JP2007204830A - Method for leaching copper sulfide ore including brass ore - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an economically efficient method for leaching copper from copper sulfide ore including brass ore with the low use amount of sulfuric acid, in an increased leaching speed and in high leaching ratio. <P>SOLUTION: In the method where copper sulfide ore including brass ore is leached from copper, the copper sulfide ore is mixed with a fixed carbon-containing material by an amount of 0.1 to 2.0 times to the whole weight of the copper mineral in the copper sulfide ore, thereafter, the obtained mixture is dipped into an iron sulfate aqueous solution in which the concentration of iron is controlled to 1 to 20 g/L and pH is controlled to 2.6 to 3.5. Further, as the fixed carbon-containing material, active carbon is used. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a method for leaching copper sulfide ores containing chalcopyrite, and more specifically, economically efficient for leaching copper from a sulfide ore containing chalcopyrite with a low sulfuric acid consumption, a high leaching rate and a high leaching rate. Related to different methods.

  Conventionally, as one of the methods for recovering copper from copper ore, a method has been used in which copper is leached with sulfuric acid or the like, and the leached copper is concentrated by solvent extraction and recovered as a copper cathode by electrowinning. ing. In this method, when the copper contained in the copper ore is in the form of oxide or carbonate, 40 to 90% of the copper contained by simple acid leaching can be easily leached, and the copper can be obtained in a high yield. Can be recovered.

Further, when the copper mineral in the copper ore is a secondary sulfide mineral such as chalcocite (Cu ₂ S), porphyry (Cu ₅ FeS ₄ ), a bacterial leaching method is used. In this method, copper can be efficiently leached by using a leaching solution containing iron sulfate as an oxidizing agent under the conditions in which microorganisms such as iron-oxidizing bacteria coexist. All of the above methods can recover copper economically and efficiently, and are widely used in large-scale copper mines in North and South America.

However, when the copper mineral contained in the copper ore is chalcopyrite (CuFeS ₂ ), the leaching rate of copper becomes extremely slow. Therefore, in general bacterial leaching, it is about several to 20%. There was a problem that the copper leaching rate was remarkably impaired. This cause is related to the redox potential of the leachate. That is, Fe ³⁺ ions contained in the leachate act as an oxidant and promote the dissolution of sulfide minerals. At this time, they are reduced to Fe ²⁺ ions, so that the redox potential of the leachate decreases as the leaching reaction proceeds. At this time, microorganisms such as iron-oxidizing bacteria naturally inhabiting the deposited ore dump have a role of oxidizing the Fe ²⁺ ions to Fe ³⁺ ions and increasing the redox potential of the leachate again.

For example, when the copper mineral contained in the copper sulfide ore is a secondary sulfide mineral such as chalcocite (Cu ₂ S) or porphyry (Cu ₅ FeS ₄ ), these are more easily dissolved as the redox potential is higher. Therefore, the more copper is eluted as the bacteria are actively activated and the Fe ³⁺ ions in the leachate increase. On the other hand, when the copper mineral is chalcopyrite (CuFeS ₂ ), which is a primary sulfide mineral, leaching is extremely slow in a redox potential region of 500 to 700 mV (Ag / AgCl electrode standard) where bacteria are actively active. And hardly leached under conditions suitable for leaching of the secondary sulfide mineral. Further, leaching can be accelerated by making the potential higher than this, but it is difficult to maintain the high potential only by the oxidizing action of bacteria.

  By the way, generally, copper contained in the low-grade copper ore, for example, the primary enrichment zone below the porphyry type ore is chalcopyrite. Moreover, copper ores including chalcopyrite are widely distributed throughout the world. However, since these ores are not suitable for copper recovery by the above leaching method, the copper concentrate must be recovered by an economically disadvantageous flotation method or disposed as waste ore.

  As a solution to this, as a method of leaching chalcopyrite, a method of adding pressure sulfuric acid and an oxidizing agent and leaching under pressure, a method of heating using hydrochloric acid, etc. have been proposed. Not economical. For example, a technique using a carbonaceous additive as a reaction accelerator at the time of oxidative pressure leaching with a sulfuric acid solution of copper concentrate (for example, see Patent Document 1) has been proposed. This method is an effective method for hardly leaching copper minerals such as chalcopyrite, but oxidative pressure leaching is performed under severe conditions of leaching reaction temperature of 90 to 220 ° C. and pressure of 100 to 3000 kPa. It is. Therefore, the leaching method under mild conditions such as bacterial leaching is fundamentally different in the expected leaching rate.

  Furthermore, the present inventors have made a mixture of copper sulfide ore containing chalcopyrite and powdered carbon with an iron concentration of 1 to 20 g / L, a pH of 1.0 to 2.5, and a redox potential (Ag / AgCl). A method of leaching copper from a copper sulfide ore by immersing it in an iron sulfate aqueous solution whose electrode standard is adjusted to 350 to 450 mV has been proposed (for example, see Patent Document 2). Thus, copper can be leached at a high leaching rate by increasing the leaching rate, but in order to obtain a high leaching rate, it is necessary to lower the pH to less than 2.5, preferably less than 2.0. There was a problem that the amount of sulfuric acid used was increased.

In view of the above situation, there is a demand for a method that is highly economical because it uses a copper sulfide ore containing chalcopyrite to leach copper at a high leaching rate by increasing the leaching rate.
US Pat. No. 5,730,776 Japanese Patent Laying-Open No. 2005-15864 (first page, second page)

  An object of the present invention is to provide an economically efficient method of leaching copper from a copper sulfide ore containing chalcopyrite with a low sulfuric acid consumption, a high leaching rate and a high leaching rate in view of the problems of the prior art. It is to provide.

  In order to achieve the above object, the present inventors have conducted extensive research on a method of leaching copper from chalcopyrite containing chalcopyrite. When immersed in an aqueous iron sulfate solution adjusted to the conditions, it was found that copper can be leached at a high leaching rate by increasing the leaching rate of copper with a low amount of sulfuric acid used, thereby completing the present invention.

That is, according to the first invention of the present invention, a method of leaching copper from a copper sulfide ore containing chalcopyrite,
After mixing a fixed carbon-containing material in an amount of 0.1 to 2.0 times the total weight of the copper mineral in the copper sulfide ore with the copper sulfide ore, the resulting mixture was adjusted to an iron concentration of 1 to 20 g / There is provided a leaching method of copper sulfide ore characterized by immersing in an aqueous iron sulfate solution adjusted to L and pH of 2.6 to 3.5.

  According to a second aspect of the present invention, there is provided a copper sulfide ore leaching method characterized in that, in the first aspect, the fixed carbon-containing material is activated carbon.

  According to a third invention of the present invention, the copper sulfide ore according to the first or second invention is characterized in that the oxidation-reduction potential (Ag / AgCl electrode standard) of the iron sulfate aqueous solution is adjusted to 350 to 450 mV. A method of leaching is provided.

  The leaching method of copper sulfide ore containing chalcopyrite of the present invention can increase the leaching rate of copper with a low amount of sulfuric acid and leaching copper at a high leaching rate from copper ore containing chalcopyrite. Target value is extremely high.

Hereinafter, the method for leaching copper sulfide ore containing chalcopyrite according to the present invention will be described in detail.
The method for leaching a copper sulfide ore containing chalcopyrite according to the present invention is a method for leaching copper from a copper sulfide ore containing chalcopyrite. The copper sulfide ore contains 0. 0% relative to the total weight of the copper mineral in the copper sulfide ore. After mixing 1 to 2.0 times the amount of fixed carbon-containing material, the resulting mixture is immersed in an iron sulfate aqueous solution adjusted to an iron concentration of 1 to 20 g / L and a pH of 2.6 to 3.5. It is characterized by that.

  In the present invention, the copper sulfide ore containing chalcopyrite is mixed with a fixed carbon-containing material in an amount of 0.1 to 2.0 times the total weight of the copper mineral in the copper sulfide ore, and the mixture is subjected to predetermined conditions. It is important to leach copper by immersing it in an aqueous iron sulfate solution. Thereby, in the sulfuric acid aqueous solution, the chalcopyrite reacts in a specific oxidation-reduction potential region and is leached at high speed. In addition, the amount of sulfuric acid used for adjusting the pH can be reduced.

  Here, the effect | action of the fixed carbon containing material in this invention is demonstrated based on the leaching reaction of a chalcopyrite in sulfuric acid aqueous solution. In general, chalcopyrite in a sulfuric acid aqueous solution is leached in a certain oxidation-reduction potential region according to a two-step reaction shown in the following reaction formulas (1) and (2).

^{_{CuFeS 2 + 3Cu 2+ + 3Fe 2+}} = 2Cu 2 S + 4Fe 3+ (1)
Cu ₂ S + 4Fe ³⁺ = 2Cu ²⁺ + S + 4Fe ²⁺ (2)

  That is, first, based on the formula (1), chalcopyrite is reduced in a low redox potential region, and chalcopyrite having a higher oxidation elution rate is generated as a reaction intermediate. Thereafter, based on the formula (2), the chalcocite is oxidized and copper is eluted. In order to establish such a reaction mechanism, it is an essential condition that the oxidation-reduction potential E of the solution satisfies the following formula (3).

Eox <E <Ec (3)
(In the formula, Ec represents the redox potential of formula (1), and Eox represents the redox potential of formula (2).)

Regarding the reaction mechanism, the relationship between the reaction rate and the oxidation-reduction potential (hereinafter sometimes referred to as potential), and the coexistence effect of the fixed carbon-containing material according to the present invention will be described in detail with reference to the drawings. .
FIG. 1 shows the relationship between the dissolution rate of chalcopyrite and the potential.
As shown in FIG. 1, when the condition of the formula (3) is satisfied, the chalcopyrite is reduced, and a chalcopyrite having a higher oxidation elution rate is generated as a reaction intermediate. That is, in the vicinity of Ec, the chalcopyrite reduction reaction (Cu ₂ S formation reaction: R) and the Cu ₂ S oxidation reaction (O), the reduction reaction of chalcopyrite controls the entire process, so the copper elution rate K Increases with decreasing potential. On the other hand, in the vicinity of Eox, the Cu ₂ S oxidation reaction becomes a rate-limiting step, and the elution rate K of copper increases as the potential increases. Therefore, the elution rate of copper is maximized at the potential (Eop) at which the chalcopyrite reduction reaction (R) and the Cu ₂ S oxidation reaction (O) intersect. Moreover, when Ec <E, since copper elutes from chalcopyrite directly by the chalcopyrite oxidation reaction (D), the elution rate of copper becomes low.

FIG. 2 shows the relationship between the elution rate of chalcopyrite and the potential when the fixed carbon-containing material coexists.
As shown in FIG. 2, the chalcopyrite oxidation reaction (O) is promoted, and the copper elution rate K increases at Eop as shown in the new chalcopyrite oxidation reaction (O ′).
Here, the fixed carbon-containing material functions as a catalyst for oxidizing divalent Fe to trivalent Fe, and has an effect of returning the value to the vicinity of the optimum value when the solution potential is excessively lowered. In addition, the leaching rate is increased even at the same potential because the dissolution reaction is accelerated by adsorbing and removing H ₂ S, which is one of the products of the chalcopyrite dissolution reaction.
From the above, it can be seen that the fixed carbon-containing material plays a role of promoting leaching by maintaining the solution potential in a range suitable for the leaching of chalcopyrite.

  The copper sulfide ore containing chalcopyrite used for the raw material of the present invention is not particularly limited, and copper sulfide ore in which part or most of the contained copper mineral is chalcopyrite, or flotation from the copper sulfide ore, etc. A copper concentrate enriched with copper is used.

  The copper sulfide ore is crushed and used in order to expose most of the copper mineral. The crushing method is not particularly limited, and the crushing method is performed by a normal method using blasting during mining or various crushers. Here, the particle size of the crushed product is not particularly limited, and an optimum pulverized particle size may be selected by comprehensively judging the properties and profitability of the raw ore. When the target is copper concentrate, it is already fine and does not need to be crushed.

The fixed carbon-containing material used in the present invention is not particularly limited, and a fixed carbon-containing material having a structure having a functional group made of carbon capable of adsorbing H ₂ S or a compound thereof is used. Activated carbon (fixed carbon 90% or more), coal (fixed carbon 30 to 95%), coke (fixed carbon 75 to 85%), charcoal (fixed carbon about 85%), and the like. Among these, activated carbon is particularly preferable in consideration of economy.

  The particle size of the fixed carbon-containing material is not particularly limited, but is preferably crushed into a powder form in order to sufficiently exhibit the effect as a leaching accelerator. For example, a particle size of 75 μm or less is used.

  The addition ratio of the fixed carbon-containing material is 0.1 to 2.0 times, preferably 0.2 to 1.0 times the total weight of the copper mineral in the copper sulfide ore. That is, when the addition ratio is less than 0.1 times, the effect as a leaching accelerator cannot be sufficiently exhibited. On the other hand, if the addition ratio exceeds 2.0 times, the cost increases and the economic efficiency is impaired. Since the optimum amount of the fixed carbon-containing material varies depending on the composition and particle size of the copper sulfide ore, the optimum amount can be determined within the above range for the target copper sulfide ore by performing a preliminary test each time.

  The aqueous iron sulfate solution used in the present invention is a leachate for eluting copper from copper sulfide ore, and the pH and iron concentration are adjusted. For example, as will be described later, when the leaching method of the present invention is used in a leaching step of a hydrometallurgical process for recovering copper from chalcopyrite containing copper ore, normally, after recovering copper from the leaching product liquid A leaching circulating liquid, such as an extraction residual liquid generated by solvent extraction, is used by adjusting pH and iron concentration so as to satisfy predetermined conditions.

The pH of the iron sulfate aqueous solution is adjusted to 2.6 to 3.5. That is, at a low pH, since the secondary reaction of H ₂ S is not adsorbed and removed, the dissolution reaction is difficult to be promoted, so that pH of 2.0 or more is desirable from the viewpoint of copper leaching rate. However, there is a problem that the lower the pH, the more the sulfuric acid is used, which is economically disadvantageous. Accordingly, a pH of 2.6 or higher is used, which provides an economical high leaching rate with a low amount of sulfuric acid. On the other hand, when the pH exceeds 3.5, there arises a problem that the leaching rate of copper is lowered and the insoluble iron compound is precipitated to prevent the leaching reaction.
The method for adjusting the pH is not particularly limited, and a mineral acid such as sulfuric acid or hydrochloric acid is added to the aqueous solution or the leaching circulating solution. In particular, it is preferable to use inexpensive sulfuric acid from the viewpoint of economy.

  The iron concentration of the iron sulfate aqueous solution is adjusted to 1 to 20 g / L, preferably 5 to 10 g / L. That is, the higher the iron concentration, the higher the copper leaching rate. However, when the iron concentration is less than 1 g / L, the copper leaching rate decreases and the recovery efficiency decreases. On the other hand, when the iron concentration exceeds 20 g / L, the viscosity of the liquid increases and precipitation of insoluble iron compounds increases, which hinders leaching.

  The method for adjusting the iron concentration of the aqueous iron sulfate solution is not particularly limited, and it is preferable to add ferrous sulfate or ferric sulfate to the aqueous solution or the leaching circulating liquid. Here, since the form of the iron sulfate to be added is greatly related to the potential of the aqueous iron sulfate solution, the one that allows easy adjustment of the potential is appropriately selected.

  The addition amount of the iron sulfate aqueous solution is not particularly limited, and at least an amount that sufficiently spreads over the entire copper sulfide ore is added, but according to the shape of the reaction vessel to be used, the situation of the downstream process after leaching, etc. Adjust as appropriate. Among these, since the density | concentration of the leaching noble liquid (leaching production | generation liquid) obtained will become thin too much and the efficiency in solvent extraction etc. of a downstream process will fall when there is too much quantity of a leaching liquid, 20 times or less of a copper sulfide ore is preferable.

  In the method of the present invention, in order to control the leaching reaction, it is preferable to measure the pH and potential of the aqueous iron sulfate solution during the reaction at regular intervals. Here, the potential of the leaching solution gradually decreases due to the reducing power of the copper mineral itself, but is usually kept at a certain value by the oxidizing power of oxygen dissolved from the air.

The oxidation-reduction potential (Ag / AgCl electrode standard) of the aqueous iron sulfate solution used in the present invention is not particularly limited and is preferably adjusted to 350 to 450 mV, more preferably 380 to 420 mV. That is, maintaining the potential in this range is suitable for leaching of chalcopyrite.
As a method for adjusting the oxidation-reduction potential, the following means are used. For example, when the oxidation-reduction potential (Ag / AgCl electrode standard) is less than 350 mV, a part of the leachate in the reaction vessel is extracted, and the potential is increased by replenishing with a new aqueous iron sulfate solution containing ferric sulfate. . On the other hand, when the oxidation-reduction potential (Ag / AgCl electrode standard) exceeds 450 mV, a portion of the leachate is similarly extracted and replenished with a new aqueous iron sulfate solution containing ferrous sulfate to lower the potential. The amount and iron concentration of the iron sulfate aqueous solution to be replenished are appropriately adjusted so that the potential of the leachate and the iron concentration during the reaction are maintained within the above ranges.

  The leaching method used in the present invention is not particularly limited, and is a method of leaching by immersing a mixture of copper sulfide ore and fixed carbon-containing material in the aqueous iron sulfate solution, for example, leaching while stirring in a reaction vessel. , Heap leaching method, butt leaching method or column leaching method is used.

  The noble liquid containing copper obtained by the method of the present invention can be recovered intermittently by replenishment of the leachate into the reaction vessel, a method of continuously collecting small amounts of leachate, and all the noble liquids once. However, it can be separated from the leaching residue and taken out of the system by a method such as recovery, but a method suitable for the form and capacity of the downstream process can be appropriately selected.

The method of the present invention is suitably used as a method of leaching copper at a high leaching rate with a low amount of sulfuric acid used in a leaching step of a hydrometallurgical process for recovering copper from a copper sulfide ore containing chalcopyrite. Hereinafter, an example of the process using the leaching method of the present invention will be described with reference to the drawings. FIG. 3 shows a schematic process diagram of a hydrometallurgical process for recovering electrolytic copper from a copper sulfide ore containing chalcopyrite using the leaching method of the present invention.
In FIG. 3, first, in the leaching step 1, a mixture 7 containing the copper sulfide ore 5 and the fixed carbon-containing material 6 is immersed in an aqueous iron sulfate solution 8 adjusted to a predetermined composition, and copper is leached. Next, in the solvent extraction process 2 in which an acidic extractant is generally used, the back extraction product liquid 11 in which copper is concentrated and separated from the leaching product liquid 10 obtained by solid-liquid separation from the leaching residue 9 in the leaching process 1. And an extraction residual liquid 12 containing iron are obtained. At this time, when an acidic extractant is used, the higher the pH at the time of extraction, the higher the copper extraction rate, so the pH used in the method of the present invention is more convenient. That is, at the time of extraction, copper can be separated from the leaching product liquid 10 with high efficiency without adjusting the pH using a neutralizing agent or the like.
Next, electrolytic copper 15 is obtained from the back extraction product solution 11 by the copper electrolysis process 3 using an insoluble electrode. Further, the extraction residual liquid 12 containing iron sulfate is repeated in the leaching step 1 as a leaching circulating liquid. At this time, a predetermined amount of sulfuric acid 13 and ferrous sulfate or ferric sulfate 14 is necessary in the leachate adjustment step 4 to adjust pH, iron concentration, oxidation-reduction potential, etc. of the aqueous iron sulfate solution 8 that is the leachate. However, according to the leaching method of the present invention, the amount of sulfuric acid used can be reduced.

Hereinafter, the present invention will be described in more detail by way of examples and comparative examples of the present invention, but the present invention is not limited to these examples. In addition, the analysis method of the metal used in an Example and a comparative example, a mineral ratio, and fixed carbon is as follows.
(1) Metal analysis: ICP emission analysis was performed.
(2) Analysis of mineral ratio: Determined by microscopic observation.
(3) Analysis of fixed carbon: Determined according to JIS K 2425.

  In addition, Table 1 shows the chemical analysis values and mineral ratios of the copper concentrates used in the examples and comparative examples. From Table 1, it can be seen that almost all of the copper contained in the copper concentrate is chalcopyrite.

  In addition, Table 2 shows analytical values of fixed carbon of commercially available activated carbon used in Examples and Comparative Examples as a fixed carbon-containing material.

Example 1
As the raw material, the copper concentrate was washed with alcohol to sterilize microorganisms and then naturally dried in a sterilization chamber. Further, as the leachate, ferrous sulfate (reagent special grade) dissolved in water to have an iron concentration of 5 g / L was used. The pH of the leachate was adjusted to 2.6 by adding dropwise dilute sulfuric acid (H ₂ SO ₄ concentration: 64% by weight).
First, 10.0 g of the copper concentrate (8.8 g as a copper mineral) and 8.8 g of the activated carbon pulverized to 75 μm or less were weighed into a 300 mL flask, and 100 mL of a leachate was added to the flask. A sponge-like stopper was applied to the mouth of the flask. Thereafter, the flask was fixed to a shaker installed in a thermostatic chamber adjusted to 30 ° C. in order to make the leaching conditions constant, and swirled at a rotational speed of 120 rpm.
One week later, the flask was taken out and weighed to replenish the evaporated water. Thereafter, after solids were sufficiently settled, 50 mL of the supernatant was collected and used as a sample for analysis. To the remaining sample solution, dilute sulfuric acid was added dropwise to adjust the pH to 2.6, and 50 mL of the leachate was newly replenished and shaken again. Here, the reagents, glass instruments used for the adjustment of the exudate, pipettes, etc. were all sterilized, and sufficient consideration was given so that contamination of bacteria did not occur.
This operation was repeated every week to continue leaching. The redox potential (Ag / AgCl electrode standard) of the leachate in the reaction vessel was maintained in the range of 350 to 450 mV. Thereafter, copper was analyzed using the analytical sample to determine the transition of the Cu leaching rate. Table 3 shows the results of leaching days 21 and 42. Table 3 shows the amount of dilute sulfuric acid (H ₂ SO ₄ concentration: 64% by weight) used at this time.

(Example 2)
Except that the pH of the leachate was adjusted to 3.0, the same procedure as in Example 1 was performed, and then copper was analyzed to determine the transition of the Cu leaching rate. Table 3 shows the results of leaching days 21 and 42. Table 3 shows the amount of dilute sulfuric acid (H ₂ SO ₄ concentration: 64% by weight) used at this time. The redox potential (Ag / AgCl electrode standard) of the leachate in the reaction vessel was maintained in the range of 350 to 450 mV.

(Example 3)
Except that the pH of the leachate was adjusted to 3.5, it was performed in the same manner as in Example 1, and then the copper was analyzed to determine the transition of the Cu leaching rate. Table 3 shows the results of leaching days 21 and 42. Table 3 shows the amount of dilute sulfuric acid (H ₂ SO ₄ concentration: 64% by weight) used at this time. The redox potential (Ag / AgCl electrode standard) of the leachate in the reaction vessel was maintained in the range of 350 to 450 mV.

(Comparative Example 1)
Except having adjusted the pH of the leaching solution to 2.0, it carried out similarly to Example 1, and analyzed copper and calculated | required transition of Cu leaching rate after that. Table 3 shows the results of leaching days 21 and 42. Table 3 shows the amount of dilute sulfuric acid (H ₂ SO ₄ concentration: 64% by weight) used at this time. The redox potential (Ag / AgCl electrode standard) of the leachate in the reaction vessel was maintained in the range of 350 to 450 mV.

(Comparative Example 2)
Except that the pH of the leachate was adjusted to 1.5, it was carried out in the same manner as in Example 1, and then the copper was analyzed to determine the transition of the Cu leach rate. Table 3 shows the results of leaching days 21 and 42. Table 3 shows the amount of dilute sulfuric acid (H ₂ SO ₄ concentration: 64% by weight) used at this time. The redox potential (Ag / AgCl electrode standard) of the leachate in the reaction vessel was maintained in the range of 350 to 450 mV.

(Comparative Example 3)
Except that the activated carbon was not added and the pH of the leaching solution was adjusted to 2.0, it was performed in the same manner as in Example 1, and then the copper was analyzed to determine the transition of the Cu leaching rate. Table 3 shows the results of leaching days 21 and 42. Table 3 shows the amount of dilute sulfuric acid (H ₂ SO ₄ concentration: 64% by weight) used at this time.

  From Table 3, in Examples 1-3, after mixing fixed carbon containing material as a leaching promoter, the obtained mixture was immersed in the iron sulfate aqueous solution adjusted to predetermined iron concentration and pH, and the method of this invention Thus, it can be seen that the leaching rate of copper can be increased and leaching can be performed at a high leaching rate, and the amount of sulfuric acid used can be reduced. On the other hand, in Comparative Examples 1 to 3, either the pH of the leaching solution or the addition of the fixed carbon-containing material does not meet these conditions, so it should be satisfied in either the leaching rate of copper or the amount of sulfuric acid used. It turns out that a result is not obtained.

  As is clear from the above, the leaching method of copper sulfide ore containing chalcopyrite of the present invention is suitable as a leaching method of copper mineral used in the copper refining field. In particular, it is useful as a method of leaching copper with a low amount of sulfuric acid and a high leaching rate in a hydrometallurgical process for recovering copper from a hardly leachable copper ore whose main mineral is chalcopyrite.

It is a conceptual diagram showing the relationship between the elution rate of chalcopyrite and electric potential. It is a conceptual diagram showing the relationship between the dissolution rate of chalcopyrite and electric potential in the presence of fixed carbon-containing materials. It is a schematic process drawing of the hydrometallurgical process which collects electrolytic copper from copper sulfide ore containing chalcopyrite using the leaching method of the present invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Leaching process 2 Solvent extraction process 3 Copper electrolysis process 4 Leaching liquid adjustment process 5 Copper sulfide ore 6 Fixed carbon containing material 7 Mixture 8 Iron sulfate aqueous solution 9 Leaching residue 10 Leaching product liquid 11 Back-extraction product liquid 12 Extraction residual liquid 13 Sulfuric acid 14 Ferrous or ferric sulfate 15 Electrolytic copper

Claims (3)

A method of leaching copper from a copper sulfide ore containing chalcopyrite,
After mixing a fixed carbon-containing material in an amount of 0.1 to 2.0 times the total weight of the copper mineral in the copper sulfide ore with the copper sulfide ore, the resulting mixture was adjusted to an iron concentration of 1 to 20 g / A method of leaching copper sulfide ore characterized by immersing in an aqueous iron sulfate solution having L and pH adjusted to 2.6 to 3.5.   The copper sulfide ore leaching method according to claim 1, wherein the fixed carbon-containing material is activated carbon.   The copper sulfide ore leaching method according to claim 1 or 2, wherein an oxidation-reduction potential (Ag / AgCl electrode standard) of the iron sulfate aqueous solution is adjusted to 350 to 450 mV.

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