Method for selectively recovering arsenic-containing copper mineral

Abstract

Provided is a method for selectively recovering an arsenic-containing copper mineral from a slurry of a mixture containing the arsenic-containing copper mineral and an arsenic-free copper mineral in order to reduce arsenic, which is a harmful substance in copper concentrate.　This method for selectively recovering an arsenic-containing copper mineral from a slurry of a mixture containing the arsenic-containing copper mineral and an arsenic-free copper mineral comprises a flotation step for adding, to the slurry, a flotation agent containing, as a collector, a sulfide compound having an R1-S-R2 structure (in the formula, R1 is an alkyl group having 5-10 carbon atoms and R2 is an alkyl group having 1-10 carbon atoms), and selectively floating and concentrating the arsenic-containing copper mineral, and further comprises a conditioning agent adding step for adding a conditioning agent to the slurry.

Description

Method for selectively recovering arsenic-containing copper minerals

[0001] The present invention relates to a method for selectively recovering arsenic-containing copper minerals from a slurry of a mixture containing arsenic-containing copper minerals and arsenic-free copper minerals.

[0002] In Japan, copper concentrate is imported from foreign countries (for example, South American countries such as Chile and Peru) that are known as mining countries, and is smelted domestically to produce copper bullion. Copper ore mined overseas generally contains copper minerals that contain arsenic (for example, enargite and tetrahedrite) and copper minerals that do not contain arsenic (for example, chalcopyrite, bornite, covellite, and chalcocite), but in recent years the arsenic content in copper concentrate has tended to increase.

[0003] The arsenic contained in copper concentrate is distributed to slag, dust, etc. during the smelting process, and although these are fixed in a stable form and processed at the smelter, there are concerns about increased processing costs due to the increased content and problems with storage space inside and outside the smelter. Therefore, there is a need for a technology that can selectively recover arsenic-containing copper minerals in the process preceding the copper smelting process. Flotation is known as one such ore-benefiting method.

[0004] Non-Patent Document 1 discloses the results of a study investigating flotation pretreatment parameters for efficiently separating enargite and chalcopyrite from a mixed ore of mineral specimens. Specifically, Non-Patent Document 1 describes that the effects of varying the slurry pH, flotation time, and the amount of PAX (potassium amyl xanthate) added as a collector on the recovery rate and separation efficiency of each mineral were investigated.

[0005] Materials Transactions, Vol. 53, No. 4 (2012) pp. 707-715

[0006] However, according to the investigations of the present inventors, the flotation separation method described in Non-Patent Document 1 focuses only on the separation of enargite and chalcopyrite, and it has been found that there is room for further improvement from the viewpoint of selective recovery.

[0007] The present invention aims to provide a method for selectively recovering arsenic-containing copper minerals from a slurry of a mixture containing arsenic-containing copper minerals and arsenic-free copper minerals in order to reduce the amount of arsenic, a harmful substance, in copper concentrate. In particular, the present invention aims to provide a method for selectively recovering arsenic-containing copper minerals with high separation efficiency from a post-bulk flotation arsenic-rich copper concentrate slurry containing arsenic-containing copper minerals and arsenic-free copper minerals.

[0008] The present inventors have conducted extensive experiments and intensive studies to solve the above problems, and as a result have completed the present invention.

[0009] That is, the gist of the present invention is as follows. [1] A method for selectively recovering an arsenic-containing copper mineral from a slurry of a mixture containing an arsenic-containing copper mineral and an arsenic-free copper mineral, the method comprising: a flotation step of adding a flotation agent containing a collector represented by the following formula (1) to the slurry, thereby selectively floating and beneficiating the arsenic-containing copper mineral; and a modifier addition step of adding a modifier to the slurry. [2] The recovery method according to [1], wherein the modifier addition step includes a step of adding the modifier and mixing for 0.5 to 10 minutes. [3] The recovery method according to [2], wherein the modifier is H2O2. [4] The recovery method according to [1], wherein R1 of the collector is a linear alkyl group. [5] The recovery method according to [1], wherein R2 of the collector is a linear alkyl group. [6] The recovery method according to [1], comprising a pH adjustment step of adjusting the pH of the slurry. [7] The recovery method according to [1], comprising an activator addition step of adding a copper-containing activator. [8] The recovery method according to [7], wherein the activator is CuSO4. [9] The recovery method according to [1], wherein the arsenic-containing copper mineral comprises enargite, arsenictetrahedrite, or a combination thereof.

[10] The recovery method according to [1], wherein the arsenic-free copper mineral comprises chalcopyrite, bornite, covellite, or chalcocite, or a combination thereof.

[11] The recovery method according to [1], wherein the arsenic-containing copper mineral and the arsenic-free copper mineral contained in the mixture are bulk concentrates obtained by bulk flotation of raw ore.

[0010] The present invention provides a method for selectively recovering an arsenic-containing copper mineral from a slurry of a mixture containing an arsenic-containing copper mineral and an arsenic-free copper mineral, thereby reducing the arsenic content in a copper concentrate to be subjected to a copper smelting process.

[0011] Fig. 1 is a flow diagram showing an example of the steps of the recovery method of the present embodiment. Fig. 2 is a diagram plotting separation efficiency against flotation time (minutes) for Example 1 and Comparative Example 1. Fig. 3 is a diagram plotting separation efficiency against flotation time (minutes) for Example 2 and Comparative Example 2. Fig. 4 is a diagram plotting separation efficiency against flotation time (minutes) for Examples 3-1 to 3-3. Fig. 5 is a diagram plotting separation efficiency against flotation time (minutes) for Examples 4-1 and 4-2.

[0012] An example of a preferred embodiment of the present invention will be described below. However, the following embodiment is an example for explaining the present invention, and the present invention is not limited to the following embodiment.

[0013] The recovery method of this embodiment is a method for selectively recovering an arsenic-containing copper mineral from a slurry of a mixture containing an arsenic-containing copper mineral and an arsenic-free copper mineral. An example of the steps of the recovery method of this embodiment is shown in a flow diagram in Figure 1. As shown in Figure 1, the recovery method of this embodiment includes a step of adding a modifier to the slurry (modifier adding step: S1), a step of adjusting the pH of the slurry (pH adjusting step: S2), a step of adding a flotation agent containing a collector to the slurry (addition step: S3), and a step of selectively floating and beneficiating the arsenic-containing copper mineral (flotation step: S4).

[0014] Arsenic-containing copper minerals are copper minerals that contain arsenic. More specifically, they refer to copper minerals that contain arsenic (As) as a chemical composition, such as enargite (Cu3AsS4), tennantite (Cu6[Cu4(Fe,Zn)2]As4S13), giradite (Cu6[Cu4(Fe,Zn)2]As4Se13), goldfieldite (Cu6Cu4Te2(Sb,As)4S13), and argentotenantite (Ag6[Cu4(Fe,Zn)2]As4S13).

[0015] Arsenic-free copper minerals are copper minerals that do not contain arsenic. More specifically, they are copper minerals that do not contain arsenic element in their chemical composition. Examples of such copper minerals include chalcopyrite (CuFeS2), bornite (Cu5FeS4), covellite (CuS), and chalcocite (Cu2S).

[0016] The arsenic-containing copper mineral may contain single-edged particles with the arsenic-free copper mineral. The arsenic-free copper mineral may also contain a trace amount (e.g., 0.1 wt % or less) of single-edged particles with the arsenic-containing copper mineral. The arsenic-free copper mineral may also contain a trace amount (e.g., 0.1 wt % or less) of arsenic as an impurity.

[0017] The slurry of a mixture containing an arsenic-containing copper mineral and an arsenic-free copper mineral may be a mixture of an arsenic-containing copper mineral and an arsenic-free copper mineral. For example, it may be a mixture of fine particles of an arsenic-containing copper mineral and fine particles of an arsenic-free copper mineral that have been pulverized and atomized. It may also be a copper concentrate containing an arsenic-containing copper mineral and an arsenic-free copper mineral, or a copper ore containing an arsenic-containing copper mineral and an arsenic-free copper mineral.

[0018] The mixing ratio of the arsenic-containing copper mineral and the arsenic-free copper mineral in the slurry of the mixture of the arsenic-containing copper mineral and the arsenic-free copper mineral is not particularly limited as long as the arsenic-containing copper mineral can be selectively recovered. For example, the arsenic-containing copper mineral and the arsenic-free copper mineral may be mixed in the same ratio, or the arsenic-containing copper mineral may be mixed in a larger amount than the arsenic-free copper mineral, or vice versa.

[0019] In this embodiment, the term "slurry" refers to a fluid in which mineral particles (arsenic-containing copper mineral particles and arsenic-free copper mineral particles) are suspended in an aqueous solution. The water contained in the slurry of the mixture containing the arsenic-containing copper mineral and the arsenic-free copper mineral is not particularly limited and may be, for example, distilled water, tap water, natural water, industrial water, or process water (water recycled from water used in the flotation process). It may also be water (RO water) obtained by filtering tap water or natural water through an ultrafine reverse osmosis membrane filter known as an RO membrane. The water content of the slurry of the mixture containing the arsenic-containing copper mineral and the arsenic-free copper mineral is not particularly limited as long as a slurry is formed, and may be, for example, 500 mL to 30,000 mL per 310 g of the mixture containing the arsenic-containing copper mineral and the arsenic-free copper mineral.

[0020] In the recovery method of this embodiment, a modifier is added to the slurry in a modifier addition step S1 (modifier addition step). Note that the timing of adding the modifier is not particularly limited to this step, and for example, the modifier may be added to a slurry to which a flotation agent has also been added.

[0021] Examples of the modifier used in the modifier addition step include hydrogen peroxide, sodium percarbonate, sodium peroxide, and sodium hypochlorite. Among these, hydrogen peroxide and sodium percarbonate are preferred, with hydrogen peroxide being particularly preferred, from the standpoints of separation efficiency and the arsenic (As) content in the sink. When hydrogen peroxide is used as the modifier, the amount of hydrogen peroxide added is preferably 1 to 20 kg / t or more based on the weight of the high-arsenic copper concentrate, from the standpoints of separation efficiency and flotation time. By using hydrogen peroxide in combination with a collector such as di-n-octyl sulfide (hereinafter sometimes referred to as "DOS"), the recovery rate of arsenic-containing copper mineral can be selectively increased and separation efficiency can also be improved, as shown in the examples described below. Furthermore, for example, in the treatment of a high-arsenic copper concentrate slurry that has xanthate salts and the like remaining after bulk flotation, arsenic-containing copper minerals and arsenic-free copper minerals can be separated extremely efficiently by using hydrogen peroxide and a collector such as DOS in combination in each step of the recovery method.

[0022] In the modifier addition step, it is preferable to add the modifier to the slurry and mix by stirring for a predetermined time. The mixing method is not particularly limited, but mechanical stirring using an impeller or the like can be used. The timing of mixing is not particularly limited in this step, and for example, the modifier may be added to the slurry to which the flotation agent has also been added, and then mixed for a predetermined time.

[0023] From the viewpoint of separation efficiency, the time required for the modifier addition step is preferably 10 minutes or less, more preferably 5 minutes or less, and even more preferably 1 minute or less.

[0024] In the recovery method of this embodiment, an activator addition step (not shown in FIG. 1 ) may be performed before the modifier addition step S1, in which a Cu-containing compound is added to the slurry. The timing of adding the activator is not particularly limited to this step. For example, the activator may be added to the slurry to which the modifier has been added, or to the slurry to which both the flotation agent and the modifier have been added. Examples of Cu-containing compounds used in the activator addition step include copper sulfate, copper chloride, and copper nitrate. Among these, copper chloride and copper sulfate are preferred, with copper sulfate being particularly preferred, in terms of the separation efficiency and the shortening of the flotation time. When copper sulfate is used as the activator, the amount of copper sulfate is preferably 1 to 1,000 g / t based on the weight of the mixture containing the arsenic-containing copper mineral and the arsenic-free copper mineral, from the viewpoints of separation efficiency and flotation time. As the amount of Cu added increases, the recovery rate of the arsenic-containing copper mineral can be selectively increased, and separation efficiency can also be improved, as shown in the examples described below.

[0025] In the activator addition step, it is preferable to add an activator containing Cu to the formed slurry and mix them for a predetermined time. The mixing method is not particularly limited, but mechanical stirring using an impeller or the like can be used.

[0026] The time required for mixing in the activator addition step is preferably 1 minute or more, more preferably 2 minutes or more, and even more preferably 5 minutes or more, from the viewpoint of separation efficiency.

[0027] In the recovery method of this embodiment, the pH of the slurry obtained in the modifier addition step S1 is adjusted (pH adjustment step S2). Note that the timing of adjusting the pH is not particularly limited to this step, and for example, the pH of the slurry may be adjusted before the modifier is added, or the pH of the slurry to which the flotation agent has also been added may be adjusted.

[0028] In the pH adjustment step S2, the pH of the slurry adjusted is preferably equal to or higher than 7. In this embodiment, the arsenic-containing copper mineral tends to easily float in a slurry in the neutral to alkaline range.

[0029] The temperature of the slurry is not particularly limited as long as it is a temperature at which the arsenic-containing copper mineral can be floated, and may be, for example, a normal temperature of 20 to 25°C.

[0030] In the recovery method of this embodiment, a flotation agent containing a collector is added to the slurry adjusted in the pH adjustment step S2 (addition step S3). The timing of adding the flotation agent is not particularly limited to this step, and for example, the flotation agent may be added to the slurry before the modifier is added, or may be added to the slurry before the pH is adjusted.

[0031] The flotation agent used in the addition step S3 is not particularly limited as long as it contains a collector of the following formula (1): R1-S-R2 (1) (In the above formula (1), R1 is an alkyl group having 5 to 10 carbon atoms, and R2 is an alkyl group having 1 to 10 carbon atoms).

[0032] R1 of the collector may be a linear alkyl group. When R1 is a linear alkyl group, hydrophobicity is improved, and the arsenic-containing copper mineral tends to be more easily floated. R1 may be a linear alkyl group having 7 to 9 carbon atoms.

[0033] R1 and R2 of the collector may be alkyl groups having the same structure. When R1 and R2 are alkyl groups having the same structure, the efficiency of separating arsenic-containing copper minerals from arsenic-free copper minerals, such as di-n-octyl sulfide (DOS), tends to improve.

[0034] R2 of the collector may be a linear alkyl group. When R2 is a linear alkyl group, the efficiency of separation between arsenic-containing copper minerals and arsenic-free copper minerals tends to improve, for example, as in methyl n-octyl sulfide or the aforementioned DOS.

[0035] Examples of the collector of formula (1) include methyl n-octyl sulfide, di-n-octyl sulfide (DOS), methyl n-amyl sulfide, di-n-amyl sulfide, di-n-hexyl sulfide, methyl n-heptyl sulfide, di-n-heptyl sulfide, di-n-nonyl sulfide, di-n-decyl sulfide, methyl n-decyl sulfide, etc. Among these, from the viewpoints of separation efficiency and the arsenic (As) content in the sinking ore, methyl n-octyl sulfide and di-n-octyl sulfide are preferred, with methyl n-octyl sulfide being particularly preferred.

[0036] The amount of collector added may be 5 g to 500 g, 20 g to 300 g, or 50 g to 150 g per ton of the mixture containing the arsenic-containing copper mineral and the arsenic-free copper mineral. If the amount of collector added is less than 5 g per ton of the mixture containing the arsenic-containing copper mineral and the arsenic-free copper mineral, the recovery rate of the arsenic-containing copper mineral tends to decrease, and if the amount is more than 200 g, the recovery rate does not improve significantly and instead selectivity tends to decrease.

[0037] The flotation agent may contain, in addition to the collector, a suppressor, a foaming agent, etc. Alternatively, the flotation agent may be the collector itself without containing any other substance than the collector.

[0038] As described above, the flotation reagent of this embodiment is used in a method for selectively recovering an arsenic-containing copper mineral from a slurry of a mixture containing an arsenic-containing copper mineral and an arsenic-free copper mineral, and contains a collector represented by the following formula (1): R1-S-R2 ... (1) (In the above formula (1), R1 is an alkyl group having 5 to 10 carbon atoms, and R2 is an alkyl group having 1 to 10 carbon atoms).

[0039] In the recovery method of the present embodiment, the arsenic-containing copper mineral is selectively floated and beneficiated from the slurry to which the flotation agent containing the collector has been added in the adding step S3 (flotation step S4).

[0040] In this embodiment, selectively recovering the arsenic-containing copper mineral means ore-benefiting by floating the arsenic-containing copper mineral to the surface of the slurry in a flotation step, including selectively separating the arsenic-containing copper mineral from the arsenic-free copper mineral, and the floating float (froth) contains the arsenic-containing copper mineral. Here, the floating float may contain not only the arsenic-containing copper mineral but also the arsenic-free copper mineral, other minerals, impurities, and the like. In this embodiment, selectively recovering the arsenic-containing copper mineral also means efficiently removing the arsenic-containing copper mineral from a mixture of the arsenic-containing copper mineral and the arsenic-free copper mineral, and copper can be obtained by removing arsenic from the selectively recovered arsenic-containing copper mineral in a subsequent smelting step.

[0041] In the recovery method of this embodiment in which the arsenic-containing copper mineral is floated and beneficiated, the arsenic-free copper mineral can also be recovered by allowing it to settle to the bottom of the slurry. That is, by a so-called reverse flotation process, a concentrate containing arsenic-free copper mineral and having a low arsenic content can be efficiently obtained from a mixture of arsenic-containing copper mineral and arsenic-free copper mineral.

[0042] Flotation is a separation method that utilizes the phenomenon in which air is blown into a slurry of mineral particles suspended in water, causing hydrophobic particles among the mineral particles to adhere to the air bubbles and float up, while hydrophilic particles among the mineral particles cannot adhere to the air bubbles and remain in the slurry. The collector comprises a moiety that selectively adsorbs to the target mineral particles and a hydrophobic group that easily adheres to the air bubbles. In this embodiment, reverse flotation is a method of increasing the concentration of desired mineral particles in the slurry by attaching air bubbles to unwanted mineral particles and floating them up for separation. The collector of this embodiment has hydrophobic groups and does not adsorb to arsenic-free copper minerals, but has a moiety that selectively adsorbs to arsenic-containing copper minerals. As a result, only arsenic-containing copper minerals (particles) adhere to the air bubbles and selectively float to the top of the slurry, resulting in a froth that becomes a high-arsenic copper concentrate with concentrated arsenic. Furthermore, efficient separation is possible by performing a reverse flotation process that increases the concentration of arsenic-free copper minerals (particles) in the slurry. As a result, the arsenic-free copper minerals are concentrated in the sink (tailings), and the sink becomes a low-arsenic copper concentrate with reduced arsenic. That is, the recovery method of this embodiment can also be described as a method for selectively recovering arsenic-containing copper minerals from a slurry of a mixture containing arsenic-containing copper minerals and arsenic-free copper minerals, and includes a reverse flotation step in which a flotation agent containing a collector is added to the slurry to selectively float and beneficiate the arsenic-containing copper minerals, and the arsenic-free copper minerals are concentrated in the slurry.

[0043] In this embodiment, the recovery rate and separation efficiency can be determined as follows: Note that some of the formulas have been described using the case where the arsenic-containing copper mineral is enargite as an example.

[0044]

[0045]

[0046]

[0047] In this embodiment, the recovery rate and separation efficiency of the arsenic-containing copper mineral are preferably high. In addition, a high recovery rate of the arsenic-containing copper mineral is also preferable in that the arsenic-free copper mineral (particles) in the slurry is concentrated, and the resulting ore becomes a low-arsenic copper concentrate with a reduced arsenic content.

[0048] The copper-bearing mineral targeted by this embodiment is not limited to arsenic-rich copper concentrate slurry, but may also be copper concentrate slurry, copper flotation tailings slurry, repulped copper concentrate, repulped arsenic-rich copper concentrate, a slurry containing an arsenic-containing copper mineral and an arsenic-containing copper mineral, or a copper ore slurry after reaction with a collector. The recovery method of this embodiment for copper ore after reaction with a collector involves first recovering a copper concentrate containing a large amount of impurities using a conventional flotation method, and then separating the arsenic-containing copper mineral from the arsenic-free copper ore according to the steps of the recovery method of this embodiment, thereby recovering a high-arsenic-grade copper concentrate and a low-arsenic-grade copper concentrate. In this case, there is no particular limitation on the copper grade of the impurity-rich copper concentrate used as an intermediate raw material.

[0049] When flotation (flotation separation) is performed, the ore can be separated more effectively if the arsenic-containing copper mineral and the arsenic-free copper mineral exist as single particles, so it is desirable to perform pretreatment such as crushing so that most of the arsenic-containing copper mineral and the arsenic-free copper mineral are separated into single particles. The average particle size of the mixture of the finely powdered arsenic-containing copper mineral and the arsenic-free copper mineral is preferably 10 μm or more, as this tends to make the mineral particles more likely to be adsorbed by air bubbles.

[0050] As described above, according to the recovery method of this embodiment, an arsenic-containing copper mineral can be efficiently and selectively recovered from a slurry of a mixture containing an arsenic-containing copper mineral and an arsenic-free copper mineral. Furthermore, the present invention can provide a method for selectively recovering an arsenic-containing copper mineral with high separation efficiency from a flotation-fed high-arsenic copper concentrate containing an arsenic-containing copper mineral and an arsenic-free copper mineral. As a result, the arsenic in the copper concentrate to be supplied to the copper smelting process can be efficiently reduced.

[0051] The effects of the present invention will be described in more detail below with reference to examples. However, the present invention is not limited to these examples. [Example 1] A high-arsenic copper concentrate slurry obtained at a mineral processing plant was used as a sample. The elemental quality of the sample was determined using the following analytical flow. First, the slurry was filtered and dried at 105°C for 24 hours. The dried sample was weighed, then microwave-heated and dissolved in acid, and the solution was diluted to a constant volume to obtain an analytical sample solution. Each analytical sample solution was subjected to ICP analysis using an ICP-OES 5110 manufactured by Agilent Technologies, and quantitatively analyzed to determine the elemental concentration in the solution. Specifically, the solution volume after dilution was multiplied by the solution concentration of each component element analyzed by ICP, and the result was divided by the weight of the acid-dissolved sample to obtain the elemental quality (wt%). The results are shown below. As 2.17 wt% Cu 19.21 wt% Fe 26.13 wt% Next, the mineral composition (mineral content) of the sample was determined using the following flow. First, the sample was embedded in resin, and the surface was polished to prepare an analytical sample. Each of these analytical samples was subjected to quality analysis using an MLA (Quanta 650) manufactured by FEI. MLA stands for Mineral Liberation Analyzer, and is an automatic mineral analysis device in which mineral analysis software is incorporated into an SEM-EDS. Using the MLA, the mineral content (Modal Mineralology) was measured as a quantitative analysis, and the composition ratio of the mineral composition was determined. The chemical formulas of each composition are arsenopyrite (CuAsS), arsenotetrahedrite ((Cu, Fe, Zn)AsS), chalcopyrite (CuFeS), bornite (CuFeS), chalcocite (CuS), and pyrite (FeS). The results are shown below. arsenopyrite 9.02 wt% arsenopyrite 9.91 wt% chalcopyrite 9.09 wt% bornite 2.59 wt% chalcocite 8.32 wt% pyrite 50.46 wt% A separation evaluation test was carried out using an Agitair flotation tester according to the following procedure. First, 1 L of a slurry containing 310 g of high-arsenic copper concentrate was added to a 1 L cell for the Agitair flotation tester.Next, hydrogen peroxide HO was added at a rate of 1 kg / t, followed by the addition of 0.05 M HSO to set the pH to 7, and the pH was adjusted over 1 minute. Next, di-n-octyl sulfide (DOS) was added as a collector (flotation agent) at a rate of 127.7 g / t (0.49 mol / t), and the mixture was mixed in the cell for 30 seconds. Mixing was then continued, and air was blown in at a flow rate of 2 liters / minute (LPM), and separation by flotation was performed for 8 minutes. The dried weight and grade of the float and sink ores obtained in the flotation process for each flotation time interval (1, 2, 4, and 8 minutes) were determined according to the procedure described in [Example 1] in the detailed description of the invention above, and the recovery rate and separation efficiency were determined according to the procedures described in [Equation 1] to [Equation 4]. The recovery rates and separation efficiencies of arsenic-containing copper minerals and arsenic-free copper minerals are shown in Table 1, and the separation efficiencies are shown in Figure 2.

[0052] Comparative Example 1 In Comparative Example 1, a separation evaluation test was carried out in the same manner as in Example 1, except that hydrogen peroxide H2O2 was not added. The results are shown in Table 1 and FIG.

[0053]

[0054] (Results and Discussion) As shown in Table 1, by adding 1 kg / t of H2O2 (Example 1), the recovery rate of arsenic-containing copper minerals in the float ore was improved compared to when H2O2 was not added (Comparative Example 1), and the separation efficiency was also improved as shown in Figure 2. Thus, by using the collectors DOS and H2O2 in combination in each process, the separation efficiency was significantly improved. This is thought to be because the addition of H2O2 modified the surface condition of the raw copper concentrate so that the specific collector DOS could function and act efficiently.

[0055] [Example 2] In Example 2, a separation evaluation test was carried out in the same manner as in Example 1, except that the flow rate of air blown during flotation was set to 4 liters per minute (LPM). The results are shown in Table 2 and Figure 3.

[0056] In Comparative Example 2, a separation evaluation test was carried out in the same manner as in Example 2, except that sodium isopropyl xanthate (SIPX) was used as the collector serving as the flotation agent in an amount of 78.2 g / t (0.49 mol / t). The results are shown in Table 2 and FIG.

[0057]

[0058] (Results and Discussion) As shown in Table 2, even when 1 kg / t of H2O2 was added, when SIPX (xanthate salt) was used instead of DOS as the collector (Comparative Example 2), the separation efficiency was negative and the absolute value was close to zero, so almost no separation was achieved. In contrast, by using H2O2 and the collector DOS in combination (Example 2), rather than the combination of H2O2 and the collector SIPX (Comparative Example 2), the recovery rate of arsenic-containing copper minerals in the float ore could be maintained higher than the recovery rate of arsenic-free copper minerals, and a high fraction efficiency was obtained, as shown in Figure 3. As such, it was found that the effect of adding H2O2 in combination varies greatly depending on the type of collector used. This is thought to be because the addition of H2O2 modified the surface condition of the raw copper concentrate, allowing the specific collector DOS to function and act efficiently.

[0059] [Example 3] In Example 3, the separation evaluation test was conducted in the same manner as in Example 2, except that the amount of H2O2 added was 20 kg / t, copper sulfate (CuSO4) was added and mixed for 5 minutes before adding H2O2, and after adding the collector and mixing for 30 seconds, 10 g / t of foaming agent was added and mixed for an additional 30 seconds. An experiment without adding copper sulfate (copper sulfate addition amount: 0) was also conducted. The experiments with copper sulfate addition amounts of 0 g / t, 100 g / t, and 200 g / t are referred to as Examples 3-1, 3-2, and 3-3, respectively. The results are shown in Table 3 and Figure 4.

[0060]

[0061] (Results and Discussion) As shown in Table 3, increasing the amount of copper sulfate added improved the recovery rate of arsenic-containing copper minerals in the float. Also, as shown in Figure 4, separation was performed more efficiently in a shorter time, improving separation efficiency. Thus, when the collectors DOS and H2O2 were used in combination in each process, adding CuSO4, a copper-containing activator, enabled flotation treatment to be performed more efficiently in a shorter time, improving separation efficiency. This is thought to be because the addition of the CuSO4 addition process and the H2O2 addition process modified the surface condition of the raw copper concentrate so that the specific collector DOS could function and act efficiently.

[0062] [Example 4] In Example 4, a separation evaluation test was conducted in the same manner as in Example 3-1, except that the amount of CuSO4 added was 300 g / t and the time for adding hydrogen peroxide H2O2 and mixing treatment was shortened or extended. Experiments conducted with H2O2 treatment times of 1 minute and 60 minutes are referred to as Examples 4-1 and 4-2, respectively. The results are shown in Table 4 and Figure 5.

[0063]

[0064] (Results and Discussion) As shown in Table 4, when H2O2 treatment times of 1 minute (Example 4-1) and 60 minutes (Example 4-2) were compared, it was found that the recovery rate of arsenic-containing copper minerals in the float was higher with a treatment time of 60 minutes, but the separation efficiency was higher with a treatment time of 1 minute. Thus, it is believed that by optimizing the treatment time with the addition of H2O2, it is possible to modify the surface condition of the raw copper concentrate so that DOS, a specific collector, can function and act efficiently.

[0065] INDUSTRIAL APPLICABILITY The present invention provides a method for selectively recovering an arsenic-containing copper mineral from a slurry of a mixture containing an arsenic-containing copper mineral and an arsenic-free copper mineral, and as a result, the arsenic content in the copper concentrate to be subjected to a copper smelting process can be reduced, and therefore has industrial applicability.

Claims

1. A method for selectively recovering an arsenic-containing copper mineral from a slurry of a mixture containing an arsenic-containing copper mineral and an arsenic-free copper mineral, the method comprising: a flotation step of adding a flotation agent containing a collector represented by the following formula (1) to the slurry, where the arsenic-containing copper mineral is selectively floated and beneficiated; and a modifier addition step of adding a modifier to the slurry.

2. The recovery method of claim 1, wherein the step of adding the modifier comprises adding the modifier and mixing for 0.5 to 10 minutes.

3. The recovery method of claim 2, wherein the modifier is H2O2.

4. The recovery method according to claim 1, wherein R1 of the collector is a straight-chain alkyl group.

5. The recovery method according to claim 1, wherein R2 of the collector is a straight-chain alkyl group.

6. The recovery method according to claim 1, further comprising a pH adjustment step of adjusting the pH of the slurry.

7. The recovery method according to claim 1, further comprising an activator addition step of adding an activator containing copper.

8. The recovery method of claim 7, wherein the activator is CuSO4.

9. The method of claim 1, wherein the arsenic-containing copper mineral comprises enargite, arsenite, or a combination thereof.

10. The recovery method of claim 1, wherein the arsenic-free copper mineral comprises any one or combination of chalcopyrite, bornite, covellite, or chalcocite.

11. The recovery method according to claim 1, wherein the arsenic-containing copper mineral and the arsenic-free copper mineral contained in the mixture are bulk concentrates obtained by bulk flotation of raw ore.

Images