Preparation and application method of copper-sulfur separation inhibitor for copper removal in copper-containing gold concentrate flotation

Abstract

The application provides a preparation and application method of a copper-sulfur separation inhibitor for copper removal in copper-containing gold concentrate flotation, and belongs to the technical field of mineral processing reagents. In the application, a mercapto silane solution is added to a polysaccharide low-molecular biomass compound suspension in an acid state, preliminary modification is carried out under stirring, and further reaction is carried out to completion through heating treatment, so that the functional groups on the surface of the polysaccharide low-molecular biomass compound are changed by silanization treatment, and the prepared copper-sulfur separation inhibitor has a strong selective inhibition effect on copper minerals. The copper-sulfur separation inhibitor prepared in the application is applied to the copper removal process of copper-containing gold concentrate flotation, copper minerals in the copper-containing gold concentrate can be effectively removed in a neutral or weakly acidic environment with a small amount of copper-sulfur separation inhibitor, copper removal of the copper-containing gold concentrate is simply and efficiently realized, a low-copper gold concentrate with a higher gold grade is obtained at a higher gold recovery rate, and the application has a high practical application value.

Description

Technical Field

[0001] This invention relates to the field of mineral processing reagents, specifically to a method for preparing and applying a copper-sulfur separation inhibitor for copper removal in the flotation of copper-bearing gold concentrate. Background Technology

[0002] In the leaching process of copper-bearing gold concentrate, the presence of copper minerals increases cyanide consumption, reduces the concentration of free cyanide ions in the pulp, and slows down the gold leaching rate. Furthermore, copper minerals form a thin film on the gold surface, hindering gold leaching. Therefore, to achieve efficient gold leaching from copper-bearing gold concentrate, it is necessary to remove copper minerals first.

[0003] Gold in copper-bearing gold concentrate is primarily found in pyrite, while copper minerals such as chalcopyrite are closely associated with pyrite. The process of separating these two minerals is called copper-sulfur separation. Copper-sulfur separation has always been a crucial issue in mineral processing. Because chalcopyrite and pyrite have similar floatability under low-alkali conditions, the conventional method for copper-sulfur separation involves using lime as a copper-sulfur separation inhibitor during flotation to suppress pyrite, thus achieving copper-sulfur separation through sulfur suppression and copper flotation. However, due to the high pyrite content in gold concentrate, using lime to suppress pyrite requires large amounts of lime, which not only poses safety hazards but also leads to excessive costs, equipment corrosion, and environmental pollution.

[0004] In the prior art, patent CN112604816A discloses a copper-sulfur separation inhibitor, a lime-free copper-sulfur flotation separation method, and its application. This patent prepares a copper-sulfur separation inhibitor by mixing raw materials such as sodium carbonate, ammonium sulfate, calcium chloride, and sodium hydroxide in specific proportions, enabling it to replace traditional lime inhibitors. However, the copper-sulfur separation inhibitor used in this patent still requires alkaline raw materials such as sodium carbonate and sodium hydroxide, and this type of copper-sulfur separation inhibitor is more suitable for the flotation of copper minerals and not for the flotation removal of copper from copper-containing gold concentrates.

[0005] In view of this, it is still necessary to provide an improved method for the preparation and application of a copper-sulfur separation inhibitor for copper removal in the flotation of copper-bearing gold concentrate, in order to solve the above problems. Summary of the Invention

[0006] In view of the technical problems existing in the background art, this application provides a method for preparing and applying a copper-sulfur separation inhibitor for copper removal by flotation of copper-bearing gold concentrate. The aim is to develop a low-toxicity, high-efficiency, biodegradable, strong inhibitory force, and good selectivity copper-sulfur separation inhibitor for effective selective inhibition of copper minerals such as chalcopyrite, thereby achieving efficient copper removal by flotation of copper-bearing gold concentrate.

[0007] In a first aspect, embodiments of this application provide a method for preparing a copper-sulfur separation inhibitor for copper removal in the flotation of copper-containing gold concentrate, comprising the following steps:

[0008] S1. Prepare polysaccharide low molecular weight biomass compound suspension and mercaptosilane solution respectively;

[0009] S2. Add a pH adjuster to the polysaccharide low molecular weight biomass compound suspension to prepare an acidic polysaccharide low molecular weight biomass compound suspension;

[0010] S3. Add the mercaptosilane solution to the acidic polysaccharide low molecular weight biomass compound suspension and stir thoroughly to obtain a preliminarily modified polysaccharide low molecular weight biomass compound suspension;

[0011] S4. The preliminarily modified polysaccharide low molecular weight biomass compound suspension is heated and treated. After the reaction is complete, the product is washed and dried to obtain a copper-sulfur separation inhibitor.

[0012] In the technical solution of this application embodiment, by modifying the low-molecular-weight polysaccharide biomass compound with a mercaptosilane solution, new functional groups are introduced while maintaining the polymer molecular skeleton. This enables the prepared inhibitor to have a strong selective inhibition effect on copper minerals such as chalcopyrite, and only a small amount is needed to effectively selectively inhibit copper minerals, achieving efficient flotation removal of copper from copper-bearing gold concentrate. Furthermore, the low-molecular-weight polysaccharide biomass compound used in this application is a bio-based raw material with good biodegradability, making it more environmentally friendly than conventional inhibitors, in line with the development concept of green mining, and expanding the types of copper-sulfur separation inhibitors in the mineral resources industry.

[0013] In some embodiments, in step S1, the polysaccharide low molecular weight biomass compound includes one or more of nanocellulose, hemicellulose, and hemicellulose-polylactic acid composite polysaccharide; the mercaptosilane includes one or more of 3-mercaptopropyltrimethoxysilane and γ-mercaptopropyltriethoxysilane.

[0014] In this embodiment, by employing specific types of low-molecular-weight polysaccharide biomass compounds and mercaptosilanes, the selectivity of the prepared copper-sulfur separation inhibitor can be improved more effectively.

[0015] In some embodiments, in step S1, the mass concentration of the polysaccharide low molecular weight biomass compound suspension is 0.1% to 5%, and the mass concentration of the mercaptosilane solution is 10% to 20%.

[0016] In this embodiment, the low molecular weight polysaccharide biomass compound in the polysaccharide low molecular weight biomass compound suspension can be fully dispersed, and the mercaptosilane in the mercaptosilane solution can be fully dissolved to facilitate the subsequent reaction.

[0017] In some embodiments, in step S2, the pH value of the acidic polysaccharide low molecular weight biomass compound suspension is 3 to 5.

[0018] In this embodiment, adjusting the pH of the polysaccharide low molecular weight biomass compound suspension to a specific range is beneficial to promoting the reaction between mercaptosilane and polysaccharide low molecular weight biomass compound.

[0019] In some embodiments, in step S3, the mass of mercaptosilane in the added mercaptosilane solution is 0.5 to 1.5 times the solid mass of the low molecular weight polysaccharide biomass compound in the acidic polysaccharide low molecular weight biomass compound suspension.

[0020] In this embodiment, a better modification effect can be obtained by adjusting the ratio between mercaptosilane and polysaccharide low-molecular-weight biomass compound.

[0021] In some embodiments, during step S4, the heating temperature is 60–100°C and the heating time is 3–5 hours.

[0022] In this embodiment, by heating the pre-modified polysaccharide low-molecular-weight biomass compound at a specific temperature for a certain period of time, the pre-modified polysaccharide low-molecular-weight biomass compound can be further reacted to complete, thereby improving the modification effect and thus improving the selective inhibition of copper minerals by the obtained copper-sulfur separation inhibitor.

[0023] Secondly, embodiments of this application provide a method for applying a copper-sulfur separation inhibitor for copper removal in the flotation of copper-containing gold concentrate. The copper-sulfur separation inhibitor prepared in the above scheme is applied to the copper removal process in the flotation of copper-containing gold concentrate, comprising the following steps:

[0024] After grinding, the copper-bearing gold concentrate is formulated into a slurry.

[0025] The copper-sulfur separation inhibitor was dissolved in water to prepare an inhibitor suspension;

[0026] The pH of the slurry is adjusted to 6-7, then the inhibitor suspension is added, and after thorough stirring, a collector and a frother are added for flotation to obtain high-copper-gold concentrate and low-copper-gold concentrate.

[0027] In the technical solution of this application embodiment, by applying the copper-sulfur separation inhibitor prepared in the above solution to the copper removal process of copper-containing gold concentrate, flotation can be carried out in a neutral or weakly acidic environment, and copper minerals in copper-containing gold concentrate can be effectively removed with a small amount of copper-sulfur separation inhibitor, thus achieving copper removal from copper-containing gold concentrate in a simple and efficient manner, and obtaining low-copper gold concentrate with higher gold recovery rate.

[0028] In some embodiments, the grinding fineness of the grinding process is such that 60% to 90% of the particles are smaller than 400 mesh; and the mass concentration of the slurry is 25% to 35%.

[0029] In some embodiments, the mass concentration of the copper-sulfur separation inhibitor in the inhibitor suspension is 1% to 10%.

[0030] In some embodiments, the flotation operation includes one roughing stage and 1 to 4 scavenging stages; during the roughing stage, the amount of copper-sulfur separation inhibitor used is 10 to 1000 g / t, and during each stage of scavenging, the amount of copper-sulfur separation inhibitor used is halved in turn.

[0031] In this embodiment, since the copper-sulfur separation inhibitor used has a good selective inhibition effect on copper minerals, a good inhibition effect can be achieved with a small amount, which effectively reduces the amount of reagent used and lowers the reagent cost.

[0032] The above description is only an overview of the technical solution of this application. In order to better understand the technical means of this application and to implement it in accordance with the contents of the specification, and to make the above and other objects, features and advantages of this application more obvious and understandable, the following are specific embodiments of this application. Attached Figure Description

[0033] To more clearly illustrate the technical solutions of this application, the accompanying drawings used in this application will be briefly described below. Obviously, the drawings described below are merely some embodiments of this application. For those skilled in the art, other drawings can be obtained from these drawings without any creative effort.

[0034] Figure 1 This is a schematic diagram of the flotation process in which copper-sulfur separation inhibitors are applied to copper-containing gold concentrate for copper removal in the embodiments of this application. Detailed Implementation

[0035] The embodiments of the technical solution of this application will now be described in detail with reference to the accompanying drawings. These embodiments are only used to more clearly illustrate the technical solution of this application and are therefore merely examples, and should not be used to limit the scope of protection of this application.

[0036] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application pertains; the terminology used herein is for the purpose of describing particular embodiments only and is not intended to limit the application; the terms “comprising” and “having”, and any variations thereof, in the specification, claims, and foregoing description of the drawings are intended to cover non-exclusive inclusion.

[0037] In this document, the term "embodiment" means that a particular feature, structure, or characteristic described in connection with an embodiment may be included in at least one embodiment of this application. The appearance of this phrase in various places throughout the specification does not necessarily refer to the same embodiment, nor is it a separate or alternative embodiment mutually exclusive with other embodiments. It will be explicitly and implicitly understood by those skilled in the art that the embodiments described herein can be combined with other embodiments.

[0038] Traditional copper-sulfur separation methods primarily use alkaline raw materials such as lime as copper-sulfur separation inhibitors to suppress pyrite, thereby achieving copper-sulfur separation through sulfur suppression and copper flotation. However, this method is not suitable for gold concentrates with high pyrite content, as it can lead to problems such as excessive inhibitor dosage, equipment corrosion, and environmental pollution.

[0039] To address the aforementioned issues, this application provides a method for preparing and applying a copper-sulfur separation inhibitor for copper removal in the flotation of copper-bearing gold concentrate. By silanizing a low-molecular-weight polysaccharide biomass compound, the functional groups on its surface are altered, enabling it to selectively inhibit copper minerals such as chalcopyrite. This achieves efficient copper removal from copper-bearing gold concentrate through copper suppression and sulfur flotation.

[0040] In a first aspect, embodiments of this application provide a method for preparing a copper-sulfur separation inhibitor for copper removal in the flotation of copper-containing gold concentrate, comprising the following steps:

[0041] S1. Prepare polysaccharide low molecular weight biomass compound suspension and mercaptosilane solution respectively;

[0042] S2. Add a pH adjuster to the polysaccharide low molecular weight biomass compound suspension to prepare an acidic polysaccharide low molecular weight biomass compound suspension;

[0043] S3. Add the mercaptosilane solution to the acidic polysaccharide low molecular weight biomass compound suspension and stir thoroughly to obtain a preliminarily modified polysaccharide low molecular weight biomass compound suspension;

[0044] S4. The preliminarily modified polysaccharide low molecular weight biomass compound suspension is heated and treated. After the reaction is complete, the product is washed and dried to obtain a copper-sulfur separation inhibitor.

[0045] In the technical solution of this application embodiment, by modifying the low-molecular-weight polysaccharide biomass compound with a mercaptosilane solution, new functional groups are introduced while maintaining the polymer molecular backbone. This enables the prepared inhibitor to have a strong selective inhibition effect on copper minerals such as chalcopyrite, achieving targeted capture capability of the target element. Simultaneously, the abundant derivatization sites in the molecular backbone of the low-molecular-weight polysaccharide biomass compound ensure high-density chemical bonding of functional groups, resulting in a higher density of functional groups in the unit chain segments. Compared with traditional reagent dosages, only a smaller amount is needed to effectively selectively inhibit copper minerals, achieving efficient flotation removal of copper from copper-bearing gold concentrates while meeting the expected goal of low cost. Furthermore, the low-molecular-weight polysaccharide biomass compound used in this application is a bio-based raw material with good biodegradability, making it more environmentally friendly than conventional inhibitors, aligning with the development concept of green mining, and expanding the types of effective copper-sulfur separation inhibitors available in the mineral resources industry.

[0046] Furthermore, in some embodiments, in step S1, the mass concentration of the polysaccharide low molecular weight biomass compound suspension is 0.1% to 5%, and the mass concentration of the mercaptosilane solution is 10% to 20%.

[0047] In the technical solution of this application embodiment, the preparation method of the polysaccharide low molecular weight biomass compound suspension can be as follows: add the polysaccharide low molecular weight biomass compound to water, and stir with a magnetic stirrer for 10 minutes to fully disperse the polysaccharide low molecular weight biomass compound, thereby obtaining the polysaccharide low molecular weight biomass compound suspension. The preparation method of the mercaptosilane solution can be as follows: add mercaptosilane to a solvent, and stir with a magnetic stirrer for 10 minutes to fully dissolve the mercaptosilane, thereby obtaining the mercaptosilane solution, wherein the solvent is preferably ethanol. Based on this, by controlling the mass concentration of the polysaccharide low molecular weight biomass compound suspension at 0.1% to 5% and the mass concentration of the mercaptosilane solution at 10% to 20%, it is beneficial to fully disperse the polysaccharide low molecular weight biomass compound and fully dissolve the mercaptosilane, which facilitates the subsequent reaction.

[0048] Furthermore, in some embodiments, in step S1, the polysaccharide low molecular weight biomass compound includes one or more of nanocellulose, hemicellulose, and hemicellulose-polylactic acid composite polysaccharide; the mercaptosilane includes one or more of 3-mercaptopropyltrimethoxysilane and γ-mercaptopropyltriethoxysilane.

[0049] In the technical solution of this application embodiment, by using specific types of low molecular weight polysaccharide biomass compounds and mercaptosilanes, functional groups of mercaptosilyl groups or mercaptosilane chains can be introduced onto the surface of the low molecular weight polysaccharide biomass compounds, thereby more effectively improving the selectivity of the prepared copper-sulfur separation inhibitor.

[0050] Furthermore, in some embodiments, in step S2, the pH value of the acidic polysaccharide low molecular weight biomass compound suspension is preferably 3 to 5, more preferably 4; the pH value adjuster is preferably hydrochloric acid.

[0051] In the technical solution of this application embodiment, by adjusting the pH value of the polysaccharide low molecular weight biomass compound suspension to a specific range, it is beneficial to promote the reaction between mercaptosilane and polysaccharide low molecular weight biomass compound.

[0052] Furthermore, in some embodiments, in step S3, the mass of the mercaptosilane in the added mercaptosilane solution is 0.5 to 1.5 times the solid mass of the low molecular weight polysaccharide biomass compound in the acidic polysaccharide low molecular weight biomass compound suspension.

[0053] In the technical solution of this application embodiment, a better modification effect can be obtained by adjusting the ratio between mercaptosilane and low-molecular-weight polysaccharide biomass compound. Furthermore, after adding the mercaptosilane solution, it is preferable to stir with a magnetic stirrer at room temperature for 2.5 to 3.5 hours to allow the mercaptosilane and low-molecular-weight polysaccharide biomass compound to react fully.

[0054] Furthermore, in some embodiments, in step S4, the heating temperature is 60–100°C and the heating time is 3–5 hours.

[0055] In the technical solution of this application embodiment, by heating the pre-modified polysaccharide low-molecular-weight biomass compound at a specific temperature for a certain period of time, the pre-modified polysaccharide low-molecular-weight biomass compound can be further reacted to complete reaction, improving the modification effect and thus improving the selective inhibition effect of the obtained copper-sulfur separation inhibitor on copper minerals. Furthermore, the heating treatment method is preferably water bath heating to ensure uniform heating.

[0056] Furthermore, in some embodiments, the washing solution used in step S4 is preferably deionized water or ethanol solution, and the washing can be repeated multiple times, preferably 3 to 5 times.

[0057] Secondly, embodiments of this application provide a method for applying a copper-sulfur separation inhibitor for copper removal in the flotation of copper-containing gold concentrate. The copper-sulfur separation inhibitor prepared in the above scheme is applied to the copper removal process in the flotation of copper-containing gold concentrate, comprising the following steps:

[0058] After grinding, the copper-bearing gold concentrate is formulated into a slurry.

[0059] The copper-sulfur separation inhibitor was dissolved in water to prepare an inhibitor suspension;

[0060] The pH of the slurry is adjusted to 6-7, then the inhibitor suspension is added, and after thorough stirring, a collector and a frother are added for flotation to obtain high-copper-gold concentrate and low-copper-gold concentrate.

[0061] In the technical solution of this application embodiment, by applying the copper-sulfur separation inhibitor prepared in the above solution to the copper removal process of copper-containing gold concentrate, flotation can be carried out in a neutral or weakly acidic environment, and copper minerals in copper-containing gold concentrate can be effectively removed with a small amount of copper-sulfur separation inhibitor, thus achieving copper removal from copper-containing gold concentrate in a simple and efficient manner, and obtaining low-copper gold concentrate with higher gold recovery rate.

[0062] Furthermore, in some embodiments, the grinding fineness of the grinding process is such that 60% to 90% of the particles are smaller than 400 mesh; and the mass concentration of the slurry is 25% to 35%.

[0063] Furthermore, in some embodiments, the mass concentration of the copper-sulfur separation inhibitor in the inhibitor suspension is 1% to 10% to allow for better dispersion of the inhibitor; meanwhile, the collector is preferably prepared as a collector solution before use, and the mass concentration of the collector in the collector solution is preferably 1% to 5%.

[0064] Furthermore, in some embodiments, the flotation operation includes one roughing stage and 1 to 4 scavenging stages; during the roughing stage, the dosage of the copper-sulfur separation inhibitor is 10 to 1000 g / t, the dosage of the collector is 0 to 100 g / t, and the dosage of the frother is 10 to 50 g / t; during each stage of scavenging, the dosages of the copper-sulfur separation inhibitor, collector, and frother are halved sequentially. It should be noted that in this application, the dosage of each reagent is determined based on the quality of the raw ore, i.e., the reagent dosage per ton of copper-gold concentrate.

[0065] Furthermore, in some embodiments, after adding the inhibitor suspension, the mixture is stirred for 5–10 minutes; then the collector is added, and the mixture is stirred for 2–5 minutes; then the frother is added, and the mixture is stirred for 2–3 minutes; followed by aeration roughing for 4–6 minutes. This facilitates sufficient contact and reaction between the reagents and the mineral particles, improving the flotation effect.

[0066] In the application of copper-sulfur separation inhibitors, the copper-sulfur separation inhibitors used have a good selective inhibition effect on copper minerals, and a good inhibition effect can be achieved with a small amount, which effectively reduces the amount of reagent used and lowers the reagent cost.

[0067] The following are some specific embodiments. It should be noted that the embodiments described below are exemplary and are only used to explain this application, and should not be construed as limiting this application. Where specific techniques or conditions are not specified in the embodiments, they shall be performed in accordance with the techniques or conditions described in the literature in this field or according to the product instructions. Reagents or instruments whose manufacturers are not specified are all conventional products that can be obtained commercially.

[0068] Example 1

[0069] This embodiment provides a method for preparing and applying a copper-sulfur separation inhibitor for copper removal in the flotation of copper-bearing gold concentrate. The preparation method of the copper-sulfur separation inhibitor specifically includes the following steps:

[0070] S1. Add 50g of nanocellulose to 950mL of water and stir with a magnetic stirrer for 10min to prepare a nanocellulose suspension with a mass concentration of 5%; add 50g of 3-mercaptopropyltrimethoxysilane to 200g of ethanol and stir with a magnetic stirrer for 10min to prepare a mercaptosilane solution with a mass concentration of 20%.

[0071] S2. Add hydrochloric acid to the nanocellulose suspension to adjust the pH value of the nanocellulose suspension to 4.

[0072] S3. Add the freshly prepared mercaptosilane solution dropwise to the nanocellulose suspension with a pH of 4 using a pipette, and stir with a magnetic stirrer for 3 hours at room temperature to allow 3-mercaptopropyltrimethoxysilane to fully react with the polysaccharide low molecular weight biomass compound, thereby obtaining a preliminarily modified nanocellulose suspension.

[0073] S4. The preliminarily modified nanocellulose suspension was placed in a beaker and heated in a water bath to 85°C to further react until complete, with a reaction time of 4 hours. Afterward, the product was washed with distilled water and dried to obtain a copper-sulfur separation inhibitor.

[0074] The copper-sulfur separation inhibitor prepared in this embodiment can be applied to the flotation of copper-bearing gold concentrate. In this embodiment, the gold grade of the copper-bearing gold concentrate is 18.70 g / t, the copper grade is 1.48%, and the sulfur grade is 33.97%. The gold-bearing mineral in the ore is mainly pyrite, and the copper-bearing minerals are mainly chalcopyrite and bornite. The process flow diagram for applying the copper-sulfur separation inhibitor to the flotation of this copper-bearing gold concentrate for copper removal is shown below. Figure 1 As shown, the specific steps include:

[0075] The copper-gold concentrate was ground using a ball mill until 90% of the particles were smaller than 400 mesh, and then prepared into a slurry with a concentration of 28%. The pH of the slurry was adjusted to 6, and the prepared copper-sulfur separation inhibitor was diluted with water to prepare a 10% (w / w) inhibitor suspension. 500g of copper-sulfur separation inhibitor was added per ton of ore, and the suspension was stirred for 10 minutes. Then, 10g / t of isoamyl xanthate and 5g / t of butylammonium black were added as collectors, and the mixture was stirred for 5 minutes. Finally, 10g / t of No. 2 oil was added as a frother, and the mixture was stirred for 2 minutes for roughing to obtain a roughing concentrate and roughing tailings. Then, the roughing tailings are subjected to three scavenging processes, with the dosage of reagents being halved in each process (i.e., the amount of inhibitor added in the first scavenging is 400g / t, the second scavenging is 200g / t, and the third scavenging is 100g / t, and the dosage of other reagents is determined in the same way). The concentrate obtained from each scavenging process is combined with the roughing concentrate to form a concentrate, namely low-copper gold concentrate, which can be used for gold smelting. The tailings obtained at the end of the scavenging process are high-copper gold concentrate, which can be used for copper smelting.

[0076] Comparative Examples 1-3

[0077] Compared with Example 1, the only difference in Comparative Example 1 is that no copper-sulfur separation inhibitor was added during the copper removal process of copper-containing gold concentrate flotation; the only difference in Comparative Example 2 is that the copper-sulfur separation inhibitor prepared in Example 1 was replaced with an equal amount of nanocellulose; and the only difference in Comparative Example 3 is that the mercaptosilane solution used in Example 1 was replaced with an equal amount of N-propyltriethoxysilane. The remaining steps in each comparative example are consistent with those in Example 1 and will not be repeated here.

[0078] After removing copper from the same copper-bearing gold concentrate by flotation according to the methods provided in Example 1 and Comparative Examples 1-3, the results are shown in Table 1.

[0079] Table 1. Flotation results of Example 1 and Comparative Examples 1-3

[0080]

[0081] As shown in Table 1, without the use of a copper inhibitor, the recovery rates of gold and copper were similar, and both gold and copper minerals exhibited good floatability. Using unmodified nanocellulose, while inhibiting copper minerals, it also had a certain inhibitory effect on the flotation of gold-bearing minerals. Using N-propyltriethoxysilane to silanize nanocellulose significantly inhibited the flotation of both gold and copper minerals. When using the copper inhibitor from Example 1, the introduction of thiol groups enhanced inhibitor selectivity, resulting in a significant difference in the recovery rates of gold and copper minerals, demonstrating a clear targeted inhibition capability.

[0082] Example 2

[0083] This embodiment provides a method for preparing and applying a copper-sulfur separation inhibitor for copper removal by flotation of copper-containing gold concentrate. Compared with Example 1, the difference lies in the change of the nanocellulose suspension and mercaptosilane solution prepared in step S1, and the pH value of the slurry is adjusted to 7 during application. The remaining steps are the same as in Example 1, and will not be repeated here.

[0084] In this embodiment, 10g of nanocellulose was added to 990mL of water and stirred for 10min using a magnetic stirrer to prepare a nanocellulose suspension with a mass concentration of 1%; 50g of γ-mercaptopropyltriethoxysilane was added to 450g of ethanol and stirred for 10min using a magnetic stirrer to prepare a mercaptosilane solution with a mass concentration of 10%.

[0085] Comparative Examples 4-6

[0086] Compared to Example 2, Comparative Example 4 differs only in that no copper-sulfur separation inhibitor was added during the copper removal flotation of copper-containing gold concentrate; Comparative Example 5 differs only in that step S2 of Example 2 was omitted, the pH value of the nanofiber suspension was not adjusted, and the mercaptosilane solution was directly added to the prepared nanofiber suspension; Comparative Example 6 differs only in that the water bath heating step in step S4 of Example 2 was omitted, and the preliminarily modified nanocellulose was directly used as the copper-sulfur separation inhibitor. The remaining steps in each comparative example are the same as in Example 1, and will not be repeated here.

[0087] After removing copper from the same copper-bearing gold concentrate by flotation according to the methods provided in Example 2 and Comparative Examples 4-6, the results are shown in Table 2.

[0088] Table 2. Flotation results of Example 2 and Comparative Examples 4-6

[0089]

[0090]

[0091] As can be seen from Table 2, the copper inhibitor in Example 2 has better selectivity and significantly increased the difference in gold and copper recovery rates compared to Comparative Example 4. According to Comparative Examples 5 and 6, the selectivity of the copper inhibitor was affected to some extent if the pH of the nano-suspension was not adjusted or the water bath heating process was omitted.

[0092] Examples 3-5

[0093] Examples 3-5 provide methods for preparing and applying copper-sulfur separation inhibitors for copper removal in the flotation of copper-containing gold concentrates. Compared with Example 1, the only difference is the type of low-molecular-weight polysaccharide biomass compound and mercaptosilane. The remaining steps are the same as in Example 1 and will not be repeated here. The types of low-molecular-weight polysaccharide biomass compounds and mercaptosilanes used in each example are shown in Table 3.

[0094] Table 3. Types of low molecular weight polysaccharide biomass compounds and mercaptosilanes in Examples 3-5.

[0095]

[0096]

[0097] After removing copper from the same copper-bearing gold concentrate by flotation according to the methods provided in Examples 3 to 5, the results are shown in Table 4.

[0098] Table 4. Flotation results of Examples 3-5

[0099]

[0100] As shown in Table 4, the copper inhibitor obtained by silanizing nanocellulose with a 1:1 mixture of two different mercaptosilane solutions still exhibits significant targeting. Modification of hemicellulose and hemicellulose-polylactic acid composite lactose with 3-mercaptopropyltrimethoxysilane resulted in inhibitors with significant copper mineral inhibition effects and strong copper-inhibiting capabilities.

[0101] In summary, this application provides a method for preparing and applying a copper-sulfur separation inhibitor for copper removal in the flotation of copper-bearing gold concentrate, belonging to the field of mineral processing reagents technology. This application involves adding a mercaptosilane solution to an acidic suspension of a low-molecular-weight polysaccharide biomass compound, first performing preliminary modification under stirring, and then further reacting to complete reaction through heating. This silanization treatment alters the functional groups on the surface of the low-molecular-weight polysaccharide biomass compound, resulting in a copper-sulfur separation inhibitor with a strong selective inhibition effect on copper minerals. Applying the copper-sulfur separation inhibitor prepared in this application to the copper removal process in the flotation of copper-bearing gold concentrate allows for flotation in neutral or weakly acidic environments, effectively removing copper minerals from the concentrate with a small amount of the inhibitor. This simple and efficient method achieves copper removal from copper-bearing gold concentrate, resulting in a higher gold recovery rate and a lower-grade copper gold concentrate, demonstrating significant practical application value.

[0102] It should be noted that this application is not limited to the above-described embodiments. The above embodiments are merely examples, and any embodiments with the same structure and effect as the technical concept within the scope of this application are included in the technical scope of this application. Furthermore, various modifications that can be conceived by those skilled in the art to the embodiments, and other ways of constructing by combining some of the constituent elements of the embodiments, without departing from the spirit of this application, are also included in the scope of this application.

Claims

1. A method for preparing a copper-sulfur separation inhibitor for copper removal in the flotation of copper-bearing gold concentrate, characterized in that, Includes the following steps: S1. Prepare polysaccharide low molecular weight biomass compound suspension and mercaptosilane solution respectively; S2. Add a pH adjuster to the polysaccharide low molecular weight biomass compound suspension to prepare an acidic polysaccharide low molecular weight biomass compound suspension; S3. Add the mercaptosilane solution to the acidic polysaccharide low molecular weight biomass compound suspension and stir thoroughly to obtain a preliminarily modified polysaccharide low molecular weight biomass compound suspension; S4. The preliminarily modified polysaccharide low molecular weight biomass compound suspension is heated and treated. After the reaction is complete, the product is washed and dried to obtain a copper-sulfur separation inhibitor.

2. The method for preparing the copper-sulfur separation inhibitor for copper removal in the flotation of copper-bearing gold concentrate according to claim 1, characterized in that, In step S1, the polysaccharide low molecular weight biomass compound includes one or more of nanocellulose, hemicellulose, and hemicellulose-polylactic acid composite polysaccharide; the mercaptosilane includes one or more of 3-mercaptopropyltrimethoxysilane and γ-mercaptopropyltriethoxysilane.

3. The method for preparing the copper-sulfur separation inhibitor for copper removal in the flotation of copper-bearing gold concentrate according to claim 1, characterized in that, In step S1, the mass concentration of the polysaccharide low molecular weight biomass compound suspension is 0.1% to 5%, and the mass concentration of the mercaptosilane solution is 10% to 20%.

4. The method for preparing the copper-sulfur separation inhibitor for copper removal by flotation of copper-bearing gold concentrate according to claim 1, characterized in that, In step S2, the pH value of the acidic polysaccharide low molecular weight biomass compound suspension is 3 to 5.

5. The method for preparing the copper-sulfur separation inhibitor for copper removal in the flotation of copper-bearing gold concentrate according to claim 1, characterized in that, In step S3, the mass of the mercaptosilane in the added mercaptosilane solution is 0.5 to 1.5 times the solid mass of the low molecular weight polysaccharide biomass compound in the acidic polysaccharide low molecular weight biomass compound suspension.

6. The method for preparing the copper-sulfur separation inhibitor for copper removal in the flotation of copper-bearing gold concentrate according to claim 1, characterized in that, In step S4, the heating temperature is 60-100℃ and the heating time is 3-5 hours.

7. A method for applying a copper-sulfur separation inhibitor for copper removal in the flotation of copper-bearing gold concentrate, characterized in that, Applying the copper-sulfur separation inhibitor prepared by the method described in any one of claims 1 to 6 to the copper removal process of copper-containing gold concentrate includes the following steps: After grinding, the copper-bearing gold concentrate is formulated into a slurry. The copper-sulfur separation inhibitor was dissolved in water to prepare an inhibitor suspension; The pH of the slurry is adjusted to 6-7, then the inhibitor suspension is added, and after thorough stirring, a collector and a frother are added for flotation to obtain high-copper-gold concentrate and low-copper-gold concentrate.

8. The method for applying the copper-sulfur separation inhibitor for copper removal in the flotation of copper-bearing gold concentrate according to claim 7, characterized in that, The grinding fineness of the grinding process is 60% to 90% of the particles smaller than 400 mesh; the mass concentration of the slurry is 25% to 35%.

9. The method for applying the copper-sulfur separation inhibitor for copper removal in the flotation of copper-bearing gold concentrate according to claim 7, characterized in that, The mass concentration of the copper-sulfur separation inhibitor in the inhibitor suspension is 1% to 10%.

10. The method for applying the copper-sulfur separation inhibitor for copper removal in the flotation of copper-bearing gold concentrate according to claim 7, characterized in that, The flotation operation includes one roughing stage and 1 to 4 scavenging stages. During the roughing stage, the amount of copper-sulfur separation inhibitor used is 10 to 1000 g / t. During each stage of scavenging, the amount of copper-sulfur separation inhibitor used is halved.

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