JPS5956590A - Method for recovering nickel sulfate from waste liquid of copper electrolysis - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

[Detailed description of the invention] The present invention relates to a method for treating 1I41d' municipal wastewater.

When made of copper 1U solution T111, the N contained in the anode
], AS, F13. Impurities such as Sb, Bj, etc.
It elutes into the Tft solution and has an adverse effect on the purity of the cathode, so T should not exceed a certain concentration.
A part of the solution is extracted from the system, and these slugs are removed and 1j71 is recovered.

The conventional treatment method for the copper electrolytic waste solution discharged from the string is that a part of the copper content is first recovered by the moon w method, decopper removal-1-IL decomposition (') 3, etc., and then further decopper removal is carried out. Electrolysis is performed to remove and recover most of Cu, as well as remove As, Sb, B1, etc., and remove the copper. (After dissolution, the liquid is evaporated and concentrated and cooled to obtain a product of nickel sulfate.7!11 The mother liquor is evaporated and concentrated.
As sulfuric acid and nickel sulfate mud, 41 [(+IC acid is copper 71
ff unraveling 11,! Free llI! Repeat for 2iiiIIIi supply, (lA) the old [crystals of acid nickel and IIIe acid nickel slurry]
Fe-.

After removing impurities such as As, the 1'JV nickel sulfate is crystallized by evaporation concentration and cooling. It has the disadvantage of requiring a large amount of energy.In addition, the copper electrolytic waste solution contains organic materials caused by organic additives that were not used in the process.
Although NH and the like are contained, these dull substances cannot be sufficiently removed by the above-mentioned conventional method, and have the disadvantage that they are mixed into purified nickel sulfate.

The present invention overcomes the drawbacks of the above-mentioned conventional methods and provides a method for recovering nickel sulfate from a copper electrolytic waste solution, which makes it possible to obtain an extremely pure nickel sulfate aqueous solution with low energy consumption.

In order to achieve this second objective, the method of the present invention uses copper? Copper removal treatment is performed on the lf solution 1, and dialysis is performed to remove copper from the decoppered reconcentrate.
After recovering a part or most of the lft + steam, add alkali to bring the pH to 9, add hydrogen peroxide, remove the precipitate, and then add alkali to bring the pH to 9. ~//, the precipitate containing nickel hydroxide is recovered from the solution, and the facial precipitate is leached with dilute sulfuric acid (to obtain an aqueous nickel II pentate solution).

The present invention will now be described in detail.

The copper-removal treatment of the copper electrolytic waste liquid is performed by a known method.

After neutralizing the free sulfuric acid by adding copper scraps, etc., the neutralized liquid may be evaporated and concentrated to cool it and collect the moon world, or the moon!
(Instead of the copper removal electrolytic method, it is also possible to apply the decoppering electrolytic method. After these treatments, approximately /3-.20 g/l of O remains in the waste liquid, so further decoppering electrolytic treatment is performed to remove O. g//
! Remove and recover to a certain extent.

In this copper removal electrolytic treatment step, As, Sb, Bj,
A part of it mixes into the decoppered slime, and a part of it becomes hydride and volatilizes. After the copper removal electrolytic treatment, the waste liquid Lt is subjected to dialysis treatment to recover a part or most of the free fIfj acid.

The free sulfuric acid concentration is preferably 700-/sog7' or higher. The 1lff free sulfuric acid concentration has the advantage of reducing the alkali consumption low in the low oxidation process, but it increases the cost of dialysis treatment, so the free We acid concentration of 114 may be selected as appropriate. When alkali is added to the waste liquid after dialysis treatment to make the pH pH 1-2, and hydrogen peroxide solution is added, F
e, Cu becomes hydroxide and precipitates, and organic matter is decomposed. The more hydrogen peroxide solution I11 is added, the higher the nlh degree is, the more effective it is in decomposing organic matter.

Hydrogen peroxide solution should be at least 0.7% by volume (35%) of the waste liquid.
-% concentration). It is desirable that the crystallinity is higher than yoc. After removing the precipitate, when an alkali is added to the filtrate to bring the pH to 9~//, most of the Ni in the filtrate is precipitated as nickel hydroxide, and the dissolved NH is separated and volatilized. For NH removal, the higher the pH,
A culm with a high temperature is preferable, and it is desirable that the temperature is 600 or higher. The precipitate contains nickel hydroxide, and if this is separated from the mother liquor and leached with dilute sulfuric acid, an aqueous solution of nickel sulfate can be obtained. The resulting aqueous solution of nickel sulfate has an extremely low concentration of heavy metals, TOC, and Nl, and by evaporating and concentrating it and cooling it, high-purity nickel sulfate crystals can be obtained.

In the invention, if slaked lime is used as the alkali, N
It is possible to obtain an aqueous solution of nickel oxide containing less a, and this solution can also be subjected to nickel electrolysis.

As is clear from the above description, the present invention has the advantage that it consumes less energy than conventional methods and can recover nickel with high purity.

Fruiting: m pieces / Add right ear powder to left copper electrolysis waste solution to remove copper / 1 g / 1. Add,
IV, t Cool the liquid temperature from t1'' to 2Or or higher to remove supersaturated Ca and SO as 11.
Separate the filtrate and add JJI+? After crystallization, diffusion dialysis was performed in two stages to recover free sulfuric acid. The copper-removed final solution, recovered sulfuric acid (7th and 2nd), dialysis wet solution 171, and the concentrations of each component are not shown in Table 1.

There is no change in the winter purification content of Sekiyoshi) B ~ D.) 1 Add 30% slaked lime slurry to the obtained dialysis solution until the pH becomes left, then raise the temperature of the solution to AOC and add 33% peroxide. Hydrogen water was added to the mixture (equivalent to 0, ? volume %), stirred once for 7 hours, and then filtered to obtain a seventh neutralization solution and a gypsum plate. Subsequently, while maintaining the liquid temperature at tOC, a 30% slaked lime slurry was added to adjust the pH to 10, and after stirring for 1 hour, the mixture was filtered to obtain a secondary neutralized liquid and a neutralized precipitate. In this process, P117. From around λ to NH
3Q: was admonished. The obtained neutralized precipitate was repulped into a mixed solution of 61/sub-recovered sulfuric acid and water S shown in Table 1, and 0.3
After stirring for an hour, the eluate and plaster were obtained. Dialysis wetted, 7
Secondary neutralizing liquid, plaster mounting material, - secondary neutralizing liquid, neutralizing precipitate, molten liquids
The quantities of liquid and gypsum and the concentrations of each component are shown in Table 1.

To(j, N
l(, Na content is sufficiently low, even if it evaporates and crystallizes after shrinkage, it is different from J, and nickel flfffi
It is a kneaded tγ that can be subjected to H.

Example 3 The dialysis reconcentrate ht shown in Table 3 was used as the stock solution, and slaked lime 3 was added to it.
Add 0% slurry and adjust the pH to 3 levels from 1l to O and temperature 3.
With the combination of 0C and Otsu OC, PH4'~/θ
Nori water ring! For each combination of 3 water groups with 0.3 volume i)% hydrogen peroxide added at 1 degree 30C and 1 degree OC, 1 inch i', Toe z NH, 8s, respectively.
, the behavior of Fθ was investigated. The reaction time for each water cloth was 7j minutes. The results are shown in Table 3.

Details store 7j”, I+ (no change in content) 77 no cj/
From the results in Table 3, it can be seen that most of As and Fe precipitate by pH 4, and that 1'oc is
Most of the Ni can be removed at pH 9 to 6, Ni begins to precipitate at pH 9 to 14, and most of it precipitates at pH 9 to 14.
It can be seen that (7 and above) 1 can be removed well with high culms, and that 19 is as good as 19 in terms of removal of NH3, which is the precipitate of Ni.

This result shows the effectiveness of the present invention, in which the seventh neutralization brings the pH to 1l~B, the hydrogen peroxide solution is added, and the second neutralization brings the PI-19~//.

Applicant: Sumitomo Gold Co., Ltd. 111 Co., Ltd. I1, Representative BH Patent Attorney '11i=R Proceedings/Procedural Amendments (Method) Showa S7 Il Special D 乍 Application No. 1BSGS, 2'j
3 In relation to the 211 cases of persons making supplements I1 Place Shinbashi S-chome, Minato-ku, Tokyo No. 3 Agent 5 Date of amendment order Showa Sg 2116, Invention that can increase power by amendment number (no change in content)

Claims (1)

[Claims] (1) After decoppering the copper electrolytic waste solution and recovering a part or most of the free NI-1 pipe from the decopper-removed wetted solution by dialysis,
Add alkali to make P, H ~ B, add hydrogen peroxide solution, remove all the formed precipitate, add alkali to make P)19~//, add nickel hydroxide to a
Collect the precipitate in one drop. * A method for collecting l+rf5 acid Nisola fathom J1 from copper 71f decomposition waste, which is characterized by leaching the precipitate with dilute sulfuric acid to obtain a nickel sulfate aqueous solution.