JPS6044255B2 - How to recover nickel components - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for efficiently recovering a nickel component at a high concentration from an aqueous solution containing the nickel component.

Aqueous solutions containing nickel components are generated, for example, from nickel wet scouring processes, especially solvent extraction processes, liquid purification processes, and wet or semi-wet desulfurization processes, and metal surface treatment processes, especially aluminum electrolytic coloring processes. Usually, these aqueous solutions often contain calcium components, magnesium components, other heavy metal components, alkali metal components, etc.

Conventionally, methods for removing nickel components from aqueous solutions containing nickel components include the coagulation precipitation method and the method of ionizing the nickel component and then treating it with a chelate resin. cannot be completely processed because it forms a complex nickel-ammine complex.

For this reason, some methods have been used to form nickel sulfide using a sulfurization method and separate it by precipitation, but this method not only makes it difficult to reuse the recovered nickel sulfide from both a technical and cost perspective. Since hydrogen sulfide is used, it is inevitable that the workability (bad odor) is poor. On the other hand, the method using chelate resin is superior in terms of equipment and workability, and is incomparable to other conventional methods, especially in that it can completely remove and recover the nickel component.

The present inventors have conducted various research on recovery methods for nickel components using chelate resins, and have already filed a patent application for an effective recovery method.As a result of further research, they discovered that nickel components can be recovered as a specific nickel-ammine complex. The inventors of the present invention found that treatment with a chelate resin significantly improves the rate of adsorption between the chelate resin and nickel, resulting in a significant improvement in the actual adsorption capacity.

That is, in the present invention, when an aqueous solution containing a nickel component is treated with a chelate resin to recover the nickel component,
The aqueous solution is treated with an ammonia-containing alkaline agent to make an alkaline aqueous solution, then treated with a chelate resin having nitrogen as a chelate ligand to adsorb the nickel component, and further eluted with a mineral acid aqueous solution to obtain a highly concentrated aqueous solution. This is a method for recovering a nickel component, which is characterized in that it is recovered as an aqueous nickel salt solution.

In the method of the present invention, an aqueous solution containing a nickel component is treated with an ammonia-containing alkaline agent to form an alkaline aqueous solution, and this alkaline aqueous solution is treated with a chelate resin.

This pretreatment is to convert the nickel component into a nickel-ammine complex ion, but normally in such treatment, Ni (
A mixture of complex ions of NH3)N2+ (where n=1 to 6) is formed, and the amount of each nickel-ammine complex ion varies depending on the pH. That is, on the acidic side of pH 7 or lower, there are many nickel-ammine complex ions with n = 1, 2, on the alkaline side with pH 7 or higher, there are many nickel-ammine complex ions with n = 3 to 6, and especially on the pH 7.5 or higher, there are almost no nickel-ammine complex ions. Those with n=2 or less are not contained. The method of the present invention selectively adsorbs the nickel component as a nickel-ammine complex ion, especially a nickel-triamine complex ion with n=3 or more, using a chelate resin having nitrogen as a chelate ligand. However, it is not clear why such nickel-ammine complex ions with n=3 or more are particularly likely to be adsorbed by chelate resins.

However, for example, the reason why nickel-ammine complex ions with n=3 or more are particularly easy to exchange adsorption with Uniselect Electrolyte-30 (manufactured by Unitika), which has an iminodiacetic acid group in the chelate group, is that the complex ions are adsorbed in the form shown in the following formula. Since nickel exhibits a hexadentate ligand, three NH3 ligands are bound together, and the remaining NH3 becomes ammonium ions, which exhibit a buffer effect and improve the exchange adsorption rate.

The chelate resin that has adsorbed nickel components in this way is eluted with an aqueous mineral acid solution such as sulfuric acid or hydrochloric acid! , the nickel component is easily desorbed from the chelate resin and becomes nickel sulfate,
It can be recovered as an aqueous solution of nickel salts such as nickel chloride.

If you want to avoid contamination with ammonia during this recovery, first elute the ammonia by treating with dilute acid, then
It can be treated with a normal mineral triacid aqueous solution. The chelate resin having nitrogen as a chelate ligand used in the present invention includes, for example, a base resin such as polystyrene, phenol-formalin resin, or polyacrylic resin, a functional group of a monoamine, diamine, or polytetraamine compound, iminodiacetic acid,
Also included are derivatives thereof, amino acids such as glycine, and those having functional groups such as derivatives thereof.

Treatment with an ammonia-containing alkaline agent refers to the addition of ammonia water, ammonia gas, etc., and substantially removes the contained nickel component from the nickel triamine complex ion (n
=3 to 6) complex ions (PH7 or higher). In particular, it is desirable that the treatment with an ammonia-containing alkaline agent adjusts the pH of the aqueous solution to 7.5-11. In the method of the present invention, the temperature at which the nickel component is exchanged and adsorbed by the chelate resin may be at room temperature, but in some cases it may be desirable to raise the temperature to about 40 to 60°C in order to maintain the solubility of the nickel component.

The exchange adsorption method for nickel components usually involves filling a cylindrical column (often with rubber lining on the inside) filled with chelate resin, and passing water through a pretreated nickel-containing aqueous solution from above the column to perform exchange adsorption. .

The water flow rate at this time is 1 to 20 [1] in space velocity (SV).
/HO is practically preferable. This water flow rate also depends on the concentration of nickel component, and the nickel concentration is several hundred mg/
If less than e, S■ = 5 to 20 [1/Hr], several 100
From m9/' to around 10g/f, SVl~8[1/HO
degree is preferred.

If it exceeds this range, the adsorption efficiency will substantially deteriorate, and if it is too slow, the initial cost of the device will increase, which is economically disadvantageous. A three-tower merry-go-round or a two-tower merry-go-round system is advantageous for the column arrangement. The nickel component adsorbed on the chelate resin may be eluted and recovered by a general mineral acid elution method. As a mineral acid, the usual 2~? Using sulfuric acid and hydrochloric acid aqueous solutions, this is applied from the top of the column at a flow rate of SV.
The liquid is passed at a rate of approximately 0.5 to 2 [1/Hr]. If only acid is passed during this treatment, the amount of free acid in the eluent will be excessive and the quality of the eluent will deteriorate. After that, all you have to do is to run water at a constant flow rate and do what is called "watering". The quality of the recovered liquid obtained in this manner is 45 g/e or more in terms of nickel concentration, and if the nickel is further separated and recovered, a high-concentration nickel salt solution with a nickel concentration of 60 to 70 g/l or more can be recovered. The fact that a highly concentrated nickel salt aqueous solution can be recovered in the method of the present invention indicates that the chelate resin has a large exchange adsorption capacity for nickel. Furthermore, the effects obtained by the method of the present invention are, for example, 1
5 g/f of nickel is contained in concentrated ammonium sulfate of about 0.00 g/', the pH is changed, water is passed through the chelate resin layer, and the exchange capacity (BTC) at the flow-through point where the nickel outflow concentration is 5 mg/e is measured. The result (temperature 40'C, SV=2
[1/Hr]), on the acidic side of PH5-7, BTC is only about 0.3 m0I/EResin, but at PH7
If the pH is above 7.5, it will rise rapidly, and if the pH is above 7.5, BTC will be 0.
．． This is clear from the fact that it is 6m01/e-Resin or more. Furthermore, even in the normal method, that is, when treating a nickel-containing aqueous solution with a chelate resin as an acidic aqueous solution, the exchange capacity at the AC point where the nickel outflow concentration is 5 m9/f is approximately 0.2 to 0.4 m01/ERe under the same conditions.
It is clear that the method of the present invention is an excellent method for recovering nickel components. The method of the present invention improves the exchange adsorption rate of the chelate resin for the nickel component, thereby improving the utilization rate of the exchange adsorption capacity. Therefore, in actual processing, the number of resin exchange and regeneration treatments can be reduced or the processing speed can be improved. This makes it possible to significantly reduce processing costs.

Furthermore, since the nickel salt aqueous solution recovered by the method of the present invention has a high concentration, it is convenient to recycle the recovered nickel component. Furthermore, since the method of the present invention does not lose its effectiveness even when it contains ammonium sulfate etc. at a high concentration, the method of the present invention is applied to an ammonium sulfate aqueous solution containing a nickel component used in the wet smelting process of nickel. Then, the nickel component can be recovered at a high concentration, and at the same time, the treated water can be recycled as it is to the nickel wet scouring process for reuse.

Next, the present invention will be explained in more detail with reference to Examples.

Example 1 FIG. 1 shows an example of an adsorption experimental apparatus for carrying out the method of the present invention.

In Fig. 1, a glass column 1 with an inner diameter of 1.2 cm and a length of 150 (7 ft) is filled with a predetermined amount of chelate resin 2, and the glass column 1 is covered with a hot water jacket 3. Control the temperature.

Thermometer 5 checks the temperature during operation. This glass column 1 consists of 3 model raw water tank 6, sulfuric acid tank 7, and ion water tank 8.
A metering pump 9 is used to pump a specified amount of liquid from two tanks.
It is connected to these three tanks 6, 7, and 8 via.

Furthermore, the liquid passed through the chelate resin layer and treated is separated and received by a fraction collector 10, and sampled and analyzed at regular intervals.

On the other hand, as a model raw water, dissolve nickel sulfate as a nickel salt in 100 y/f of ammonium sulfate, adjust it to 5 g/' in terms of nickel, and adjust the pH of the raw water to 8.5 with ammonia water.
Adjusted to ±0.1.

The jacket temperature was set to 40°C, the chelate resin Uniselect UR-30 (manufactured by Unitika) containing iminodiacetic acid groups was filled to a height of 80 cm (resin amount 90 m1), and the model raw water was pumped from the raw water tank 6 using the pump 9. 2 [1/Hr]
Water was passed through the glass column 1 at a flow rate of .

The nickel component leaked out from around the area (where the model raw water flow rate is 8 times that of the chelate resin) (corresponding to zone A), but the flow continued and the model raw water flow was stopped at 1 volume (corresponding to zone C). )did. Next, ionized water was passed through the ionized water tank 8 in an amount twice that of the chelate resin (corresponding to zone D) for washing. moreover? -Sulfuric acid in H2SO4 aqueous solution tank 7 is SV=
Flow 36 mL (0.4 times the amount of chelate resin) at a flow rate of 1 (corresponding to zone B), then add 144 mL of ionized water at the same rate.
A so-called watering operation was carried out by pouring ml of chelate resin (1.00 g of chelate resin).

The analysis results of the water-treated liquid at this time are shown in Figure 2.

Figure 2 shows the respective solutions in which the fraction corresponding to zone B (one volume of 12.8 to 13.8 times the chelate resin, i.e. 90 ml) was used as the recovered liquid, and the treated water was used in zone A. The quality was as follows.

On the other hand, an aqueous solution (solution A) containing 5 g/e of nickel sulfate in terms of nickel, and an additional 100 g/e of ammonium sulfate.
When water was passed through the chelate resin layer under the same conditions, an aqueous solution in which nickel was dissolved (B solution...no pH adjustment by addition of ammonia) was passed through the chelate resin layer under the same conditions. started leaking.

Therefore, the chelate resin was treated with an aqueous solution of sodium chloride to change the terminal end of the chelate ligand to Na type, and the solution was passed through the resin in the same manner. However, in this case as well, the nickel component leaked out when three times the amount of resin was passed through solution A and twice the amount of resin was passed through solution B, and both were far inferior to the method of the present invention. Ta.

[Brief explanation of the drawing]

FIG. 1 shows an example of an experimental apparatus for carrying out the method of the present invention. 1... Glass column, 2... Chelate resin, 3... Jacket, 4... Constant temperature chamber,
5...Thermometer, 6...Model raw water tank, 7
...Sulfuric acid tank, 8...Ion water tank, 9.
... Metering pump, 10 ... Fraction collector. Figure 2 shows the analysis results of the treated liquid when the method of the present invention was carried out using the apparatus shown in Figure 1, and the horizontal axis shows the amount of liquid passed through the chelate resin as a multiple of the resin volume. The vertical axis shows the concentration of nickel ions in the treatment solution [g/e].

Claims (1)

[Claims] 1. When recovering the nickel component by treating an aqueous solution containing a nickel component with a chelate resin, the aqueous solution is treated with an ammonia-containing alkaline agent to make an alkaline aqueous solution, and then the chelate ligand is 1. A method for recovering a nickel component, which comprises treating the nickel component with a chelate resin containing a nickel salt to adsorb the nickel component, and further eluting the nickel component with an aqueous mineral acid solution to recover it as a highly concentrated aqueous nickel salt solution. 2. The recovery method according to claim 1, wherein the alkaline aqueous solution has a pH of 7.5 to 11. 3 Highly concentrated nickel salt aqueous solution has 45% nickel content as a nickel component.
The recovery method according to claim 1 or 2, which contains nickel in an amount of g/l or more.