JP2018130690A - Pressure reactor and leaching processing method of valuable metal using the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a pressure reactor capable of efficiently segmenting bubbles of air introduced inside the reactor to achieve a smaller bubble diameter, as well as capable of preventing a flooding phenomenon from occurring even if an introduction amount of the air increases.SOLUTION: A pressure reactor is, for instance, an autoclave device 1, and includes an agitator 20 (agitation shaft 21) and an air blowing tube 30. The pressure reactor is arranged in such a location that a position and a direction of a center of an outlet of the air blowing tube 30 satisfy following equations: 0.45H≤h≤0.50H, 1.1R≤r≤1.4R, and 20°≤θ≤60°.SELECTED DRAWING: Figure 3

Description

  The present invention relates to a pressurized reaction apparatus and a valuable metal leaching treatment method using the same.

  As a reaction apparatus such as a chemical plant, a device that performs chemical treatment by introducing a gas into a liquid phase such as a liquid or a slurry in a reaction vessel and reacting it with stirring is often used.

  For example, Patent Document 1 includes a shaft that can rotate around a longitudinal axis of a container, and first and second impellers that are attached to the shaft and are radially spaced apart from each other. A mixing vessel is disclosed. Specifically, in this mixing vessel, the first impeller includes a plurality of curved blades operable to move fluid axially toward the second impeller, the second impeller being axially A plurality of curved blades operable to move the fluid toward the first impeller are included, and a gas inlet is provided on the bottom surface of the container. By adopting such a configuration, a strong turbulent region is generated in the central portion of the mixing container so that the mixing of the liquid in the container can be easily controlled.

  However, in the mixing container described in Patent Document 1, when a large bubble is introduced from a large gas inlet at the center, it reaches the liquid level at the top of the mixing container before the bubble diameter becomes small in the mixing container. There is a problem that it ends up. Therefore, even if such a mixing container is applied as a reaction container used for a chemical reaction, the amount of gas that does not contribute to the reaction increases and the reaction efficiency decreases.

  It is important to reduce the bubble diameter in the liquid phase in the vessel as the gas used for the chemical reaction in the reaction vessel. The smaller the bubble, the larger the area of the gas-liquid interface, In addition, since the time during which bubbles circulate and stay in the liquid becomes longer, the amount of the gas component dissolved in the liquid phase increases, and as a result, the gas concentration in the liquid phase is increased and the effect of improving the reaction efficiency can be expected. Because. That is, in the reaction vessel, it is important to maximize the amount of bubbles by making the introduced gas into small bubbles in the liquid phase.

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

  However, when trying to apply the sparger to a pressurized reactor that introduces gas, the pressure of the gas blown into the device from the sparger is the sum of the internal pressure of the reaction vessel and the pressure loss of the sparger. It is necessary to pressurize beyond. Moreover, since the sparger has a large pressure loss due to the small bubble outlet diameter, there is a problem that the cost of the pressurizing equipment is increased. In addition, depending on the reaction, reaction products including intermediates and post-reaction residues may become adhering matter, blocking the small bubble outlet of the sparger. There is also a problem of lowering. Due to these various problems, it has been difficult to use a sparger in a pressure reactor.

  In a pressurized reaction apparatus that introduces gas, it is preferable to increase the diameter of the gas blowing pipe and the outlet diameter as much as possible in order to minimize pressure loss. However, it is well known that the bubble diameter of the bubbles released from the gas blowing tube depends on the outlet diameter of the gas blowing tube, and the bubble diameter becomes large if pressure loss is to be minimized. A large 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, there has been a demand for a technique for reducing a large bubble diameter released from a large outlet diameter with a small pressure loss into a small bubble diameter.

  Furthermore, 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 making a large-sized bubble released from a large outlet diameter with a small pressure loss a small bubble diameter and preventing the flooding phenomenon from occurring even when the amount of introduced gas increases.

Special table 2009-536095 JP 2014-113564 A

  The present invention has been made in view of such circumstances, and can efficiently divide the gas bubbles introduced into the apparatus to have a small bubble diameter and increase the amount of gas introduced. Another object of the present invention is to provide a pressure reactor capable of suppressing the occurrence of flooding.

  This inventor repeated earnest examination in order to solve the subject mentioned above. As a result, in a pressure reactor equipped with a stirrer and a gas blowing tube, the gas bubbles can be efficiently discharged by arranging the outlet position of the gas blowing tube in a specific position and direction with respect to the stirrer. The present invention has been completed by finding that the occurrence of flooding can be suppressed even if the amount of gas introduced is increased.

(1) A first invention of the present invention is a pressurized reaction device provided with a stirrer and a gas blowing tube, the stirrer being a stirring shaft suspended from the upper part of the pressurized reaction device, The pressure reactor is viewed in front in a cross section along the axial direction of the stirring shaft, and a line extending from the stirring shaft is added to the stirring shaft. When the height from the position intersecting the inner wall of the pressure reactor to the height position of the stirring blade is H, and the maximum length of the stirring blade from the center of the stirring shaft is R, the outlet center of the gas blowing tube is The height from the position where the line extending from the stirring shaft intersects the inner wall of the pressurized reactor is h, the distance from the center of the stirring shaft is r, and the gas in a cross section perpendicular to the stirring shaft The direction of extension of the outlet center line of the blowing pipe is the positive direction of the stirring flow generated by the stirrer. An angle formed between a tangential direction of a circle formed by a distance r from the center of the stirring shaft at the outlet center of the gas blowing tube and an extension direction of the outlet center line of the gas blowing tube. The pressure reactor is provided at a position satisfying the following expression when θ is set.
0.45H ≦ h ≦ 0.50H
1.1R ≦ r ≦ 1.4R
20 ° ≦ θ ≦ 60 °

  (2) The second invention of the present invention is the pressurized reactor according to the first invention, wherein the outlet diameter of the gas blowing tube is 10 mm to 150 mm.

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

  (4) According to a fourth aspect of the present invention, in any one of the first to third aspects, 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. This is a pressure reactor used for the purpose.

  (5) The fifth invention of the present invention is a leaching treatment of valuable metal, wherein the valuable metal is leached from the solid matter contained in the slurry using the pressurized reactor 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 to have a small bubble diameter, and even if the amount of introduced gas is increased, the occurrence of flooding can be suppressed. A pressure reactor can be provided.

  In addition, by using such a pressure reactor to perform a leaching process in which valuable metals contained in the solid matter in the slurry are leached, the reaction efficiency is increased due to the increase in 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 the cross-sectional top view which showed the internal structure typically by cut | disconnecting an autoclave apparatus horizontally, (b) is an internal structure by cut | disconnecting an autoclave apparatus perpendicularly | vertically It is the vertical side view which showed typically. It is a schematic diagram showing the AA cross section in Fig.1 (a), and is a figure for demonstrating the stirring flow by a stirrer. It is a schematic diagram showing the BB cross section in FIG. 2, and is a figure for demonstrating the stirring flow by a stirrer. It is a schematic diagram showing a cross section perpendicular | vertical to a stirring axis, and is a figure for demonstrating arrangement | positioning of the exit position of a gas blowing pipe | tube. It is a graph which shows the result of the stirring power relative value in the process in Example 1 and Comparative Example 1. It is a graph which shows the relationship between angle (theta) and the amount of air in a liquid. It is a graph which shows the relationship between angle (theta) and stirring power relative value.

  Hereinafter, a specific embodiment of the present invention (hereinafter referred to as “the present embodiment”) will be described in detail. In addition, this invention is not limited to the following embodiment, A various change is possible in the range which does not change the summary of this invention. In this specification, the notation “X to Y” (X and Y are arbitrary numerical values) means “X or more and Y or less”.

  The pressurized reaction apparatus according to the present embodiment includes a stirrer and a gas blowing tube, and enables a reaction under high pressure. This pressurization reaction apparatus can be applied as an autoclave apparatus which is a heat-resistant pressure-resistant reaction vessel that makes the inside high-temperature and high-pressure with saturated steam. In the following, the autoclave apparatus and the chemical reaction carried out in the apparatus will be described in detail. However, the present invention is not limited to this, and the liquid phase is chemically treated in a pressurized reaction apparatus equipped with a stirrer and a gas blowing tube. If it is the apparatus made to react, there exists the same effect.

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

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

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

  Moreover, about the process conditions in the autoclave apparatus 1, it pressurizes to 3 atmospheres or more as an internal pressure, for example, and temperature shall be 100 degreeC or more.

  As shown in FIG. 1, the autoclave device 1 includes a plurality of compartments 10. Each compartment 10 is a space serving as a reaction field for performing a process such as a leaching process on the slurry in the autoclave apparatus 1. Specifically, the compartment 10 is divided into a plurality of partitions 40 provided in the autoclave apparatus 1. In the example of the autoclave apparatus 1 shown in FIG. 1, five compartments 10 (10A, 10B, 10C, 10D, 10E) partitioned into five compartments by four partition walls 40 (40A, 40B, 40C, 40D) are provided. ing. Note that the number of compartments in the autoclave apparatus can be set as appropriate 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. ing.

[Leaching treatment in the compartment]
The compartment 10 continues in order from the upstream side (left side in FIG. 1) to the first compartment 10A, the second compartment 10B,..., And the most downstream side (right side in FIG. 1) is the final fifth. It is composed of a compartment 10E. In the autoclave apparatus 1, a slurry as a raw material is charged into the most upstream first compartment 10 </ b> A, and a solution such as sulfuric acid is turned into a slurry via a pipe suspended from the top of the first compartment 10 </ b> A. Supplied. Then, in the first compartment 10A, valuable metal contained in the solid matter in the slurry is leached into the solution by stirring by a stirrer 20A described later and oxygen supplied by the gas blowing tube 30A.

  At the same time as the slurry is stirred 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. And transferred to the second compartment 10B. In the second compartment 10B, in the same manner as the treatment in the first compartment 10A, the leaching process proceeds sequentially by stirring with the stirrer 20B. At this time, also in the second compartment 10B, a pipe or the like can be suspended from the upper part to supply a solution such as sulfuric acid, slurry, or the like used for leaching.

  Thereafter, the slurry is transferred to the third compartment 10C and the fourth compartment 10D mainly by overflow, and the leaching process proceeds in each compartment 10. Similarly, when the leaching process is performed on the slurry in the fifth compartment 10E, which is the most downstream, via the leachate discharge pipe (not shown) provided in the fifth compartment 10E. The slurry containing the leachate obtained by leaching the metal is discharged.

[Composition of the compartment]
In the compartment 10, as described above, the stirrer 20 for stirring the slurry inside and the gas blowing pipe 30 for supplying a gas such as oxygen necessary for the reaction are provided (FIG. 2, see FIG. Further, among the compartments 10, at least the first compartment 10A is provided with a raw material slurry charging pipe (not shown) for charging the raw material slurry. Through which a slurry containing solids is charged.

  The compartment 10 is also provided with various supply pipes for supplying an acid solution such as sulfuric acid, slurry, steam, and the like, for example, depending on the upper part thereof.

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

  As the stirrer 20, for example, as shown in FIG. 2 representing the AA cross section of the compartment 10 </ b> B in FIG. 1A and the schematic diagram of FIG. 4, A propeller-shaped one having a plurality of stirring blades 22 provided perpendicular to the stirring shaft 21 at the lower end position can be used. Thus, the stirrer 20 is suspended from the upper ceiling of each compartment 10, and when the autoclave device 1 is viewed from above (see FIG. 1A), the stirrer shaft 21 is positioned at the central portion of each compartment 10. Can be provided. In addition, it is good also as a stirrer provided with two or more sets of the propeller shape provided with the several stirring blade with respect to the stirring shaft.

  The stirrer 20 rotates the stirring shaft 21 at a predetermined speed, for example, clockwise, and stirs the slurry by the stirring blade 22. By the stirring by the stirrer 20, a liquid flow in a predetermined direction is generated in the slurry in the compartment 10. Normally, a liquid flow is generated from the stirring blades 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 compartment 10. To be stirred.

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

Here, when the autoclave apparatus 1 is used for the leaching process for a slurry containing at least a mixed sulfide of nickel and cobalt, the reaction during the leaching process of nickel sulfide or cobalt sulfide in each compartment 10 is represented 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 process under high temperature and high pressure, it is necessary to supply oxygen (O ₂ ) necessary for the reaction into the slurry. In supplying oxygen to the slurry, it is usual to supply air, and air is supplied through the gas blowing tube 30.

  As shown in FIG.2 and FIG.4, as the gas blowing pipe | tube 30, it is not restricted to the aspect provided only in one in each compartment 10, For example, multiple, such as two, may be provided.

  In the autoclave apparatus 1, in addition to the gas blowing pipe 30, water for maintaining a high temperature and high pressure state, sulfuric acid for supplying sulfuric acid or other acid to make a sulfuric acid leachate, water for adjusting the concentration, etc. In this embodiment, a pipe for supplying a gas necessary for the reaction is used as a gas blowing pipe 30, and other supplies are provided. It is distinguished from the piping for the purpose of supply.

[Liquid flow in the compartment]
Here, FIG. 2 is a schematic diagram in the AA cross section of FIG. 1 (a), and the stirring flow generated in the compartment 10 by the stirrer 20 is in the axial direction of the stirring shaft 21, that is, up to the liquid level. The flow in the height direction is shown. In addition, in order to make a stirring flow easy to see, the gas blowing pipe | tube 30 is represented with the broken line in FIG. FIG. 3 is a schematic diagram in the BB cross section of FIG. 2, and shows the direction of the gas blowing pipe outlet 30 a and the main stirring region S for the stirring flow generated in the compartment 10 by the stirrer 20. Is.

  As described above, in the compartment 10, the stirring is usually performed so that a stirring flow is generated in the downward direction opposite to the liquid surface from the stirring blade 22. It becomes the stirring flow in the diagonally downward direction toward the wall surface 1w. Then, as shown by the arrows in FIG. 2, the main stirring flow collides with the inner wall surface 1w of the autoclave device 1 and then flows upward along the inner wall surface 1w. The flow is directed downward along the wall surface 1w.

  Therefore, the stirring flow propelled in the diagonally right direction on FIG. 2 by the stirrer 20 spreads from the stirrer 20 over the liquid level and the inner wall surface 1w of the autoclave device 1 and has a large counterclockwise flow (FIG. 2). The thick bold arrow X) and the small flow velocity generated at the lower right of the stirrer 20 are slow and small clockwise flows (thin arrow Y in FIG. 2). A large counterclockwise flow that is a main stirring flow generated by the stirrer 20 is combined with a horizontal flow parallel to the liquid surface and flows upward while swirling.

  When such a stirring flow is viewed 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 rate as indicated by a thick arrow X. When this region is exceeded, there is a region where the stirring flow flows at a slow flow rate 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 where the stirring flow flows at a high flow rate (hereinafter referred to as “main stirring region S”) is formed in a donut shape. Will be. The direction of the agitation flow in the main agitation region S is a spiral shape that goes outward in the counterclockwise direction, as indicated 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 put on the stirring flow to reduce the amount of bubbles in the liquid phase. It is preferable that it can be increased.

  The reason why the amount of bubbles in the liquid phase is increased by causing bubbles to flow in the stirring flow is that, as described above, in the main stirring region S, the stirring flow is swirled upward while swirling. This is considered to be due to the longer time for the bubbles to move together with the stirring flow and reach the liquid level relatively because the flow is directed toward. On the other hand, the bubble located in the place where the stirring flow is weak has a higher speed of rising toward the liquid surface due to buoyancy, and the time to reach the liquid surface is relatively short. Also, at the position where the stirring flow is weak, the bubbles become larger due to the coalescence of bubbles, and the rising speed due to buoyancy increases depending on the bubble diameter, so the time until the larger bubbles reach the liquid level further. It will be shorter.

  On the other hand, the gas supplied from the gas blowing tube 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 advance in the direction in which the gas blowing pipe outlet 30a faces, and the initial kinetic energy is the reason why the bubbles actually flow along the stirring flow. After canceling the resistance caused by the stirring flow. In consideration of the initial kinetic energy of the bubbles, the bubbles flow in the liquid phase along the stirring flow after traveling a certain distance from the gas blowing tube outlet 30a toward the stirrer 20. This certain distance becomes longer as the gas supply amount increases. Therefore, when the gas blowing tube outlet 30a is installed in the direction toward the stirring shaft 21, as the amount of gas supplied from the gas blowing tube 30 increases, the bubbles pass through the main stirring region S in the arrow Y direction. The amount of stirring flow shown reaches the region where it flows at a slow flow rate. As a result, bubbles tend to accumulate in the lower portion of the stirring shaft 21 (lower portion of the stirring blade 22), and the flooding phenomenon is likely to occur.

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

  Thereby, the gas bubbles supplied from the gas blowing tube 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 tube outlet 30a intersects the stirring shaft 21. The air bubbles on the main stirring region S flow along the upward flow while swirling. Therefore, even if the amount of gas supply increases, most of the bubbles are placed in the main stirring region S, and the flooding phenomenon can be effectively suppressed.

Hereinafter, the installation position and the installation direction of the gas blowing pipe outlet 30a will be specifically described. As shown in FIG. 4, the autoclave device 1 is viewed from the front in a cross section along the axial direction of the stirring shaft 21, and the stirring blades from the position where the line extending from the stirring shaft 21 intersects the inner wall surface 1 w of the autoclave device 1 When the height up to 22 is H, and the maximum length of the stirring blade 22 from the center of the stirring shaft 21 is R, the center of the gas blowing tube outlet 30a is a line extending from the stirring shaft 21 in the autoclave. When the height from the position intersecting the inner wall surface 1w of the apparatus 1 is h and the distance from the center of the stirring shaft 21 is r, the apparatus 1 is provided at a position that satisfies the following expressions (i) and (ii). .
0.45H ≦ h ≦ 0.50H (i)
1.1R ≦ r ≦ 1.4R (ii)

  Here, H at the height position of the stirring blade 22 refers to the height of the central axis of the stirring blade 22 provided perpendicular to the axial direction of the stirring shaft 21, and the central axis of the stirring blade 22 is The axis represented by the line C1 in FIG. Further, with respect to the maximum length R of the stirring blade 22 from the center of the stirring shaft 21, the center of the stirring shaft 21 refers to the center of the axis represented by the line C2 in FIG. 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 is said.

  As for the position of the gas blowing pipe outlet 30a, when the height h is less than 0.45H (0.45H> h) or more than 0.50H (0.50H <h), the gas blowing pipe outlet 30a is supplied from the gas blowing pipe outlet 30a. The bubbles of the gas that have been removed will deviate from the main agitation region S, or the flow distance will be shortened. As a result, the effect of dividing the bubbles is reduced, and it is difficult to obtain small diameter bubbles. As described above, since the size of the bubble affects the rising speed due to buoyancy, if the effect of dividing the bubble is reduced, it means that the time until the bubble reaches the liquid surface is shortened, and the inside of the liquid phase The amount of bubbles decreases.

  Further, regarding the position of the gas blowing tube outlet 30a, if the distance r between the center of the outlet and the center of the stirring shaft 21 exceeds 1.4R (1.4R <r), bubbles are stirred in the main stirring region S. Accordingly, 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). Bubbles on the thin line arrow Y) will increase. The bubbles in the weak flow are likely to collect in the lower part of the stirrer 20 (lower part of the stirring blades 22) and have a low flow rate, so that they are likely to coalesce and increase in diameter. As a result, the flooding phenomenon is likely to occur, and the amount of bubbles in the liquid phase is relatively reduced.

Moreover, in the autoclave apparatus 1 mentioned above, the direction of the gas blowing pipe | tube exit 30a is provided so that the following conditions may be satisfied. That is, the gas blowing tube outlet 30a has, in a cross section perpendicular to the stirring shaft 21, a tangent L of a circle formed by the distance r from the center of the stirring shaft 21 at the outlet center of the gas blowing tube outlet 30a, and the gas blowing tube outlet. The angle θ formed by the extension direction D of the outlet center line 30a is arranged in a direction that satisfies the following formula (iii).
20 ° ≦ θ ≦ 60 ° (iii)

  Here, the angle θ formed between the tangent L of the circle at the outlet center of the gas blowing tube outlet 30a and the extending direction D of the outlet center line of the gas blowing tube outlet 30a is an acute angle among the angles formed by both. Refers to the angle. The gas blowing tube 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 formed in a straight line, and the direction of the tangent line when formed in a curved line.

  With respect to the direction of the gas blowing tube outlet 30a, the angle θ formed by the tangent L of the circle centering on the stirring shaft 21 and the extending direction D of the outlet center line is less than 20 °, and the gas blowing tube outlet 30a is supplied. The gas bubbles are out of the main stirring region S or the distance of flowing through the main stirring region S is shortened. As a result, the effect of dividing the bubbles is reduced, and it is difficult to obtain small diameter bubbles. On the other hand, when the angle θ exceeds 60 °, the gas bubbles supplied from the gas blowing tube outlet 30a exceed the main stirring region S when the gas supply amount increases as described above. The bubbles on the weak clockwise flow generated below 20 increase and easily accumulate in the lower part of the stirring shaft 21, and therefore the flooding phenomenon is likely to occur.

  As described above, according to the autoclave device 1 in which the position of the gas blowing tube outlet 30 is arranged at a specific position, the gas bubbles introduced into the device can be efficiently divided into a small bubble diameter. The amount of 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, the time for the bubbles to flow in the main stirring region S is increased even if the gas supply amount increases, Since it is difficult to accumulate, it is difficult for the flooding phenomenon to occur and it is easy to increase the amount of gas supply. Further, by using such an autoclave apparatus 1 to perform a leaching process for leaching valuable metals contained in solids in the slurry, the reaction efficiency can be increased by increasing the amount of bubbles in the liquid phase or increasing the amount of gas supply. The valuable metal can be effectively leached into the liquid.

  In the present embodiment, since the gas blowing tube outlet 30a is arranged at a specific position and direction as described above, the bubbles are efficiently divided by the stirring flow generated by the stirrer 20 to reduce the diameter. The flooding phenomenon is unlikely to occur even when the gas supply amount increases. Therefore, it is not necessary to restrict the pipe diameter and 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 tube 30 is not particularly limited, and may be appropriately adjusted according to a value (outlet flow velocity) obtained by dividing the gas flow rate under pressure required for the reaction by the outlet area.

However, among them, in an industrial scale reactor of, for example, about 5 m ³ , the outlet diameter of the gas blowing tube 30 is preferably 10 mm to 150 mm. If the outlet diameter of the gas blowing tube 30 is less than 10 mm, the pressure loss at a required air flow rate (for example, 300 Nm ³ / h) or more may increase, and the pressure of the gas to be blown is only expensive. In some cases, a reaction product or a residue after the reaction adheres and the outlet is blocked. Moreover, if the outlet diameter of the gas blowing pipe 30 exceeds 150 mm, the pipe itself may change the flow of the stirring flow, which is not preferable.

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

  In a one-compartment chamber of the autoclave device, air (oxygen) is blown into the slurry in which the mixed sulfide (solid matter) containing nickel and cobalt, which is a liquid phase, is added to sulfuric acid, while stirring, to the solid matter in the slurry. The valuable metal contained was subjected to a high-temperature pressure leaching treatment. Specifically, as shown in the schematic diagrams shown in FIGS. 3 and 4, an autoclave device including 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 the coalescence and splitting in the dispersed phase in the Euler-Euler coordinate system, and the volume of bubbles in the liquid phase The rate was analyzed, and the total amount of air in the liquid phase was calculated from the integral 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 revolutions was 159 rpm. Moreover, 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 slurry (continuous phase) accommodated in the compartment.

  Here, with reference to FIG. 4, in Example 1, the height h of the outlet position of the gas blowing tube 30, the distance r from the center of the stirring shaft, and the center of the stirring shaft at the outlet center of the gas blowing tube 30. The angle θ between the tangential direction L of the circle formed by the distance r and the extending direction D of the outlet center line of the gas blowing tube is (h, r, θ) = (0.55H, 1.27R, 40 °), and processed using an apparatus controlled to be

  On the other hand, in the comparative example 1, it processed using the apparatus controlled so that it might become (h, r, (theta)) = (0.50H, 1.38R, 90 degrees).

In FIG. 5, the result of the stirring power relative value of a stirrer in the process in Example 1 and Comparative Example 1 is shown. Stirring power relative value of agitator for stirring power P ₀ of the agitator when no blown air, which is the value of stirring power P _g agitator during air blowing. As shown in FIG. 5, in Example 1, the stirring power relative value is maintained high even when the air blowing amount is increased. In Comparative Example 1, when the air blowing amount is increased, the stirring power relative value is increased. Was found to be decreasing. In Example 1, since the outlet position of the gas blowing tube 30 is arranged in a specific position and direction, even if the amount of air blowing increases, bubbles are unlikely to accumulate in the lower part of the stirrer, and flooding phenomenon is unlikely to occur. It is believed that there is. On the other hand, in Comparative Example 1, since the outlet of the gas blowing tube 30 faces the stirring shaft, it is considered that when the amount of air blowing increases, bubbles are accumulated below the stirring shaft and a flooding phenomenon occurs.

Hereinafter, the angle θ of the gas blowing tube 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 stirring power relative value. The conditions (h, r, θ) in FIGS. 6 and 7 are as follows, and the relative air blowing amount was 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, as the angle θ increases, the amount of air in the liquid increases. When the angle θ exceeds 20 °, the amount of air in the liquid exceeds 0.05 m ³ , which is a preferable amount of air in the liquid for the leaching process. I understand that If the angle θ is less than 20 °, it is considered that the bubbles supplied from the gas blowing tube 30 are out of the main stirring region S or the distance through which the main stirring region S flows is short. On the other hand, as shown in FIG. 7, when the angle θ exceeds 60 °, the stirring power relative value starts to decrease. If the angle θ exceeds 60 °, the flooding phenomenon is likely to occur. The angle θ is from 20 ° from the viewpoint that the air supplied from the gas blowing tube 30 is efficiently divided into a small bubble diameter, and even if the supply amount of air is increased, the occurrence of the flooding phenomenon is suppressed. 60 ° is preferred.

DESCRIPTION OF SYMBOLS 1 Autoclave apparatus 1w Inner wall surface of autoclave apparatus 10, 10A-10E Compartment chamber 20, 20A-20E Stirrer 21 Stirrer shaft 22 Stirrer blade 30 Gas blow pipe 30a Gas blow pipe outlet center

Claims (5)

A pressure reactor equipped with a stirrer and a gas blowing tube,
The stirrer has a stirring shaft suspended from the upper part of the pressure reactor, and a stirring blade provided perpendicular to the stirring shaft,
The pressure reactor is viewed in front in a cross section along the axial direction of the stirring shaft,
When the line extending from the stirring shaft intersects the inner wall of the pressurized reactor to the height position of the stirring blade is H, and the maximum length of the stirring blade from the center of the stirring shaft is R ,
The outlet center of the gas blowing tube is
The height from the position where the line extending from the stirring shaft intersects the inner wall of the pressurized 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 extending direction of the outlet center line of the gas blowing tube is directed to the positive direction side of the stirring flow generated by the stirrer,
When 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 tube and the extending direction of the outlet center line of the gas blowing tube is θ,
It is provided at a position that satisfies the following formula,
Pressure reactor.
0.45H ≦ h ≦ 0.50H
1.1R ≦ r ≦ 1.4R
20 ° ≦ θ ≦ 60 ° The pressurized reactor according to claim 1, wherein an outlet diameter of the gas blowing tube is 10 mm to 150 mm. It is an autoclave apparatus. The pressurization reaction apparatus of any one of Claim 1 or 2. The pressurization reactor according to any one of claims 1 to 3, which is used for leaching a slurry containing a mixed sulfide of nickel and cobalt by adding an acid under high temperature and high pressure. A valuable metal leaching treatment method for leaching a valuable metal from a solid contained in a slurry using the pressurized reaction apparatus according to any one of claims 1 to 4.

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