JP2000119764A - Adjusting method of copper concentration in leaching liquid in cleaning process of wet zinc metallurgy and adjusting equipment therefor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an adjusting method and adjusting equipment for copper concentration in a leaching liquid in a cleaning process of wet zinc metallurgy in which copper quarity in a residue obtained in a copper removing process is high and the precipitability of copper in the leaching liquid in the copper removing process is excellent. SOLUTION: This adjusting method of copper concentration in a leaching liquid in a cleaning process of wet zinc metallurgy is for separating the leaching liquid from a zinc calcined one by a sulfuric acid solution, adding zinc powder in one of the leaching liquid after the liquid separation and mixing them to separate and remove the copper and mixing the resultant leaching liquid with the other leaching liquid after the liquid separation to adjust the copper concentration. The adjusting equipment of the copper concentration in the leaching liquid is used for the adjusting method of the copper concentration in the leaching liquid.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method and an apparatus for adjusting the concentration of copper in a leachate in a cleaning process of a wet zinc smelting process. The present invention relates to a method and an equipment for adjusting the copper concentration in a leachate in a cleaning process of wet zinc smelting, which is excellent in the sedimentation of copper in a leachate in a copper process.

[0002]

2. Description of the Related Art In a wet zinc smelting process, zinc concentrate is roasted, the obtained zinc ore is dissolved in a sulfuric acid solution, and the resulting leaching solution is electrolyzed into zinc (: electric zinc). ) To manufacture. In this case, if heavy metal impurities such as copper (Cu) and cobalt (Co) are present in the leaching solution, not only will the zinc precipitate during zinc electrolysis and the purity of zinc will decrease, but also the current efficiency during zinc electrolysis will significantly decrease. .

[0003] Therefore, in the electrowinning of zinc (Zn), a cleaning step is required to remove impurities more noble than Zn such as Cu and Co in the leachate before electrolysis. FIGS. 2 and 3 show process diagrams relating to a facility for adjusting the concentration of copper in a leachate and a facility for removing impurities in a leachate in a conventional cleaning process of wet zinc smelting. FIG. 2 shows a system using a thickener as a solid-liquid separator in the copper separation and removal process, and FIG. 3 shows a system using a filter press as the solid-liquid separation device in the copper separation and removal process.

In FIG. 2, reference numeral 1 denotes a zinc leaching tank (:
Dissolution tank), 1b is a sulfuric acid solution (: leachate), 2 is a solid-liquid separation device (: neutral thickener) of a leachate, which is a solution of zinc ore, 2b, 4b, 5Aa, 6b, 8b is a leachate, 3 is a leachate heat exchanger for leachate heating, 4 Cu ²⁺ by addition of zinc dust
Leachate removal copper tank (hereinafter also referred to as copper removal tank) for substituting and precipitating a part of copper, 4a is a supply device of zinc dust into leachate removal copper tank 4, 4c, 6c, 8c is a stirrer driving device, 5A Is Sicuna, 5A
b is a copper recovery process, 6 is a cleaning tank for replacing and depositing Co ²⁺ , Ni ²⁺ , and Cu ²⁺ (hereinafter also referred to as a decobalt tank), and 6a supplies zinc dust and arsenite to the cleaning tank 6 Feeding device,
7 and 9 are filter presses, 8 is a cleaning tank for replacing and precipitating Cd (hereinafter also referred to as a decadmium tank), 8a is a supply device of zinc powder into the cleaning tank 8, 10 is a zinc electrolytic tank, and 11 is a zinc electrolytic tank. A supply pipe for the electrolytic tail solution, which is a sulfuric acid solution, to the leaching tank 1, 21 is a high-temperature and high-acid dissolving tank, 71 is a cobalt recovery step, 91 is a cadmium recovery step, and P is a pump.

In FIG. 3, 5B indicates a filter press, 5Bb indicates a copper recovery step, and other reference numerals indicate the same contents as in FIG. In the leaching step and the cleaning step of the conventional wet zinc smelting shown in FIG. 2, first, in a leaching tank 1, a zinc ore obtained by roasting a zinc concentrate and sulfuric acid used in a zinc electrolytic tank 10 are used. An oxidizing agent such as an electrolytic tail solution and potassium permanganate (KMnO ₄ ), which are solutions, is supplied, and zinc ore is leached (dissolved).

[0006] The obtained leachate is sent to the copper removal tank 4 via the solid-liquid separator 2, mixed with zinc dust supplied to the copper removal tank 4, stirred, and then sent to the thickener 5A. Is done. The leachate passed through the thickener 5A is heated to about 60 to 80 ° C. in the heat exchanger 3 and then mixed and stirred with zinc dust and arsenous acid supplied to the cleaning tank 6 in the cleaning tank (decobalt tank) 6. After that, the solution is sent to the filter press 7.

[0007] The leachate passed through the filter press 7 is:
After being mixed and stirred with zinc dust supplied to the cleaning tank 8 in the cleaning tank (: de-cadmium tank) 8, the liquid is sent to the filter press 9. The leachate after cleaning through the filter press 9 is sent to a zinc electrolytic cell 10 to produce electrozinc by electrolysis of zinc sulfate.

The leachate having a reduced zinc concentration in the zinc electrolytic cell 10 (electrolysis tail liquid) is circulated and supplied to the leach tank 1 to replenish zinc. In the above-described leaching, cleaning, and zinc electrolysis steps, zinc ore is leached and by the following reaction
The impurities of Fe, As, Sb, Ge, Cu, Co, Ni, and Cd are removed.

[Fe in the leaching tank 1 and the solid-liquid separation device 2,
Removal of As, Sb, and Ge:] As Fe (OH) ₃ formed by oxidizing Fe ²⁺ in the leachate with an oxidizing agent, As, Sb, and Ge are co-precipitated and removed. [Removal of Cu in copper removal tank 4, thickener 5A:]
Cu is precipitated by the substitution and precipitation (precipitation) reaction by (1), and the deposited Cu is separated from the leaching solution by the thickener 5A, and the separated Cu is sent to the copper recovery step 5Ab.

Cu ²⁺ + Zn → Zn ²⁺ + Cu ↓ (1) As a method for separating precipitated Cu, a filter press 5B can be used as shown in FIG. [Removal of Co and Ni in cleaning tank (: de-cobalt tank) 6 and filter press 7:] To completely remove Co and Ni, arsenous acid is added together with zinc powder to replace and precipitate Co and Ni. The precipitated Co and Ni are separated from the leachate by the filter press 7, and the separated Co is sent to a cobalt recovery step 71.

In this case, the remaining Cu ²⁺ is replaced and precipitated,
Co-precipitates with o and Ni. [Purification tank (: decadmium tank) 8, filter press 9
Removal of Cd in :) Addition and mixing of zinc dust to the leachate, Cd is replaced and precipitated, and the deposited Cd is separated from the leachate by the filter press 9 and sent to the cadmium recovery step 91. .

As described above, the leaching in the conventional wet zinc smelting,
Although the cleaning step has been described, the replacement of Co and Ni in the cleaning tank (: de-cobalt tank) 6 shown in FIGS.
For precipitation, co-precipitation with Cu is necessary, and the cleaning tank (:
It is necessary to control the concentration of Cu ²⁺ ions in the leachate of the cobalt removal tank 6 within a certain range. That is, in the copper removal tank 4, a certain amount of zinc powder is added, and Cu ²⁺ is replaced with Cu.
When precipitated, Cu in the leachate supplied to the decobalt tank 6
²⁺ concentration lower than the amount required for coprecipitation with Co, Ni, C
The removal of o ²⁺ and Ni ²⁺ does not proceed, and the amount of impurities in the leachate supplied to the zinc electrolytic cell 10 increases.

Conversely, when the amount of zinc dust added in the copper removal tank 4 is less than a certain amount, the amount of Cu ²⁺ replaced by Cu in the copper removal tank 4 and the amount of precipitation are reduced, and the amount of copper added to the cobalt removal tank 6 is reduced. The load increases, the removal of Co ²⁺ and Ni ²⁺ does not progress, and the amount of impurities in the leachate supplied to the zinc electrolytic cell 10 increases. That is, in the cleaning step of the wet zinc smelting, it is important to adjust the copper concentration in the leachate by the copper removal tank 4, but conventionally, the following problems have been encountered.
There were (1) and (2).

(1) The problem of the Cu quality in the residue obtained by the solid-liquid separator in the copper removal step: The Cu quality in the residue obtained by the thickener 5A in FIG. 2 or the filter press 5B in FIG.
The load in the copper recovery steps 5Ab and 5Bb was heavy. (2) Problem of sedimentation of Cu replaced and deposited in copper removal process: Fig. 2
The sedimentation of Cu replaced and precipitated in the copper removal tank 4 in the thickener 5A was poor, and it was necessary to limit the amount of the leachate to be sent or to increase the volume of the thickener in order to increase the amount of the leachate.

[0015]

DISCLOSURE OF THE INVENTION The present invention solves the above-mentioned problems of the prior art, has high copper quality in the residue obtained in the decoppering step, and further has the effect of removing copper in the leachate in the decopperizing step. It is an object of the present invention to provide a method and an equipment for adjusting the copper concentration in a leachate in a cleaning process of wet zinc smelting having excellent sedimentation properties.

[0016]

According to a first aspect of the present invention, a leachate of a calcined ore with a sulfuric acid solution is separated, zinc powder is added to one of the leachates after the separation, mixed, and copper is separated and removed. And a method for adjusting the copper concentration in the leachate in the cleaning step of the wet zinc smelting, which comprises mixing the leachate obtained as described above and the other leachate after the separation to adjust the copper concentration in the leachate. .

In the above method for adjusting the copper concentration in a leachate according to the first invention, the mixed leachate having the copper concentration adjusted by the adjustment method further comprises adding zinc dust, arsenous acid, antimony acid, antimony tartrate and potassium antimony tartrate to the mixed leachate. After adding and mixing with one or more kinds selected from the group consisting of, a precipitate in the mixed leachate is separated and removed, and is suitably used in a method for removing impurities in a leachate in a cleaning step of wet zinc smelting ( Preferred embodiment of the first invention).

Further, in the above-mentioned first invention and preferred embodiments of the first invention, the Cu ²⁺ concentration in the leachate obtained by the above-mentioned mixing becomes a predetermined Cu ²⁺ concentration M ₀ .
It is preferable to adjust the liquid separation ratio of the leaching solution. Further, in the above-mentioned first invention and preferred embodiments of the first invention,
The Cu ²⁺ concentration M of the leachate before zinc powder addition (ie, the leachate without zinc powder added) such as the leachate before liquid separation is analyzed, and the Cu ²⁺ concentration of the leachate obtained by mixing is predetermined Cu ²⁺ The liquid separation ratio (: F ₁ / F) is determined based on the following equations (2) and (3) so that the concentration becomes M _0.
It is more preferable to control the amount X (addition) of zinc powder to F ₂ ) and one of the leaching solutions after the liquid separation.

Separation ratio = F ₁ / F ₂ = (M ₀ ) / (M−M ₀ ) (2) Addition of zinc dust to one leachate after the above-mentioned separation (: supply) Amount X (mol-Zn / hr) ≧ (1000F ₂ ) × M (mol-Cu ²⁺ / l− leaching solution) (3) In the above formulas (2) and (3), F ₁ is The processing amount (or flow rate) of one leachate after the above-described separation (m ³ / hr), and F ₂ is the processing amount (or flow rate) of the other leachate after the above-described separation (or flow rate) (m
³ / hr).

M ₀ is a predetermined Cu ²⁺ concentration of the leachate obtained by mixing. That is, M ₀ indicates the target Cu ²⁺ concentration of the mixed leachate in a state in which a reaction (= Co, Ni removal reaction) due to the addition of a chemical such as zinc dust, arsenous acid, antimony acid, etc. Co ^{2+ in}
It can be set from the concentration or both the Co ²⁺ concentration and the Ni ²⁺ concentration.

According to a second aspect of the present invention, a solid-liquid separation device 2 for leaching liquid provided on the outlet side of a leaching tank 1 for leaching zinc ore with a sulfuric acid solution and a solid-liquid separation device 2 provided as a post-process. Clean tank
60, and a second liquid feed system 102 branched from the first liquid feed system 101 and connected to the cleaning tank 60. Liquid sending system 102
In addition, a leachate removal copper tank 40 provided with a supply device 40a for feeding zinc powder into the tank, a solid-liquid separation device 50 for the leachate flowing out of the leachate removal copper tank 40, and a leachate flowing out of the solid-liquid separation device 50 This is a facility for adjusting the copper concentration in the leachate in the cleaning step of wet zinc smelting, wherein a liquid supply system 102c for feeding the leachate to the cleaning tank 60 is provided.

The above-mentioned equipment for adjusting the concentration of copper in a leachate according to the second aspect of the present invention further comprises the step of adding zinc powder and arsenous acid, antimony acid, antimony tartrate and antimony potassium tartrate to the cleaning tank (60). A feeder (60a) for supplying one or more selected ones and a solid-liquid separator (70) for the leachate flowing out of the tank (70) are provided. It is suitably used for a removal facility (a preferred embodiment of the second invention).

In the above-mentioned second and second aspects of the present invention, the leachate is supplied to the first liquid supply system 101 and the second liquid supply system 102 by any of the following methods: It is preferable to provide flow meters FM ₁ and FM ₂ and a leachate flow rate control valve CV. : The leachate flow meters FM ₁ and FM ₂ are attached to both the first liquid feed system 101 and the second liquid feed system 102, and the first liquid feed system after branching the second liquid feed system 102 A leachate flow rate control valve CV is attached to at least one of the liquid feed system 101b and the second liquid feed system 102 which is 101.

A leachate flow meter is provided in the liquid sending system 101a, which is the first liquid sending system 101 and is not branched from the second liquid sending system 102.
In addition to the FM ₁ , the first liquid supply system 101 after branching the second liquid supply system 102, the liquid supply system 101 b, and the second
The leachate flow rate control valve CV is attached to at least one of the liquid supply systems 102 among the liquid supply systems 102. : While attached leachate flow meter FM ₁ to the first liquid supply line 101b is a feeding line 101 after it is branched to the second liquid supply system 102 and a first feeding line 101, the second Liquid supply system 10
2 is equipped with a leachate flow rate control valve CV.

The leachate flow meter FM is supplied to the second liquid sending system 102.
₂ , and a leachate flow rate control valve CV is added to the liquid supply system 101b, which is the first liquid supply system 101 after branching the second liquid supply system 102. Further, the second invention, the second invention,
In a preferred embodiment of the invention, the first liquid feeding system described above
It is preferable that the copper concentration analyzer 20 be attached to at least one of the second liquid feed system 102 and the liquid feed system 102a on the upstream side of the leachate removing copper tank 40.

Further, in the facility for adjusting the copper concentration in the leachate and the facility for removing impurities in the leachate according to the second aspect of the present invention and the preferred aspect of the second aspect of the invention, the first liquid supply system 101 and the second supply The leachate flow meter FM ₁ and / or the leachate flow meter
FM ₂ and a leachate flow rate control valve CV are attached, and the first
A copper concentration analyzer 20 is attached to at least one of the liquid supply systems 101 and the second liquid supply system 102, which is the liquid supply system 102a on the upstream side of the leachate removing copper tank 40, (1)
Analyzed value M of the copper concentration obtained by the copper concentration analyzer 20, (2) target Cu ²⁺ concentration M _{0 of} the leachate to be sent to the cleaning tank 60 (: total leachate) and (3) leachate flow meter FM ₁ and it is more preferable / or for attaching a control unit 100 for controlling the opening of the leachate flow control valve CV based on the three-way flow measurements obtained by leachate flow meter FM _2.

Further, the above-mentioned control device 100 has the following formula:
It is more preferable that the control device controls the opening degree of the leachate flow rate control valve CV based on (2) and (4). F ₁ / F ₂ = (M ₀ ) / (M−M ₀ ) (2) F ₁ = F−F ₂ ……………………… (4) In (2) and (4), F is the first liquid feed system 101 and the liquid feed system 101a before branching off the second liquid feed system 102.
Leachate flow is fed to, F ₁ is obtained in a clean tank 60 directly feeding the leachate to flow to, F ₂ copper concentration analyzer 20 leachate flow, M is described above for feeding to Datsudoso 40 The analysis value of the copper concentration, M ₀ , indicates the target Cu ²⁺ concentration of the leachate (total leachate) sent to the cleaning tank 60.

The target Cu ²⁺ concentration M ₀ of the leaching solution (total leaching solution) to be sent to the cleaning tank 60 is determined by the Co ^{2+ of the} leaching solution.
It is preferable to determine the concentration or the Co ²⁺ concentration and the Ni ²⁺ concentration of the leachate.

[0029]

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, the present invention will be described in more detail. Means for Solving the Problems The present inventors have conducted intensive studies in order to solve the above-mentioned problems of the prior art, and as a result, have arrived at the following method and equipment for adjusting the copper concentration in a leachate. That is, the conventional cleaning tank (: cobalt removal tank) 6 controls the concentration of Cu ²⁺ in the leachate by controlling the amount of zinc dust added to the copper removal tank 4 shown in FIGS. For partial decopperization, the idea was completely changed, and the leachate of zinc ore was separated, and the total amount of Cu ^{2+ in} the leachate was replaced and precipitated by one of the leachate after separation. adding a sufficient amount of zinc powder to remove Cu ^2+, and the resulting leachate, by mixing the other leachate containing Cu ²⁺ after separation, Cu ²⁺ concentration in the leaching solution Of the method and apparatus for adjusting the copper concentration in the leachate to control the temperature to a predetermined value.

The whole leachate after the above liquid separation is decoppered, and the obtained leachate is mixed with the other leachate after the liquid separation,
By supplying it to the cleaning tank (: decobalt tank), it is possible to remove Co in the leachate stably at a high removal rate and to obtain a high Cu grade residue in the copper removal process. Further, it was possible to greatly improve the sedimentation of Cu in the leachate in the copper removal step.

That is, the essence of the first invention is to separate a leachate of calcined ore, add zinc powder to one of the leachate after the separation, and replace, precipitate, separate and remove Cu to obtain the leachate. When,
This is a method for adjusting the copper concentration in the leachate in the cleaning step of wet zinc smelting, in which the separated leachate is mixed with the other leachate to adjust the copper concentration in the leachate. Further, the gist of a preferred embodiment of the first invention is the above-mentioned first invention, wherein the obtained mixed leaching solution contains zinc powder and one or more selected from arsenous acid, antimony acid, antimony tartrate and antimony potassium tartrate. This is a method for removing impurities in a leachate in a cleaning step of wet zinc smelting, in which two or more kinds are added to replace and precipitate Co, coprecipitate with Cu, and separate and remove.

The gist of the second invention is a first liquid sending system 101 which connects a solid-liquid separation device 2 for a leachate with a sulfuric acid solution of a calcined ore, and a cleaning tank (a decobalt tank) 60, A second liquid feed system 102 branched from the first liquid feed system 101 and connected to the cleaning tank 60;
In addition, a leachate removal copper tank (:
A copper removal tank) 40; a solid-liquid separation device 50 for the leachate flowing out of the copper removal tank 40; and a liquid supply system 102c for the leachate flowing out of the solid-liquid separation device 50 to the cleaning tank 60. This is a facility for adjusting the copper concentration in the leachate in the cleaning process of wet zinc smelting.

The gist of a preferred embodiment of the second invention is that, in the above-mentioned second invention, the above-mentioned cleaning tank 60 contains zinc dust and arsenous acid, antimony acid, antimony tartrate and antimony potassium tartrate in the tank. One or two selected
This is a facility for removing impurities in leachate in the cleaning process of wet zinc smelting, which is provided with a supply device 60a for supplying seeds or more and a solid-liquid separation device 70 for leachate flowing out of the tank.

Hereinafter, the present invention will be described with reference to the drawings. FIG. 1 shows an example of a process diagram relating to a facility for adjusting the copper concentration in a leachate and a facility for removing impurities in a leachate in the cleaning step of the wet zinc smelting of the present invention. In FIG. 1, part A shows an example of a facility for adjusting the copper concentration in a leachate of the present invention, and part B shows an example of a facility for removing impurities in a leachate of the present invention.

In FIG. 1, reference numeral 20 denotes a Cu concentration analyzer (: Cu concentration automatic analyzer), 40 denotes a leachate copper removal tank (: copper removal tank) for replacing and depositing a part of Cu ²⁺ , and 40a denotes a copper removal tank. Copper dust removal tank 40
Inlet device, 40b, 50a, 60b is leachate, 40c, 60
c is a stirrer drive, 50 is a solid-liquid separator such as thickener, 50b is a copper recovery process, 51 is a storage tank, 60 is Co ²⁺ , Ni ²⁺ ,
Purification tank for replacing and depositing Cu ²⁺ (: decobalt tank), 60a is zinc powder and one or two kinds selected from arsenous acid, antimony acid, antimony tartrate and antimony potassium tartrate in cleaning tank 60 A supply device that supplies the above, 70 is a solid-liquid separation device such as a filter press, 100
Indicates a control device.

Reference numeral 101 denotes a solid-liquid separating device 2 for leaching liquid provided on the outlet side of the leaching tank 1 and a cleaning tank (a decobalt tank) 60 provided as a post-process of the solid-liquid separating device 2. A first liquid sending system 101a is a first liquid sending system 101 and a liquid sending system before branching a second liquid sending system 102, and 101b is a first liquid sending system 101. After branching the second liquid supply system 102, the first liquid supply systems 101 and 102 are connected to the first liquid supply system 101.
, A liquid supply system 102a branched from the first liquid supply system 101 and connected to the copper removal tank 40, and 102b a copper removal tank connected to the copper removal tank 40. A liquid feeding system connecting the solid-liquid separator 40 and the solid-liquid separator 50, and 102c is a solid-liquid separator.
A system for sending the leachate flowing out of the tank 50 to the decobalt tank 60,
103 is a system for returning the slurry (or filter cake) containing the seed crystals separated by the solid-liquid separator 50 to the copper removal tank 40, CV is a leachate flow rate control valve, F is the flow rate of the leachate flowing out of the leach tank 1, F ₁ is a first liquid supply system 101 (liquid supply line 101a, 101
b) the flow rate of leachate sent directly to the cleaning tank 60 via
F ₂ is a copper removal tank via the liquid feed system 102 (liquid feed system 102a)
Leachate flow rate to be sent to 40, FM ₁ and FM ₂ are leachate flow meters,
l ₁ , l ₂ , l ₃ , l ₄ , l ₅ are liquid feed pipes, P is a pump,
Other symbols indicate the same contents as in FIGS.

The control unit 100 also includes a copper concentration analysis value M obtained by the copper concentration analyzer 20, a target Cu ²⁺ concentration M _{0 of} the leachate (total leachate) to be sent to the cleaning tank 60, and a leachate flow meter.
An FM _1, flow measurements obtained in FM ₂ F, a control device for controlling the opening of the leachate flow control valve CV based on the 4's F _2, the flow rate F ₂ which is defined by the following formula (5) As described above, the control device controls the opening degree of the leachate flow rate control valve CV.

F ₂ = [(M−M ₀ ) / M] × F (5) The target Cu ²⁺ concentration M ₀ of the leaching solution (total leaching solution) to be sent to the cleaning tank 60 is: , Determined from the Co ²⁺ concentration of the leachate. Further, as the solid-liquid separation device 50 shown in FIG. 1, a solid-liquid separation device such as a filter press can be used, and the method of solid-liquid separation is not limited.

According to the present invention, the solid-liquid separation device 50
When using any solid-liquid separation device such as thickener, filter press, etc., the residue in the solid-liquid separation
This is because it is possible to enhance Cu quality. In the equipment A for adjusting the copper concentration in the leachate and the equipment B for removing impurities in the leachate shown in FIG. 1, the liquid is sent from the leach tank 1 via a solid-liquid separator (: neutral thickener) 2 and a heat exchanger 3. The separated leachate is separated, and one of the separated leachate is directly sent to the cleaning tank (: cobalt removal tank) 60 by the liquid sending system 101b.

On the other hand, the other leachate after liquid separation is supplied to a liquid sending system.
It is sent to the copper removal tank 40 by 102a, the leachate containing precipitated Cu obtained in the copper removal tank 40 is sent to the solid-liquid separator 50 by the liquid sending system 102b, and the leachate after removing the precipitated Cu is removed. The solution is sent to the cleaning tank (: de-cobalt tank) 60 by the liquid sending system 102c,
Is removed. In the copper removal tank 40, preferably, zinc powder in an amount equivalent to or more than Cu ²⁺ in the supplied leachate is added, and all the Cu ²⁺ in the leachate is replaced and precipitated with Cu, and the obtained leachate is fed. The solution is sent to the solid-liquid separation device 50 by the liquid system 102b, and after substantially removing Cu ²⁺ and Cu in the leachate, the solution is sent to the cleaning tank (: cobalt removing tank) 60 by the liquid sending system 102c.

According to the above-described method, in the decoppering tank 40, preferably, zinc powder in an amount equivalent to or more than the amount of Cu ²⁺ ions in the supplied leachate is added and mixed, thereby forming a thickener and a filter. In the case of using any of the solid-liquid separation devices 50 such as a press, a residue of high Cu quality can be obtained, and the sedimentation of Cu in the leachate has been greatly improved.

The slurry or cake containing the solid content obtained in the solid-liquid separator 50 is sent to the copper recovery step 50b. When a thickener is used as the solid-liquid separator 50 in the present invention, a part of the slurry or cake containing the solid content obtained by the solid-liquid separator 50 is used as a seed crystal as a seed crystal and returned to the copper removal tank 40 via the return system 103. By returning, sedimentation can be further improved.

On the other hand, the other leachate after liquid separation is supplied to a liquid sending system.
According to 101b, the solution is directly sent to the cleaning tank (: cobalt removal tank) 60, or mixed with the leachate decopperized in the copper removal tank 40, and then sent to the cleaning tank 60. According to the above-described method and equipment of the present invention, a leachate having a Cu ²⁺ concentration supplied from the copper removal tank 40 of substantially 0 and a leachate having the same Cu ²⁺ concentration as the leachate obtained in the leach tank 1 are used. By controlling the concentration of Cu ²⁺ in the leachate supplied to the cleaning tank 60 by mixing
Substitution of Co ²⁺ in, precipitation, and co-precipitation with Cu can be sufficiently performed, and as shown in Examples described later, it becomes possible to obtain a high Cu grade residue in the decoppering step. The sedimentation of Cu in the leachate in the copper removal process was greatly improved.

Further, in the present invention described above, FIG.
As shown in, the leachate flowmeters FM ₁ and FM ₂ and the leachate flow rate control valve CV are used to remove the copper so that the Cu ²⁺ concentration of the leachate (total leachate) sent to the cleaning tank 60 becomes a predetermined concentration. It is preferable to adjust the separation ratio between the leachate to be sent to the tank 40 and the leachate to be sent directly to the cleaning tank 60. For this, the copper removal tank 40
The amount of liquid to be separated into the liquid sending system 102 via the
It is preferable that the amount of liquid to be separated is determined based on the concentration of Cu ^{2+ in} the leachate.

More specifically, a leachate before zinc powder addition, such as a leachate before liquid separation (: a leachate without zinc powder added)
Analyze the Cu ²⁺ concentration M of the leachate (:
The liquid separation ratio (: F ₁ / F ₂ ) is controlled based on the following equation (2) so that the Cu ²⁺ concentration of the total leaching solution becomes a predetermined Cu ²⁺ concentration M _0, and further, the following equation ( It is preferable to control the supply amount of zinc dust supplied to the copper removal tank 40 based on 3).

Separation ratio = F₁/ F_Two= (M₀) / (MM)₀) (2) Supply amount of zinc dust to be supplied to the copper removal tank 40 X (mol-Zn / hr) ≧ (1000F_Two) × M (mol-C u²⁺/ l- leachate) ............ (3) As described above, M₀Is the leachate before decobaltation
Co inside²⁺Concentration or Co ²⁺Concentration and Ni²⁺From both concentrations
Can be set.

That is, the above-mentioned optimal control method of the copper concentration in the present invention is as follows, and can be controlled by the control device 100 shown in FIG. [Optimal control method:] Analysis of Cu ²⁺ concentration M in leachate flowing out of leach tank 1 (: Cu concentration automatic analyzer 20) Total leachate supplied to cleaning tank 60 (: flow rate = F ₁ +
Setting of target Cu ²⁺ concentration M ₀ of F ₂ ) Measurement of flow rate L of leachate flowing out of leach tank 1 Measurement of flow rate L ₂ of leachate supplied to copper removal tank 40 Flow rate of leachate supplied to copper removal tank 40 Setting of F ₂ (based on the above formula (5)) → Control of the leachate flow rate control valve CV Measurement of the flow rate F ₂ of the leachate supplied to the copper removal tank 40 → Control described above Zinc dust supplied to the copper removal tank 40 (Based on the above formula (3)) (Cu ^{2+ of the} leachate supplied to the copper removal tank 40)
According to the method and apparatus of the present invention described above, the following excellent effects can be obtained.

(1) Co in a cleaning tank (: decobalt tank)
Substitution of ²⁺ , precipitation, and coprecipitation with Cu can be performed stably and sufficiently. (2) It became possible to obtain a high Cu grade residue in the copper removal process. (3) The sedimentation of Cu in the leachate in the copper removal step is greatly improved. (4) The throughput of the leachate in the copper removal step is reduced, and the solid-liquid separation device such as a copper removal tank, thickener, filter press, etc. can be miniaturized.

[0049]

EXAMPLES Hereinafter, the present invention will be described more specifically based on examples. (Example) An impurity removal test was performed using the equipment for adjusting the copper concentration in the leachate and the equipment for removing impurities in the leachate in the cleaning step of the wet zinc smelting of the present invention shown in FIG. 1 described above.

As a solid-liquid separation device 50 in the copper removal step, a thickener was provided. The operating conditions (average value during the test period) in this test are as follows, and the cleaning tank (:
Total leachate to be sent to the decobalt tank (60): (Solution sending system 101b)
The leachate flow control valve CV is controlled by the control device 100 and the above-described optimal control method so that the target Cu ²⁺ concentration M _{0 of} the leachate to be sent from both the liquid supply system 102 to the cleaning tank 60 is 300 mg / l. Was controlled.

The above-mentioned target Cu ²⁺ concentration M ₀ was set based on the Co ²⁺ concentration in the leachate before the removal of cobalt. [Operating conditions:] Flow rate of leachate flowing out of leach tank 1 = F = 70 m ³ / hr Cu ²⁺ concentration of leachate flowing out of leach tank 1 M = 700 mg / l Supply amount of zinc dust supplied to copper removal tank 40 X = 1.25 times equivalent of the amount of Cu ^{2+ in} the leachate supplied to the copper removal tank 40 The flow rate of the leachate directly sent to the cleaning tank (: cobalt removal tank) 60 F ₁ = (3/7) F = 30 m ³ / hr Flow rate of leachate sent to copper removal tank 40 F ₂ = (4/7) F = 40m ³
/ hr Chemical to be supplied to cleaning tank (: decobalt tank) 60: zinc powder +
Liquid temperature of leachate at the outlet of the arsenous acid heat exchanger 3 = 85 ° C The average Co concentration of the leachate at the solid-liquid separator (: neutral thickener) 2 at the time of this test: 20 mg / l, and the filter press
The average Co concentration in the leachate at outlet 70 was 9 μg / l.

Further, the concentration of the suspended substance in the leachate at the outlet of the solid-liquid separation device (: Thickener) 50 at the time of this test was 45 to 80 mg.
The concentration remained low at / l. During the test, the leachate supplied to the solid-liquid separator 50 from the copper removal tank 40 was sampled,
The sedimentation of suspended matter in the leachate was examined. That is, 1000 ml of the sampled leachate was dispensed into a 1-liter graduated cylinder and allowed to stand for 5 minutes, and then the upper part: 750 ml and the lower part: 25
0 ml of each was taken and filtered.

Next, each filtration residue was washed with water, dried and weighed to determine the sedimentation defined by the following equation (6). Sedimentability = [(residual amount in lower layer) / (residual amount in upper layer + residual amount in lower layer)] x 100 (wt%) ... (6) As a result, the sedimentation property was 94.3 wt%. there were.

From the above test results, according to the present invention,
It was found that the sedimentation of Cu in the leachate in the copper removal process was significantly improved. Furthermore, as a result of analyzing the Cu quality of the residue obtained in the solid-liquid separation device 50, the Cu content in the residue was 80 wt.
% And Zn content were 3 wt%, and it was found that according to the present invention, it is possible to obtain a residue of high Cu quality in the copper removal step.

(Comparative Example) The conventional leaching shown in FIG.
Uses equipment for adjusting copper concentration in liquid and equipment for removing impurities in leachate
Then, an impurity removal test was performed. Operation in this test
The conditions (average value during the test period) are as follows. [Operating conditions:] Flow rate of leachate flowing out of leach tank 1 = F = sent to copper removal tank 4
Leaching liquid flow rate = sent to cleaning tank (: decobalt tank) 6
Leachate flow rate = 70m^Three/ hr Cu of leachate flowing out from leach tank 1²⁺Concentration = 700mg / l Target Cu of leachate sent to cleaning tank 6²⁺Concentration = 300 mg / l Supply amount of zinc dust supplied to copper removal tank 4 = [(supplied to copper removal tank 4
Cu in leachate supplied ²⁺Amount)-(Supply to the cleaning tank 60)
Cu in leachate²⁺1.4 times the equivalent of the target amount)) Chemicals to be supplied to the cleaning tank (: de-cobalt tank) 6: zinc powder +
Arsenous acid Liquid temperature of leachate at heat exchanger 3 outlet = 85 ° C Concentration of suspended solids in leachate at thickener 5A outlet during this test
Showed a high concentration of 200-300 mg / l.

At the time of this test, the leachate supplied to the thickener 5A from the copper removal tank 40 was sampled, and the sedimentation of suspended substances in the leachate was examined in the same manner as in the above-described embodiment. As a result, the sedimentation defined by the above formula (6) was 21.8 wt%. Furthermore, as a result of analyzing the Cu quality of the residue obtained by thickener 5A, the Cu content in the residue was 50 to 60 wt%, and the Zn content was 6 to 10 wt%, indicating a low Cu quality.

In the above-described embodiment, zinc powder and arsenous acid were used as the chemicals to be supplied to the cleaning tank (decobalt tank) 60. Alternatively, even if two or more selected from these four agents are used, the high cobalt removal rate shown in the above-described embodiment can be stably obtained.

In the above-described embodiment, a thickener is used as the solid-liquid separation device 50 in the copper removal step. However, a filter press can be used, and in that case, a high Cu grade residue can be obtained. It is.

[0059]

According to the present invention, the following excellent effects can be obtained. (1) The replacement and precipitation of Co ²⁺ and the coprecipitation with Cu in the cleaning tank (: decobalt tank) can be performed stably and sufficiently. (2) It became possible to obtain a high Cu grade residue in the copper removal process.

(3) The sedimentation of Cu in the leachate in the copper removal step is greatly improved. (4) Solid-liquid separators such as a copper removal tank, thickener, and filter press can be miniaturized.

[Brief description of the drawings]

FIG. 1 is a process diagram relating to equipment for adjusting the copper concentration in a leachate (part A) and equipment for removing impurities in a leachate (part B) in the cleaning step of the wet zinc smelting of the present invention.

FIG. 2 is a process diagram relating to a facility for adjusting a copper concentration in a leachate and a facility for removing impurities in a leachate in a conventional cleaning process of wet zinc smelting.

FIG. 3 is a process diagram relating to a facility for adjusting the concentration of copper in a leachate and a facility for removing impurities in a leachate in a conventional cleaning process of wet zinc smelting.

[Explanation of symbols]

1 Leaching tank for zinc ore (: dissolution tank) 1b Sulfuric acid solution (: leachate) 2,50 Solid-liquid separator for leachate 2b, 4b, 6b, 8b, 40b, 5Aa, 50a, 60b Leachate 3 Heat exchanger 4, 40 Leaching liquid copper removal tank (copper removal tank) 4a, 40a Supply device for zinc powder into copper removal tank 4c, 6c, 8c, 40c, 60c Stirrer drive 5A thickener 5B, 7,9 Filter press 6,60 Cleaning Tank (: decobalt tank) 6a, 60a Supply device 8 Purification tank (: decadmium tank) 8a Supply device for zinc powder into decadmium tank 10 Zinc electrolytic tank 11 Supply pipe for leaching tank of electrolytic tail liquid 20 Copper Concentration analyzer (: Copper concentration automatic analyzer) 21 High-temperature and high-acid dissolving tank 5Ab, 5Bb, 50b Copper recovery process 51 Storage tank 71 Cobalt recovery process 91 Cadmium recovery process 100 Control device 101 Consists of liquid supply systems 101a and 101b First liquid supply system 102 Second liquid supply system 101a, 101b, 102a, 102b, 102c composed of liquid supply systems 102a, 102b, 102c Liquid supply system 103 Separation by solid-liquid separation device Species back line CV leachate flow from the control valve F leaching vessel 1 to the flow F ₁ cleaning tank 60 of the leaching solution exiting direct feeding to leachate flow F ₂ Datsudoso crystal to copper removal tank slurry or cake containing a flow rate FM ₁ exudates to feed to 40, FM ₂ leachate flow meter _{l 1, l 2, l 3} , l 4, l 5 liquid feed pipe P pump

Claims (2)

[Claims] 1. A leachate obtained by a zinc sulfate ore sulfuric acid solution is separated, zinc powder is added to one of the separated leachates, mixed, and copper is separated and removed. A method for adjusting the copper concentration in a leachate in a cleaning process of wet zinc smelting, comprising mixing the other leachate after the liquid with the other leachate to adjust the copper concentration in the leachate. 2. A leaching tank for leaching zinc ore with a sulfuric acid solution.
A solid-liquid separation device (2) for leaching liquid provided on the outlet side of (1) and a cleaning tank (60) provided as a post-process of the solid-liquid separation device (2)
And a second liquid feeding system (102) branched from the first liquid feeding system (101) and connected to the cleaning tank (60). And the second liquid sending system
(102), a leachate removal copper tank (40) provided with a supply device (40a) for feeding zinc powder into the tank, and a solid-liquid separation device (50) for leachate flowing out of the leachate removal copper tank (40) And a liquid sending system (102c) of the leachate flowing out from the solid-liquid separation device (50) to the cleaning tank (60).
A facility for adjusting the concentration of copper in a leachate in the cleaning process of hydro-zinc smelting, wherein