JP6593191B2 - Leach tank - Google Patents

Description

  The present invention relates to a leaching tank for leaching a powder of a solid metal-containing material contained in a slurry with an oxidizing gas.

  In general, as a method for leaching a solid metal-containing powder with an oxidizing gas, a technique of blowing chlorine gas, air, oxygen gas, or the like into a slurry obtained by repulping the solid metal-containing powder into an acidic aqueous solution is used. It has been.

  As an example, in the smelting of nickel and cobalt, sulfides containing nickel and cobalt are leached using the oxidizing action of chlorine gas, and the leached nickel ions and cobalt ions are electrowinned to obtain electric nickel and electric A chlorine leaching process that is commercialized as cobalt has been put into practical use.

  In the chlorine leaching process in the chlorine leaching process, Patent Literature 1 and Patent Literature 2 disclose the following techniques.

  Patent Document 1 describes that by providing a baffle plate, the slurry in the leaching tank is uniformly convected, so that a sufficient leaching reaction time can be secured and the leaching rate is improved. Patent Document 1 describes that the hydrostatic cylinder is a long member having a U-shaped cross section, and the upper end of the hydrostatic cylinder is attached to the back surface of the lid of the leaching tank.

  Patent Document 2 describes that the stirring ability is improved by making the stirring device in a vertically long shape in order to secure an installation space for the baffle. Patent Document 2 describes that the hydrostatic cylinder has a semi-cylindrical shape extending along the side wall of the stirring tank and is provided so as to cover the outlet of the stirring tank.

JP 2013-166984 A Japanese Patent Laying-Open No. 2015-054272

  Even if the hydrostatic cylinders described in Patent Document 1 and Patent Document 2 described above are provided, for example, the unreacted slurry in the leaching tank flows into the opening in the upper part of the hydrostatic cylinder and is discharged to the subsequent tank. Etc., a short pass occurred. Therefore, development of a leaching tank equipped with a hydrostatic cylinder that can prevent a short pass is desired.

  Patent Document 1 and Patent Document 2 recognize the description of the hydrostatic cylinder provided in the leaching tank. However, although the technology relating to the structure of the leaching tank and the stirring structure has been disclosed, it does not feature the shape of the hydrostatic cylinder, and the problem relating to the hydrostatic cylinder has not been solved.

  Then, this invention is proposed in view of the problem of the said prior art, and it aims at providing the leaching tank provided with the still water cylinder which can prevent a short path | pass completely.

  In order to achieve the above-mentioned object, the present inventors have made extensive studies on the structure of the hydrostatic cylinder, and as a result, optimized the lower and upper shapes of the hydrostatic cylinder and specified the rising flow velocity of the hydrostatic cylinder. The inventors have found that it is possible to capture the slurry after the reaction constituting the lower swirling flow, prevent a short pass and improve the leaching rate, and complete the present invention.

That is, the leaching tank according to an aspect of the present invention is a leaching tank for leaching a powder of a solid metal-containing material contained in a slurry with an oxidizing gas, the bottomed cylindrical leaching tank body, and the leaching tank A stirrer having a rotating shaft provided substantially parallel to the central axis of the main body, a stirring blade attached to the rotating shaft, a hydrostatic cylinder provided inside the leaching tank body, and the leaching tank body A lid portion that seals the gas phase portion of the hydrostatic tube, and the hydrostatic cylinder is formed with an opening in a side surface facing the side wall of the brewing tank body, an overflow pipe is connected to the opening, and a lower end of the hydrostatic cylinder the parts, captures the swirling flow of the slurry after leaching the reaction generated by said stirrer, have a inlet for induced to the upward flow in the static within the water bottle, the upper end portion of the static water bottle is the leaching It is arranged at a position higher than the lid part of the tank body, and the static Cylinder is characterized in that it is supported by the lid portion of the leaching tank body.

  In the leaching tank according to an aspect of the present invention, it is preferable that the hydrostatic cylinder is controlled so that the rising speed of the slurry is 0.1 m / second or more and 0.3 m / second or less.

  Further, in the brewing tank according to one aspect of the present invention, the hydrostatic cylinder is disposed at a position higher than the liquid level of the slurry in the brewing tank main body and lower than the lid, and the side wall of the brewing tank main body It is preferable to have an air vent on the side of the hydrostatic cylinder that does not face.

  Further, in the leaching tank according to one aspect of the present invention, the hydrostatic cylinder is formed as a square cylinder, and the opening surface of the introduction port is on one side facing the swirling flow of the slurry from the lower end edge of the introduction port. It is preferable to be inclined and notched. Furthermore, in the leaching tank according to one aspect of the present invention, the hydrostatic cylinder is preferably formed as a square cylinder, and the opening surface of the introduction port is preferably cut out on one side facing the swirling flow of the slurry. Furthermore, in the leaching tank according to one aspect of the present invention, the hydrostatic cylinder is formed as a square cylinder, and the opening surface of the inlet is notched on one side facing the swirling flow of the slurry, and is further adjacent to one side. It is preferable that the side surface is also notched.

  In addition, the leaching tank according to one embodiment of the present invention is preferably applied as a chlorine leaching tank for leaching a sulfide containing nickel and cobalt using an oxidizing action of chlorine gas.

  According to the present invention, it is possible to prevent a short pass, so that the leaching rate can be improved.

It is a schematic diagram which shows the leaching tank in which the conventional hydrostatic cylinder was installed. It is a top view which shows the leaching tank which concerns on one Embodiment of this invention. It is X-X 'sectional drawing which shows the leaching tank in FIG. It is a perspective view which shows a static water cylinder, (A) is a perspective view which shows the static water cylinder with which the leaching tank which concerns on 1st Embodiment is equipped, (B) is a perspective view which shows the conventional static water cylinder. It is a perspective view which shows the still water cylinder with which the leaching tank which concerns on 2nd Embodiment is equipped. It is a perspective view which shows the still water cylinder with which the leaching tank which concerns on 3rd Embodiment is equipped. It is a figure which shows a time-dependent change of lithium concentration, (A) is a figure which shows a time-dependent change of lithium concentration in Example 1, (B) is a figure which shows a time-dependent change of lithium concentration in the comparative example 1. FIG.

  Hereinafter, preferred embodiments of the present invention will be described in detail. The present embodiment described below does not unduly limit the contents of the present invention described in the claims, and all the configurations described in the present embodiment are essential as means for solving the present invention. Not necessarily.

  First, a leaching tank according to an embodiment of the present invention includes a leaching tank body, a stirrer, a hydrostatic cylinder, and a lid. Furthermore, the lower end part of the still water cylinder provided in the leaching tank according to the embodiment of the present invention has an introduction port. For this reason, the slurry after the leaching reaction constituting the lower swirl flow can be captured, a short pass can be prevented, and the leaching rate can be improved.

  The leaching tank according to an embodiment of the present invention is generally applicable to a leaching tank in which a solid metal-containing powder contained in a slurry is leached with an oxidizing gas, and in particular, a sulfide containing nickel and cobalt. Can be suitably applied to a chlorine leaching tank that leaches using the oxidizing action of chlorine gas.

  Here, as an embodiment of the present invention, description will be made below by taking as an example an application to a chlorine leaching tank in which the above-described sulfide containing nickel and cobalt is leached using the oxidizing action of chlorine gas.

1. Chlorine leaching process (1) Outline In smelting of nickel and cobalt, sulfides containing nickel and cobalt are leached using the oxidizing action of chlorine gas, and the leached nickel ions and cobalt ions are obtained by electrowinning. Chlorine leaching processes commercialized as electrical nickel and electrical cobalt have been put into practical use.

  In the chlorine leaching process of the chlorine leaching process, a mixture of nickel sulfide and cobalt sulfide, called mixed sulfide, and cementation residue described later are repulped into an aqueous chloride solution, and then nickel gas is injected by blowing chlorine gas into the slurry. And leaching cobalt into aqueous chloride solution.

In the substitution leaching step, a copper leaching solution containing divalent copper chloro complex ions as an oxidant obtained in the chlorine leaching step is brought into contact with a crushed Ni ₃ S ₂ and a nickel mat containing metal nickel as main components to make copper. And nickel, the nickel in the nickel mat is replaced and leached into the liquid, and the copper ions are in the form of Cu ₂ S or Cu ⁰ (metallic copper) and become solid (part of the cementation residue). Become.

The cementation residue composed of the substitution leaching final solution, the nickel mat substitution leaching residue, and the solid precipitated in the form of Cu ₂ S or Cu ⁰ (metal copper) is solid-liquid separated, and then the substitution leaching. The final liquid is sent to the next cleaning process, and the solid cementation residue is sent to the chlorine leaching process.

  In this liquid purification step, impurities such as iron, lead, copper, and zinc are removed from the obtained substitution leaching final solution, and cobalt in the substitution leaching final solution is separated using a method such as solvent extraction.

  Next, nickel is electrolytically collected to produce electric nickel.

  The above-mentioned method for producing electrical nickel from sulfides containing nickel and cobalt is simple and realizes efficient and economical production, such as reusing chlorine gas generated by electrowinning for leaching. It can be said that.

(2) Chlorine leaching process In the chlorine leaching process, the mixed sulfide and cementation residue are repulped into an aqueous chloride solution, and then chlorine and gas are blown into the slurry to mix nickel and cobalt in the mixed sulfide with cementation. Nickel and copper in the residue are leached into an aqueous chloride solution to obtain a chlorine leaching solution.

  In this chlorine leaching process, chloro complex ions of divalent copper act as a direct leaching agent for dissolving mixed sulfides and metals in cementation residue, and chlorine gas divalently converts copper monovalent ions into divalent ions. It is indirectly involved in the leaching reaction by oxidation to ions.

Specifically, in this chlorine leaching step, a chlorine leaching reaction mainly represented by the following formulas (1) to (4) occurs.
NiS + 2CuCl ₄ ²⁻ → Ni ²⁺ + S ⁰ + 2Cl ⁻ + 2CuCl ₃ ²⁻ (1)
Cu ₂ S + 2CuCl ₄ ²⁻ + 4Cl ⁻ → 4CuCl ₃ ²⁻ + S ⁰ (2)
Cu ⁰ + CuCl ₄ ²⁻ → 2CuCl ₃ ²⁻ (3)
2CuCl ₃ ²⁻ + Cl ₂ → 2CuCl ₄ ²⁻ (4)

  In this chlorine leaching step, the chlorine leaching reaction conditions are that the oxidation-reduction potential of the nickel chloride aqueous solution during the reaction is 480 to 560 mV, and the temperature is 105 to 115 ° C.

2. Leaching tank (1) Conventional chlorine leaching tank FIG. 1 is a schematic view of a leaching tank in which a conventional hydrostatic cylinder is installed. As shown in FIG. 1, the leaching tank 10 has a hydrostatic cylinder 20 provided inside the leaching tank 10, and an overflow pipe 30 is attached to the upper end portion 21 of the hydrostatic cylinder 20. In the leaching tank 10, after slurry is supplied from a preceding tank (not shown) via a slurry supply pipe (not shown), the slurry rises from the lower end portion 22 of the hydrostatic cylinder 20, and the subsequent tank is discharged by the overflow pipe 30. (Not shown).

  For example, when the pressure loss in the hydrostatic cylinder 20 is significantly increased, the flow rate of the slurry rising in the hydrostatic cylinder 20 may be insufficient with respect to the flow rate of the slurry supplied from the previous stage tank.

  Then, in the leaching tank 10, as the liquid level in the leaching tank 10 increases as shown by the black arrow shown in FIG. It will flow into the opening part 21a of this, and will be supplied to a back | latter stage tank. That is, a short pass occurs in the leaching tank 10 in which the conventional hydrostatic cylinder 20 is installed.

  Moreover, in the leaching tank 10, since the leaching reaction is an exothermic reaction, the liquid temperature in the leaching tank 10 locally exceeds the boiling point, and a boiling phenomenon called bumping may occur. Also at that time, a short pass occurs in the leaching tank 10 in which the conventional hydrostatic cylinder 20 is installed, as described above.

  Furthermore, in the leaching tank 10, a hydrostatic cylinder 20 configured with three side surfaces having a U-shaped horizontal cross section may be installed along the inner wall of the leaching tank 10. At that time, in the leaching tank 10 in which the conventional hydrostatic cylinder 20 is installed, a short path is generated from the gap between the hydrostatic cylinder 20 and the inner wall of the leaching tank 10.

  As described above, in the leaching tank 10 in which the conventional hydrostatic cylinder 20 is installed, the leaching rate of nickel and cobalt, which are the target metals, is not improved because chlorine leaching is insufficient by a short path.

(2) 1st Embodiment Next, the leaching tank 100 which concerns on 1st Embodiment is demonstrated with FIG.2, FIG.3 and FIG.4. FIG. 2 is a plan view showing a leaching tank according to an embodiment of the present invention. FIG. 3 is a sectional view taken along line XX ′ showing the leaching tank in FIG. FIG. 4 is a perspective view showing a hydrostatic cylinder provided in the leaching tank.

  The leaching tank 1 according to the first embodiment is a leaching tank 100 for leaching a powder of a solid metal-containing material contained in a slurry with chlorine gas, as shown in FIGS. A leaching tank main body 110, a rotating shaft 121 provided substantially parallel to the central axis of the leaching tank 100, an agitator 120 having a stirring blade 122 attached to the rotating shaft 121, and the leaching tank 100 main body A hydrostatic cylinder 130 provided inside, a lid 140 that seals the gas phase part of the leaching tank body 110, a chlorine blowing pipe 150 that supplies chlorine gas, and a supply pipe 160 that supplies slurry.

  As shown in FIGS. 3 and 4, the hydrostatic cylinder 130 is formed in a square cylinder shape, and an opening 131 a is formed in a side surface 131 that faces the side wall 111 of the brewing tank body 110. As shown in FIGS. 2 and 3, an overflow pipe 132 is connected to the opening 131 a of the hydrostatic cylinder 130. Further, as shown in FIG. 3, an inlet 133 a that captures the swirling flow of the slurry generated by the stirrer 120 and guides it to rise in the static water cylinder 130, at the lower end 133 of the static water cylinder 130. Have.

  The shape of the leaching tank main body 110 is not particularly limited, and examples thereof include a bottomed cylindrical shape and a bottomed rectangular tube shape. Further, the material of the leaching tank main body 110 may be appropriately selected according to the properties of the slurry existing in the tank. For example, the material of the leaching tank main body 100 is preferably acid-resistant brick lining or titanium when leaching the sulfide containing nickel and cobalt using the oxidizing action of chlorine gas.

  The stirrer 120 includes a motor 123, a rotating shaft 121 that rotates by driving the motor 123, and a stirring blade 122 attached to the rotating shaft 121. The motor 123 is provided substantially at the center of the lid 140, and the rotating shaft 121 is provided on the central axis of the brewing tank body 110. With the agitator 120, the slurry in the leaching tank main body 110 can be agitated.

  Although the material of the stirrer 120 is not specifically limited, Titanium and stainless steel can be used conveniently.

  The shape of the hydrostatic cylinder 130 is not particularly limited, and examples thereof include a square cylinder and a cylinder. The material of the hydrostatic cylinder 130 is not particularly limited, but titanium or stainless steel can be preferably used.

  In the leaching tank 100 according to the first embodiment, the hydrostatic cylinder 130 is provided inside the leaching tank main body 110. The hydrostatic cylinder 130 is formed in a cylindrical shape, and an opening 131a is formed in a side surface 131 that faces the side wall 111 of the leaching tank main body 110. An overflow pipe 132 that discharges slurry to a subsequent tank is connected to the opening 131a. The lower end 133 of the hydrostatic cylinder 130 has an inlet 133 a that captures the swirling flow of the slurry generated by the stirrer 120 and guides it to rise in the hydrostatic cylinder 130. This will be described below.

  In the chlorine leaching step, the slurry containing the solid raw material and the acidic solution and the oxidizing gas are mixed, and the metal in the solid raw material is leached. At that time, in the chlorine leaching step, it is important to secure a leaching reaction time, that is, a residence time in the tank, in order to efficiently leach more metal into the acidic solution.

  However, in the reaction between the slurry and the oxidizing gas, there is a limit to the time during which the blown oxidizing gas can stay in the slurry. Therefore, the uniformity of the reaction is strongly demanded from securing the residence time in the tank. It is done.

  As a means of uniformity, it is possible to reduce the diameter of the solid raw material to increase the contact area with the oxidizing gas, to increase the chance of contact by strengthening the stirring, and also to make the residence time uniform It becomes a means.

  In addition, in the leaching tank responsible for the chlorine leaching reaction, when the reaction is performed in a large single tank, the mixed state of the slurry and the oxidizing gas in the tank becomes non-uniform. It is composed of a plurality of leaching tanks connected in series for the purpose of improving the contact efficiency.

  In a plurality of leaching tanks connected in series, the slurry is supplied to the middle leaching tank other than the first and last stages with respect to the flow direction of the slurry by overflow from the previous tank, and the slurry after leaching is overflowed. In many cases, a structure is used to discharge to the subsequent tank.

  As described above, in a plurality of leaching tanks connected in series, the residence time in the leaching tank varies greatly locally, and the slurry flowing in from the previous tank does not sufficiently stay in the leaching tank, and is transferred to the subsequent tank. A phenomenon called a short pass in which the slurry flows out may occur. When a short pass occurs, the raw material that has not been sufficiently leached is discharged to the subsequent tank, so that the metal content remaining in the solid without being leached significantly increases. Lack of leaching in this chlorine leaching process directly leads to an increase in metal loss, that is, a decrease in leaching rate.

  Therefore, in order to prevent the slurry before the leaching reaction from short-passing, the leaching tank 100 needs to be equipped with a hydrostatic cylinder 130 for discharging the slurry out of the tank due to overflow.

  First, the slurry containing the metal sulfide is formed in the upper part of the liquid phase part in the leaching tank main body 110 by the supply pipe 160 shown in FIGS. It is thrown. Next, the charged slurry moves to the lower part of the tank by an axial flow along the rotating shaft 121 and then comes into contact with chlorine gas added from the tip of the chlorine blowing pipe 150 provided at the lower part. Next, the slurry stays in the tank for a certain time along the swirling flow in the lower part of the liquid phase portion in the leaching tank 110, and then the nickel and cobalt are leached with the progress of the leaching reaction. The particle size of the metal sulfide contained therein is reduced, and the inside of the hydrostatic cylinder 130 is raised and drained to the rear tank through the overflow pipe 132.

  On the other hand, even if a hydrostatic cylinder is provided, for example, as shown in FIG. 1, the unreacted slurry in the leaching tank 10 used conventionally flows into the opening 21a of the upper part 21 of the hydrostatic cylinder 20 and flows into the subsequent tank. In some cases, the short pass occurs, such as being discharged. The reason for this is that, as shown in FIG. 4 (B), the conventional hydrostatic cylinder 20 is shaped so that the inlet 22a provided at the lower end 22 of the hydrostatic cylinder 20 can capture the swirling flow of slurry. Not done. For this reason, in the leaching tank 10 having the conventional hydrostatic cylinder 20, a short path as described above occurs because of a problem in the balance between the amount of slurry supplied from the preceding tank and the amount of slurry supplied to the subsequent tank.

  From the above, in the leaching tank 100 according to the first embodiment, the hydrostatic cylinder 130 is important for preventing a short pass.

  As described above, the inlet 133a of the hydrostatic cylinder 130 shown in FIG. 3 has a shape that is open with respect to the flow direction of the swirling flow, thereby reducing the rising flow velocity in the hydrostatic cylinder using the flow velocity of the swirling flow. Can be prevented. Furthermore, in the hydrostatic cylinder 130 provided in the leaching tank 100 according to the first embodiment, as shown in FIG. 4A, the opening surface of the inlet 133a is changed to a swirling flow of slurry from the lower edge 133b of the inlet 133a. By forming the cut-out on the opposite side surface side, the flow velocity of the swirling flow can be used effectively. For this reason, by enlarging the size of the opening surface of the inlet 133a, it is possible to capture the swirling flow of the slurry more reliably, and to raise the inside of the hydrostatic cylinder 130 using the flow velocity of the swirling flow.

  Moreover, in the hydrostatic cylinder 130 with which the leaching tank 100 according to the first embodiment is provided, it is preferable that the rising speed of the slurry is controlled to be 0.1 m / second or more and 0.3 m / second or less.

  First, it is necessary to determine the cross-sectional area and cross-sectional shape of the hydrostatic cylinder 130 in consideration of pressure loss. The ascending flow rate inside the still water cylinder 130 is determined by the cross-sectional area of the still water cylinder 130. If the ascending flow rate inside the still water cylinder 130 is too fast, a raw material having a large particle size that is not sufficiently leached is discharged. End up. On the other hand, when the flow rate is slow, the leaching residue mainly composed of leached sulfur does not pass through the hydrostatic cylinder 130 and is not discharged to the subsequent tank, so that the leaching residue that is a solid deposits in the leaching tank 100.

The critical settling velocity of the slurry is involved in this flow rate. The critical sedimentation rate of this slurry is calculated from the Stokes equation shown in the following equation (5).
V = D ² × (ρ _s −ρ _f ) × g ÷ α × (1 ÷ 18) (5)
V: Limit sedimentation velocity D: Particle size ρ _s : Residual density ρ _f : Liquid density g: Gravity acceleration α: Liquid viscosity

  In addition, if the cross-sectional area of the hydrostatic cylinder 130 is reduced in order to increase the ascending flow rate of the slurry, the liquid level in the leaching tank rises above the opening provided at the upper end of the hydrostatic cylinder due to an increase in pressure loss. The slurry containing the leaching residue flows into the overflow pipe 132 and flows out to the subsequent tank without passing through the hydrostatic cylinder 130.

  The calculation using the above formula (5) etc., the fluid calculation by the finite volume method, and further the experiment, not to raise the liquid level in the leaching tank, but also to not discharge the unreacted solid content (residue), The condition that the residue after the leaching reaction is not increased in the leaching tank 100 must be satisfied. As described above, the inventors have found that it is optimal that the ascending flow rate of the slurry is controlled to be 0.1 m / second or more and 0.3 m / second or less as a result of research.

  When the ascending flow rate is less than 0.1 m / sec, the leaching residue mainly composed of leached sulfur does not pass through the hydrostatic cylinder 130 and is not discharged to the subsequent tank, so that the leaching residue that is solid in the leaching tank 100 Will accumulate. On the other hand, when the ascending flow rate exceeds 0.3 m / sec, if the ascending flow rate of the slurry in the hydrostatic cylinder 130 is too fast, a raw material having a large particle size that has not been sufficiently leached is discharged to the rear tank. End up.

Therefore, in the hydrostatic cylinder 130 provided in the leaching tank 100 according to the first embodiment, it is preferable that the ascending flow rate of the slurry is controlled to be 0.1 m / second or more and 0.3 m / second or less.
Specifically, the ascending flow rate can be adjusted by the cross-sectional area of the installed still water cylinder. That is, if the flow rate to be flowed is determined, the flow velocity is obtained by dividing it by the cross-sectional area. At that time, the pressure loss due to the inner wall of the hydrostatic cylinder and the inflow speed of the swirling flow are also taken into consideration. Further, the rising flow velocity in the hydrostatic cylinder 130 is not uniform in the cross-sectional direction, and further fluid analysis and fluid calculation are required. Therefore, the cross-sectional area and shape of the determined hydrostatic cylinder 130 can be confirmed by experiments to finally determine the optimal hydrostatic cylinder 130. The experiment may be, for example, an experiment using a reduced model, but there is also a method of collecting necessary data by attaching to an actual machine for a limited period.

  The lid part 140 seals the gas phase part of the leaching tank main body 110. The shape of the lid 140 is not particularly limited. Although the material of the cover part 140 is not specifically limited, Titanium and stainless steel can be used conveniently.

  Further, as shown in FIG. 3, the leaching tank 100 according to the first embodiment is arranged such that the upper end portion 135 of the hydrostatic cylinder 130 is higher than the lid part 140 of the leaching tank main body 110, and the hydrostatic cylinder 130 is leached. It is preferably supported by the lid portion 140 of the tank body 110.

  This is because, in the leaching tank main body 110, since the gas phase part in the leaching tank main body 110 and the gas phase part in the still water cylinder 130 are separated by the side wall 136 of the still water cylinder 130, the liquid level in the leaching tank main body 110. No short path will occur even if the value rises.

  Moreover, in the leaching tank 100 according to the first embodiment, as shown in FIG. 4A, the hydrostatic cylinder 130 has an air vent port 134 on the side surface of the hydrostatic cylinder that does not face the side wall 111 of the leaching tank body. The air vent port 134 is preferably disposed at a position higher than the liquid level of the slurry in the leaching tank main body 110 and lower than the lid portion 140. Thereby, even if a bumping phenomenon occurs in the leaching tank 100, the gas phase part in the leaching tank main body 110 and the gas phase part in the still water cylinder 130 are equalized, so the hydrostatic cylinder 130 serves as a chimney. Thus, the slurry exceeding 100 ° C. can be prevented from being blown up from the upper lid of the hydrostatic tube 130.

  As shown in FIGS. 2 and 3, the chlorine blowing pipe 150 penetrates the lid portion 140 and is attached perpendicularly to the lid portion 140. By closing the inspection port (not shown) with the lid 140 to which the chlorine blowing pipe 150 is attached, the chlorine blowing pipe 150 is arranged in parallel with the central axis of the brewing tank main body 110. Further, one end of the chlorine blowing pipe 150 is inserted into the slurry in the leaching tank main body 110, and the other end is arranged outside the leaching tank main body 110.

  As shown in FIGS. 2 and 3, the chlorine blowing pipe 150 has a length in which one end reaches the vicinity of the bottom of the brewing tank body 110, and a chlorine gas supply source is connected to the other end. Therefore, chlorine gas can be blown into the slurry from near the bottom of the leaching tank main body 110. Note that the chlorine blowing pipe 150 is disposed at a position where it does not interfere with the stirrer 120. Further, the chlorine blowing pipe 150 is provided at two locations away from the overflow pipe 132.

  The upper end portion of the leaching tank main body 110 is covered with a lid portion 140. A supply pipe 160 is connected to the lid 140 so that slurry can be supplied to the inside of the leaching tank main body 110. This slurry passes through the hydrostatic cylinder 130 from the inside of the leaching tank main body 110 and is then discharged through the overflow pipe 132.

  The supply pipe 160 is connected to the lid portion 140 and can supply slurry to the inside of the leaching tank main body 110. The supply pipe 160 is disposed at a position that does not interfere with the stirrer 120.

  First, in the leaching tank 100 according to the first embodiment, slurry containing sulfides made of nickel and cobalt is fed into the leaching tank body from the preceding stage through the supply pipe 160. Next, this slurry is the upper part of the liquid phase part in the leaching tank main body 110, and the horizontal swirl part generated by the stirrer 120 is stirred. Next, the charged slurry is moved to the lower part of the tank by the axial flow in the vertical direction along the rotating shaft 121 and then added from the tip of the chlorine blowing pipe 150 provided at the lower part of the leaching tank main body 110. Contact with chlorine gas. Next, after staying in the tank for a certain time along the swirling flow below the liquid phase part in the leaching tank main body 110, nickel and cobalt are leached as the chlorine leaching reaction proceeds, so that The particle size of the contained metal sulfide is reduced. Thereby, this slurry is converted into a slurry after the leaching reaction in which the leaching reaction has sufficiently progressed. Next, the slurry after the leaching reaction is introduced into the inlet 133a provided at the lower end portion 133 of the hydrostatic cylinder 130 shown in FIG. 4 (A) by the swirling flow in the lower part as shown by the black arrow shown in FIG. The The slurry after the leaching reaction rises in the hydrostatic cylinder 130 according to the upward flow from the inlet 133a provided in the hydrostatic cylinder 133 using the flow velocity of the lower swirling flow. Then, the slurry after the leaching reaction reaches the overflow pipe 132 connected by the hydrostatic cylinder 130 and is discharged to the subsequent tank which is the next leaching tank.

(3) Second Embodiment Next, a leaching tank according to a second embodiment will be described with reference to FIG. FIG. 5 is a perspective view showing the hydrostatic cylinder 230 provided in the leaching tank according to the second embodiment. Similar to the brewing tank 100 according to the first embodiment, the brewing tank according to the second embodiment includes a brewing main body tank, a stirrer, a hydrostatic cylinder, a lid, a chlorine blowing pipe, and a supply pipe.

  As shown in FIG. 5, the hydrostatic cylinder 230 is formed in a square cylinder, and the opening surface of the inlet 231 is characterized by notching one side facing the swirling flow of slurry.

  The inlet 231 of the hydrostatic cylinder 230 shown in FIG. 5 has a shape that is open with respect to the direction of flow of the swirling flow, thereby preventing a decrease in the rising flow velocity in the hydrostatic cylinder 230 using the flow velocity of the swirling flow. be able to. Furthermore, the flow velocity of the swirling flow can be effectively used by cutting out one side facing the swirling flow of the slurry. For this reason, by enlarging the size of the opening surface of the inlet 231, the swirling flow of the slurry can be captured more reliably, and can be raised in the hydrostatic cylinder 230 using the flow velocity of this swirling flow.

  In addition, an opening 232 is formed in the hydrostatic cylinder 230 shown in FIG. 5, similarly to the brewing tank 100 according to the first embodiment, and an overflow pipe (not shown) is connected to the opening 232. Furthermore, an air vent 233 can be provided on the side surface of the hydrostatic cylinder 230.

  In addition, in the hydrostatic cylinder 230 provided in the leaching tank according to the second embodiment, the rising flow rate of the slurry is 0.1 m / second or more in the same manner as the hydrostatic cylinder 130 provided in the leaching tank 100 according to the first embodiment. It is preferably controlled to be 3 m / second or less.

  In the leaching tank according to the second embodiment, similarly to the leaching tank 100 according to the first embodiment, the slurry charged from the preceding tank is sufficiently converted into a slurry after the leaching reaction due to the progress of the leaching reaction. Then, the slurry after the leaching reaction overflows to the subsequent tank through the overflow pipe.

(4) Third Embodiment Next, a leaching tank according to a third embodiment will be described with reference to FIG. FIG. 6 is a perspective view showing a hydrostatic cylinder provided in the leaching tank according to the third embodiment. In the leaching tank according to the third embodiment, the hydrostatic cylinder 330 is formed in a square cylinder, and the opening surface of the inlet 331 is cut out on one side facing the swirling flow of the slurry, and further on one side on the side It is characterized by being cut out.

  The inlet 331 of the hydrostatic cylinder 330 shown in FIG. 6 has a shape that is open with respect to the direction of flow of the swirling flow, thereby preventing a decrease in the ascending flow velocity in the hydrostatic cylinder 330 using the flow velocity of the swirling flow. be able to. Furthermore, the opening surface of the inlet 331 is formed by cutting out one side facing the swirling flow of the slurry and further cutting out one side of the adjacent side, thereby effectively utilizing the flow velocity of the swirling flow. Can do. In addition, the introduction port 331 of the static water cylinder 330 provided in the leaching tank according to the third embodiment is different from the introduction port 331 of the static water cylinder 330 provided in the brewing tank according to the second embodiment, and the leaching tank main body shown in FIG. The side surface of the inlet 331 of the hydrostatic cylinder 330 facing the side wall 111 side of 110 is cut out. For this reason, by enlarging the size of the opening surface of the inlet 331, the swirl flow of the slurry can be captured more reliably, and can be raised in the hydrostatic cylinder 330 using the flow velocity of the swirl flow.

  In addition, in the hydrostatic cylinder 330 provided in the leaching tank according to the third embodiment, the rising flow rate of the slurry is 0.1 m / second or more in the same manner as the hydrostatic cylinder 130 provided in the leaching tank 100 according to the first embodiment. It is preferably controlled to be 3 m / second or less.

  In the leaching tank according to the third embodiment, similarly to the leaching tank 100 according to the first embodiment, the slurry charged from the preceding tank is sufficiently converted into a slurry after reaction leaching due to the progress of the leaching reaction. The slurry after the reaction leaching is overflowed to the subsequent tank through the overflow pipe.

(Summary)
As described above, the leaching tank 100 according to the present embodiment is a leaching tank 100 for leaching a powder of a solid metal-containing material contained in a slurry with an oxidizing gas, and has a bottomed cylindrical leaching tank body 110, A stirrer 120 having a rotating shaft 121 provided substantially parallel to the central axis of the leaching tank main body 110, and a stirring blade 122 attached to the rotating shaft 121, and a hydrostatic cylinder provided inside the leaching tank main body 110. 230 and a lid portion 140 that seals the gas phase portion of the leaching tank main body 110. In the leaching tank 100 according to this embodiment, the hydrostatic cylinder 130 has an opening 131a formed on the side surface 131 facing the side wall 111 of the leaching tank body 110, and an overflow pipe 132 is connected to the opening 131a. The lower end 133 of the hydrostatic cylinder 130 has an introduction port 133a that captures the swirling flow of the slurry generated by the stirrer 120 and guides it to rise in the hydrostatic cylinder 130.

  Thereby, in the leaching tank 100 according to the present embodiment, since a short pass does not occur at all, the leaching rate of the target metal can be improved.

  EXAMPLES Hereinafter, although this invention is demonstrated further in detail using an Example and a comparative example, this invention is not limited to these Examples and a comparative example.

Example 1
In Example 1, the chlorine leaching operation was performed using the leaching tank 100 shown in FIG. 3 provided with the hydrostatic cylinder 130 shown in FIG. The chlorine leaching reaction conditions in this chlorine leaching operation were set such that the oxidation-reduction potential of the nickel chloride aqueous solution during the reaction was 480 to 560 mV and the temperature was 105 to 115 ° C.

  In Example 1, the leaching tank A and the leaching tank B were prepared as the leaching tank 100 according to this embodiment. The leaching tank A corresponds to the third stage of the series of seven leaching tanks connected in series, and the leaching tank B corresponds to the fourth stage, which is the latter stage of the leaching tank A.

  In Example 1, lithium ions not involved in the chlorine leaching reaction were added to the slurry, and the occurrence of short paths in the leaching tank A and the leaching tank B was confirmed. The slurry itself does not contain lithium ions.

  Specifically, in Example 1, lithium ions that are not involved in the chlorine leaching reaction are added to the overflow pipe at the outlet of the preceding tank of the leaching tank A, and a slurry sample is collected from the overflow pipe at the outlet of the leaching tank A and then chlorinated. The lithium concentration in the aqueous solution was measured, and the change with time of the lithium concentration was confirmed.

  In addition, lithium ions are added to the overflow pipe at the outlet of the leaching tank A at a different time from that added to the overflow pipe at the outlet of the preceding tank of the leaching tank A, and the slurry is discharged from the overflow pipe at the outlet of the leaching tank B. A sample was taken and the lithium concentration in the aqueous chloride solution was measured, and the change over time in the lithium concentration was confirmed. The lithium concentration was measured by atomic absorption method. The result is shown in FIG.

  Further, the nickel content of the leaching residue obtained by solid-liquid separation of the slurry collected from the overflow pipe at the outlet of the leaching tank A and the slurry collected from the overflow pipe at the outlet of the leaching tank B by a small centrifuge analyzed. The nickel content was measured by ICP (Inductively Coupled Plasma) emission spectroscopy. The results are shown in Table 1.

  The nickel content in the leaching residue in Example 1 was confirmed to be 6.0% by weight for leaching tank A and 3.7% by weight for leaching tank B.

  Moreover, in Example 1, as a result of measuring the ascending flow velocity in the hydrostatic cylinder 130, it was 0.12 m / sec.

(Comparative Example 1)
In Comparative Example 1, a chlorine leaching operation was performed using the leaching tank 10 shown in FIG. 1 provided with the conventional hydrostatic cylinder 20 shown in FIG. 4 (B). The chlorine leaching reaction conditions in this chlorine leaching operation were set such that the oxidation-reduction potential of the nickel chloride aqueous solution during the reaction was 480 to 560 mV and the temperature was 105 to 115 ° C.

  In the leaching tank 10 in Comparative Example 1, as in Example 1, the leaching tank A and the leaching tank B were prepared. The leaching tank A corresponds to the third stage of the series of seven leaching tanks connected in series, and the leaching tank B corresponds to the fourth stage, which is the latter stage of the leaching tank A.

  In Comparative Example 1, as in Example 1, in order to confirm the occurrence of a short path, lithium ions were added to the overflow pipe at the outlet of the preceding tank of the leaching tank A, and the slurry sample was discharged from the overflow pipe at the outlet of the leaching tank A. The lithium concentration in the aqueous chloride solution was measured and the change over time in the lithium concentration was confirmed.

  In addition, lithium ions are added to the overflow pipe at the outlet of the leaching tank A at a different time from that added to the overflow pipe at the outlet of the preceding tank of the leaching tank A, and the slurry is discharged from the overflow pipe at the outlet of the leaching tank B. A sample was taken and the lithium concentration in the aqueous chloride solution was measured, and the change over time in the lithium concentration was confirmed. The lithium concentration was measured by atomic absorption method. The result is shown in FIG.

  In Comparative Example 1, a lithium concentration peak appears in the initial stage of addition, and in the leaching tank A, the lithium concentration at the leaching tank outlet increased after 0.003 hours, that is, 11 seconds, and then decreased. It was. In addition, in the leaching tank B, the lithium concentration at the leaching tank outlet increased after 0.01 hours, that is, 36 seconds after the addition, and then decreased.

  In Comparative Example 1, as in Example 1, the slurry collected from the overflow pipe at the outlet of the leaching tank A and the slurry collected from the overflow pipe at the outlet of the leaching tank B were solid-liquid separated by a small centrifuge. The leaching residue obtained was analyzed for nickel content. The nickel content was measured by ICP emission spectroscopy. The results are shown in Table 1.

  The nickel content in the leaching residue in Comparative Example 1 was confirmed to be 10.2% by weight for leaching tank A and 6.8% by weight for leaching tank B.

(Discussion)
In Example 1, as shown to FIG. 7 (A), it can be estimated that the peak of lithium concentration is not expressed and the short path | pass has not generate | occur | produced. On the other hand, in Comparative Example 1, as shown in FIG. 7B, a peak of lithium concentration appears in the initial stage of addition, and it can be estimated that a short path has occurred.

  In Example 1, as shown in Table 1, since the short path could be prevented, the variation in the residence time in the leaching tank 100 was reduced, and the nickel content in the leaching residue was 6.0 wt% in the leaching tank A. %, And decreased to 3.7 wt% in leaching tank B. On the other hand, in Comparative Example 1, as shown in Table 1, due to the occurrence of a short pass, the nickel content in the leaching residue was 10.2% by weight in leaching tank A and 6.8% by weight in leaching tank B. Compared with Example 1, the nickel content rate in the leaching residue increased to about 1.7 to 1.8 times.

  As described above, in the leaching tank 100 according to the embodiment of the present invention, the swirling flow of the slurry after the leaching reaction generated by the stirrer 120 is captured at the lower end portion 133 of the static water cylinder 130, and the upward flow of the static water cylinder An inlet port 133a for guiding is formed, and the opening surface of the inlet port 133a is formed by notching from the lower end edge 133b of the inlet port 133a to one side surface facing the swirling flow of the slurry after the leaching reaction. It was confirmed that it was useful. As a result, short paths can be prevented, and the leaching rate of the target metal can be improved.

DESCRIPTION OF SYMBOLS 100 Leaching tank, 110 Leaching tank main body, 120 Stirrer, 121 Rotating shaft, 122 Stirring blade, 130 Hydrostatic cylinder, 131a Opening, 132 Overflow pipe, 133a Inlet, 134 Air vent, 140 Lid, 230 Hydrostatic cylinder, 231 Inlet port, 232 aperture, 233 Air vent port, 330 Hydrostatic tube, 331 Inlet port, 332 aperture, 333 Air vent port

Claims (7)

A leaching tank for leaching the powder of the solid metal-containing material contained in the slurry with an oxidizing gas,
A bottomed cylindrical leachate tank body;
A stirrer having a rotating shaft provided substantially parallel to the central axis of the brewing tank body and a stirring blade attached to the rotating shaft;
A hydrostatic cylinder provided inside the leaching tank body;
A lid for sealing the gas phase part of the leaching tank body,
The hydrostatic cylinder has an opening formed on a side surface facing a side wall of the leaching tub body,
An overflow pipe is connected to the opening,
Wherein the lower end of the static water bottle, to capture a swirling flow of the slurry generated by said stirrer, have a inlet for induced to the upward flow in the static within the water bottle,
The leaching tank, wherein an upper end portion of the static water cylinder is disposed at a position higher than the lid part of the leaching tank main body, and the static water cylinder is supported by the lid part of the leaching tank main body .   2. The leaching tank according to claim 1, wherein the hydrostatic cylinder is controlled so that the rising velocity of the slurry is 0.1 m / second or more and 0.3 m / second or less. The hydrostatic cylinder has an air vent on the side surface of the hydrostatic cylinder that does not face the side wall of the leaching tank body,
The said air vent is arrange | positioned in the position higher than the liquid level of the said slurry in the said brewing tank main body, and the said cover part, The leaching tank of Claim 1 or Claim 2 characterized by the above-mentioned. The hydrostatic cylinder is formed into a square cylinder;
Opening surface of the inlet is to one of claims 1 to 3, characterized by comprising notched inclined to one side opposite to the swirling flow of the slurry from the conductor inlet of the lower edge The described leaching tank. The hydrostatic cylinder is formed into a square cylinder;
The leaching tank according to any one of claims 1 to 3 , wherein an opening surface of the introduction port is formed by notching one side surface facing the swirling flow of the slurry. The hydrostatic cylinder is formed into a square cylinder;
Opening surface of the inlet port, one of claims 1 to 3, characterized in that notched one side opposite to the swirling flow of the slurry, formed by notching the one side surface of the further adjacent Leaching tank as described in The leaching tank according to any one of claims 1 to 6 , wherein the leaching tank is applied as a chlorine leaching tank for leaching a sulfide containing nickel and cobalt by utilizing an oxidizing action of chlorine gas.