JP2770122B2 - How to produce high-purity iron from scrap metal processing - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION The present invention relates to waste iron, which is a waste material of metal working, for example, for research base metal, special alloy raw material,
The present invention relates to a method for producing high-purity iron, which is very highly required for various research and development.

[0002]

2. Description of the Related Art In the various industries of cutting or grinding metal, enormous amounts of chips are generated. Waste metal processing is generated as long as machining continues. The Recycling Law was enacted to use discarded iron with great care, and the focus is on reusing resources. However, it is economically very difficult to effectively reuse waste iron. The reason is that the price of iron scraps has fallen, and the profitability of reusing waste iron by recyclers has been reduced. Even in such an environment, discarded iron is an important resource, and there is an urgent need to use it effectively. In fact, companies that generate large amounts of waste iron dispose of it, ignoring profitability.

[0003] Waste metal generated when cutting or grinding metal is very bulky and time-consuming to dispose of. In order to make it compact, they are pressed together to make waste metal solids, which are then melted in a furnace to make steel again.

[0004] In recent years, the types of iron alloys obtained by adding various metals to iron and steel materials have become more and more enormous, and the enormous amount has made recycling of waste metals even more difficult. The present inventor has paid attention to the fact that a solution of waste iron is electrolyzed into high-purity electrolytic iron and effectively reused as a high-value-added metal. A technique of electrolyzing a solution of a metal to obtain high-purity iron is described in Japanese Patent Publication No. 3-53394. In the method for producing electrolytic iron described in this publication, iron of a predetermined shape is connected to an anode, and high-purity electrolytic iron is deposited on a cathode.

[0005]

In the production method described in this publication, it is difficult to quickly dissolve the raw material iron connected to the anode in the acid solution, and it is not possible to increase the production per hour. If the raw iron cannot be dissolved in the acid solution, the electrolytic iron cannot be deposited on the cathode. This is because the dissolved iron is electrolyzed and attached to the cathode. In particular, when a high current is applied to iron in a state in which the raw material iron cannot be sufficiently dissolved, ferrous ions contained in the solution become ferric ions. In order to produce high-purity electrolytic iron, the solution must be the first
Must be iron ions. This is because, when the ferric ion is used, the solution becomes turbid in reddish brown and high-purity iron cannot be precipitated. Waste iron is a huge amount of metal processing waste.
Therefore, even a method with a small processing capacity cannot be used, even if it becomes high value-added electrolytic iron. Further, the method for producing electrolytic iron described in this publication has a drawback that the raw material iron has a predetermined shape, so that the raw material cost is high and the production price of the electrolytic iron to be produced is high.

Further, Japanese Patent Publication No. 53-28156 discloses a method of recovering iron by electrolyzing waste acid obtained by pickling iron and steel. Iron ions contained in large amounts in waste acid,
It is a method to recover by electrolysis. According to this method, iron contained in waste acid can be recovered and used effectively, but waste iron, which is waste material added to metal, cannot be converted into high-purity electrolytic iron.

The inventor of the present invention has developed a technique for dissolving waste iron in an acid solution and electrolyzing the same to obtain high-purity electrolytic iron in order to solve these conventional various problems ( International Application No. PTC / JP 92/00982). This method electrolyzes almost valueless waste iron into high-purity electrolytic iron, and thus has the advantage that it can be effectively reused as a metal material with extremely high added value. In this method, in order to more efficiently electrolyze a large amount of waste iron, the waste iron is dissolved in a dissolving tank separate from the electrolytic tank. Polishing chips and cutting chips of metal, which are waste materials of metal processing, are dissolved in a melting tank. The solution is transferred to an electrolytic cell to efficiently convert a large amount of waste iron into electrolytic iron. According to this method, a large amount of waste iron can be efficiently dissolved by enlarging a waste iron melting tank. However, since the solution in which the waste iron is dissolved is transferred to the electrolytic cell for electrolysis, it is necessary to adjust the amount of dissolution according to the amount of electrolysis in the electrolytic cell. For this reason, there is a disadvantage that a huge amount of waste iron cannot be dissolved at a time in a large amount.

Further, in the method in which a solution containing iron ions is transferred to an electrolytic cell for electrolysis, the iron ions are oxidized when the current density is increased. When the current density of the electrode is increased, the solution in which the waste iron is dissolved becomes ferrous ions or ferric ions. When the solution in which ferrous ions are converted to ferric ions is electrolyzed, it becomes turbid in reddish brown and cannot deposit high-quality electrolytic iron.

It is another object of the present invention to eliminate these defects. An important object of the present invention is to provide a metal working for efficiently reusing a large amount of waste iron efficiently and as high-quality electrolytic iron. Another object of the present invention is to provide a method for producing high-purity iron from waste wood.

[0010]

According to the present invention, there is provided a method for producing high-purity iron from waste metal processing, comprising the following constitution to achieve the above-mentioned object. In the regeneration treatment of electrolysis of waste iron to produce high-purity electrolytic iron, it is important to dissolve the waste iron promptly. This is because the dissolution rate affects the amount of waste iron that can be processed per unit time. A solution having a high iron ion concentration can deposit a large amount of electrolytic iron by applying a large current to the electrode of the electrolytic cell. Furthermore, a solution having a high iron ion concentration reduces the electric resistance between the electrodes, reduces the power loss in the electrolytic cell, and increases the power use efficiency. This is extremely important for a device for electrolyzing waste iron. This is because electrolytic iron consumes large power and is deposited on the surface of the electrode. The amount of electrolytic iron deposited on the surface of the electrode is proportional to the current. However, the power supplied to the electrolytic cell is the product of the current and the voltage between the electrodes. For this reason, it is very important to lower the voltage between the electrodes in order to reduce the power loss of the electrolytic cell. The method for producing high-purity iron of the present invention has a unique configuration, and quickly dissolves waste iron in a dissolving solution to efficiently produce electrolytic iron.

That is, in the method for producing high-purity iron of the present invention, waste iron containing easily-dissolved abrasive chips or cutting chips is dissolved in a dissolving tank, and the dissolved solution is supplied to an electrolytic tank for electrolysis. Block-shaped waste iron that cannot be easily dissolved is dissolved in a conductive anode container connected to the + side of the power supply. The block-shaped waste iron placed in the anode container is electrically connected to the anode container and is energized. The energized block-shaped waste iron is dissolved as iron ions. The block-shaped waste iron is not easily dissolved in the dissolving liquid like the abrasive waste or the cutting waste, but is reliably brought into electrical contact with the anode container. This is because it is in heavy mass and strongly contacts the anode container. Since the polishing debris and cutting debris are small and light, it is difficult to reliably make electrical contact with the anode container, but they can be easily dissolved. For this reason, waste iron such as polishing dust and cutting waste is melted in the melting tank without being put in the anode container.

Further, in the method of the present invention, in order to efficiently treat a large amount of waste iron, the waste iron is dissolved in a solution in a separate tank from the electrolytic tank, and the solution is supersaturated. The waste iron is precipitated in the form of a metal salt, and the precipitated metal salt is supplied to an electrolytic cell. The metal salt supplied to the electrolytic cell is
It is dissolved in the solution and replenishes the solution with iron ions. The metal salt from which impurities have been removed is dissolved in the dissolving solution more quickly than waste iron. The solution in which the iron ion concentration is increased by the metal salt is electrolyzed, and high-purity iron is produced from waste metal processing. Further, waste iron in the form of a block is put in the anode of the electrolytic cell to perform electrolysis. The block-shaped waste iron placed in the anode container is electrically contacted with the anode container and is energized to be turned into iron ions and dissolved in the solution in the electrolytic cell.

[0013]

According to the method of the present invention for producing high-purity iron from waste materials of metal working, the apparatus shown in FIG. 1, which is a preferred embodiment, is used to convert waste iron into high-purity electrolytic iron in the following steps.

In the melting tank 1, waste iron 2 containing polishing waste or cutting waste, which is waste material of metal working, is melted. The dissolution tank 1 is filled with an acid solution such as sulfuric acid. The waste iron 2 is dissolved in the acid solution to form a solution 3. Since the waste iron 2 is a swarf obtained by polishing or grinding a metal, the waste iron 2 has a large surface area with respect to the weight and is quickly dissolved. Dissolved solution 3 in which waste iron 2 is dissolved
Is a highly concentrated solution containing a large amount of iron ions.

A solution containing a high concentration of iron ions is brought into a supersaturated state to precipitate a metal salt. When the solution 3 in a supersaturated state is allowed to stand, a metal salt is precipitated. To precipitate more metal salt, the solution 3 is cooled. The apparatus shown in FIG. 1 dissolves waste iron in the main tank 1A, filters this through the filter 12, and sends it to the filtration tank 1B. The temperature of the solution 3 in the main tank 1A increases due to the heat of dissolution of the waste iron. A high temperature solution can dissolve a large amount of waste iron in the form of iron ions. Dissolved solution 3 in main body tank 1A in which a large amount of waste iron was dissolved
Is transmitted through the filter 12 to the filtration tank 1B.
Since the filtration tank 1B is not heated by the heat of fusion, heat is released and the liquid temperature drops. When the temperature of the solution 3 decreases, the solubility of the metal decreases, and the supersaturated metal salt 14 precipitates. The precipitated metal salt 14 is taken out and transferred to the electrolytic cell 4. The electrolysis tank 4 includes a metal salt 14 precipitated in the filtration tank 1B and the filtration tank 1
Both of the B solution 3 can be transferred.

The metal salt 14 is dissolved in the solution 3 in the electrolytic cell 4. Dissolution 3 of electrolytic bath 4 in which metal salt 14 has been dissolved
Increases the iron ion concentration. The electrolytic bath 4 can raise the liquid temperature to increase the iron ion concentration. The solution 3 having a high iron ion concentration is electrolyzed in the electrolytic cell 4. When the solution 3 is electrolyzed, the dissolved metal adheres and is deposited on the surface of the negative electrode 5. The metal such as iron deposited here is electrolytic iron having high purity. The solution 3 in which the iron ions electrolyzed in the electrolytic cell 4 are deposited on the electrodes has a low iron ion concentration. The electrolytic cell 4 electrolyzes a block-shaped waste iron 2A in an anode container 6A serving as a positive electrode 6. The block-shaped waste iron 2A is energized through the anode container 6A to replenish the solution 3 with iron ions. The block-shaped waste iron replenishes ferrous ions from the anode container 6A. The ferrous ions supplied to the solution 3 from the anode container 6A prevent the divalent iron ions contained in the solution 3 from being oxidized to trivalent iron ions. Further, ferrous ions are supplied to the solution 3, and electrolytic iron is deposited on the negative electrode 5. The waste iron in the anode container 6A is dissolved as the electrolysis proceeds. When the waste iron dissolves and decreases, the block-shaped waste iron 2A is supplied to the anode container 6A.

[0017]

Embodiments of the present invention will be described below with reference to the drawings. However, the following examples illustrate a method for embodying the technical idea of the present invention, and the present invention does not specify a method for producing high-purity iron as follows.

Further, in this specification, in order to make it easy to understand the claims, the numbers corresponding to the members shown in the embodiments are indicated in the "claims" and "actions" columns. Are added to the members to be used. However, the members described in the claims are not limited to the members of the embodiments.

Hereinafter, a specific example of treating the largest amount of waste iron as waste metal as a waste material of metal processing will be described in detail.

FIG. 1 shows an apparatus for producing a high-purity metal used in an embodiment of the present invention. This apparatus comprises a dissolving tank 1 for dissolving waste iron 2 as a waste material of metal working in an acid solution, a supply means 8 for supplying waste iron 2 to the dissolving tank 1, and a dissolving tank 1 for dissolving waste iron 2 in the dissolving tank 1. Transfer means 9 for transferring the dissolved solution 3 to the electrolytic cell 4, an electrolytic tank 4 for electrolyzing the dissolved liquid 3 supplied from the transfer means 9 to deposit a metal on the surface of the electrode 5, Reflux means 7 for circulating solution 3 to dissolution tank 1
And acid solution supply means 17 for supplying an acid solution to the dissolving tank 1 and the electrolytic tank 4 to maintain the pH at a predetermined value.

The supply means 8 includes a hopper 8A for storing the waste iron 2 and a conveyor 8B for transferring the waste iron 2 from the hopper 8A to the melting tank 1. The conveyor 8B is controlled by the control means 10 for measuring the metal ion concentration in the melting tank 1,
The metal ion concentration in the dissolving tank 1 is controlled by setting it to a saturated state. When the conveyor 8B supplies the waste iron 2 to the melting tank 1,
The concentration of metal ions in the solution 3 increases.

The control means 10 operates the conveyor 8B when the metal ion concentration in the melting tank 1 becomes lower than the set value. When the metal ion concentration becomes higher than the set value, the operation of the conveyor 8B is stopped. The control means 10 is connected to a sensor (not shown) for detecting the concentration of metal ions in the solution 3. A sensor for measuring the conductivity of the solution 3 can be used as the metal ion concentration sensor. This is because the higher the metal ion concentration, the higher the conductivity of the solution 3. The control means 10 shown in FIG. 1 also controls the heater 11A for heating the solution 3. The heater 11A heats the solution 3 to make the waste metal easier to melt. However, since heat is generated when iron, which is a waste metal, is dissolved in sulfuric acid, the heater 11A does not need to constantly heat the solution 3. When the temperature of the solution 3 reaches the set value, the control means 10 stops the energization of the heater 11A.

The dissolving tank 1 is for dissolving the degreased waste iron 2 in an acid solution, and includes a main body tank 1A for dissolving the waste iron 2 and a filtration tank 1B. For the acid solution to be put into the main tank 1A,
Although strong acids such as sulfuric acid, hydrochloric acid and nitric acid can be used, sulfuric acid is most suitable. This is because hydrochloric acid generates chlorine and nitric acid generates nitrogen oxides.

The filtration tank 1B filters the solution 3 in the main tank 1A with a filter 12, and stores the solution 3 that has passed through the filter 12. The filter 12 is connected to the suction side of the supply pump 16. The filter 12 is a porous tube built in a watertightly closed casing and removes carbon, silicon, and the like that are not dissolved in the acid solution, and removes solid matter mixed in the solution 3. The filtration tank 1B cools the solution 3 and deposits the metal salt 14 on the bottom.

The transfer means 9 is a pump for transferring the solution 3 stored in the filtration tank 1B to the electrolytic tank 4. The pump supplies the solution 3 having a high metal ion concentration from the filtration tank 1B to the electrolytic tank 4B.
To maintain the metal ion concentration in the electrolytic cell 4 at a high concentration. The method for producing high-purity iron of the present invention does not necessarily require a transfer means. Metal salt 1 precipitated in filtration tank 1B
4 can be transferred to the electrolytic cell 4 for dissolution. The transfer means 9 is used to transfer the solid metal salt 14 to the electrolytic cell 4 and to transfer the solution 3 having a high metal ion concentration from the filtration tank 1B to the electrolytic cell 4.

The electrolytic cell 4 has a negative electrode 5 in the center and a positive electrode 6 on both sides thereof. -A stainless plate can be used for the electrode 5. -In the vicinity of the stainless steel plate which is the electrode 5,
The dissolving solution 3 is supplied by the transfer means 9. The positive electrode 6 is an anode container 6A made of a conductive metal in the form of a cage and is filled with waste iron. The anode container 6A is electrically connected to the waste iron. Waste iron energized via the anode container 6A replenishes the solution 3 with ferrous iron.
A block type waste iron is used for the anode container 6A. This is because the block-shaped waste iron 2A has good electrical contact with the anode container 6A.

The electrolytic cell 4 has a built-in heater 11B. The heater 11B heats the solution 3 in the electrolytic cell 4 to a predetermined temperature. In the heated solution 3, the mobility of ions is improved and the electric resistance is reduced. Therefore, a large current can be made to flow by lowering the electrode voltage, and power can be used effectively.

The concentration of metal ions in the solution 3 in the electrolytic cell 4 decreases as the electrolysis proceeds. The reflux means 7
The dissolving solution 3 having a reduced metal ion concentration is transferred to the dissolving tank 1 by the transfer pump of the electrolytic tank 4. In the apparatus shown in FIG. 1, the pump of the reflux means 7 and the pump of the transfer means 9 are continuously operated, and the solution 3 having a high metal ion concentration is electrolyzed from the dissolving tank 1 to the electrolytic tank 4, and the solution 3 having a low metal ion concentration is electrolyzed. Circulation from the tank 4 to the dissolution tank 1. Further, the metal salt 14 precipitated in the filtration tank 1B is supplied to the electrolysis tank 4 to keep the metal ion concentration in the electrolysis tank 4 high.

The acid solution supply means 17 includes the electrolytic tank 4 and the main tank 1.
A is supplied with sulfuric acid to maintain the pH at the set value. A pH sensor for detecting pH is provided in the electrolytic cell 4 and the main tank 1A. The pH is set to a set value by detecting the pH with a pH sensor and adjusting the amount of sulfuric acid to be supplied.

A method of collecting high-purity electrolytic iron from waste metal processing using the apparatus for producing high-purity iron shown in FIG. 1 will be described with reference to the flowchart of FIG. Three types of waste iron, which is a waste material under the control of metal, are used: powdered grinding waste, thin, linear cutting waste, and block-shaped solid iron waste. (1) Degreasing Step ((1) in FIG. 2) When depositing a metal on the cathode using the electrolysis method, it is not preferable that the solution 3 is contaminated with oil. In order to prevent the dissolution solution 3 from being stained, the waste iron as a raw material is washed in advance. If the waste iron is water-soluble, wash the waste iron with water. Waste iron of non-water-soluble dirt is alkaline degreasing,
Or clean with acetone. (2) Step of Chemical Dissolution in Acid Solution ((2) in FIG. 2) An acid solution is charged into the main body tank 1A, which is the dissolution tank 1. Sulfuric acid is used for the acid solution. A strong acid such as hydrochloric acid or nitric acid can be used instead of sulfuric acid. The acid solution may be at room temperature, but is preferably 6
Heat to 0-70 ° C. This is to increase the solubility of waste iron. When the waste iron is dissolved in the acid solution, a solution containing ferrous ions is obtained. The solution containing high-concentration ferrous ions is electrolyzed at a large current density to efficiently produce electrolytic iron.

The waste iron is dissolved by the acid solution contained in the main tank 1A of the dissolving tank 1. The waste iron that dissolves in the main tank 1A contains abrasive chips or cutting chips. Ideally, this waste iron is preferably entirely abrasive or cutting waste.
This is because the polishing debris or the cutting debris is quickly dissolved. In the apparatus shown in FIG. 1, the supply means 8 is used to feed polishing waste, which is powdery waste iron, and cutting waste, which is flake-like waste iron. The introduced waste iron is dissolved in the acid solution to increase the iron ion concentration of the solution.

The solution 3 having a high iron ion concentration is filtered by the filter 12 to precipitate the metal salt 14 at the bottom of the filtration tank 1B, or sent to the electrolytic tank 4 by the transfer means 9. The solution 3 sent to the electrolytic cell 4 is electrolyzed to reduce iron ions. The solution 3 having a reduced iron ion concentration is returned to the main tank 1A by the reflux means 7. The circulating solution 3 dissolves waste iron in the main body tank 1A and transfers it to the electrolytic tank 4, and circulates the solution 3 having a reduced iron ion concentration in the electrolytic tank 4 to the dissolving tank 1 for disposal. Makes iron easier to dissolve. Therefore, the dissolving solution can be used efficiently and the transfer means 9 can be used.
And the reflux means 7 are continuously operated, and the electrolytic cell 4 is always filled with high-concentration ferrous ions so that electrolytic iron can be produced efficiently.

When the electrolysis of the electrolytic cell 4 progresses and the pH of the solution 3 increases, the acid solution supply means 17 replenishes sulfuric acid to maintain the pH at a set value. The acid solution supply means 17 keeps the pH of the electrolytic cell 4 preferably in the range of 1.8 to 2.5.

The waste iron, which is abrasive waste and cutting waste, has a large surface area with respect to the weight, and dissolves very quickly in the acid solution in the main body tank 1A. This is very important for converting a large amount of waste iron into electrolytic iron. This is because the processing capacity per time can be increased.

(3) Filtration Step (Step (3) in FIG. 2) The solution 3 in which the waste iron is dissolved in the main tank 1A is filtered by the filter 12. This is for removing impurities such as insoluble carbon and silicon. The filter 12 is provided with the reflux means 7.
The oxidized precipitate contained in the solution 3 sent from the electrolytic cell 4 can also be removed. Further, the filter 12
The oxidized precipitate that accumulates in the solution 3 is redissolved in the flowing solution 3 to be reduced, and is reduced and flows down to the filtration tank 1B. Filtration can be performed by primary and secondary filtration as required. Furthermore, a solution containing only ferrous ions can be obtained by ion exchange.

(4) Step of Precipitating Iron Sulfate as a Metal Salt (Step (4) of FIG. 2) The solution 3 filtered by the filter 12 and stored in the filtration tank 1 B becomes a supersaturated iron sulfate solution. Then, iron sulfate precipitates at the bottom and is deposited. If the filtration tank 1B is heated to room temperature without heating, a large amount of iron sulfate is deposited. The precipitated iron sulfate is taken out of the filtration tank 1B and stored in the storage tank 15, or is directly transferred to the electrolytic tank 4 without storage. The iron sulfate in the storage tank 15 is transferred to the electrolytic tank 4 by the replenishing means 18,
Alternatively, they can be transferred manually. The iron sulfate replenishing means 18 detects the iron ion concentration in the electrolytic cell 4 and
When the iron ion concentration of the iron oxide decreases, iron sulfate can be replenished. Further, as shown in FIG.
The electrolytic solution can be supplied to the electrolytic cell 4 in a bag 19 through which the liquid can freely permeate. The iron sulfate in the bag 19 is dissolved to supply iron ions. The method of temporarily storing the iron sulfate taken out from the filtration tank 1B in the storage tank 15 without immediately transferring the iron sulfate to the electrolytic tank 4 and supplying the iron sulfate to the electrolytic tank 4 is based on the method of dissolving the waste iron per hour and the dissolving ability. There is no need to balance the per-hour performance of the process of electrolyzing the liquid to produce high-purity iron.
Even if the capacity per hour of the step of dissolving a large amount of waste iron in the dissolution tank 1 and dissolving the waste iron exceeds the capacity per hour of the step of electrolyzing the solution to obtain high-purity iron, the capacity exceeds the capacity. This is because the portion can be stored in the storage layer 15 in the state of iron sulfate.

The electrolytic cell 4 can be replenished with a large amount of iron sulfate so that the solution 3 becomes saturated. In the electrolytic cell 4, when iron sulfate precipitates at the bottom and the ferrous ion abundance decreases, the iron sulfate dissolves and the ferrous ion concentration is kept constant.

(5) Step of electrolyzing the solution 3 in the electrolytic cell 4 (FIG. 2)
Step (5)) The electrodes of the electrolytic cell 4 are energized to electrolyze the solution 3.
As the electrolysis proceeds, ferrous ions contained in the solution 3 precipitate on the surface of the negative electrode 5. The amount of iron deposited on the electrode 5 is proportional to the magnitude and time of the current flow; Theoretically, when 96500 coulombs of electricity are supplied,-
One gram equivalent of iron is deposited on the electrode 5.

As the electrolysis proceeds, ferrous ions, which are useful divalent iron ions contained in the solution, become trivalent iron ions harmful to the production of electrolytic iron by air oxidation or anodic oxidation. Is the ferric ion. Further, the concentration of ferrous ions contained in the solution decreases, and the rate of producing electrolytic iron decreases. In order to replenish the electrolytic tank 4 with ferrous ions, solid iron scraps, which are block-shaped waste irons 2A, are placed in the anode container 6A of the positive electrode 6 and electrolyzed. The solid iron scrap contacts the anode container 6A and is energized, gradually dissolves in the solution 3, replenishes the ferrous ions, and prevents oxidation of the ferrous ions into ferric ions.

In order to prevent carbon or the like contained in the solid iron scrap put in the anode container 6A from being mixed into the solution 3 to form slag, the anode container 6A
Covered by 3. As described above, the method in which the solid iron scrap is put into the anode basket serving as the anode container 6A and electrolyzed has a feature that the solid iron scrap can be effectively used. The cathode is made of stainless steel and is disposed between the anode baskets on both sides to deposit electrolytic iron on both sides.

When the electrolytic cell 4 electrolyzes the solution 3,
When the temperature of the solution 3 is increased, the conductivity of the solution is improved, and a large amount of electrolytic iron can be deposited by electrolysis at a high current density. Specifically, the solution 3 is heated to about 50 to 90 ° C. by the heater 11B.

(6) Step of transferring the low-concentration iron ion solution to the dissolving tank 1 (step (6) in FIG. 2) This step is a step in which the electrolytic solution is processed while being electrolyzed in the electrolytic tank 4. As the electrolysis continues, the ferrous ion concentration decreases. The reflux means 7 sucks the solution 3 at the bottom of the electrolytic cell 4 and circulates the solution 3 in the solution tank 1. The dissolving tank 1 dissolves the waste iron and regenerates the iron sulfate solution sent from the electrolytic tank 4 to the dissolving tank 1. When the pH of the main tank 1A increases in this step, the acid solution supply means 17 replenishes sulfuric acid to maintain the pH at the set value.

(7) (8) Washing and Drying The obtained electrolytic iron is washed and dried so that the obtained electrolytic iron does not rust, and the production of the objective high-purity electrolytic iron is completed.

When the solution of waste iron was electrolyzed under the conditions shown in Table 1 in an electrolysis environment, high-purity electrolytic iron having the components shown in Table 2 could be produced.

[0045]

[Table 1]

[0046]

[Table 2]

[0047]

The method of the present invention for producing high-purity iron from waste metal processing has the following excellent features. According to the production method of the present invention, an enormous amount of abrasive waste or cutting waste, which is waste iron, is dissolved in a melting tank, and the block-shaped waste iron is put into an anode container of an electrolytic tank and melted. The block-shaped waste iron placed in the anode container is dissolved to replenish iron ions to the electrolytic cell. In particular, the waste iron in the form of a block placed in the anode container comes into electrical contact with the anode container and becomes easily energized. The block-shaped waste iron to be energized replenishes the electrolytic cell with iron ions. The block-shaped waste iron is not easily dissolved in the dissolving liquid like the abrasive waste or the cutting waste, but is reliably brought into electrical contact with the anode container. This is because it is in heavy mass and strongly contacts the anode container. Since the polishing debris and the cutting debris are small and light, it is difficult to reliably make electrical contact with the anode container.
Therefore, waste iron such as grinding dust and cutting waste is dissolved in the dissolving tank without being put in the anode container, and block-shaped waste iron that is easily in electrical contact with the anode container is put in the anode container and melted in the electrolytic tank. . Therefore, the method for producing high-purity iron of the present invention has a feature that high-purity iron can be efficiently produced using both waste iron such as grinding waste and cutting waste and block-like waste iron as raw materials.

[0048]Furthermore, the production method of the present invention treats a large amount of waste iron.
To produce high-purity electrolytic iron efficiently and in large quantities.
There is a head. In particular, the method of the present invention
And both block-type waste iron and
And supplied to the electrolytic solution, and the first
Prevents iron ions from turning into ferric ions, resulting in large currents
The feature is that high quality electrolytic iron can be deposited by flowing. Electrolytic iron
To produce large quantities of per unit time,
Current must be increased. Production volume of electrolytic iron
This is because it increases in proportion to the current. For this reason, a large amount
In order to produce electrolytic iron efficiently, a large current
It is important to understand. Electricity of electrolyte containing iron ions
Decomposition is a unique property that is different from electrolysis of other metals
There is. That is, iron becomes divalent or trivalent depending on conditions
Because it changes. When electrolyzed, contained in electrolyte
Ferrous ion is trivalent ferric ion Become an ion
This makes it impossible to produce high-quality electrolytic iron. However,
That is, when the electrolytic solution is electrolyzed with a large current,
The iron ions contained in ferrous ions are changed from ferrous ions to ferric ions.
Tend to be. Ferrous ion contained in lysate is reduced
When it comes to ferric ions, the quality of electrolytic iron is not good.
You. The method of the present invention overcomes this disadvantage in a unique way
It was a success. Polishing easy to dissolve in acid solution
Waste iron, including scraps and cuttings, is quickly turned into acid solution in the melting tank.
Dissolve, but block-type waste iron is applied to the anode.
Dissolve in the node container. Supplied to the anode container
Block type waste iron is electrolyzed during the electrolysis process.
The gas is energized in a gaseous manner, and is forcibly dissolved in the electrolytic solution.
Replenish iron ions. Blocks placed in the anode container
The waste iron in the form of iron is electrically energized and is forcibly converted into an electrolyte.
Is dissolved, so it is proportional to the magnitude of the current
The amount of dissolution also increases. Therefore, a large current is passed
In an environment where ions can easily become ferric ions,
Replenish the ions, ferrous ions become ferric ions
To effectively prevent And block-shaped waste iron is
By being energized, more is dissolved. others
To produce high-purity iron from waste metal processing of the present invention
The method is to electrolyze with a large current and to produce a large amount of electrolytic iron in a short time
High quality of electrolytic iron produced despite its production
Realize the outstanding features that can be achieved. That is,
Ming's manufacturing method uses a large amount of waste iron
In addition to the fact that
And, with the block-shaped waste iron put in the anode container,
While preventing ferrous ions from turning into ferric ions,
By electrolysis with a large current, a large amount of high
Realizes the feature that can produce high purity electrolytic iron. Large amount of waste
To produce a large amount of high-purity electrolytic iron per unit time from iron
In addition, at least two requirements are important. It's a lot
Dissolving the waste iron in the dissolving solution in a shorter time
By increasing the current of gas decomposition, a large amount of high purity
Is to deposit as electrolytic iron. Production method of the present invention
Has achieved this in a unique way
It is.  Furthermore, the waste iron is dissolved in a separate tank from the electrolytic tank.
Precipitate in the form of metal salt, supply metal salt to electrolytic cell
The production method of the present invention, in which gas is decomposed, generates a huge amount of waste iron.
Dissolves in a small amount to produce high-purity iron efficiently.
You. It dissolves waste iron in acid solution and keeps it in the form of metal salts.
Because they can exist. The stored metal salt is supplied to the electrolytic cell
Then, it is electrolyzed into high-purity iron. Discard in this way
The method of treating iron to high-purity iron is to use a melting tank with an electrolytic tank.
There is no need to dissolve waste iron according to the ability to electrolyze.
No. The melting tank dissolves a large amount of waste iron
Can manufacture salt and save excess metal salt
You. The metal salt to be stored is supplied to the electrolytic cell to
Replenished and electrolyzed into high-purity iron.

Therefore, the method for producing high-purity iron of the present invention realizes the effective reuse of waste iron as high-purity electrolytic iron with very high added value. That is, the method of the present invention realizes an epoch-making feature that waste iron, which is considered to be difficult to recycle economically, can be effectively reused as high-purity iron with high utility value. The technology of the present invention, which makes effective use of discarded iron that has been discarded without being used effectively and turns it into highly valuable high-purity iron, has made it possible to save resources on a global scale and will be increasingly used in the future Effective utilization of important resources can be realized.

[Brief description of the drawings]

FIG. 1 is a block diagram showing a specific example of an apparatus for producing high-purity iron from waste metal processing according to an embodiment of the present invention.

FIG. 2 is a flowchart for producing high-purity iron using the apparatus shown in FIG. 1;

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Dissolution tank 1A ... Main body tank 1B ... Filtration tank 2 ... Waste iron 2A ... Block-shaped waste iron 3 ... Dissolution liquid 4 ... Electrolysis tank 5 ...- Electrode 6 ... + electrode 6A ... Anode container 7 ... Reflux means 8 ... Supply Means 8A ... Hopper 8B ... Conveyor 9 ... Transfer means 10 ... Control means 11A ... Heater 11B ... Heater 12 ... Filter 13 ... Anode bag 14 ... Metal salt 15 ... Storage tank 16 ... Supply pump 17 ... Acid solution supply means 18 ... Supply means 19 ... bag

 ──────────────────────────────────────────────────続 き Continuation of the front page (56) References JP-A-59-67396 (JP, A) JP-A-58-174531 (JP, A) JP-A-55-2796 (JP, A) JP-A-4- 9490 (JP, A)

Claims (2)

(57) [Claims] Claims: 1. A waste material for metal working, which comprises polishing waste or cutting.
Waste iron containing shavings (2) and block-shaped waste iron (2A)
In the method for producing high-purity electrolytic iron by dissolving both of them into iron ions and electrolyzing a solution (3) containing iron ions in an electrolytic cell (4) to precipitate iron on the electrodes, Waste iron (2) containing scraps or cuttings is dissolved in an acid solution in a dissolving tank (1), and a solution (3) in which the waste iron is dissolved is supplied to an electrolytic tank (4). (2A) replenishes the solution (3) of the electrolytic cell (4) with iron ions by placing it in a conductive anode container (6A) connected to the + side of the power supply, (5) A method for producing high-purity iron from waste metal processing, characterized by depositing electrolytic iron. 2. A waste material on a metal coating, wherein the waste material is abrasive dust or cutting.
Dissolve both waste iron containing shavings and block-shaped waste iron in an acid solution, and electrolyze the dissolved solution in which the waste iron is dissolved in an electrolytic tank. In the method for producing a wastewater, waste iron (2) containing polishing waste or cutting waste is dissolved in a solution in a separate tank from the electrolytic cell (4), and the solution is supersaturated to precipitate waste iron in a metal salt state. The precipitated metal salt (1
4) is supplied to the electrolytic cell (4), and the waste iron (2)
A) replenishes the solution (3) of the electrolytic cell (4) with iron ions by placing it in a conductive anode container (6A) connected to the + side of the power supply, and then dissolving the solution (3) in the electrolytic cell (4). A method for producing high-purity iron from waste metalworking, characterized by electrolyzing 3) to deposit electrolytic iron on the electrode (5).