₃ aqueous solution per 15 cc of resin, the resin was Returned to the original color.
[0018]
【The invention's effect】
As described above, according to the present invention, it is possible to reduce the treatment cost by reducing the amount of treated water when removing As in the copper electrolyte. Further, the As concentration in the initial elution liquid and the late elution liquid is higher than that in the copper electrolyte, so that the arsenic removal cost is reduced.
Further, when the eluent is repeatedly used (claims 2 and 3), a semi-closed processing system is obtained, and the cost can be further reduced.
Finally, by regenerating the chelate resin (Claim 4), if the chelate resin is used for a long time, the resin basic unit can be kept low.
[Brief description of the drawings]
FIG. 1 is a process flowchart according to an embodiment of the present invention.

Claims

After contacting the copper electrolyte containing copper and arsenic with the chelating resin for arsenic adsorption, and discharging the post-adsorption liquid from the chelating resin for arsenic adsorption, the chelating resin after the arsenic adsorption is eluted with an acid solution without washing with water. And removing the arsenic from the copper electrolyte, wherein the solution after elution at the beginning of elution is purified.

2. The method for removing arsenic from a copper electrolyte according to claim 1, wherein a solution after elution at a later stage of elution is repeatedly used as an acid solution for elution.

3. The copper electrolyte solution according to claim 2, wherein the post-elution solution in the latter stage of elution is subjected to sulfurization treatment to remove arsenic, then desulfurized, and after passing through the dummy resin step, the post-elution solution is repeatedly used for elution. How to remove arsenic inside.

4. The method for removing arsenic in a copper electrolyte solution according to claim 3, wherein the chelate resin is regenerated by a nitric acid treatment or an oxidation treatment, followed by adsorption and elution.