JP2010196143A - Method for recovering metal in solution by reduction, and apparatus for recovering the same by reduction - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a reducing and recovering method for reducing metal ions such as copper and bismuth contained in a solution and efficiently recovering the metal, and to provide an apparatus therefor. <P>SOLUTION: In the method for reducing metal ions by bringing a treatment solution containing the metal ions in contact with a reducing agent and recovering the metal, the method for recovering the metal in the solution by reduction includes: setting a contact part of the treatment solution with the reducing agent at the upper part of the liquid surface of the treatment solution to separate a contact reduction region from the inside of the treatment solution; making the treatment solution which has contacted the reducing agent flow down to a treatment solution tank in a lower part; and recovering precipitated metal which deposits in the treatment solution tank. The apparatus for reducing the metal ions and recovering the metal includes: the treatment solution tank having a solid-liquid separation function; a reducing-agent storage part placed above the liquid surface of the treatment solution tank; a means for extracting the treatment solution and sending it to the reducing agent storage part; and a means for extracting the precipitated metal which has deposited on the bottom of the tank. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a reduction recovery method and apparatus for efficiently recovering metal ions such as copper and bismuth contained in a liquid by reduction.

As a method for recovering metal ions contained in factory effluent, etc., a method and apparatus for performing metal ion reduction and precipitation using a metal having a lower oxidation-reduction potential than these metal ions, and separating and solid-liquid separation. Is conventionally known. For example, the recovery of copper ions by iron is known, as shown in the following formula, in which copper ions in the liquid are reduced by iron and the precipitated copper precipitates are recovered by solid-liquid separation. Cu ⁺² + Fe = Fe ⁺² + Cu ↓

  Specifically, for example, as an apparatus for reducing and recovering copper from molten slag of copper smelting, a storage tank for storing molten slag, a metal iron contact portion suspended so as to contact the molten slag in the storage tank, the contact portion There is known an apparatus for recovering metallic copper deposited on the bottom of a tank by bringing metallic iron into contact with molten slag, reducing and precipitating copper ions in the slag, and means for moving the metal up and down (Japanese Patent Laid-Open No. Hei 8). -193229).

Further, the following apparatuses are known as apparatuses for reducing and recovering copper ions and bismuth ions contained in the drainage liquid using iron scrap or iron powder. An outline of a conventional reduction recovery apparatus is shown in FIG.
(A) An apparatus for supplying iron scrap and original liquid to a drum-type reduction tank and reacting them, and separating and recovering the post-reduction liquid containing iron ions and metallic copper powder or metallic bismuth powder.
(B) An apparatus (US Pat. No. 4,201,573) for supplying iron scrap and an original solution to a vibrating reduction tank and reacting them to separate and recover the post-reduction solution containing iron ions and metallic copper powder or metallic bismuth powder. (Publication).
(C) A cone-shaped net-like storage unit is provided in the reduction tank, iron scrap is put into the storage unit, and the original solution is supplied from the bottom of the tank so that the iron scrap is immersed, and the post-reduction liquid containing iron ions That overflows from the top of the tank and collects metal copper powder or metal bismuth powder from the bottom of the tank.
(D) In a corn type reduction tank, the original liquid supplied from the tank bottom and the iron powder charged from the top into the tank are reacted, and the post-reduction liquid containing iron ions and metallic copper powder or metallic bismuth powder. For solid-liquid separation and recovery (described in US Pat. No. 3,154,411).

JP-A-8-193229 U.S. Pat. No. 4,201,573 U.S. Pat. No. 3,154,411

  The reduction recovery apparatus of patent document 1 was proposed by the present applicant, and can control the reduction reaction by moving the metal iron contact portion up and down to efficiently and easily reduce and recover copper from the molten slag. It has the advantage that it can. However, it requires a means for vertically moving the metal iron contact portion.

  All of the above devices (a) to (d) have a problem that it is difficult to control the reduction reaction because the catalytic reduction zone is in the processing liquid. Furthermore, in the apparatus (b), since iron scrap is mixed in the liquid, it takes time to separate the solid and the liquid. Further, the apparatus (b) is economically disadvantageous because it consumes a lot of energy to vibrate the entire apparatus. Furthermore, since the apparatus (d) uses iron powder, the reduction reaction is fast, but the control of the reaction is difficult. Therefore, there is a problem that the reduction reaction proceeds excessively and hydrogen gas or the like is generated. Moreover, since iron powder is expensive compared with iron scrap, it is economically disadvantageous. Furthermore, iron powder is likely to be mixed into the recovered metal powder, and a large amount of metal powder-containing slurry equal to the amount of liquid flow needs to be subjected to solid-liquid separation.

  For this reason, the apparatus (c) is widely used, but since it is a reduction reaction in liquid, the reaction cannot be stopped immediately, and there is a problem that it is difficult to take measures for temperature control and gas generation.

  The present invention solves the above-mentioned problems in the conventional recovery method or recovery device, and the contact reduction zone is formed by placing the contact portion between the treatment liquid containing metal ions and the reducing agent above the liquid surface of the treatment liquid. Separating from the treatment liquid, making it easy to control the reduction reaction, and suppressing the mixing of the reducing agent into the treatment liquid, facilitating the recovery of the precipitated metal, and the deposited metal and the supernatant treatment liquid in the treatment liquid tank And a method for recovering and recovering metal in the liquid and reusing the supernatant treatment liquid.

The present invention relates to a method and apparatus for reducing and recovering metal in a liquid, which has solved the conventional problems with the following configuration.
[1] In a method of reducing a metal ion by bringing a metal ion-containing treatment solution into contact with a reducing agent and recovering the metal ions, contact reduction is performed by placing a contact portion between the treatment solution and the reducing agent above the surface of the treatment solution. The metal in the liquid is characterized by separating the zone from the liquid of the processing liquid, causing the processing liquid in contact with the reducing agent to flow down to the lower processing liquid tank and recovering the deposited metal deposited in the processing liquid tank Collection method.
[2] A part of the processing liquid is extracted, poured into a reducing agent installed above the liquid level of the processing liquid tank, the processing liquid and the reducing agent are brought into contact with each other, and the processing liquid flows down to the processing liquid tank together with the deposited metal. The treatment liquid tank has a solid-liquid separation function, and the deposited metal is allowed to sink to the bottom of the tank. On the other hand, the supernatant treatment liquid is extracted and brought into contact with the reducing agent, and the deposited metal deposited on the tank bottom is removed. The reduction recovery method according to the above [1] for recovery.
[3] The reduction according to [2], wherein the treatment liquid contains at least one of copper, bismuth, arsenic, and antimony, uses iron scrap as a reducing agent, and reduces and recovers the metal ions contained in the treatment liquid. Collection method.
[4] A treatment liquid tank having a solid-liquid separation function, a reducing agent storage section installed above the liquid level of the processing liquid tank, means for extracting the processing liquid and feeding it to the reducing agent storage section, and depositing on the tank bottom An apparatus for reducing and recovering metal ions, comprising means for extracting a deposited metal.
[5] The reduction recovery apparatus according to [4], wherein the reducing agent storage unit is formed of a net material or a porous material, and iron scrap is stored in the reducing agent storage unit.
[6] A storage tank is provided together with the processing liquid tank, the processing liquid is supplied to the storage tank, and the supernatant processing liquid is introduced into the storage tank, and the processing liquid is extracted and sent to the reducing agent storage unit. The reduction recovery apparatus according to [4] or [5], wherein the means is connected to a storage tank.
[7] The reduction recovery apparatus according to any one of [4] to [6], wherein a mechanical pump or an air lift is provided as means for extracting a part of the processing liquid and sending it to the reducing agent storage unit.
[8] The reduction recovery apparatus according to any one of [4] to [7] above, wherein a heating unit is provided in a conduit for sending the treatment liquid to the reducing agent storage unit, and the temperature of the treatment liquid can be adjusted.

  In the reduction recovery method and apparatus of the present invention, the contact reduction zone of the treatment liquid and the reducing agent is separated from the liquid, and not the method of immersing the reducing agent in the treatment liquid, but the surface of the reducing agent such as iron scrap is treated with the treatment liquid. Therefore, the surface of the reducing agent is washed with the treatment liquid, the flow rate of the treatment liquid on the surface of the reducing agent is large, the force to peel off the metal particles deposited on the surface of the reducing agent is increased, and the reduction reaction is performed. Facilitate.

  In the reduction and recovery method and apparatus of the present invention, the deposited metal that has flowed down to the treatment liquid tank together with the treatment liquid is accumulated at the bottom of the treatment liquid tank, while the upper part of the treatment liquid becomes a supernatant treatment liquid from which the precipitated metal has been removed. The metal and the supernatant treatment liquid are separated in the tank. The supernatant treatment liquid is extracted, returned to the reducing agent storage section, poured into the reducing agent, and can be used for the reduction reaction. Therefore, the reduction reaction can be efficiently performed, and the treatment liquid is repeatedly circulated and used. Therefore, the metal in the liquid can be recovered at a low cost.

  Furthermore, since the treatment liquid is extracted from the tank and used for the reduction reaction, the liquid temperature and the liquid amount of the treatment liquid can be easily controlled, and the reduction reaction can be easily controlled. In addition, as a means for sending the treatment liquid to the reducing agent storage unit, an air lift that pumps the treatment liquid by introducing compressed air, an inert gas, a reducing gas, or compressed steam into the liquid supply pipe line is used. Even if metal powder is mixed in the liquid, the apparatus can be operated without any problem.

The schematic sectional drawing of the reduction | restoration collection apparatus of this invention. The schematic sectional drawing of this invention reduction | restoration collection | recovery apparatus using an air lift. The schematic sectional drawing of this invention reduction | restoration collection | recovery apparatus using another air lift. The schematic sectional drawing of the reduction | restoration collection apparatus of this invention which provided the storage tank. The schematic sectional drawing of the reduction | restoration collection | recovery apparatus of this invention which provided the other heating means inside the storage tank. The schematic sectional drawing of the reduction | restoration collection | recovery apparatus of this invention which provided the air lift in the storage tank. The schematic sectional drawing of the reduction | restoration collection | recovery apparatus of this invention which provided the other air lift in the storage tank. (A) to (G) are graphs showing the results of Example 2. The schematic diagram which shows the conventional apparatus structure.

The reduction recovery method and apparatus of the present invention will be specifically described below based on embodiments.
[Reduction recovery method]
The reduction recovery method of the present invention is a method in which a metal ion-containing treatment liquid is brought into contact with a reducing agent to reduce and recover the metal ions, and the contact portion between the treatment liquid and the reducing agent is installed above the liquid surface of the treatment liquid. To separate the contact reduction zone from the liquid of the processing liquid, flow down the processing liquid in contact with the reducing agent to the lower processing liquid tank, and collect the deposited metal deposited in the processing liquid tank. This is a method for reducing and recovering metal in liquid.

  In the reduction recovery method of the present invention, the contact reduction between the treatment liquid and the reducing agent is performed above the liquid surface of the treatment liquid, and the treatment liquid in contact with the reducing agent is caused to flow down to the lower treatment liquid tank together with the metal deposited by the reduction reaction. . The contact reduction zone is separated from the liquid of the processing liquid by placing the contact portion of the processing liquid and the reducing agent above the liquid surface of the processing liquid. On the other hand, any of the conventional apparatuses (A) to (D) is configured to put iron scrap or iron powder into the treatment liquid or to be immersed in the treatment liquid, and the catalytic reduction zone is in the liquid. For this reason, the conventional reduction recovery method and apparatus have problems that it is difficult to control the reduction reaction and that the deposited metal adheres to the iron scrap surface of the reducing agent to slow down the reduction reaction.

  In the reduction recovery method and apparatus of the present invention, the contact reduction zone is separated from the liquid of the processing liquid, and the catalytic reduction is performed above the liquid level of the processing liquid, so that the liquid volume and liquid temperature of the processing liquid can be easily controlled. In addition, since the treatment liquid flows down the surface of the reducing agent such as iron scrap, the reducing agent surface is washed by the treatment liquid, and the flow rate of the treatment liquid on the reducing agent surface is large. The force to peel off the metal particles deposited on the surface is increased, and the reduction reaction is promoted.

  The processing liquid is extracted from the processing liquid tank, sent to the contact reducing unit, poured into the reducing agent storage unit, brought into contact with the reducing agent, and metal ions in the processing solution are reduced. What is necessary is just to adjust the liquid volume of a process liquid according to the usage-amount of a reducing agent. As a processing liquid, the liquid etc. which arise in a copper smelting process can be used, for example.

  As the reducing agent, scrap metal that is lower than the metal contained in the treatment liquid is used. Specifically, iron is preferable as the reducing agent for the treatment liquid containing copper (Cu), bismuth (Bi), arsenic (As), antimony (Sb), tellurium (Te), and the like. The reducing agent iron is preferably iron scrap rather than iron powder. Iron powder has a larger surface area than plate-like or lump-like iron scraps, and the reduction reaction is quick, but it flows down with the treatment liquid and collects at the bottom of the treatment liquid tank, causing gas generation or being mixed into the deposited metal. Is also undesirable because it is often seen. The amount of precipitation of copper, bismuth, arsenic and antimony contained in the treatment liquid increases in proportion to the catalytic reduction time and the liquid temperature.

  When iron scrap is used, tin and nickel contained in the treatment liquid are hardly reduced and remain in the liquid. Therefore, the copper and bismuth group and the tin and nickel group can be separated from the treatment liquid containing tin and nickel together with copper and bismuth by iron reduction. Further, when lead is contained in the treatment liquid, lead precipitates to some extent when the liquid temperature of the reduction reaction is 50 ° C. or lower, but hardly precipitates when the liquid temperature is 60 ° C. or higher, so by adjusting the liquid temperature, Lead can be left in the liquid or removed from the liquid by precipitating a part thereof.

  In the reduction recovery method and apparatus of the present invention, the treatment liquid flowing on the surface of the reducing agent such as iron scrap is caused to flow down together with the deposited metal into the treatment liquid tank. This treatment liquid tank has a solid-liquid separation function, and the slurry-like deposited metal flowing down into the treatment liquid tank sinks to the bottom of the tank, and the upper part of the tank becomes a supernatant treatment liquid from which the precipitated metal has been removed. The supernatant treatment liquid can be extracted, returned again to the reducing agent storage section, poured into the reducing agent, and used for the reduction reaction. The deposited metal deposited in the tank low is withdrawn from the tank bottom outlet and collected.

  According to the reduction and recovery method and apparatus of the present invention, the slurry-like deposited metal sinks to the bottom of the processing liquid tank, and the upper part of the tank becomes the supernatant processing liquid, and this processing liquid can be extracted and repeatedly circulated for use. Therefore, the reduction reaction can proceed efficiently, and the metal in the liquid can be recovered at low cost.

[Reduction recovery equipment]
The structural example of the reduction | restoration collection apparatus of this invention is shown in FIGS.
The apparatus of FIG. 1 includes a processing liquid tank 10, a reducing agent storage unit 11 installed above the liquid level of the processing liquid tank 10, and a circulation path for extracting the processing liquid from the processing liquid tank 10 and feeding it to the reducing agent storage unit 11. 12 and a circulation pump 13 are provided. A discharge path 15 for extracting the deposited slurry-like deposited metal is connected to the center of the bottom of the processing liquid tank 10, and a valve 16 is provided in the discharge path 15. A receiving tank 17 is installed below the discharge path 15.

  The reducing agent storage unit 11 is formed of a net material or a porous material, and is formed so that the processing liquid injected while holding the iron scrap 18 flows downward. The circulation path 12 extends above the reducing agent storage unit 11, and the treatment liquid introduced through the circulation path 12 flows into the iron scrap 18.

  The tank of the processing liquid tank 10 is partitioned by a partition plate 14, a reducing agent storage unit 11 is provided on one tank wall side, and a processing liquid supply means 20 and a water vapor supply means are provided on the other tank wall side. 21 is connected. In addition, a circulation pump (mechanical pump) 13 is connected to a partition portion (referred to as a supply pipeline side partition) where the supply means 20 and 21 are provided. The slurry-like deposited metal that flows down from the reducing agent storage unit 11 is deposited on the bottom of the tank and is blocked by the partition plate 14 so as not to flow into the supply line side section. The processing liquid is extracted from the supply pipe side section by the circulation pump 13 and sent to the reducing agent storage unit 11 through the circulation path 12.

  The processing liquid sent to the reducing agent storage unit 11 is sprayed on the iron scrap 18, and metal ions nobler than iron such as copper and bismuth contained in the processing liquid come into contact with the iron scrap and are reduced. The slurry-like deposited metal generated by the reduction treatment flows into the tank together with the treatment liquid, accumulates in the tank bottom, and is extracted through the discharge path 15. In this way, the deposited metal sinks to the bottom of the tank, so that solid-liquid separation is performed in the processing liquid tank, and the precipitated metal is removed from the processing liquid near the liquid surface to become a supernatant processing liquid.

  The treatment liquid near the liquid surface from which the deposited metal has been removed overflows the partition plate 14 and flows into the supply pipe side section. This portion is provided with a pipe for the water vapor supply means 21, the pipe end of which extends near the bottom of the tank, through which water vapor is introduced into the processing liquid and the processing liquid is heated. The heated processing liquid is extracted by the circulation pump 13, sent to the reducing agent storage unit 11, and used again for the reduction processing.

  A drainage pump 19 is connected to the tank bottom on the reducing agent storage unit side, and most of the processing liquid that has undergone the reduction process is discharged out of the tank by the pump 19. The slurry-like deposited metal deposited on the bottom of the tank is extracted to the receiving tank 17 through the discharge path 15.

  In the apparatus of FIG. 2, an air lift is used as a circulating means for the processing liquid. If an air lift is used, even if metal powder or the like is mixed into the processing liquid, the liquid can be fed without any trouble. Specifically, in the apparatus of FIG. 2, the inside of the processing liquid tank 10 is partitioned by a partition plate 14, and a circulation path 12 and a processing liquid supply means 20 are provided in the supply pipe side section. . Further, a water vapor introducing means 21 and a compressed gas introducing means 22 for air lift are provided. Other configurations are the same as those of the apparatus of FIG.

  The circulation path 12 extends from the tank bottom to the reducing agent storage unit 11, and a compressed gas introduction means 22 is connected to the vicinity of the tank bottom. The compressed gas is introduced into the circulation path 12 through the pipe line, whereby the processing liquid is pumped up in the circulation path 12 and sent to the reducing agent storage unit 11. Air, an inert gas, or a gas having a reducing action may be used as the compressed gas.

  The pipe of the water vapor introducing means 21 extends into the pipe of the circulation path 12, and the steam is introduced into the treatment liquid in the circulation path through the pipe to heat the treatment liquid. The heated treatment liquid is sent to the reducing agent storage unit 11 through the circulation path 12 and dispersed on the iron scrap 18. Metal ions such as copper and bismuth contained in the treatment liquid come into contact with iron scrap and are reduced, and the slurry-like deposited metal generated by this reduction treatment flows down into the tank together with the treatment liquid and accumulates at the bottom of the tank.

  The treatment liquid in the vicinity of the liquid surface where the deposited metal has settled on the bottom of the tank overflows the partition plate 14 and flows into the supply pipe side section, and is again sent to the reducing agent storage unit 11 through the circulation path 12 by the air lift and flows through the pipe line. Heated with steam in between, the heated treatment liquid is sprinkled on the iron scrap, and a reduction treatment similar to the apparatus of FIG. 1 is performed. The slurry-like deposited metal is taken out through the discharge passage 15.

  In the apparatus of FIG. 3, a common conduit 23 for the water vapor introducing means 21 and the compressed gas introducing means 22 is formed inside the circulation path 12. The inside of the processing liquid tank 10 is partitioned by a partition plate 14, and a circulation path 12 and a processing liquid supply means 20 pipe are provided in the supply pipe side partition portion. The circulation path 12 extends from the tank bottom to the reducing agent storage unit 11, and a common pipeline 23 for the water vapor introduction means 21 and the compressed gas introduction means 22 is provided in the pipe. A water vapor introducing means 21 and a compressed gas introducing means 22 are connected to the upper end of the pipe line 23. Other configurations are the same as those of the apparatus shown in FIG.

  A gas such as compressed air and water vapor are introduced into the tank through the common pipe 23, and the processing liquid is pumped into the circulation path 12 by the compressed gas and simultaneously heated by the water vapor. The heated processing liquid is sent to the reducing agent storage unit 11 through the circulation path 12, and the reduction process similar to the apparatus of FIGS. 1 to 2 is performed, and the slurry-like deposited metal is taken out through the discharge path 15. According to the apparatus configuration shown in FIG. 3, the apparatus can be formed in a small size.

  4 to 7, a storage tank 30 is attached to the processing liquid tank 10. The processing liquid is supplied to the storage tank 30 and sent from the storage tank 30 to the reducing agent storage unit 11. By providing the storage tank 30, the liquid amount can be easily adjusted, and the processing liquid tank can be formed in a small size.

  In the apparatus of FIG. 4, the processing liquid tank 10 is not provided with a partition plate, and the reducing agent storage unit 11 is provided at the upper center of the processing liquid tank 10. The tank bottom of the processing liquid tank 10 is inclined toward the center, and the discharge path 15 is connected. The reducing agent storage unit 11 is formed of a net material or a porous material, and stores iron scrap 18. The treatment liquid is sprayed on the reducing agent storage unit 11, and metal ions such as copper and bismuth contained in the treatment liquid come into contact with the iron scrap and are reduced. The slurry-like deposited metal generated by this reduction treatment flows down into the tank together with the treatment liquid, accumulates at the bottom of the tank, and is extracted to the receiving tank 17 through the discharge path 15. Moreover, when the deposited metal sinks to the bottom of the tank, solid-liquid separation is performed in the treatment liquid tank, and the deposited metal is removed from the treatment liquid near the liquid surface.

  The storage tank 30 is connected to the processing liquid tank 10 through a pipe line 31 and a pipe line 32. The pipe line 31 is provided slightly below the liquid level of the processing liquid tank 10, and the pipe line 32 is provided below the storage tank 30. A valve 33 is provided in the pipe line 32. Further, the storage tank 30 is provided with a treatment liquid supply means 20 and a water vapor introduction means 21. Further, a circulation path 12 from the bottom of the storage tank 30 to the reducing agent storage unit 11 is connected. A circulation pump 13 is provided in the circulation path 12, and a drainage path 34 is branched and connected.

  The processing liquid is supplied to the storage tank 30 through the supply means 20, and the supernatant processing liquid of the processing liquid tank 10 is introduced into the storage tank 30 through the conduit 31. Water vapor is introduced into the treatment liquid in the storage tank 30 through the introduction means 21 to adjust the liquid temperature. The treatment liquid in the storage tank 30 is sent to the reducing agent storage unit 11 through the circulation path 12, and is sprayed on the iron scrap to perform the reduction process. When continuous processing is not required, the valve of the processing liquid supply means 20 or the valve of the circulation path 12 is closed, the valve of the drainage path 34 is opened, and the liquid in the storage tank 30 is discharged by the circulation pump 13. Next, the valve 33 of the processing liquid tank 10 is opened, and most of the liquid in the processing liquid tank flows into the storage tank 30 through the conduit 32 and is discharged.

  The apparatus of FIG. 5 is provided with a heat exchange coil 35 in the storage tank 30 as a heating means. The liquid temperature of the processing liquid in the storage tank 30 is adjusted by the heat exchange coil 35. The other structure is the same as that of the apparatus of FIG.

  In the apparatus of FIG. 6, an air lift is provided in the storage tank 30 as means for circulating the processing liquid. Specifically, the circulation path 12 and the treatment liquid supply means 20 are provided in the tank of the storage tank 30. The circulation path 12 extends from the tank bottom to the reducing agent storage unit 11, and a compressed gas introduction means 22 is connected to the vicinity of the tank bottom. When the compressed gas is introduced into the circulation path 12 through the pipe line, the processing liquid is pumped into the circulation path 12 and sent to the reducing agent storage unit 11. Instead of air as the compressed gas, an inert gas such as nitrogen or a reducing gas such as sulfur dioxide may be used.

  The pipe of the water vapor introducing means 21 extends into the pipe of the circulation path 12, and the steam is introduced into the treatment liquid in the circulation path through the pipe to heat the treatment liquid. The heated treatment liquid is sent to the reducing agent storage unit 11 through the circulation path 12 and dispersed on the iron scrap 18. Metal ions such as copper and bismuth contained in the treatment liquid come into contact with iron scrap and are reduced, and the slurry-like deposited metal generated by this reduction treatment flows down into the tank together with the treatment liquid and accumulates at the bottom of the tank. Other configurations are the same as those of the apparatus shown in FIGS.

  The supernatant treatment liquid in the vicinity of the liquid surface of the treatment liquid tank 10 is guided to the storage tank 30 through the pipe line 31, is again sent to the reducing agent storage unit 11 through the circulation path 12 by the air lift, and is heated by water vapor while flowing through the pipe line, The heated processing liquid is sprayed on the iron scrap, and the reduction process similar to the apparatus of FIGS. 4-5 is performed.

  In the apparatus of FIG. 7, pipes for the water vapor introducing means 21 and the compressed gas introducing means 22 are formed inside the circulation path 12. In the tank of the storage tank 30, a circulation path 12 and a pipe for the processing liquid supply means 20 are provided. The circulation path 12 extends from the tank bottom to the reducing agent storage unit 11, and a common pipeline 23 for the water vapor introduction means 21 and the compressed gas introduction means 22 is provided in the pipe. A water vapor introducing means 21 and a compressed gas introducing means 22 are connected to the upper end of the pipe line 23. Other configurations are the same as those of the apparatus shown in FIG.

  Compressed air and water vapor are introduced into the storage tank 30 through the shared pipe 23, and the processing liquid is pumped into the circulation path 12 by the compressed air and simultaneously heated by the water vapor. The heated processing liquid is sent to the reducing agent storage unit 11 through the circulation path 12, and the same reduction processing as that of the apparatus shown in FIGS. According to the apparatus configuration shown in FIG. 7, the apparatus can be formed in a small size.

[Example 1]
Using the apparatus shown in FIG. 1, the reduction and recovery method of the present invention was carried out on the effluent (1 L) of the copper smelting process. As a reducing agent, 20 g of iron scrap was used. The composition of the treatment liquid is an acidic solution containing 50 g / L hydrochloric acid and 100 g / L sulfuric acid in addition to the metal ions shown in Table 1 (before treatment). The liquid temperature was maintained at 60 ° C., and the liquid was extracted from the treatment liquid tank at a flow rate of 60 ml / min and sprayed on iron scrap, and the reduction reaction was performed by circulating the treatment liquid. The components of the treatment liquid before the reaction and the components of the treatment liquid when treated for 20 to 100 minutes are shown in Table 1.
As shown in Table 1, the concentrations of bismuth, arsenic, copper, and antimony in the liquid are greatly reduced in proportion to the treatment time, and the recovery rate is high. On the other hand, the concentrations of nickel, tin, and lead in the liquid remain almost unchanged and remain in the liquid. Accordingly, the separability between the metal group of bismuth, arsenic, copper and antimony and the metal group of nickel, tin and lead is good.

[Example 2]
In the same apparatus as in Example 1, 400 ml of the treatment liquid (copper smelting effluent) is adjusted to a liquid temperature of 22 ° C. to 70 ° C. (lead is 30 ° C. to 95 ° C.) and extracted from the treatment liquid tank at a circulation flow rate of 500 ml / min. The reduction recovery method of the present invention was carried out. The results are shown in FIG. Fig. 8 (b) is bismuth concentration change, (b) is arsenic concentration change, (c) is copper concentration change, (d) is antimony concentration change, (e) is lead concentration change, (f) Is a graph showing changes in tin concentration, and (g) is a graph showing changes in nickel concentration.

  As shown in FIGS. 5A to 5D, according to the reduction and recovery method of the present invention, the concentration of copper, bismuth, arsenic, and antimony is larger as the liquid temperature is higher, and the recovery rate is higher. On the other hand, as shown in FIG. 5 (e), the concentration change of lead is larger as the liquid temperature is lower, and the concentration hardly changes when the liquid temperature is 70 ° C to 95 ° C. The concentration decreases. Further, as shown in FIGS. 5F and 5G, the concentrations of tin and nickel hardly change regardless of the liquid temperature.

10-treatment liquid tank, 11-reducing agent storage section, 12-circulation path, 13-circulation pump, 14-partition plate, 15-discharge path, 16-valve, 17-receiving tank, 18-iron scrap, 19-drainage Pump, 20-treatment liquid supply means, 21-water vapor introduction means, 22-compressed gas introduction means, 23-shared pipe, 30-storage tank, 31-pipe, 32-pipe, 33-valve, 34-drainage Road.

Claims (8)

In the method of bringing a metal ion-containing treatment liquid into contact with a reducing agent and reducing and recovering the metal ions, the contact reduction zone is treated by placing the contact portion between the treatment liquid and the reducing agent above the liquid surface of the treatment liquid. A method for reducing and recovering a metal in a liquid, comprising separating a liquid from the liquid and bringing the treatment liquid in contact with the reducing agent down into a treatment liquid tank below, and collecting deposited metal deposited in the treatment liquid tank.
A part of the treatment liquid is extracted, poured into a reducing agent installed above the liquid surface of the treatment liquid tank, the treatment liquid and the reducing agent are brought into contact with each other, and the treatment liquid is allowed to flow down into the treatment liquid tank along with the deposited metal, and the treatment is performed. The liquid tank has a solid-liquid separation function, and the deposited metal is allowed to sink to the bottom of the tank. On the other hand, the supernatant treatment liquid is extracted and brought into contact with the reducing agent, and the deposited metal deposited on the bottom of the tank is recovered. The reduction recovery method according to Item 1.
The reduction according to claim 1 or 2, wherein the treatment liquid contains at least one of copper, bismuth, arsenic, and antimony, uses iron scrap as a reducing agent, and reduces and recovers the metal ions contained in the treatment liquid. Collection method.
A processing liquid tank having a solid-liquid separation function, a reducing agent storage part installed above the liquid level of the processing liquid tank, means for extracting the processing liquid and feeding it to the reducing agent storage part, and deposited metal deposited on the bottom of the tank An apparatus for reducing and recovering metal ions, characterized by comprising means for extracting.
The reduction recovery apparatus according to claim 4, wherein the reducing agent storage unit is formed of a net material or a porous material, and iron scrap is stored in the reducing agent storage unit.
A storage tank is provided together with the processing liquid tank, the processing liquid is supplied to the storage tank, and a supernatant processing liquid is introduced into the storage tank, and a means for extracting the processing liquid and feeding it to the reducing agent storage unit is the storage tank. The reduction recovery device according to claim 4 or 5 connected to.
The reduction recovery apparatus according to any one of claims 4 to 6, wherein a mechanical pump or an air lift is provided as means for extracting a part of the processing liquid and sending it to the reducing agent storage unit.
The reduction recovery apparatus according to any one of claims 4 to 7, wherein a heating unit is provided in a pipe line for sending the treatment liquid to the reducing agent storage unit, and the temperature of the treatment liquid can be adjusted.

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