JP6848507B2 - Pressurized reaction device and leaching treatment method of valuable metal using it - Google Patents

Description

The present invention relates to a pressure reaction apparatus and a method for leaching valuable metals using the same.

As a reaction device of a chemical plant or the like, a reaction device in which a gas is introduced into a liquid phase such as a liquid or a slurry in a reaction vessel to react with stirring is often used to perform a chemical treatment.

For example, Patent Document 1 includes a shaft that is rotatable around a longitudinal axis of a container, and first and second impellers that are attached to the shaft and are arranged apart in the axial direction and extend in the radial direction. The mixing container is disclosed. Specifically, in this mixing vessel, the first impeller includes a plurality of curved blades that can move the fluid axially toward the second impeller, and the second impeller is axial. It includes a plurality of curved blades capable of moving the fluid toward the first impeller, and is provided with a gas inlet on the bottom surface of the container. With such a configuration, a strong turbulent region is generated in the central portion of the mixing container, and the mixing of the liquid in the container can be easily controlled.

However, in the mixing container described in Patent Document 1, when large bubbles are introduced from the gas introduction port provided in the center, the liquid level reaches the upper part of the mixing container before the bubble diameter becomes small in the mixing container. There is a problem that it will end up. Therefore, even if such a mixing vessel is applied as a reaction vessel used for a chemical reaction, the amount of gas that does not contribute to the reaction increases, and the reaction efficiency decreases.

This means that it is important for the gas used for the chemical reaction in the reaction vessel to have a smaller bubble diameter in the liquid phase in the vessel, and the smaller the bubbles, the larger the area of the gas-liquid interface. In addition, since the air bubbles circulate and stay in the liquid for a long time, the amount of the gas component dissolved in the liquid phase increases, and as a result, the gas concentration in the liquid phase increases, which is expected to have the effect of improving the reaction efficiency. Because. That is, in the reaction vessel, it is important to maximize the amount of bubbles by making the gas to be introduced into small bubbles in the liquid phase.

As a technique for reducing the bubble diameter in the liquid phase, a method using a sparger (air diffuser), a method of blowing a gas under the stirring blade and dividing the bubble by the blade, and the like are known. For example, it is known that when the amount of gas blown is large, the stirring blade spins idle due to the flooding phenomenon, and the amount of gas dissolved in the liquid becomes small. A technique has been disclosed in which a ring sparger having a larger diameter is used to place blown air bubbles on a flow of liquid circulating in the apparatus.

However, when the spurger is applied to a pressure reactor that introduces gas, the pressure of the gas blown into the device from the spurger is the sum of the internal pressure of the reaction vessel and the pressure loss of the spurger. It is necessary to pressurize beyond. Further, the spurger has a problem that the cost of the pressurizing equipment is high because the pressure loss is large because the bubble outlet diameter is small. Furthermore, depending on the reaction, reaction products containing intermediates and residues after the reaction may become deposits that block the small bubble outlets of the spudger, and the operating rate is increased by stopping the device to remove the deposits. There is also the problem that Due to these various problems, it has been difficult to use a spurger for the pressurizing reaction device.

In the pressure reactor that introduces gas, it is preferable to make the pipe diameter and the outlet diameter of the gas blowing pipe as large as possible in order to minimize the pressure loss. However, it is well known that the bubble diameter of the bubbles discharged from the gas blowing pipe depends on the outlet diameter of the gas blowing pipe, and the bubble diameter becomes large when trying to minimize the pressure loss. An increase in the bubble diameter means that a flooding phenomenon is likely to occur and the area of the gas-liquid interface is small, which is not preferable. For this reason, a technique for reducing a large diameter bubble discharged from a large outlet diameter having a small pressure loss to a small bubble diameter has been desired.

Further, if the amount of gas introduced is increased in order to promote the chemical reaction in the chemical reaction apparatus, the flooding phenomenon is likely to occur as described above. Therefore, there has been a demand for a technique for reducing a large diameter bubble discharged from a large outlet diameter having a small pressure loss to a small bubble diameter and making the flooding phenomenon less likely to occur even if the amount of gas introduced increases.

Special Table 2009-536095 Japanese Unexamined Patent Publication No. 2014-11564

The present invention has been made in view of such a situation, and it is possible to efficiently divide the gas bubbles introduced into the apparatus into a small bubble diameter and increase the amount of gas introduced. It is also an object of the present invention to provide a pressure reactor capable of suppressing the occurrence of a flooding phenomenon.

The present inventor has made extensive studies to solve the above-mentioned problems. As a result, in the pressurizing reaction apparatus provided with the stirrer and the gas blowing pipe, the gas bubbles are efficiently arranged by arranging the outlet position of the gas blowing pipe in a specific position and direction with respect to the stirrer. The present invention was completed by finding that the occurrence of the flooding phenomenon can be suppressed even if the amount of gas introduced increases.

(1) The first invention of the present invention is a pressure reaction device provided with a stirrer and a gas blowing pipe, wherein the stirrer includes a stirring shaft hanging from the upper part of the pressure reaction device. It has a stirring blade provided perpendicular to the stirring shaft, and the pressurizing reaction device is viewed from the front in a cross section along the axial direction of the stirring shaft, and a line extending from the stirring shaft is the addition. When H is defined as H from the position where it intersects the inner wall of the pressure reaction device to the height position of the stirring blade, and R is defined as the maximum length of the stirring blade from the center of the stirring shaft, the outlet center of the gas blowing pipe is located. The height from the position where the line extending from the stirring shaft intersects the inner wall of the pressure reactor is h, the distance from the center of the stirring shaft is r, and the gas is formed in a cross section perpendicular to the stirring shaft. The extension direction of the outlet center line of the blow pipe is directed to the positive side of the stirring flow generated by the stirrer, and the circle formed by the distance r from the center of the stirring shaft at the outlet center of the gas blow pipe. When the angle formed by the tangent direction and the extension direction of the outlet center line of the gas blowing pipe is θ with the direction from the tangent line toward the stirring axis as positive, the position is provided at a position satisfying the following equation. It is a pressurized reaction device.
0.45H ≤ h ≤ 0.55 H
1.1R ≤ r ≤ 1.4R
20 ° ≤ θ ≤ 60 °

(2) The second invention of the present invention is the pressurizing reaction apparatus in the first invention, wherein the outlet diameter of the gas blowing pipe is 10 mm to 150 mm.

(3) The third invention of the present invention is a pressure reaction device, which is an autoclave device in the first or second invention.

(4) In the fourth invention of the present invention, in any one of the first to third inventions, an acid is added to a slurry containing a mixed sulfide of nickel and cobalt under high temperature and high pressure to perform a leaching treatment. It is a pressure reaction device used for this purpose.

(5) In the fifth aspect of the present invention, the precious metal leaching treatment for leaching the valuable metal from the solid matter contained in the slurry by using the pressure reaction apparatus according to any one of the first to fourth inventions. Is the way

According to the present invention, the gas bubbles introduced into the apparatus can be efficiently divided into small bubble diameters, and even if the amount of gas introduced is increased, the occurrence of the flooding phenomenon can be suppressed. A pressure reactor can be provided.

Further, by performing a leaching treatment or the like in which valuable metals contained in the solid matter in the slurry are leached by using such a pressure reaction device, the reaction efficiency is enhanced by increasing the amount of bubbles in the liquid phase, which is effective. The valuable metal can be leached into the liquid.

It is a figure which shows the structure of an autoclave apparatus, (a) is a cross-sectional plan view which typically showed the internal structure by cutting the autoclave apparatus horizontally, (b) is the internal structure which cut | cut the autoclave apparatus vertically. Is a longitudinal side view schematically showing. It is a schematic diagram which shows the cross section AA in FIG. 1A, and is the figure for demonstrating the stirring flow by a stirrer. It is a schematic diagram which shows the BB cross section in FIG. 2, and is the figure for demonstrating the stirring flow by a stirrer. It is a schematic diagram which shows the cross section perpendicular to a stirring shaft, and is the figure for demonstrating the arrangement of the outlet position of a gas blowing pipe. It is a graph which shows the result of the stirring power relative value in the processing in Example 1 and Comparative Example 1. It is a graph which shows the relationship between the angle θ and the amount of air in a liquid. It is a graph which shows the relationship between the angle θ and the relative value of agitation power.

Hereinafter, a specific embodiment of the present invention (hereinafter, referred to as “the present embodiment”) will be described in detail. The present invention is not limited to the following embodiments, and various modifications can be made without changing the gist of the present invention. Further, in the present specification, the notation "X to Y" (X and Y are arbitrary numerical values) means "X or more and Y or less".

The pressurizing reaction apparatus according to the present embodiment includes a stirrer and a gas blowing pipe, and enables a reaction under high pressure. This pressurization reaction device can be applied, for example, as an autoclave device which is a heat-resistant and pressure-resistant reaction vessel whose inside is heated to a high temperature and high pressure by saturated steam. In the following, the autoclave apparatus and the chemical reaction carried out in the apparatus will be specifically described, but the present invention is not limited to this, and the liquid phase is chemically synthesized in a pressurized reactor equipped with a stirrer and a gas blowing pipe. If it is a device that reacts, the same effect can be obtained.

FIG. 1 is a diagram showing a configuration of an autoclave device. FIG. 1A is a cross-sectional plan view schematically showing the internal structure by horizontally cutting the autoclave device 1, and FIG. 1B is a schematic view of the internal structure schematically shown by cutting the autoclave device 1 vertically. It is a vertical sectional side view shown in. As shown in FIG. 1, the autoclave device 1 is, for example, a cylindrical container installed horizontally.

The autoclave apparatus 1 is, for example, a raw material slurry (suspension of a raw material solid and a leachate, hereinafter simply referred to as “slurry”) containing a mixed sulfide (solid) containing at least nickel and cobalt as a liquid phase. ) Is used for leaching treatment as a solution of sulfate or the like. More specifically, in the autoclave apparatus 1, the heated and pressurized slurry is housed, and by adding an acid such as sulfuric acid and stirring, the valuable metal contained in the solid matter in the slurry is heated to a high temperature under high temperature and high pressure. Pressurized leaching.

The valuable metal to be leached is not particularly limited, and when a mixed sulfide of nickel and cobalt is used as the raw material solid, nickel and cobalt are leached as valuable metals.

Regarding the processing conditions in the autoclave device 1, for example, the pressure inside the device is pressurized to 3 atm or more, and the temperature is 100 ° C. or more.

As shown in FIG. 1, the autoclave device 1 includes a plurality of compartments 10. Each compartment 10 is a space that serves as a reaction field for performing a treatment such as leaching treatment on the slurry in the autoclave device 1. Specifically, the partition chamber 10 is partitioned by a partition wall 40 provided in the autoclave device 1. In the example of the autoclave device 1 shown in FIG. 1, five compartments 10 (10A, 10B, 10C, 10D, 10E) divided into five compartments by four partition walls 40 (40A, 40B, 40C, 40D) are provided. ing. The number of compartments in the autoclave device can be appropriately set according to the raw materials, leaching conditions, and the like.

Each compartment 10 is provided with at least a stirrer 20 for stirring the slurry and a gas blowing pipe 30 for supplying a gas such as air to the slurry. Specifically, a stirrer 20 (20A, 20B, 20C, 20D, 20E) and a gas blowing pipe 30 (30A, 30B, 30C, 30D, 30E) are provided in each of the compartments 10A to 10E, respectively. ing.

[Leaching in the compartment]
The compartment 10 is followed by the first compartment 10A, the second compartment 10B, and the like in order from the upstream side (left side in FIG. 1), and the most downstream side (right side in FIG. 1) is the final fifth. It is composed of a compartment 10E. In the autoclave device 1, the slurry as a raw material is charged into the first compartment 10A, which is the most upstream, and a solution such as sulfuric acid is added to the slurry through a pipe hanging from the upper part of the first compartment 10A. Supplied. Then, in the first compartment 10A, the valuable metal contained in the solid matter in the slurry is leached into the solution by the stirring by the stirrer 20A described later and the oxygen supplied by the gas blowing pipe 30A.

At the same time that the slurry is agitated in the first compartment 10A, a part of the slurry overflows the upper part of the partition wall 40A that partitions the first compartment 10A and the second compartment 10B. , Transferred to the second compartment 10B. In the second compartment 10B, the leaching treatment proceeds sequentially by stirring with the stirrer 20B, as in the treatment in the first compartment 10A. At this time, also in the second compartment 10B, a pipe can be hung from the upper part thereof to supply a solution such as sulfuric acid or a slurry used for leaching.

After that, the slurry is sequentially transferred to the third compartment 10C and the fourth compartment 10D mainly by overflow, and the leaching process proceeds in each compartment 10. Then, when the slurry is leached in the same manner in the 5th compartment 10E at the most downstream, it is valuable through the leachate discharge pipe (not shown) provided in the 5th compartment 10E. The slurry containing the leachate obtained by leaching the metal is discharged.

[Composition of compartment]
As described above, the partition chamber 10 is provided with a stirrer 20 for stirring the internal slurry and a gas blowing pipe 30 for supplying a gas such as oxygen required for the reaction (FIG. 6). 2. See FIG. 4). Further, in at least the first compartment 10A of the compartments 10, a raw material slurry charging pipe (not shown) for charging the raw material slurry is provided, and the raw material slurry charging pipe is provided. A slurry containing a solid substance is charged through the slurry.

Further, the partition chamber 10 is also provided with various supply pipes for supplying an acid solution such as sulfuric acid, a slurry, steam, etc. so as to hang down from the upper portion thereof, for example.

(mixer)
The stirrer 20 is installed in each of the first compartment 10A to the fifth compartment 10E, and stirs the slurry charged and transferred into each compartment 10.

As the stirrer 20, for example, as shown in FIG. 2 showing the AA cross section of the compartment 10B in FIG. 1A and the schematic view of FIG. 4, the stirring shaft 21 hanging from the upper part and the stirring shaft 21 A propeller-shaped one having a plurality of stirring blades 22 provided at the lower end position perpendicular to the stirring shaft 21 can be used. In this way, the stirrer 20 is hung from the upper ceiling of each compartment 10, and when the autoclave device 1 is viewed from above (see FIG. 1A), the stirring shaft 21 is located in the central portion of each compartment 10. Can be provided in. It should be noted that the stirrer may be provided with a plurality of sets of propellers having a plurality of stirrer blades on the stirring shaft.

The agitator 20 rotates the agitation shaft 21 clockwise at a predetermined speed, for example, and agitates the slurry by the agitation blade 22. By stirring with the stirrer 20, a liquid flow in a predetermined direction is generated in the slurry in the partition chamber 10. Normally, a liquid flow is generated from the stirring blade 22 in the downward direction (the direction opposite to the liquid level in the axial direction of the stirring shaft 21) so that the slurry flows throughout the partition chamber 10. It is stirred as it does.

(Gas blowing pipe)
The gas blowing pipe 30 is installed in each of the first compartment 10A to the fifth compartment 10E, and supplies the gas component necessary for the reaction of the slurry inside each compartment 10.

Here, when the autoclave device 1 is used for the leaching treatment of a slurry containing at least a mixed sulfide of nickel and cobalt, the reaction during the leaching treatment of nickel sulfide and cobalt sulfide in each compartment 10 is described by the following formula. (1) and equation (2).
NiS + 2O ₂ → NiSO ₄ ... (1)
CoS + 2O ₂ → CoSO ₄ ... (2)

As shown in the above reaction formula, in the leaching treatment under high temperature and high pressure, it is necessary _{to supply oxygen (O 2} ) required for the reaction into the slurry. When supplying oxygen to the slurry, it is customary to supply air, and air is supplied through the gas blowing pipe 30.

As shown in FIGS. 2 and 4, the gas blowing pipe 30 is not limited to the mode in which only one is provided in each of the compartments 10, and a plurality of gas blowing pipes 30, for example, may be provided.

In the autoclave device 1, in addition to the gas blowing pipe 30, steam for maintaining a high temperature and high pressure state, sulfuric acid for supplying an acid such as sulfuric acid to form a sulfuric acid acidic leachate, and water for the purpose of adjusting the concentration and the like. And pipes for supplying slurry and the like may be attached as needed, but in the present embodiment, the pipe for supplying the gas required for the reaction is the gas blowing pipe 30, and other supplies. It is distinguished from the piping for the purpose of supplying.

[Liquid flow in the compartment]
Here, FIG. 2 is a schematic view in the AA cross section of FIG. 1A, and the stirring flow generated in the partition chamber 10 by the stirrer 20 is in the axial direction of the stirring shaft 21, that is, to the liquid level. It shows the flow in the height direction. In addition, in order to make the stirring flow easy to see, the gas blowing pipe 30 is represented by a broken line in FIG. FIG. 3 is a schematic view of a cross section taken along the line BB of FIG. 2, showing the direction of the gas blowing pipe outlet 30a and the main stirring region S for the stirring flow generated in the compartment 10 by the stirrer 20. It is a thing.

As described above, normally, in the partition chamber 10, stirring is performed so that a stirring flow is generated from the stirring blade 22 in the downward direction opposite to the liquid level, so that the stirring shaft 21 is inside the autoclave device 1. The stirring flow is diagonally downward toward the wall surface 1w. Then, as shown by the arrow in FIG. 2, the main stirring flow hits the inner wall surface 1w of the autoclave device 1 and then flows upward along the inner wall surface 1w, and some of the stirring flows are inside. The flow is downward along the wall surface 1w.

Therefore, the stirring flow propelled diagonally to the right on FIG. 2 by the stirrer 20 spreads from the stirrer 20 to the liquid level and the inner wall surface 1w of the autoclave device 1, and is a large counterclockwise flow having a high flow velocity (FIG. 2). The thick line arrow X) in the middle and the slow and small clockwise flow generated in the lower right of the stirrer 20 (thin line arrow Y in FIG. 2). The large counterclockwise flow, which is the main stirring flow generated by the stirrer 20, becomes an upward flow while swirling together with the horizontal flow parallel to the liquid level.

Looking at such a stirring flow in the direction from the inner wall surface 1w toward the stirring shaft 21 along the line BB in FIG. 2, there is a region where the stirring flow flows at a high flow velocity as shown by the thick line arrow X. If this region is exceeded, there is a region in which the stirring flow flows at a slow flow velocity as indicated by the thin line arrow Y. When such a stirring flow is viewed from a cross section perpendicular to the stirring axis, as shown in FIG. 3, a region in which the stirring flow flows at a high flow velocity (hereinafter, referred to as “main stirring region S”) is formed in a donut shape. It will be done. The direction of the stirring flow in the main stirring region S is a spiral shape that goes outward in a counterclockwise direction, as shown by an arrow Z in the figure.

[Arrangement of gas blowing pipe]
In the gas blowing pipe 30, the gas bubbles supplied from the gas blowing pipe 30 are divided and reduced in diameter by the stirring flow by the stirrer 20, and the bubbles are placed on the stirring flow to reduce the amount of bubbles in the liquid phase. It is preferable to be able to increase it.

The reason why the amount of bubbles in the liquid phase increases by placing bubbles on the stirring flow and flowing in the liquid phase is that, as described above, in the main stirring region S, the stirring flow swirls upward. This is thought to be because the air bubbles move along with the agitated flow and reach the liquid surface for a relatively long time because the flow is directed toward the liquid surface. On the other hand, the air bubbles located in a place where the stirring flow is weak have a higher speed of rising toward the liquid surface due to buoyancy, and the time to reach the liquid surface is relatively short. In addition, at a position where the stirring flow is weak, the diameter of the bubbles increases due to the coalescence of the bubbles, and the ascending speed due to the buoyancy increases depending on the diameter of the bubbles. It gets shorter.

On the other hand, the gas supplied from the gas blowing pipe 30 has a flow velocity (hereinafter, referred to as "initial kinetic energy") according to the supply amount. Therefore, the bubbles supplied from the gas blowing pipe 30 try to move in the direction in which the gas blowing pipe outlet 30a is facing, and the initial kinetic energy actually flows in the liquid phase along the stirring flow. It will be later after the resistance due to the stirring flow is offset. Considering the initial kinetic energy of the bubbles, the bubbles travel a certain distance from the gas blowing pipe outlet 30a toward the stirrer 20 and then flow in the liquid phase along the stirring flow. This distance increases as the gas supply increases. Therefore, when the gas blowing pipe outlet 30a is installed in the direction toward the stirring shaft 21, as the amount of gas supplied from the gas blowing pipe 30 increases, the bubbles pass through the main stirring region S and in the direction of the arrow Y. The amount of the agitated flow shown reaches the region where it flows at a slow flow rate increases. As a result, air bubbles are likely to accumulate in the lower part of the stirring shaft 21 (lower part of the stirring blade 22), and a flooding phenomenon is likely to occur.

Therefore, in the autoclave device 1 according to the present embodiment, as shown in FIGS. 3 and 4, the gas blowing pipe outlet 30a is arranged at a specific position, and the extension direction of the outlet center line of the gas blowing pipe 30 D is not directed in the direction of the stirring shaft 21, but in the positive direction (Z direction) of the stirring flow generated by the stirring machine 20.

As a result, the gas bubbles supplied from the gas blowing pipe outlet 30a pass through the main stirring region S as compared with the case where the extension direction D of the outlet center line of the gas blowing pipe outlet 30a intersects the stirring shaft 21. Is lengthened, and the bubbles in the main stirring region S flow along the upward flow while swirling. Therefore, even if the amount of gas supplied increases, most of the bubbles will be in the main stirring region S, and the flooding phenomenon can be effectively suppressed.

Hereinafter, the installation position and installation direction of the gas blowing pipe outlet 30a will be specifically described. As shown in FIG. 4, when the autoclave device 1 is viewed from the front in a cross section along the axial direction of the stirring shaft 21, the stirring blade is viewed from a position where the line extending from the stirring shaft 21 intersects the inner wall surface 1w of the autoclaving device 1. When H is set up to the height position of 22 and R is the maximum length of the stirring blade 22 from the center of the stirring shaft 21, the line extending from the stirring shaft 21 is the autoclave at the center of the gas blowing pipe outlet 30a. When the height from the position where the inner wall surface 1w of the device 1 intersects is h and the distance from the center of the stirring shaft 21 is r, the devices 1 are provided at positions that satisfy the following equations (i) and (ii). ..
0.45H ≤ h ≤ 0.55 H ... (i)
1.1R ≤ r ≤ 1.4R ... (ii)

Here, H at the height position of the stirring blade 22 means the height of the central axis of the stirring blade 22 provided perpendicular to the axial direction of the stirring shaft 21, and is the central axis of the stirring blade 22. , Refers to the axis represented by the line C1 in FIG. Further, regarding the maximum length R of the stirring blade 22 from the center of the stirring shaft 21, the center of the stirring shaft 21 means the center of the shaft represented by the line C2 in FIG. 4, and the maximum length R is the center thereof. The length from the center of the stirring shaft 21 to the tip position of the stirring blade 22 on the axis (line C1) of the stirring blade 22.

Regarding the position of the gas injection pipe outlet 30a, the height h is less than 0.45H (0.45H> h), or, and more than 0.55 H (0.55 H <h) , the gas blowing tube outlet 30a The gas bubbles supplied from the main stirring region S are out of the main stirring region S, or the flow distance is shortened. As a result, the effect of dividing the bubbles is reduced, and it becomes difficult to obtain bubbles having a small diameter. As described above, the size of the bubbles affects the rate of rise due to buoyancy, so if the effect of dividing the bubbles is reduced, it means that the time until the bubbles reach the liquid surface is shortened, which means that the time required for the bubbles to reach the liquid surface is shortened. The amount of bubbles decreases.

Further, regarding the position of the gas blowing pipe outlet 30a, when the distance r between the center of the outlet and the center of the stirring shaft 21 exceeds 1.4R (1.4R <r), the stirring flow in the stirring region S where bubbles are the main. As a result, the distance that flows in the liquid phase and reaches the liquid surface is shortened, so that the amount of bubbles in the liquid phase is relatively reduced. On the other hand, when the distance r is less than 1.1R (1.1R> r), as can be seen from FIGS. 2 to 4, a weak clockwise flow generated under the stirrer 20 (in FIG. 2). The number of bubbles on the thin line arrow Y) will increase. The bubbles in this weak flow tend to accumulate in the lower part of the stirrer 20 (lower part of the stirring blade 22), and since the flow velocity is slow, they tend to coalesce and increase in diameter, so that they become large bubbles toward the liquid surface. It rises and a flooding phenomenon is likely to occur, and the amount of bubbles in the liquid phase decreases relatively.

Further, in the above-mentioned autoclave device 1, the direction of the gas blowing pipe outlet 30a is provided so as to satisfy the following conditions. That is, the gas blowing pipe outlet 30a has a circular tangent line L formed by a distance r from the center of the stirring shaft 21 at the outlet center of the gas blowing pipe outlet 30a in a cross section perpendicular to the stirring shaft 21, and the gas blowing pipe outlet. The angle θ formed by the extension direction D of the exit center line of 30a is arranged in a direction that satisfies the following equation (iii).
20 ° ≤ θ ≤ 60 ° ... (iii)

Here, the angle θ formed by the tangent line L of the circle at the outlet center of the gas blowing pipe outlet 30a and the extension direction D of the outlet center line of the gas blowing pipe outlet 30a is the acute angle of the angles formed by both. Refers to the angle of. The gas blowing pipe outlet 30a and its vicinity may be linear or curved. The extension direction D of the outlet center line of the gas blowing pipe outlet 30a is the extension direction of the straight line when it is formed in a straight line, and the tangential direction when it is formed in a curved line.

When the angle θ formed by the tangent line L of the circle centered on the stirring shaft 21 and the extension direction D of the outlet center line is less than 20 ° with respect to the direction of the gas blowing pipe outlet 30a, the gas blowing pipe outlet 30a is supplied. The gas bubbles either deviate from the main stirring region S or the distance flowing through the main stirring region S becomes short. As a result, the effect of dividing the bubbles is reduced, and it becomes difficult to obtain bubbles having a small diameter. On the other hand, when the angle θ exceeds 60 °, when the gas supply amount increases as described above, the gas bubbles supplied from the gas blowing pipe outlet 30a exceed the main stirring region S and the stirrer. The number of bubbles in the weak clockwise flow generated below 20 increases, and the bubbles tend to accumulate in the lower part of the stirring shaft 21, so that the flooding phenomenon is likely to occur.

According to the autoclave device 1 in which the position of the gas blowing pipe outlet 30 is arranged at a specific position in this way, the gas bubbles introduced into the device can be efficiently divided into small bubble diameters, and the liquid can be made small. The amount of air bubbles present in the phase can be increased. Further, according to the autoclave device 1 in which the gas blowing pipe outlet 30a is directed in a specific direction, even if the amount of gas supplied increases, the time for the bubbles to flow in the main stirring region S becomes longer, and the lower part of the stirrer 20 Since it is difficult to accumulate, the flooding phenomenon is unlikely to occur, and it is easy to increase the amount of gas supplied. Further, by using such an autoclave apparatus 1 to perform a leaching treatment or the like for leaching valuable metals contained in solids in a slurry, the reaction efficiency is increased by increasing the amount of bubbles in the liquid phase or the amount of gas supplied. Can be effectively leached into the liquid.

In the present embodiment, since the gas blowing pipe outlet 30a is arranged at a specific position and direction as described above, the air bubbles are efficiently divided by the stirring flow generated by the stirrer 20 to reduce the diameter. This can be done, and the flooding phenomenon is unlikely to occur even if the amount of gas supplied increases. Therefore, it is not necessary to narrow down the pipe diameter and the outlet diameter of the gas blowing pipe 30 at a predetermined ratio, and pressure loss can be suppressed. Therefore, the outlet diameter of the gas blowing pipe 30 is not particularly limited, and may be appropriately adjusted according to a value (outlet flow velocity) obtained by dividing the flow rate of the gas under pressure required for the reaction by the outlet area.

However, among them, in an industrial scale ^{reaction device of, for example, about 5 m 3} , the outlet diameter of the gas blowing pipe 30 is preferably 10 mm to 150 mm. If the outlet diameter of the gas blowing pipe 30 is less than 10 mm ^{, the pressure loss at the required air flow rate (for example, 300 Nm 3} / h) or more may increase, which only increases the cost of the gas pressurizing equipment to be blown. Instead, reaction products and post-reaction residues may adhere and block the outlet. Further, if the outlet diameter of the gas blowing pipe 30 exceeds 150 mm, the flow of the stirring flow may be changed by the pipe itself, which is not preferable.

Hereinafter, examples of the present invention will be described in more detail, but the present invention is not limited to the following examples.

By blowing air (oxygen) into a slurry in which mixed sulfide (solid matter) containing nickel and cobalt as a liquid phase is added to sulfuric acid in one compartment of an autoclave device while stirring, the solid matter in the slurry is formed. A treatment was performed in which the contained valuable metal was leached under high temperature and pressure. Specifically, as shown in the schematic views shown in FIGS. 3 and 4, an autoclave device equipped with a stirrer and a gas blowing pipe is used, and the outlet position of the gas blowing pipe is arranged at a predetermined position. Using.

In this process, modeling is performed with a multiphase flow of continuous phase-dispersed phase as MUSIG (Multiple Size Group Model) considering coalescence and splitting in the dispersed phase in the Euler-Euler coordinate system, and the body integral of bubbles in the liquid phase. The rate was analyzed and the total amount of air in the liquid phase was calculated from the integrated value in the compartment. In this model, the continuous phase is a liquid phase slurry and the dispersed phase is bubbles (air).

The boundary conditions, the density of the slurry is the continuous phase: 1275kg / ^{m 3,} density of air is the dispersed phase: 11 kg / ^{m 3,} cell diameter immediately after being discharged from the air blowing surface of the gas injection tube: 5 mm, stirring The number of rotations was 159 rpm. The relative air blowing amount was set to 0.018 min ^-1 and 0.157 min ^-1 . The relative air blowing amount is the ratio of the air (dispersed phase) blowing amount (m ³ / min) to the ^{amount (m 3} ) of the slurry (continuous phase) housed in the compartment.

Here, with reference to FIG. 4, in the first embodiment, the height h of the outlet position of the gas blowing pipe 30, the distance r from the center of the stirring shaft, and the center of the outlet of the gas blowing pipe 30 from the center of the stirring shaft. The angle θ formed by the tangential direction L of the circle formed by the distance r and the extension direction D of the outlet center line of the gas blowing pipe is (h, r, θ) = (0.55H, 1.27R, 40 °)), and the treatment was performed using a device controlled to be.

On the other hand, in Comparative Example 1, processing was performed using an apparatus controlled so that (h, r, θ) = (0.50H, 1.38R, 90 °).

FIG. 5 shows the results of the relative values of the stirring power of the stirrer in the treatments of Example 1 and Comparative Example 1. The relative value of the stirring power of the stirrer is the value of _{the stirring power P g} of the stirrer when air is blown with respect to _{the stirring power P 0 of the stirrer when air is not blown.} As shown in FIG. 5, in Example 1, the relative value of the stirring power is maintained high even when the amount of air blown is large, whereas in Comparative Example 1, the relative value of the stirring power is maintained when the amount of air blown is large. Was found to be decreasing. In the first embodiment, since the outlet position of the gas blowing pipe 30 is arranged at a specific position and direction, even if the amount of air blown increases, bubbles are less likely to accumulate in the lower part of the agitator and the flooding phenomenon is less likely to occur. It is believed that there is. On the other hand, in Comparative Example 1, since the outlet of the gas blowing pipe 30 is directed toward the stirring shaft, it is considered that when the amount of air blown increases, air bubbles accumulate below the stirring shaft and a flooding phenomenon occurs.

Hereinafter, the angle θ of the gas blowing pipe 30 was examined in detail. FIG. 6 shows the relationship between the angle θ and the amount of air in the liquid. FIG. 7 shows the relationship between the angle θ and the relative value of the stirring power. The conditions (h, r, θ) in FIGS. 6 and 7 are as follows, and the relative air blowing amount is 0.157 min ^-1 .
(H, r, θ) = (0.55H, 1.25R, 0 °)
(H, r, θ) = (0.55H, 1.30R, 0 °)
(H, r, θ) = (0.55H, 1.27R, 20 °)
(H, r, θ) = (0.55H, 1.27R, 35 °)
(H, r, θ) = (0.55H, 1.27R, 40 °)
(H, r, θ) = (0.55H, 1.32R, 60 °)
(H, r, θ) = (0.47H, 1.30R, 90 °)

As shown in FIG. 6, the amount of air in the liquid increases as the angle θ increases, and when the angle θ exceeds 20 °, the amount of air in the liquid exceeds ^{0.05 m 3 which is the preferable amount of air in the liquid for leaching treatment.} You can see that. If the angle θ is less than 20 °, it is considered that the bubbles supplied from the gas blowing pipe 30 deviate from the main stirring region S or the distance flowing through the main stirring region S is short. On the other hand, as shown in FIG. 7, when the angle θ exceeds 60 °, the relative value of the stirring power starts to decrease. It is considered that this is because when the angle θ exceeds 60 °, the flooding phenomenon is likely to occur. The angle θ is from 20 ° from the viewpoint of efficiently dividing the air supplied from the gas blowing pipe 30 to a small bubble diameter and suppressing the occurrence of the flooding phenomenon even if the amount of air supplied is increased. 60 ° is preferable.

1 Autoclave device 1w Inner wall surface of autoclave device 10,10A-10E Partition room 20,20A-20E Stirrer 21 Stirring shaft 22 Stirring blade 30 Gas blowing pipe 30a Gas blowing pipe outlet center

Claims (4)

It is a pressurizing reactor equipped with a stirrer and a gas blowing pipe without a spudger (air diffuser).
The pressurization reaction device is an autoclave device in which a cylindrical container is installed horizontally to perform a reaction under high temperature and high pressure.
The stirrer has a stirrer shaft hanging from the upper part of the pressurizing reaction device and a stirrer blade provided perpendicular to the stirrer shaft.
The stirrer generates a stirring flow downward from the stirring blade, and makes the stirring flow diagonally downward from the stirring shaft toward the inner wall surface of the pressurizing reactor, and after colliding with the inner wall surface. , Constructed to form an upward agitation stream along its inner wall,
The pressurizing reactor is viewed from the front in a cross section along the axial direction of the stirring shaft.
When H is defined as the position where the line extending from the stirring shaft intersects the inner wall of the pressure reaction device to the height position of the stirring blade, and R is defined as the maximum length of the stirring blade from the center of the stirring shaft. ,
The center of the outlet of the gas blowing pipe is
The height from the position where the line extending from the stirring shaft intersects the inner wall of the pressurizing reactor is h, and the distance from the center of the stirring shaft is r.
In the cross section perpendicular to the stirring axis, the extension direction of the outlet center line of the gas blowing pipe is directed to the positive side of the stirring flow generated by the stirring machine.
The angle between the tangential direction of the circle formed by the distance r from the center of the stirring shaft at the outlet center of the gas blowing pipe and the extension direction of the outlet center line of the gas blowing pipe is determined from the tangent line to the stirring. When the direction toward the axis is positive and θ is set,
It is provided at a position that satisfies the following formula,
Pressurized reactor.
0.45H ≤ h ≤ 0.55 H
1.1R ≤ r ≤ 1.4R
20 ° ≤ θ ≤ 60 ° The pressurizing reaction apparatus according to claim 1, wherein the outlet diameter of the gas blowing pipe is 10 mm to 150 mm. The pressurizing reaction apparatus according to claim 1 or 2 , which is used for adding an acid to a slurry containing a mixed sulfide of nickel and cobalt under high temperature and high pressure to perform an leaching treatment. A method for leaching a valuable metal by leaching the valuable metal from a solid substance contained in the slurry by using the pressurizing reaction apparatus according to any one of claims 1 to 3.

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