JP2817522B2 - How to collect ferro scrap - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for removing copper from ferro scrap in order to recycle the ferro scrap as a raw material for smelting steel. More specifically, the present invention uses an aqueous ammoniacal solution containing ammonia and ammonium salt, by selectively dissolving and removing copper from copper-containing ferro scrap,
The present invention relates to a method for removing copper from ferroscrap which collects and reuses copper as copper oxide or metallic copper while obtaining highly pure ferroscrap suitable for recycling, and particularly to a method capable of accelerating the dissolution of copper.

[0002]

2. Description of the Related Art Ferro scrap often has a high copper content mainly due to the incorporation of copper wires used as electric wires and conductors, and other copper or copper alloy components. For example, waste automobiles, waste electrical appliances, mechanical waste and the like.

[0003] Copper is an element that has an adverse effect on the performance of steel products such as mechanical properties and workability. If ferro scrap mixed with copper is used as a raw material for steel melting, only low-grade steel can be produced. . Therefore, it is desirable to remove copper from ferro scrap, and various copper removal methods have been studied in the past. The following is a typical copper removal method for removing copper from ferro scrap.

[0004] A method of selectively extracting copper from molten iron into a flux mainly containing sodium sulfide or sodium sulfate (122nd and 123rd Nishiyama Memorial Technical Lecture, pp.112-118,
Japan Iron and Steel Association), a method of melting scrap at high temperature and evaporating copper of lower melting point under vacuum (CAMP-ISIJ, Vol. 1 (1988), pp.116
9-1172), a method of mechanically separating and recovering embrittled copper sulfide by compressing or crushing the scrap after sulfided copper in the scrap (Japanese Patent Laid-Open No. 2-285035), aluminum, magnesium or alloys thereof For selectively extracting copper into the molten material of JP-A-3-199314
.

However, this method requires a considerably large amount of flux in order to obtain a high copper removal rate, it is difficult to handle this flux at a high temperature, and the cost of the flux is high. To increase the evaporation rate of copper,
High temperature and high vacuum conditions requiring a large amount of energy are required, and it is difficult to recover copper. In this method, the treatment of waste gas containing sulfur oxides generated in the sulfidation step becomes a heavy burden, and the separation of sulfided copper by mechanical means can remove copper with a sufficiently high copper removal rate. Have difficulty.
Of expensive metal Al, Mg, or Al as an extractant
-Mg alloy is required.

In order to solve the drawbacks of the conventional copper removal method, the present inventor has proposed a method of removing and recovering copper from ferroscrap using an ammoniacal aqueous solution containing ammonia and an ammonium salt (hereinafter referred to as the prior application). (Referred to as an invention) (Japanese Patent Application No. 3-297375). One example of the copper removal process (an example using ammonium carbonate as an ammonium salt) in the prior invention is shown by a solid line in FIG.

In an ammoniacal aqueous solution in the presence of oxygen, copper forms an ammine copper (II) complex with ammonia,
While it dissolves easily, iron does not dissolve at all because it is passivated despite its greater ionization tendency than copper. The prior invention utilizes such properties of copper and iron. That is, when ferro scrap containing copper is treated with an aqueous ammoniacal solution in the presence of oxygen,
According to the following formula (1), copper in the scrap is replaced by ammine copper (II).
It can be selectively dissolved as a complex, and a decopperized high-grade ferro scrap can be obtained. At the same time, from an aqueous ammonia solution that dissolves copper separated from scrap,
Copper can be recovered and ammonia and ammonium salts can be regenerated. As a method for recovering copper, for example, when an ammonium carbonate salt having an anion that forms an unstable salt with copper is used as a copper solution, the copper is oxidized as shown in (2) by heating the solution. It can be recovered as copper and ammonia and ammonium carbonate are regenerated. When a water-soluble salt is formed with copper such as ammonium sulfate, a solution of copper sulfate is formed by heating the solution as shown in equation (3). This copper sulfate solution is electrolyzed, and copper can be recovered as metallic copper. The electrolytic waste liquid and the evaporated ammonia are recycled for the preparation of the solution to regenerate the ammonia and ammonium sulfate.

[0008] ^{_{Cu + 2NH 3 + 2NH 4 +}} + 1 / 2O 2 = Cu (NH 3) 4 2+ + H 2 O (1) Cu (NH 3) 4 CO 3 = CuO ↓ + 4NH 3 ↑ + CO 2 ↑ (2) Cu (NH ₃ ) ₄ SO ₄ ＝ CuSO ₄ + 4NH ₃ ↑ (3) In the copper removal process shown by the solid line in FIG. 1, ammonia and carbon dioxide are absorbed in water to remove ammonia and ammonium carbonate. An aqueous ammoniacal solution is prepared, and the aqueous solution is supplied to a dissolution tank (reaction vessel). An impure scrap containing copper is put into this dissolving tank, and an oxygen-containing gas is supplied to dissolve the copper by the reaction of the above formula (1). The decoppered high-grade scrap is taken out of the dissolving tank, and the leachate in which copper is dissolved is sent to a distillation column to evaporate ammonia and carbon dioxide gas, whereby copper is precipitated as copper oxide by the reaction of equation (2). The bottom is filtered to recover copper contained in the impure scrap as copper oxide. The filtrate is cooled and used as a solution for absorbing ammonia and carbon dioxide gas distilled from the distillation column. Since the ammoniacal aqueous solution containing ammonia and ammonium carbonate is thus regenerated, the regenerated aqueous solution is adjusted in components, circulated to the dissolution tank, and reused for copper removal.

As described above, the copper removal method of the prior invention is
As can be seen from equations (1) and (2), the ammonia and ammonium salts required for the reaction can be completely recovered in principle to regenerate the treated aqueous solution and reused.
Low chemical and wastewater treatment costs and economical. Also, the removal and recovery rate of copper from ferro scrap is high.

[0010]

In order to increase the efficiency of the method for removing copper from ferro scrap, it is important to rapidly carry out the copper dissolution reaction of the formula (1). An object of the present invention is to provide an improved method of removing copper from a copper-containing ferro-scrap according to the above-mentioned prior invention using an aqueous ammonia solution, which can promote the dissolution of copper.

[0011]

According to the present invention, there is provided a method for removing copper from ferro-scrap according to the present invention, wherein ferro-scrap containing copper is treated with an aqueous ammoniacal solution in the presence of oxygen to convert copper in the scrap into ammine copper (II). ) in removing by selective dissolution as a complex, 0.1 ammine copper (II) complex from the time of the beginning of the treatment ammoniacal aqueous solution to be used
3M concentration and the scrap treatment
Solution containing ammine copper (II) complex generated by the method
By recycling a part of the
The ammine copper (II) complex is added to the monic aqueous solution in an amount of 0.1 to
It is characterized in that it is contained at a concentration of 3M . Thereby, the dissolution rate of copper from ferro scrap is remarkably accelerated, and the treatment can be performed efficiently.

[0012]

The present invention can be carried out by a semi-continuous method or a batch method according to the process shown in FIG. Ferro scrap containing copper is immersed in the dissolving tank after being cut into appropriate dimensions if necessary. As shown in FIG. 2, the scrap 1 is stored in a liquid-permeable basket 2 (a basket made of a net or a perforated metal plate) and immersed in an aqueous ammoniacal solution 4 in a melting tank 3.
It is preferable because it can be easily taken out. In the melting tank,
An oxygen-containing gas (pure oxygen, air, or the like) is supplied as an oxidizing agent necessary for oxidizing and dissolving copper. Preferably, as shown in the figure, bubbling is performed in an aqueous solution while also stirring the solution.

In the case of the semi-continuous method, the scrap is processed in a batch system, and the processing solution is processed in a continuous system. That is, the leachate is continuously withdrawn from the dissolving tank, sent to the distillation column, the copper oxide is recovered, the ammoniacal aqueous solution is regenerated, and the components are adjusted. To continuously supply to the dissolution tank. The scrap is immersed in the melting tank until the copper content is substantially completely removed, and then replaced with the next scrap. In the case of the batch method, after performing the immersion treatment of the scrap once or twice or more in the ammoniacal aqueous solution, the whole or a part of the leachate is withdrawn,
It is subjected to the treatment below the distillation column.

The aqueous ammoniacal solution used for the treatment is an aqueous solution in which ammonia and an ammonium salt are dissolved. As the ammonium salt, ammonium carbonate, which can be prepared by blowing ammonia and carbon dioxide gas into water, is most suitable for industrial implementation of the present invention, but other ammonium salts, such as ammonium sulfate and ammonium chloride, are used. It is also possible.

The factors affecting the reaction rate of the copper dissolution reaction in the aqueous ammoniacal solution represented by the above formula (1) include the solution temperature, the intensity of the solution stirring, and the concentrations of the reaction components (ammonia and ammonium salts) in the solution. And the concentration of the reaction product (ammine copper (II) complex). Common sense,
Dissolution is promoted as the solution temperature rises and stirring is strengthened,
From the viewpoint of chemical equilibrium, it is considered that the dissolution becomes faster as the concentration of the reaction components in the solution increases, and conversely, the dissolution becomes slower as the concentration of the ammine copper (II) complex as the reaction product increases. The effects of these factors on the dissolution rate of copper were investigated in detail.

(A) Effect of Ammine Copper (II) Complex Concentration on Copper Dissolution Rate The effect of the concentration of ammine copper (II) complex, a product of the copper dissolution reaction in an aqueous ammoniacal solution, on the copper dissolution rate is investigated. Therefore, the change in the copper dissolution rate with the progress of copper dissolution was examined. As a result, contrary to common sense considering chemical equilibrium, the rate of copper dissolution increases as the copper dissolution reaction proceeds (i.e., as the concentration of the ammine copper (II) complex in the solution increases). There was found. For example, as shown in the examples below, the dissolution rate of copper at 40 ° C.
Only 8 when no ammine copper (II) complex is present in solution
While was mg / cm ² -hr, it increased the ammine copper (II) complex concentration when is present at a concentration of 0.64M to 368 mg / cm ² -hr.

The reason why the dissolution rate of copper is increased by increasing the concentration of the ammine copper (II) complex as the reaction product is considered as follows. When the ammine copper (II) complex is present in the ammoniacal aqueous solution, the dissolution of copper is
In addition to the direct oxidation of copper by oxygen as shown in the above formula (1), the following reaction also proceeds at the same time.

Cu + Cu (NH ₃ ) ₄ ²⁺ = 2Cu (NH ₃ ) ₂ ⁺ (4) 2Cu (NH ₃ ) ₂ ⁺ + 2NH ₃ + 2NH ₄ ⁺ + 1 / 2O ₂ = 2Cu (NH ₃ ) ₄ ²⁺ + H ₂ O (5) That is, when an ammine copper (II) complex is present in an ammoniacal aqueous solution, metallic copper (Cu)
It also dissolves by reaction with the (II) complex to form the ammine copper (I) complex [Cu (NH ₃ ) ₂ ⁺ ]. Ammine copper (I) formed
In the presence of oxygen, the complex is further oxidized to an ammine copper (II) complex through the reaction shown in equation (5). The total reaction of copper dissolution based on the equations (4) to (5) is the same as the direct oxidation of copper with oxygen shown in the equation (1). In other words, the overall reaction of copper dissolution does not change, but the presence of the ammine copper (II) complex (4)
Through the formula (5), the speed of the dissolution reaction is remarkably accelerated. The reason is presumed as follows.

In the direct oxidation reaction of copper with oxygen shown in the formula (1), the solubility of oxygen in an aqueous solution is low, and diffusion of oxygen into metallic copper is rate-determining, so that the reaction rate is low. On the other hand, the dissolution reaction of copper via the reactions of equations (4) to (5) does not require diffusion of oxygen into metallic copper, and the reaction speed is increased. As can be seen from the equations (4) to (5), when the concentration of the ammine copper (II) complex increases, the copper dissolution reaction shown in the equation (4) is accelerated, and the ammine copper (I) shown in the equation (5) is accelerated. The oxidation reaction of the complex is affected in the direction in which it is inhibited. The increase in copper dissolution rate with increasing concentrations of ammine copper (II) complex is due to (5)
This is because the positive effect that appears in the reaction of equation (4) is much greater than the negative effect that appears in the reaction of equation.

The concentration of the ammine copper (II) complex in the aqueous ammoniacal solution used for the treatment increases spontaneously as the dissolution of copper from the scrap proceeds, and the dissolution rate of the copper also increases spontaneously. Ammin copper for speed
(II) It takes a considerable time to reach the complex concentration. Therefore, in the present invention, the ammine copper (II) complex is contained at a concentration of 0.1 to 3 M, preferably 0.3 to 3 M from the start of the scrap treatment, and the oxidative dissolution of copper proceeds rapidly from the start of the treatment. is there. This early ammin copper (II)
If the complex concentration is lower than 0.1 M, the intended oxidative dissolution of copper is not sufficiently promoted. The higher the concentration of the ammine copper (II) complex, the higher the copper dissolution rate. However, if the concentration exceeds 3 M, the precipitation of cuprous hydroxide will be formed on the copper surface, which will hinder the dissolution of copper. , And the upper limit was 3M.

The ammine copper (I) used as a treating solution in the present invention
I) Preparation of the ammoniacal aqueous solution containing the complex, when the scrap treatment is newly started, for example, by absorbing ammonia gas and carbon dioxide gas into water, and first converting the ammoniacal aqueous solution containing ammonia and ammonium carbonate Then, powdered metallic copper or cupric oxide is added to this aqueous solution in an amount of 0.1 M or more to dissolve the solution.
(II) Complex [in this case, Cu (NH ₃ ) ₄ CO ₃ ] can be produced in situ. In order to accelerate the dissolution rate, it is desirable to use powder having a particle size of 1 mm or less and to perform appropriate stirring. When dissolving metallic copper, it is necessary to simultaneously blow oxygen.

Once the process is started, as shown by the broken line in FIG. 1, the ammine copper (II)
By circulating a part of the treatment solution containing the complex in the treatment, the ammine copper (I
I) The complex can be contained at a concentration of 0.1 to 3M.
That is, the dissolution of copper from the scrap has been completed or the leachate in the dissolving tank during dissolution (which contains a considerable concentration of the ammine copper (II) complex formed by the dissolution of copper). Take out only the part, send it to the distillation column, use it to recover copper and regenerate the ammoniacal aqueous solution, process the ammine copper (II) complex by circulating and using the remaining leachate in the dissolution tank after adjusting the components It can be contained in the processing solution from the beginning.

For example, in the case of a batch type treatment, a part of the leachate after the treatment is taken out of the dissolving tank, copper is recovered from the leachate by the steps below the distillation column, and the ammoniacal aqueous solution is regenerated. On the other hand, the leachate remaining in the dissolution tank contains a new amount of ammoniacal aqueous solution
(This may be a reconstituted aqueous ammoniacal solution.) Replenish and use it as a treatment liquid at the next treatment. In the batch-type treatment, the concentration of the ammine copper (II) complex in the treatment liquid in the dissolving tank increases with time, so the concentration of the ammine copper (II) complex at the start of the treatment may be as low as about 0.1M.

In the case of semi-continuous treatment, a part of the leachate withdrawn from the dissolution tank is continuously treated in the steps below the distillation column,
The remaining leachate is returned to the dissolution tank at a predetermined flow rate together with a regenerated and reconstituted aqueous ammoniacal solution for replenishment, so that each concentration of the ammine copper (II) complex, ammonia, and ammonium salt in the treatment liquid in the dissolution tank is reduced. Is preferably kept substantially constant. In this case, the ammine copper (II) complex exists in the treatment liquid from the time when the scrap is put into the dissolving tank.
In this case, since the concentration of the ammine copper (II) complex does not increase with time, the concentration of the ammine copper (II) complex in the treatment solution is 0.3 M
It is desirable to hold the above.

(B) Influence of temperature, reaction component concentration, and stirring intensity on copper dissolution rate As a result of examining the influence of temperature on copper dissolution rate, the reaction rate increased with increasing temperature, but ammonia evaporation also increased. Therefore, it was found that the reaction temperature is preferably 30 to 70 ° C.

The dissolution rate of copper was examined by changing the concentrations of ammonia and ammonium salt (ammonium carbonate), which are reaction components, and it was found that the ammine copper (II) complex was present at a concentration of 0.1 M or more, preferably 0.3 M or more. If you do
Ammonia and ammonium salt concentration of 0.2 M each
It was found that when the concentration was 0.1 M or more, the dissolution rate of copper did not increase so much even if the concentration was further increased. On the other hand, if the concentration of ammonia or ammonium salt is excessively increased, the evaporation of ammonia increases, resulting in poor operability. Therefore, the concentration of ammonia and ammonium salt in the aqueous ammoniacal solution used as the treatment solution is 0.2
２2M and 0.1〜1M are desirable.

It is desirable to stir the solution to promote the dissolution of copper, but it is difficult to mechanically stir using a stirrer or the like because scrap is handled. Then, oxygen-containing gas (pure oxygen or air, etc.) used as an oxidizing agent was blown into the processing solution, and the solution was stirred by bubbling. As a result, it was found that the dissolution rate of copper was increased by increasing the amount of gas blown. That is, the oxygen-containing gas not only functions as an oxidizing agent for copper but also functions as a stirring gas for the processing liquid. Since the flow rate of the oxygen-containing gas required as the stirring gas is larger than that of the oxidizing agent, as shown in FIG. 2, the gas containing unreacted oxygen is recovered from the upper space 5 of the melting tank, and the recovered oxygen-containing gas is recovered. It is preferable that the gas is sent through a gas circulation path 6 to a gas blower 8 arranged at the lower part of the dissolving tank by a pump 7 and blown into the processing solution for circulation.

In the case of pure oxygen gas, as shown in the figure, the entire amount of the recovered gas can be circulated and used. Can be continued. Therefore, no volatilization loss of ammonia occurs. In the case of air, an amount of air corresponding to the consumed oxygen is supplied to the dissolution tank or the gas circulation path, and at the same time, an amount of circulating gas corresponding to the amount of gas other than oxygen in the supply air is discharged out of the system. Therefore, it is desirable to keep the amount of circulating gas substantially constant. In this way, by circulating the oxygen-containing gas and bubbling into the treatment liquid and stirring the liquid, not only the utilization rate of oxygen can be increased, but also the volatilization loss of ammonia can be prevented or significantly reduced.

The treatment of the aqueous solution containing the ammine copper (II) complex discharged from the dissolving tank can be carried out, for example, by the process shown in FIG. 1, but this can be changed as appropriate. For example, in the illustrated example, the copper content in the aqueous solution is recovered by evaporating ammonia and carbon dioxide gas by distillation to decompose the ammine copper (II) complex and recovering it as a precipitate of copper oxide. The copper component may be recovered by electrolyzing an aqueous solution containing copper and depositing copper as metallic copper on the cathode. In this case, when the copper-containing ferro-scrap used as a raw material in the method of the present invention is used for the anode, also in this electrolysis step, copper is selectively dissolved in the electrolytic solution (ammonia-based aqueous solution) from the ferro-scrap of the anode, and Can be recovered as metallic copper.

Examples of the scrap containing copper to be treated by the method of the present invention include the above-mentioned waste automobile, waste electric products, and mechanical waste. If necessary, it is desirable to cut the scrap to a size suitable for processing before processing by the method of the present invention. Further, when an organic coating (eg, enamel coating) is applied to copper in scrap, such as a conductive wire of a motor coil, it is preferable to remove the organic coating and then remove copper. This removal of the organic coating can be carried out by heating the scrap to 400-1000 ° C. and burning off the organic coating.

[0031]

Example 1 Using a copper plate, the effects of the concentration of ammine copper (II) complex and the temperature on the dissolution rate of copper were investigated. A copper plate is immersed in 2 liters of an aqueous solution containing 1.0 M ammonia, 0.5 M ammonium carbonate, and various concentrations of ammine copper (II) complex, and oxygen is blown at 30 ° C. and 40 ° C. at a flow rate of 10 l / min. The copper was dissolved. Aqueous solution with dissolved copper
(Leachate) was sampled periodically, and the dissolution rate of copper was determined from the change in the concentration of the ammine copper (II) complex in the leachate.
The results are shown in Table 1 below.

[0032]

[Table 1]

From the results shown in Table 1, it can be seen that the dissolution rate of copper increases as the temperature increases, but increases significantly due to the presence of the ammine copper (II) complex in the aqueous solution. It can be seen that the effect of promoting the dissolution of copper is much greater with the addition of. That is, ammine copper (II)
The dissolution rate is as low as 0.1M complex
It increased more than 10 times, and increased more than 25 times when the concentration of the ammine copper (II) complex exceeded 0.3 M.

Example 2 A scrapped car was shredded with a copper content of 0.5.
Wt% ferro scrap (shredder scrap)
Using pure oxygen as an oxidant and the apparatus shown in FIG.
Processing was performed batchwise according to the method of the present invention described below.

A stainless steel dissolution tank having an internal volume of 1.5 m ³ was charged with an ammonia concentration of 2.0 M and an ammonium carbonate concentration of 1.0 M.
Injecting aqueous ammoniacal solution 1 m ³ of M, the average particle diameter of 0.05 m
About 32 kg of m 2 copper powder was added. Bubble oxygen for 30 minutes, stir the aqueous solution, completely dissolve the copper powder, NH
₃ concentration 1.0 M, was prepared (NH _{4) 2} CO ₃ concentration _{0.5 M, Cu (NH 3)} 4 CO 3 concentration 0.5 M of the treatment liquid.

The shredder scrap having a weight of 0.5 ton is placed in a dissolving tank, and pure oxygen is circulated at a temperature of about 30 ° C. at a flow rate of 1 m ³ / min for 3 hours. Was dissolved in the treatment liquid. At that time, the oxygen supply was about 380 liters in total. Thereafter, the scrap was taken out, washed with water and dried, and then melted in an electric furnace. As a result, a high-quality electric furnace steel having a copper content of 0.08% by weight was obtained. The copper removal rate was 84%.

After the scrap processing, about 80 liters of the leachate was taken out of the dissolving tank and distilled in the next step to obtain about 34 liters.
00 g of cupric oxide was recovered as a precipitate. On the other hand, about 80 liters of an ammoniacal aqueous solution having an ammonia concentration of 2.0 M and an ammonium carbonate concentration of 1.0 M were separately replenished to the leachate remaining in the dissolving tank to prepare the next treatment liquid. When the scrap was treated in the same manner as above using this treatment liquid, almost the same copper removing effect as above was obtained. In this way, by updating the appropriate amount of the processing solution each time the scrap is processed, it is possible to continue the copper removal processing of the scrap while maintaining the ammine copper (II) complex concentration in the processing solution within a predetermined concentration range. Is possible.

For the sake of comparison, the above shredder scrap was prepared by using an NH ₃ concentration of 1.0 M and (NH ₄ ) ₂ C without using the method of the present invention.
Using an aqueous solution having an O ₃ concentration of 0.5 M and treating for 3 hours while circulating oxygen in the dissolving tank in the same manner as described above, the copper content of the resulting scrap was 0.44% by weight, and the steel quality was remarkable. It was at a level that led to a decline. The copper removal rate was only 12%. According to the method of the present invention, it has been clarified that the presence of an ammine copper (II) complex in the treatment liquid from the beginning significantly improves the copper removal efficiency.

[0039]

According to the method of the present invention, copper can be selectively dissolved at high speed from copper-containing ferro-scrap and removed from the scrap, and the separation and recovery of copper from the scrap are more efficient. Becomes Contrary to common general knowledge, the method of the present invention reduces the concentration of ammonia and ammonium salt and the treatment temperature in the treatment solution by causing the reaction product, an ammine copper (II) complex, to be present in the treatment solution from the beginning. It is based on the finding that copper can be rapidly dissolved without making it too high. As a result, a high copper removal rate can be obtained by suppressing the evaporation of ammonia, and at the same time, the copper dissolved in the processing solution can be processed by a simple process.
Almost all can be recovered as copper oxide or metallic copper. Therefore, the present invention can promote the recycling of scrap, and at the same time, can effectively utilize copper resources, thereby contributing to resource saving.

[Brief description of the drawings]

FIG. 1 is a process chart showing one example of a copper removal process of the present invention.

FIG. 2 is an explanatory view showing one example of a copper removing apparatus that can be used in the method of the present invention.

[Explanation of symbols]

1: Scrap 2: Net basket
3: Dissolution tank 4: Ammonia aqueous solution 5: Upper space
6: Gas circulation path 7: Pump, 8: Gas blower
9: Gas supply route

Claims (1)

(57) [Claims] The method according to claim 1 copper in scrap is treated with ammoniacal solution of ferro scrap in the presence of an oxygen containing copper in removing by selectively dissolved as ammine copper (II) complexes, ammonia to be used The ammine copper (II) complex is contained in the aqueous solution at a concentration of 0.1 to 3 M from the start of the treatment, and is generated by the scrap treatment.
A part of the treatment solution containing the ammine copper (II) complex
Ammonia water used
Ammine copper (II) complex in solution at a concentration of 0.1-3M
Characterized in that the inclusion in, ferro scrap times
Earning method.