Peptides and their applications

Abstract

To provide a method for separating copper ore.SOLUTION: In one aspect, the present disclosure provides a peptide comprising the following amino acid sequence. (Thr, Ser)-(Thr, Ser)-(Leu, Ile, Val, Ala)-Pro-His-Tyr-(Arg, Lys)-(Leu, Ile, Val, Ala)-Gly-(Asp, Glu)-Gly {at least one of amino acids in () in the above formula is selected}.SELECTED DRAWING: None

Description

[Technical Field]

[0001] The present disclosure relates to peptides and their applications. More specifically, the present disclosure relates to novel peptides and their applications for the separation of specific minerals using the peptides. [Background technology]

[0002] Copper ores can be classified into copper oxide, secondary copper sulfide, and primary copper sulfide. Copper oxide is easily soluble in sulfuric acid. Examples of secondary copper sulfide include chalcocite and covellite. Secondary copper sulfide is easily soluble in sodium cyanide solution. Secondary copper sulfide is easily soluble in solutions containing iron(III) ions. Examples of primary copper sulfide include bornite, chalcopyrite, and enargite. Primary copper sulfide is known as a sparingly soluble mineral and is poorly soluble in the aforementioned sulfuric acid, sodium cyanide solution, and solutions containing iron(III) ions. Instead, primary copper sulfide is easily soluble in solutions containing nitric acid and perchloric acid. Primary copper sulfide is easily soluble in solutions containing iron(III) ions and iodide ions.

[0003] Patent Document 1 discloses a peptide that binds to chalcopyrite, and discloses the use of this peptide to separate enargite and chalcopyrite.

[0004] Patent Document 2 discloses a peptide that binds to arsenopyrite and the like, and discloses that the peptide can be used to efficiently separate minerals containing arsenic. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] Japanese Patent Application Laid-Open No. 2018-135279 [Patent Document 2] International Publication No. 2020 / 085219 Summary of the Invention [Problem to be solved by the invention]

[0006] As mentioned above, there are many types of copper ore. When copper ores are extracted from deposits, they are extracted as a mixture of various types of ores. Among sulfide ores, some contain arsenic (e.g., arsenopyrite). Chalcopyrite is often mined in a mixed state with arsenopyrite. However, because arsenopyrite contains arsenic, which is harmful to the environment, a technology is needed to separate chalcopyrite from arsenopyrite. On the other hand, chalcopyrite and arsenopyrite have similar flotation characteristics. For example, when subjected to flotation, both chalcopyrite and arsenopyrite tend to be distributed as float. Patent Document 1 discloses a peptide that specifically binds to chalcopyrite, but there is still room for improvement.

[0007] In view of the above, an object of the present disclosure is to provide a method for separating copper ore using a new peptide. [Means for solving the problem]

[0008] As a result of extensive research, the present inventors have discovered a new peptide that is different from the peptide described in Patent Document 1. More specifically, the new peptide has been found to have the property of specifically binding to chalcopyrite.

[0009] The invention was completed based on the above findings, and in one aspect, the present disclosure includes the following inventions. (Invention 1) A peptide comprising the following amino acid sequence: (Thr, Ser)-(Thr, Ser)-(Leu, Ile, Val, Ala)-Pro-His-Tyr-(Arg, Lys)-(Leu, Ile, Val, Ala)-Gly-(Asp, Glu)-Gly {wherein at least one of the amino acids in the ( ) of the above formula is selected} (Invention 2) A peptide comprising the following amino acid sequence, or a sequence resulting from the above sequence by inserting, deleting, substituting and / or adding 1 to 2 amino acids: Ser-Ser-Ala-Pro-His-Tyr-Arg-Val-Gly-Asp-Gly (SEQ ID NO: 1) (Invention 3) A peptide according to invention 2, comprising a sequence that is at least 90% identical to the amino acid sequence of SEQ ID NO:1. (Invention 4) A peptide according to invention 2, comprising a sequence obtained by substituting the amino acid sequence of SEQ ID NO: 1 according to one or two substitutions selected from the following: Ser⇒Thr Ala ⇒ Leu, Ile, or Val Arg⇒Lys · Val⇒Leu, Ile, Ala Asp⇒Glu (Invention 5) A peptide according to invention 2, comprising the amino acid sequence of SEQ ID NO: 1. (Invention 6) A peptide according to invention 5, which is represented by the amino acid sequence of SEQ ID NO: 1. (Invention 7) 7. The peptide according to any one of Inventions 1 to 6, wherein an alkyl group is added to the N-terminus and / or C-terminus. (Invention 8) 8. The peptide of invention 7, wherein an alkyl group is added to the N-terminus. (Invention 9) 9. The peptide of Invention 7 or 8, wherein the alkyl group has a carbon number of C6 to C18. (Invention 10) 10. The peptide of invention 9, wherein the alkyl group has a carbon number of C10 to C14. (Invention 11) 11. The peptide according to any one of Inventions 1 to 10, which is capable of binding to a mineral containing iron and copper. (Invention 12) 12. A composition for selecting minerals containing iron and copper, the composition comprising a peptide according to any one of inventions 1 to 11. (Invention 13) 12. Use of a peptide according to any one of claims 1 to 11 for sorting minerals containing iron and copper. (Invention 14) A nucleic acid encoding the peptide according to any one of inventions 1 to 11, or a nucleic acid having a sequence that is at least 90% identical to the sequence of the nucleic acid. (Invention 15) A nucleic acid that hybridizes under stringent conditions with a complementary sequence of a nucleic acid encoding the peptide according to any one of inventions 1 to 11. (Invention 16) A microorganism comprising the peptide according to any one of inventions 1 to 11 on its surface and / or the nucleic acid of invention 14 or 15. (Invention 17) 12. Precipitation particles having the peptide according to any one of inventions 1 to 11 on the surface thereof. (Invention 18) A chromatography column comprising the peptide according to any one of inventions 1 to 11. (Invention 19) 12. A flotation inhibitor comprising the peptide according to any one of inventions 1 to 11. (Invention 20) 18. A method for recovering minerals containing iron and copper using the settling particles of claim 17, said method comprising: adding the settling particles to a dispersion, the dispersion including an arsenic-containing mineral and an iron- and copper-containing mineral; precipitating the iron and copper bearing minerals; collecting the sediment; A step of subjecting the sediment to solid-liquid separation and recovering the solid portion; A method comprising: (Invention 21) 19. A method for recovering minerals containing iron and copper using a chromatographic column according to claim 18, said method comprising: passing a dispersion through the column, the dispersion comprising copper minerals containing arsenic and minerals containing iron and copper; A method comprising: (Invention 22) 19. A method for recovering iron and copper bearing minerals using the flotation inhibitor of claim 19, said method comprising: providing a mixture of an arsenic-containing mineral and an iron and copper-containing mineral; providing said flotation inhibitor; charging the mixture and the flotation inhibitor into a flotation tank; Recovering tailings from the flotation tank; A method comprising: (Invention 23) 23. The method of claim 22, further comprising the step of performing a desorption treatment prior to the step of feeding into the flotation tank. (Invention 24) 24. The method of claim 23, wherein the step of performing the desorption treatment comprises treating with an inorganic salt. (Invention 25) 25. The method of Invention 24, wherein the concentration of the inorganic salt in the desorption treatment is 3 to 5M. (Invention 26) 26. The method of invention 24 or 25, wherein the inorganic salt is NaCl. (Invention 27) 27. The method according to any one of Inventions 22 to 26, further comprising the step of introducing a collector. (Invention 28) 28. The method of Invention 27, wherein the concentration of the collector in the flotation tank is 30 to 60 g / t ore. (Invention 29) 29. The method of claim 27 or 28, wherein the collector is PAX (Potassium Amyl Xanthate). (Invention 30) 30. The method according to any one of Inventions 22 to 29, wherein the concentration of the peptide in the flotation tank is 5 to 500 g / t ore. (Invention 31) The method according to any one of Inventions 20 to 30, the arsenic-containing copper mineral includes arsenopyrite, The iron and copper containing mineral includes chalcopyrite, method. [Effects of the Invention]

[0010] In one aspect, the invention is a peptide comprising the amino acid sequence: (Thr, Ser)-(Thr, Ser)-(Leu, Ile, Val, Ala)-Pro-His-Tyr-(Arg, Lys)-(Leu, Ile, Val, Ala)-Gly-(Asp, Glu)-Gly Here, at least one of the amino acids in the parentheses of the above formula is selected.

[0011] In another aspect, the invention is a peptide comprising the following amino acid sequence: Ser-Ser-Ala-Pro-His-Tyr-Arg-Val-Gly-Asp-Gly (SEQ ID NO: 1)

[0012] In yet another aspect, the invention relates to a peptide comprising a sequence resulting from the amino acid sequence of SEQ ID NO:1 by insertion, deletion, substitution and / or addition of 1 to 2 amino acids.

[0013] These peptides allow for good separation of arsenic-containing copper minerals from iron- and copper-containing minerals. [Brief explanation of the drawings]

[0014] [Figure 1] This shows the results of separation efficiency of enargite and chalcopyrite in a test using a Hallimond tube. The horizontal axis represents time (minutes) and the vertical axis represents separation efficiency (%). [Figure 2] This shows the results of separation efficiency of enargite and chalcopyrite in a test using a Hallimond tube. The horizontal axis represents time (minutes) and the vertical axis represents separation efficiency (%). [Figure 3] This shows the results of separation efficiency of enargite and chalcopyrite in a test using a Hallimond tube. The horizontal axis represents time (minutes) and the vertical axis represents separation efficiency (%). [Figure 4] SEM-EDX analysis of minerals recovered from the froth and tailings in the Hallimond tube test is shown. [Figure 5] The amounts of elements recovered in the froth in column flotation tests were determined under three conditions: (1) without desorption treatment, 0 g / t ore of added peptide; (2) with desorption treatment, 0 g / t ore of added peptide; and (3) with desorption treatment, 5 g / t ore of added peptide. [Figure 6] The separation efficiency was calculated based on the amount of elements recovered in the froth and tailings in the column flotation test under three conditions: (1) without desorption treatment, 0 g / t ore of added peptide; (2) with desorption treatment, 0 g / t ore of added peptide; and (3) with desorption treatment, 5 g / t ore of added peptide. DETAILED DESCRIPTION OF THE INVENTION

[0015] Specific embodiments for carrying out the invention will be described below. The following description is intended to facilitate understanding of the invention and is not intended to limit the scope of the invention.

[0016] 1. Substances subject to application In one embodiment, the present disclosure relates to a peptide. In one embodiment, the peptide of the present disclosure can be applied to a method for separating a specific substance. The specific substance can be a copper-containing mineral (e.g., copper sulfide ore). More specifically, the specific substance can be an arsenic-free copper mineral. Arsenic-free copper minerals include minerals containing iron and copper, and specific examples include chalcopyrite. Preferably, the present disclosure can be applied to a method for separating an arsenic-free copper mineral from a mixture of an arsenic-containing copper mineral and an arsenic-free copper mineral.

[0017] The copper minerals containing arsenic include, but are not limited to, tetrahedrite, luzonite, and enargite. Tetrahedrite, luzonite, and enargite are often mined together with copper minerals that do not contain arsenic (e.g., chalcopyrite). Therefore, it is desirable to separate chalcopyrite from copper minerals that contain arsenic.

[0018] The minerals described in this specification are not particularly limited and may be crude ore or concentrate. Furthermore, the minerals described in this specification may be raw materials that have not been processed, or may be materials that have been processed, such as crushed.

[0019] 2. Peptides To separate the above-mentioned substances, the peptide of the present disclosure can be a peptide comprising at least the following sequence: Typically, a range of amino acids defined by two numbers selected from 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 15, and 20 (e.g., 1 to 10, 5 to 20) can be added to the N-terminus and / or C-terminus of the amino acid sequence below.

[0020] (1)(Thr, Ser)-(Thr, Ser)-(Leu, Ile, Val, Ala)-Pro-His-Tyr-(Arg, Lys)-(Leu, Ile, Val, Ala)-Gly-(Asp, Glu)-Gly {wherein at least one of the amino acids in the ( ) of the above formula is selected}

[0021] In the examples described below, an example is shown in which chalcopyrite was separated from arsenopyrite using a peptide having the following amino acid sequence: (2) Ser-Ser-Ala-Pro-His-Tyr-Arg-Val-Gly-Asp-Gly (SEQ ID NO: 1)

[0022] The amino acid sequence described in (1) above and the amino acid sequence described in (2) above are compared as follows. [Table 1]

[0023] As shown in Table 1, the first amino acid in sequence (2) is serine. Serine has a hydroxymethyl group as its amino acid side chain. Threonine has a hydroxyethyl group as its amino acid side chain. Therefore, serine and threonine have similar amino acid side chain structures. Therefore, it is highly likely that the same effect will be obtained even if serine and threonine are interchangeably converted. The same theory also applies to the second serine in sequence (2).

[0024] The third position in sequence (2) is alanine. Alanine has a hydrophobic side chain (more specifically, a methyl group). Therefore, it is thought that substituting it with leucine (with an isobutyl group as the side chain), isoleucine (with a sec-butyl group as the side chain), or valine (with an isopropyl group as the side chain), which have similar properties, would have the same effect. The same theory also applies to valine, the eighth position in sequence (2).

[0025] The seventh amino acid in sequence (2) is arginine. Arginine has a basic side chain. Therefore, as a basic amino acid, it is highly likely that the same effect will be obtained even if arginine is substituted with lysine.

[0026] The tenth amino acid in sequence (2) is aspartic acid. Aspartic acid has a methyl carboxyl group as its amino acid side chain. Glutamic acid has an ethyl carboxyl group as its amino acid side chain. Therefore, aspartic acid and glutamic acid have similar amino acid side chain structures. Therefore, it is highly likely that the same effect will be obtained by converting aspartic acid and glutamic acid to each other.

[0027] The present disclosure also relates, in one embodiment, to a peptide comprising the following amino acid sequence: (2) Ser-Ser-Ala-Pro-His-Tyr-Arg-Val-Gly-Asp-Gly (SEQ ID NO: 1) Any number of amino acids may be added to the N-terminus and / or C-terminus of amino acid sequence (2). Typically, amino acids within a range defined by two numbers selected from 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 15, and 20 (e.g., 1 to 10, 5 to 20) can be added to the N-terminus and / or C-terminus.

[0028] In one embodiment, the present disclosure also encompasses a peptide represented by the following amino acid sequence: (2) Ser-Ser-Ala-Pro-His-Tyr-Arg-Val-Gly-Asp-Gly (SEQ ID NO: 1)

[0029] The above-mentioned amino acid sequence (2) can exhibit the same function as amino acid sequence (2) even if it is subjected to minor modifications (e.g., insertion, substitution, addition, or deletion of amino acids). For example, a peptide that is 90% or more identical to amino acid sequence (2) or a peptide containing a sequence having such identity can also exhibit the same function.

[0030] The numerical value of sequence identity can be calculated by any method known in the art, for example, based on the numerical value determined by Blastp, which is used for amino acid (or protein) homology searches provided by BLAST (registered trademark).

[0031] Furthermore, in one embodiment, the present disclosure encompasses peptides comprising the following amino acid sequences in which one to two amino acids have been inserted, substituted, added, and / or deleted: (2) Ser-Ser-Ala-Pro-His-Tyr-Arg-Val-Gly-Asp-Gly (SEQ ID NO: 1)

[0032] When amino acids are substituted, examples include the following variations: Ser⇒Thr Ala ⇒ Leu, Ile, or Val Arg⇒Lys · Val⇒Leu, Ile, Ala Asp⇒Glu

[0033] The reason why the above-mentioned substitutions can also produce similar effects is due to the similarity in the properties or structures of the amino acid side chains, as described above.

[0034] In one embodiment, the peptide of the present disclosure may be chemically modified. For example, an alkyl group may be added to the N-terminus and / or C-terminus of the peptide. Modification with an alkyl group improves separation efficiency. Preferably, the alkyl group may be added to the N-terminus. The alkyl group may be linear or branched. The number of carbon atoms in the alkyl group is not particularly limited, but is C6 to C18, preferably C10 to C14. Such chemical modification further improves separation efficiency.

[0035] In one embodiment, the present disclosure also encompasses a composition containing the above-described peptide. That is, the above-described peptide can be used alone, or a composition containing other components can also exhibit the same function. The composition can contain any component (e.g., a buffer, sodium chloride, sugars, etc.) within a range that does not impair the function of the above-described peptide.

[0036] 3. Nucleic acid encoding a peptide In one embodiment, the present disclosure encompasses a nucleic acid encoding the above-described peptide. The nucleic acid may be DNA or RNA. In one embodiment, the present disclosure may also encompass a nucleic acid having a sequence complementary to the sense strand of the nucleic acid encoding the above-described peptide.

[0037] Furthermore, in one embodiment, the present disclosure encompasses a nucleic acid having a sequence that is at least 90% or more, or 95% or more identical to a nucleic acid sequence encoding the above-described peptide. Sequence identity can be calculated using known techniques, as with the amino acid sequence described above. For example, it may be based on the numerical value determined by a search using Blastn or the like of BLAST.

[0038] Furthermore, in one embodiment, the present disclosure encompasses nucleic acids capable of hybridizing with a sequence complementary to the sense strand of a nucleic acid encoding the above-described peptide. More specifically, the present disclosure encompasses nucleic acids capable of hybridizing under stringent conditions. Stringent conditions can be based on criteria known in the art. For example, the criteria described in Japanese Patent Application Laid-Open No. 2015-023831 may be used. Specifically, the term "stringent conditions" refers to conditions in which hybridization is performed at 65°C in the presence of 0.7 to 1.0 M sodium chloride using a filter on which DNA is immobilized, followed by washing the filter at 65°C using a 0.1 to 2x SSC (saline-sodium citrate) solution (1x SSC solution has a composition of 150 mM sodium chloride and 15 mM sodium citrate).

[0039] Any of the above-mentioned nucleic acids is useful for producing a peptide of interest through genetic engineering techniques. For example, any of the above-mentioned nucleic acids can be incorporated into an expression vector to express a large amount of the peptide of interest. Alternatively, phage carrying the peptide of interest on its surface can be produced using the phage display method described below.

[0040] 4. Products using peptides and / or nucleic acids The peptides and / or nucleic acids described above can be applied in a variety of ways.

[0041] 4-1. Microorganisms For example, a microorganism can be made to mass-produce a target peptide using genetic engineering techniques (e.g., by introducing the above-mentioned nucleic acid into a gene of the microorganism). Alternatively, a target peptide can be expressed on the surface of the microorganism, and the microorganism can be used to isolate a target substance. As used herein, "microorganisms" include organisms belonging to the kingdom Fungi, Monera, or Protista, as described in the five kingdom theory. Furthermore, although not strictly speaking a living organism, the term "microorganisms" as used herein also includes viruses. Typically, fungi, bacteria, and viruses are used. Particularly preferred are those for which genetic engineering techniques have been established (e.g., yeast, E. coli, lactic acid bacteria, bacteriophages, etc.). In one embodiment, the present disclosure encompasses such microorganisms.

[0042] 4-2. Sedimentation particles In one embodiment, the present disclosure relates to particles having a peptide on their surface. The peptides described above can be used. Examples of the particles include beads (e.g., magnetic beads, glass beads, resin beads, polymer beads, etc.), carriers, etc. The size of the particles is not particularly limited and may be nanoparticles (e.g., particle size 10 nm to 1000 nm), microparticles (e.g., particle size 1 μm to 1000 μm), or millimeter-sized particles (e.g., particle size 1 mm to 1000 mm), which can be adjusted appropriately depending on the application. Techniques known in the art can be used to bind peptides to the particle surface.

[0043] The peptides of the present disclosure can be supported on particles to separate a substance of interest, for example, by binding the substance of interest to the peptide and precipitating it using the method described below.

[0044] 4-3. Chromatography columns In one embodiment, the present disclosure relates to a chromatography column. Column chromatography is a method for separating a target substance. Column chromatography utilizes the property of a packing material (e.g., a carrier) in a column that selectively binds to a specific substance. In one embodiment of the present disclosure, the above-described peptide can be supported on the column. By using such a column, the target substance can be separated.

[0045] 4-4. Flotation inhibitors In one embodiment, the peptide of the present disclosure hydrophilizes the surface of a specific mineral, thereby preventing the specific mineral from floating during flotation. Therefore, the peptide of the present disclosure can be used as an inhibitor. In this case, the peptide may be used alone, in a form bound to a microorganism, or in a form bound to a specific compound. As described above, it is particularly preferable to alkylate the peptide. This improves the inhibitor's effectiveness and contributes to efficient separation.

[0046] 5. Application form (separation method) The method relating to the above-mentioned application mode will be specifically described below.

[0047] 5-1. Separation target All of the above-mentioned applications relate to separating a predetermined substance. For example, an example of a predetermined substance is a mineral containing iron and copper (e.g., chalcopyrite). More specifically, in a mixture of a copper mineral containing arsenic (e.g., arsenopyrite) and a mineral containing iron and copper but not arsenic (e.g., chalcopyrite), the peptide of the present disclosure can selectively bind to the mineral containing iron and copper (e.g., chalcopyrite).

[0048] 5-2. Isolation method using microorganisms In one embodiment, the present disclosure relates to the use of microorganisms. More specifically, the microorganisms can be used to separate substances (specifically, minerals containing iron and copper, more specifically, chalcopyrite). Any of the microorganisms described above can be used as the microorganisms. A typical example is a bacteriophage.

[0049] The method involves first introducing a nucleic acid sequence encoding the above-mentioned peptide into a microorganism by known genetic engineering techniques, allowing the sequence to be expressed on the surface of the microorganism, and then adding the microorganism to a liquid in which mineral particles are dispersed.

[0050] The amount of microorganisms to be added can be determined appropriately taking into consideration various conditions such as the amount of mineral particles dispersed in the solution.

[0051] For example, if the ratio of phage amount (pfu / mL) to mineral amount (g / L) is 0.13 × 10 8 ~5×10 8 , more preferably 0.33 × 10 8 ~1×10 8 is.

[0052] After adding the microorganisms, if the solution is left for a while, peptides on the surface of the microorganisms will bind to the mineral particles, causing them to aggregate. The minerals then settle to the bottom of the solution, which can then be collected.

[0053] 5-3. Separation method using column chromatography In one embodiment, the present disclosure relates to the use of a chromatography column containing peptides. More particularly, the disclosure relates to a separation method using column chromatography. The method can include the following steps: Passing a dispersion through a column, the dispersion containing an arsenic-containing mineral and an iron- and copper-containing mineral.

[0054] When preparing a column, the peptide described above can first be immobilized on a carrier by a known method. Then, the carrier can be introduced into a purification column as a packing material. Once the column is prepared, a dispersion is passed through the column. Then, minerals containing iron and copper (e.g., chalcopyrite) are bound to the column or are delayed in elution. This allows other minerals (e.g., minerals containing arsenic, e.g., enargite) to be preferentially eluted. Then, a dispersion containing the delayed-eluted minerals (e.g., minerals containing iron and copper, e.g., chalcopyrite) can be collected. Furthermore, an appropriate eluent may be used to elute the minerals bound to the column.

[0055] 5-4. Separation method using particles In one embodiment, the present disclosure relates to sedimentation particles having peptides on their surfaces. More specifically, the disclosure relates to a separation method using sedimentation particles having peptides on their surfaces. The method can include the following steps. adding sedimentation particles to a dispersion, the dispersion including an arsenic-containing mineral and an iron- and copper-containing mineral; Precipitation of iron and copper-containing minerals - Recovering the sediment A step of separating the sediment into solid and liquid and recovering the solids When preparing particles for sedimentation, the above-mentioned peptides can first be immobilized on the surface of the particles by known techniques. The particles can then be added to the dispersion. After adding the particles, if the particles are left for a while, the peptides on the surface of the particles bind to the iron- and copper-containing minerals, causing aggregation. The particles then settle to the bottom of the solution. The minerals that have settled to the bottom can then be collected. In another embodiment using particles, magnetic beads can be used as the particles, and the bound mineral particles can be removed using magnetic force without waiting for sedimentation.

[0056] 5-5. Separation method using flotation In one embodiment, the present disclosure relates to flotation using peptides. More specifically, in one embodiment, the peptides of the present disclosure can be used as flotation inhibitors. An inhibitor is a reagent that inhibits the floatability of certain minerals during the flotation process.

[0057] In one embodiment, the peptide of the present disclosure may be used in combination with a microorganism. More specifically, the peptide of the present disclosure may be used in a form that allows the peptide to be displayed on the surface of the microorganism. The microorganisms described in "4-1. Microorganisms" can be used. A preferred microorganism is a phage, and a more preferred microorganism is the M13 bacteriophage.

[0058] The method of flotation using peptides may include the following steps: providing a mixture of an arsenic-containing mineral and an iron- and copper-containing mineral; Providing an inhibitor for flotation The mixture and the inhibitor are added to the flotation tank. Recovering the tailings from the flotation tank

[0059] Although the following description is not intended to limit the scope of the invention, in one embodiment, the peptides of the present disclosure have the property of hydrophilizing the surface of iron- and copper-containing minerals (e.g., chalcopyrite), which is believed to prevent the iron- and copper-containing minerals from being trapped in bubbles. As a result, the iron- and copper-containing minerals tend to partition into the tailings, while the arsenic-containing minerals partition into the float.

[0060] The concentration of the peptide as a flotation inhibitor is not particularly limited, but may be 1 g / t ore or more, preferably 3 g / t ore or more, more preferably 5 to 500 g / t ore, and even more preferably 5 to 200 g / t ore.

[0061] In a preferred embodiment, the method further includes a step of performing a desorption treatment before the step of feeding the mixture into the flotation tank. The technical significance of this is as follows: First, when a mixture of an arsenic-containing mineral and an iron- and copper-containing mineral comes into contact with a flotation inhibitor, the inhibitor binds to the surface of the mineral. In one embodiment, the peptide of the present disclosure theoretically has a strong tendency to bind to the iron- and copper-containing mineral. However, in practice, some nonspecific binding also occurs. Because the amount of nonspecific binding is small, sufficient separation is still possible. However, by performing a further desorption treatment, peptides nonspecifically bound to the mineral can be desorbed. This can further improve separation efficiency.

[0062] The specific procedure for the desorption treatment involves contacting a mixture of arsenic-containing minerals and iron- and copper-containing minerals with a flotation inhibitor, followed by centrifugation and removal of the supernatant. The remaining precipitate may be subjected to ultrasonic treatment, or a desorption reagent may be added. The presence of this desorption reagent desorbs nonspecifically bound peptides. Examples of the desorption reagent include inorganic salts, RO water, glycine-HCl buffer, and surfactants (e.g., Tween 20). Inorganic salts are preferred. The inorganic salt is not particularly limited, and examples include NaCl, KCl, and MgCl2, with NaCl being particularly preferred. The concentration of the inorganic salt may be 0.3 M or higher, preferably 3 to 5 M, and more preferably 3.5 M or higher. A concentration below 0.3 M results in insufficient desorption. Furthermore, depending on the type of inorganic salt, the limit is approximately 5 M, considering the saturation concentration.

[0063] After treatment with the desorption reagent, the three steps of centrifugation, removal of the supernatant, and RO water washing are repeated several times (for example, three or more times) to remove the desorption reagent, which eliminates the influence of the desorption reagent on the subsequent flotation process.

[0064] In another preferred embodiment, the method may further include a step of adding a collector, which further improves separation efficiency. A collector is a reagent that makes the mineral surface hydrophobic in the flotation process, making it easier for bubbles to adhere to the mineral. The type of collector is not particularly limited, but examples include SIBX (sodium isobutyl xanthate), SEX (sodium ethyl xanthate), and PAX (potassium amyl xanthate), with PAX (potassium amyl xanthate) being preferred. The concentration of the collector is not particularly limited, but may be 10 to 100 g / t ore, preferably 30 to 60 g / t ore, and more preferably 35 to 45 g / t ore.

[0065] The conditions for the flotation are not particularly limited, but the flotation can typically be carried out under the following conditions. Pulp consistency 30~200(dry-g / L) Flotation time 5~30 minutes Flotation pH: 5 to 12 (preferably 7 to 11)

[0066] Because iron and copper containing minerals (e.g., chalcopyrite) tend to partition into the tailings and arsenic containing minerals (e.g., enargite) tend to partition into the float, the tailings can be recovered and monitored for the presence of arsenic while the copper ore is recovered. To recover copper from the tailings, the copper may be leached from the copper ore into solution, for example, by a leaching process.

[0067] 6. Selectivity in mineral binding The peptides described above have selectivity, binding particularly strongly to certain minerals but not to other minerals. More specifically, they bind strongly to minerals containing iron and copper (e.g., chalcopyrite) but not to minerals containing arsenic (e.g., arsenopyrite) (or the degree of binding is significantly lower than with minerals containing iron and copper). Therefore, even in a mixture containing minerals containing arsenic among minerals containing iron and copper, the arsenic-containing minerals can be separated and removed by using the method described above.

[0068] 7. How to make peptides The above-mentioned peptides can be produced by various methods. DNA encoding the above-mentioned peptides can be inserted into an expression vector and introduced into a microorganism or the like, whereby the peptides can be expressed and recovered in large quantities. Alternatively, the peptides can be synthesized by genetic engineering techniques or organic chemistry methods.

[0069] Alternatively, a phage display method can be used to produce a phage (e.g., M13 phage) that displays the above-described peptide on its surface. Microorganisms that display the desired peptide on their surface can be produced by known genetic engineering techniques. [Example]

[0070] Example 1 (Peptide Concentration) A peptide (Lauroyl-C48P) having the following chemical structure was prepared. A lauroyl group was added to the N-terminus of the peptide. [ka] Here, R1 to R11 represent the side chains of amino acids.

[0071] The peptide moiety is represented by the following formula: Ser-Ser-Ala-Pro-His-Tyr-Arg-Val-Gly-Asp-Gly (SEQ ID NO: 1)

[0072] A 500 mg sample containing chalcopyrite / arsenocite in a 9:1 ratio was prepared. The sample was crushed and sieved to a particle size range of approximately 45–75 μm. It was suspended in 7.5 mL of RO water (pH 9). Next, the lauroylated peptide was added to a concentration of 100 g / t ore, 200 g / t ore, or 500 g / t ore. After 5 minutes, the sample was transferred to a Hallimond tube. RO water was added to adjust the total volume to 150 mL. Air was supplied at 25 mL / min. The mineral floss in the Hallimond tube was then collected.

[0073] The As, Cu, and Fe in the recovered minerals were then quantified using ICP-OES (iCAP6300 Duo), and the extent to which arsenopyrite and chalcopyrite were distributed to the froth side was determined from the results. The separation efficiency was calculated using the following formula: Separation efficiency = 100 x ((amount of enargite distributed to the froth side (g)) / (amount of enargite in the original sample (g)) - (amount of chalcopyrite distributed to the froth side (g)) / (amount of chalcopyrite in the original sample (g))

[0074] The amount of enargite was calculated based on the amount of As determined above. The amount of Cu in the enargite was also calculated based on the calculated amount of enargite. On the other hand, the amount of chalcopyrite was calculated based on the amount of Cu obtained by subtracting the amount of Cu in the enargite from the total amount of Cu.

[0075] The results are shown in Figure 1. The sample with a final peptide concentration of 200 g / t ore had the highest separation efficiency. In all cases, the separation efficiency was higher than that of the blank, which had no peptide added.

[0076] Example 2 (Type of desorption reagent) A similar test to that in Example 1 was carried out. However, the final peptide concentration was set to 200 g / t ore. A desorption treatment was also carried out in advance. Specifically, two hours after adding the peptide to the sample, centrifugation (6000 × g, 1 min) was carried out and the supernatant was removed. 7.5 mL of desorption reagent was then added. Three types of desorption reagent were used: 4 M NaCl, RO water, and 0.1 M glycine-HCl buffer. One hour later, washing was carried out. Specifically, the three steps of centrifugation (6000 × g, 1 min), removal of the supernatant, and addition of 7.5 mL of RO water were repeated three times.

[0077] The results are shown in Figure 2. The NaCl desorption reagent had the highest separation efficiency.

[0078] Example 3 (Effect of collector) A similar test to that in Example 2 was carried out, except that the desorption reagent was 4 M NaCl. Furthermore, peptide was added to a final concentration of 100 g / t ore, 200 g / t ore, or 500 g / t ore. Furthermore, the collector PAX was added to a concentration of 40 g / t ore. The collector was added after the desorption treatment.

[0079] The results are shown in Figure 3. From the viewpoint of separation efficiency, there is not much difference from Example 1, but the time required to achieve maximum separation efficiency is shorter.

[0080] Example 4 (Study of other conditions) The separation efficiency was measured while varying the concentrations of peptide, NaCl, and PAX, as in Examples 1 to 3. However, flotation was carried out while occasionally stirring the tailings in the Hallimond tube. [Table 2] Condition number 1 provided the best separation efficiency.

[0081] The tailings and froth obtained under condition number 1 were analyzed by SEM-EDX mapping. The results are shown in Figure 4. In the froth, the proportion of areas displayed in red was high, indicating a large amount of enargite. On the other hand, in the tailings, the proportion of areas displayed in green was high, indicating a large amount of chalcopyrite. These results demonstrate that the above peptide can separate chalcopyrite and enargite.

[0082] Example 5 (Column Flotation) As an arsenic-containing copper ore collected from an actual copper mine, a copper concentrate sample having the following chemical composition and mineral composition was prepared.

[0083] [Table 3]

[0084] [Table 4]

[0085] The sample was crushed and sieved to a particle size range of approximately 45 to 75 μm. The sample was then washed with acetone. 15 g of the sample was then placed in a 50 mL centrifuge tube. 20 mL of ion-exchanged water (adjusted to pH 9 using NaOH solution) was added to the tube. The centrifuge tube was continuously rotated using a tube rotator (30 minutes, 12.5 rpm, room temperature). The sample was centrifuged (6,000 × g, room temperature, 1 minute) and the supernatant was removed. 20 mL of ion-exchanged water (pH 9) was added to the sample. The sample was stirred using a vortex mixer. The sample was again centrifuged (6,000 × g, room temperature, 1 minute) and the supernatant was removed. This process was repeated three times.

[0086] Then, the following "(1) peptide treatment and desorption treatment" and "(2) column flotation" were performed. As a control, "(2) column flotation" was performed without "(1) peptide treatment and desorption treatment".

[0087] (1) Peptide treatment and desorption treatment Deionized water (pH 9, 20 mL) and lauroylated peptide solution (dimethyl sulfoxide (DMSO)) were added to the washed samples to achieve the desired concentration. The amount of DMSO was then adjusted so that a total of 100 μL of DMSO was added to all samples. The samples were then mixed using a vortex mixer. The samples were continuously rotated using a tube rotator (2 hours, 12.5 rpm, room temperature). The samples were centrifuged (6,000 × g, room temperature, 1 minute) and the supernatant was removed. For the desorption treatment, 22.5 mL of 4 M NaCl solution was added to the samples, and the samples were mixed using a vortex mixer. The samples were continuously rotated using a tube rotator (1 hour, 12.5 rpm, room temperature). The samples were centrifuged (6,000 × g, room temperature, 1 minute) and the supernatant was removed. After the desorption treatment, deionized water (pH 9, 20 mL) was added to the samples, and the samples were mixed using a vortex mixer. The sample was centrifuged (6,000 × g, room temperature, 1 minute) and the supernatant was removed. This was repeated three times to remove the release agent from the sample.

[0088] (2) Column flotation The sample in the centrifuge tube was washed several times with ion-exchanged water (pH 9, 60 mL), and then the entire sample was transferred to a beaker. While stirring, the solution was added to the sample. The pH of the solution was adjusted to pH 9 using NaOH. The solution used contained the following components: PAX: 20 g / t (ton of mineral); MIBC (Methyl Iso Butyl Carbinol): 30 g / t. After stirring for 2 minutes, the pH of the solution containing the sample was adjusted to pH 9 again using NaOH just before the flotation test. The entire contents of the beaker were transferred to a column-type flotation analyzer. The column was filled with ion-exchanged water (pH 9, 25 mL) to a pulp consistency of 15%. The column contents were stirred (450 rpm) using a magnetic stirrer. Then, the column contents were aerated at 0.6 L / min using an air compressor. The time from the start of aeration was measured. When lauroyl peptide was not added, the froth and tailings were collected after 2 minutes. When lauroyl peptide was added, the froth and tailings were collected after 12 minutes. The collected samples were placed on qualitative filter paper (No. 1) using a suction bottle. The samples were then dried at 50°C overnight or more, and their dry weights were measured. The weight of the qualitative filter paper was weighed in advance, and the amount of minerals collected in the froth and tailings was determined by subtracting the weight of the qualitative filter paper from the dry weight.

[0089] (3)Analysis results Figure 5 shows the analysis results for the elements recovered in the froth. While the desorption treatment had almost no effect on As, the addition of lauroyl peptide somewhat suppressed its distribution to the froth. Specifically, the addition of peptide suppressed the distribution of arsenic-containing copper ore to the froth by approximately 20% compared to blank. On the other hand, the desorption treatment suppressed the distribution of Fe to the froth to some extent, and the addition of lauroyl peptide further suppressed its distribution to the froth significantly. Specifically, the floating of arsenic-free copper was suppressed by approximately 30%.

[0090] The separation efficiency in Example 5 was calculated based on the calculation of the separation efficiency used in Example 4. The results are shown in Figure 6. Although the amount of peptide was 5 g / t, adding the peptide increased the separation efficiency to 39.8%.

[0091] Specific embodiments of the invention have been described above. The above embodiments are merely illustrative examples, and the present invention is not limited to these embodiments. For example, technical features disclosed in one of the above embodiments may be applied to other embodiments. Furthermore, unless otherwise specified, for a particular method, the order of some steps may be interchanged, and additional steps may be added between two specific steps. The scope of the present invention is defined by the claims.

Claims

1. A peptide represented by the following amino acid sequence: Ser-Ser-Ala-Pro-His-Tyr-Arg-Val-Gly-Asp-Gly (SEQ ID NO: 1)

2. 2. The peptide according to claim 1, wherein an alkyl group is added to the N-terminus, and the alkyl group has a carbon number of C10 to C14.

3. 3. The peptide of claim 2, wherein the alkyl group has a carbon number of C12.

4. The peptide according to any one of claims 1 to 3, which is capable of specifically binding to chalcopyrite.

5. A composition for sorting chalcopyrite, the composition comprising a peptide described in any one of claims 1 to 4.

6. Use of a peptide described in any one of claims 1 to 4 for selecting chalcopyrite.

7. A nucleic acid encoding the peptide according to any one of claims 1 to 4.

8. A microorganism comprising the peptide according to any one of claims 1 to 4 on its surface and / or the nucleic acid according to claim 7.

9. A sedimentation particle having the peptide according to any one of claims 1 to 4 on its surface.

10. A chromatography column comprising the peptide according to any one of claims 1 to 4.

11. A flotation inhibitor comprising the peptide according to any one of claims 1 to 4.

12. 10. A method for recovering chalcopyrite using the settling particles of claim 9, said method comprising: adding the settling particles to a dispersion, the dispersion including arsenopyrite and chalcopyrite; allowing the chalcopyrite to settle; collecting the sediment; A step of subjecting the sediment to solid-liquid separation and recovering the solid portion; A method comprising:

13. 11. A method for recovering chalcopyrite using the chromatographic column of claim 10, said method comprising: passing a dispersion through the column, the dispersion comprising arsenopyrite and chalcopyrite; A method comprising:

14. 12. A method for recovering chalcopyrite using the flotation inhibitor of claim 11, said method comprising: providing a mixture of enargite and chalcopyrite; providing said flotation inhibitor; charging the mixture and the flotation inhibitor into a flotation tank; Recovering tailings from the flotation tank; A method comprising:

15. 15. The method of claim 14, further comprising the step of performing a desorption treatment prior to the step of charging the flotation tank.

16. 16. The method of claim 15, wherein the step of performing a desorption treatment comprises treating with an inorganic salt.

17. The method of claim 16, wherein the concentration of the inorganic salt in the desorption treatment is 3 to 5M.

18. 18. The method of claim 16 or 17, wherein the inorganic salt is NaCl.

19. 19. The method of any one of claims 14 to 18, further comprising the step of introducing a collector.

20. 20. The method of claim 19, wherein the concentration of the collector in the flotation tank is 30 to 60 g / t ore.

21. 21. The method of claim 19 or 20, wherein the collector is PAX (Potassium Amyl Xanthate).

22. 22. The method according to any one of claims 14 to 21, wherein the concentration of the peptide in the flotation tank is 5 to 500 g / t ore.

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