A method for flotation of gold-bearing copper sulfide ore based on interface selective oxidation and synergistic effect of copper ions

Abstract

The application provides a copper sulfide gold-bearing ore flotation method based on interface selective oxidation and copper ion synergistic effect, and relates to the field of mineral flotation. The method comprises the following steps: carrying out first mixing and first reaction on the pulp of copper sulfide gold-bearing ore treated by an organic sulfur inhibitor and a mild oxidation medium to obtain oxidized pulp; carrying out second mixing and second reaction on the oxidized pulp and a copper ion regulating component to obtain copper ion regulated pulp; and carrying out third mixing and flotation on the copper ion regulated pulp, a collector and a foaming agent to obtain gold-containing concentrate. The method does not aim to improve the overall floatability of copper sulfide minerals, realizes efficient recovery of gold existing in copper sulfide minerals under the premise of not damaging the original copper-molybdenum separation system selectivity, and is suitable for various copper sulfide gold-bearing ore systems.

Description

Technical Field

[0001] This application relates to the field of mineral flotation, and in particular to a flotation method for copper sulfide gold-bearing ores based on the synergistic effect of interfacial selective oxidation and copper ions. Background Technology

[0002] Associated copper-gold deposits are an important type of gold resource, characterized by a high degree of coexistence between gold and copper sulfide minerals. Gold is often found in fine-grained inclusions, surface adsorption, or isomorphous forms within copper sulfide minerals such as chalcopyrite, bornite, and chalcocite. In the flotation process of these ores, gold recovery is highly dependent on the interfacial interaction between gold and the carrier copper minerals.

[0003] In actual production, especially in copper-molybdenum separation or selective flotation of copper minerals, it is often necessary to add organic sulfur inhibitors such as sodium thioglycolate to the pulp to effectively suppress copper sulfide minerals. However, while these inhibitors cover the surface of copper minerals, they often simultaneously cover or shield the active sites of gold or gold-copper interfaces on the surface of copper minerals. This leads to a significant decrease in the interaction between gold and xanthate, black powder, or thiol collectors, resulting in reduced gold flotation recovery and unstable recovery. Existing technologies typically compensate for the decreased gold recovery under suppression conditions by increasing the collector dosage, extending the flotation time, or introducing strong oxidants or heavy metal activators. However, these methods are prone to side effects such as non-selective activation of copper minerals, excessive oxidation of the mineral surface, or increased complexity of the reagent system, making it difficult to effectively restore gold flotation behavior while ensuring the stability of copper mineral separation. Existing technologies mostly improve upon the process by enhancing the reagents or adjusting the process, but lack targeted control methods for the "gold interface under suppressed conditions". In particular, there is a lack of technical means to selectively restore the activity of the gold-carrier interface without destroying the overall suppressed state of the copper mineral.

[0004] Therefore, it is necessary to propose a new flotation method that, from the perspective of microscopic regulation of the mineral interface, can accurately restore the gold flotation behavior in copper sulfide gold-bearing ores under the condition of organic sulfur inhibition. Summary of the Invention

[0005] The purpose of this application is to provide a flotation method for copper sulfide gold-bearing ores based on the synergistic effect of interfacial selective oxidation and copper ions, so as to solve the above-mentioned problems.

[0006] To achieve the above objectives, this application provides a flotation method for copper sulfide gold-bearing ores based on the synergistic effect of interfacial selective oxidation and copper ions, comprising:

[0007] The slurry of copper-gold sulfide ore treated with organosulfur inhibitors and a mild oxidation medium are first mixed and first reacted to obtain an oxidized slurry.

[0008] The oxidized slurry and the copper ion regulating component are subjected to a second mixing and a second reaction to obtain a copper ion regulated slurry.

[0009] The copper ion-modified slurry, collector, and frother are then mixed and floated to obtain a gold-bearing concentrate.

[0010] Optionally, the copper sulfide gold-bearing ore includes at least one of chalcopyrite, bornite, and chalcocite;

[0011] And / or, the organosulfur inhibitors include sodium thioglycolate;

[0012] And / or, the organosulfur inhibitor forms a sulfur-containing organic adsorption layer in the copper sulfide gold-bearing ore and the gold-bearing interface.

[0013] Optionally, the solid content of the slurry is 20%-40%;

[0014] And / or, 75%-85% of the slurry has a fineness of -0.074 mm.

[0015] Optionally, the copper ion regulating component includes at least one of a soluble copper salt, a complexed copper ion release system, and a solid-phase copper ion sustained-release system.

[0016] The soluble copper salt includes at least one of copper sulfate, copper nitrate, and copper chloride;

[0017] The complexed copper ion release system includes at least one of copper citrate, copper tartrate, and copper ethylenediaminetetraacetate.

[0018] The solid-phase copper ion slow-release system includes at least one of cuprous oxide, basic copper carbonate, and copper-containing mineral powder.

[0019] Optionally, the copper ion regulating component, by mass parts, comprises:

[0020] 100 parts soluble copper salt, 0-30 parts complexed copper ion release system and 0-20 parts solid phase copper ion release system.

[0021] Optionally, the mild oxidizing medium includes ozone and / or hydrogen peroxide.

[0022] Optionally, the pH value of the first reaction is 6.5-8;

[0023] And / or, the time for the first reaction is 3-8 minutes;

[0024] And / or, the flow rate of ozone in the mildly oxidizing medium is 0.2-0.6 L / min; the dosage of hydrogen peroxide is 80-150 g / t slurry;

[0025] And / or, the ozone is prepared into ozone micro-nano bubble water for use.

[0026] Optionally, the pH value of the second reaction is 7-9;

[0027] And / or, the second reaction takes 3-5 minutes;

[0028] And / or, the amount of copper ions in the copper ion regulating component is 20-80 g / t slurry.

[0029] Optionally, the collector may include at least one of xanthate, pyridine, and thiol collectors;

[0030] And / or, the foaming agent is No. 2 oil.

[0031] Optionally, the flotation includes roughing, cleaning, and sweeping.

[0032] In the roughing process, the amount of collector used is 80-120 g / t slurry, the amount of frother used is 20-40 g / t slurry, and the roughing time is 8-10 min.

[0033] The purification process also includes the addition of an inhibitor, which includes water glass, at a dosage of 100-250 g / t slurry, and the purification time is 6-12 min.

[0034] The scavenging process also includes the addition of a collector and a frother. During the scavenging process, the amount of the collector is 10-30 g / t of slurry, the amount of the frother is 5-10 g / t of slurry, and the scavenging time is 4-6 min.

[0035] Compared with the prior art, the beneficial effects of this application include:

[0036] This application provides a flotation method for gold-bearing copper sulfide ores based on the synergistic effect of interfacial selective oxidation and copper ions. The method targets gold-bearing copper sulfide ores treated with organic sulfur inhibitors during copper-molybdenum separation. Targeting the characteristic that gold is mainly distributed on the surface or in finely embedded forms on copper sulfide minerals, the method performs a mild, interfacial selective oxidation treatment on the mineral interface to reduce or disrupt the adsorption state of organic sulfur inhibitors on the surface of gold-bearing copper sulfide minerals, exposing highly reactive interfacial sites associated with gold occurrence. Based on this, a copper ion regulating component is introduced, causing copper ions to preferentially adsorb or coordinate at the interfacial sites, reconstructing the local chemical environment of the gold-copper sulfide mineral interface, enhancing the interfacial affinity between gold and the collector, thereby restoring and strengthening the flotation response of gold. This method does not aim to improve the overall floatability of copper sulfide minerals, but achieves efficient recovery of gold from copper sulfide minerals without compromising the selectivity of the original copper-molybdenum separation system. The process conditions are mild and applicable to various copper sulfide gold-bearing ore systems. Attached Figure Description

[0037] To more clearly illustrate the technical solutions of the embodiments of this application, the accompanying drawings used in the embodiments will be briefly described below. It should be understood that the following drawings only show some embodiments of this application and should not be regarded as a limitation on the scope of this application.

[0038] Figure 1 This is a schematic diagram of the process for the flotation method of copper sulfide gold-bearing ore based on the synergistic effect of interfacial selective oxidation and copper ions, as provided in Example 1. Detailed Implementation

[0039] To address the problems of low gold flotation recovery and poor stability in associated copper-gold ores under the action of organosulfur inhibitors in existing technologies, this application aims to provide a flotation method for copper-sulfide gold-bearing ores based on interfacial selective oxidation and synergistic regulation of copper ions. By adjusting the microscopic chemical state of the mineral surface under the inhibited state, the effective active sites of gold in copper-sulfide minerals are reconstructed in a directional manner. Without removing or significantly weakening the overall inhibitory effect of copper minerals, the interfacial interaction between gold and collector is restored and enhanced, thereby improving the flotation recovery and flotation stability of gold.

[0040] First, the solution provided in this application will be explained in more detail as follows:

[0041] This application provides a flotation method for copper sulfide gold-bearing ores based on the synergistic effect of interfacial selective oxidation and copper ions, comprising:

[0042] The slurry of copper-gold sulfide ore treated with organosulfur inhibitors and a mild oxidation medium are first mixed and first reacted to obtain an oxidized slurry.

[0043] It is important to note that gold in copper sulfide gold-bearing ores is mainly hosted on the surface, grain boundaries, defect sites, or near-surface layers of copper sulfide minerals. Organic sulfur inhibitors are used as inhibitors in pre-flotation treatment or copper-molybdenum separation processes. They form a sulfur-containing organic adsorption layer at the interface between the copper sulfide mineral and the gold-bearing mineral, thereby reducing the flotation responsiveness of gold. This application involves a controlled interface-selective oxidation treatment on the surface of copper sulfide minerals inhibited by organic sulfur inhibitors. This treatment preferentially destroys or weakens the covering effect of organic sulfur inhibitors at the gold-bearing interface and forms discontinuously distributed oxidation active sites at the gold or gold-copper transition interface. At the same time, it avoids the formation of a continuous and dense oxide film on the main crystal surface of the copper sulfide mineral, thereby maintaining the overall inhibition state of the copper mineral without significant damage, thus weakening or destroying the adsorption or complexation structure formed by organic sulfur inhibitors at the gold-bearing interface.

[0044] It should also be noted that the first reaction is interfacial selective oxidation treatment, with the control principle being to prevent the formation of a continuous and dense oxide film on the mineral surface of copper sulfide gold-bearing ore, so that the overall floatability of copper sulfide gold-bearing ore minerals is not significantly enhanced.

[0045] The oxidized slurry and the copper ion regulating component are subjected to a second mixing and a second reaction to obtain a copper ion regulated slurry.

[0046] It is important to note that copper ions preferentially adsorb or complex at the active sites of the gold-bearing interface exposed after selective interfacial oxidation, acting as interfacial bridging centers between gold and xanthate, dithiocyanate, or thiol collectors, restoring the collecting responsiveness of gold in the inhibited state, rather than acting as an overall activator for copper sulfide minerals, thus avoiding non-selective flotation of copper minerals. This improves the flotation recovery and flotation stability of gold hosted in copper sulfide minerals that are inhibited by organosulfur inhibitors, without significantly increasing the overall floatability of gold-bearing copper sulfide minerals.

[0047] The copper ion-modified slurry, collector, and frother are then mixed and floated to obtain a gold-bearing concentrate.

[0048] It should be noted that, without changing the conventional flotation process structure, collectors and frothers can be added for flotation to recover gold-bearing concentrate.

[0049] It should also be noted that this application achieves precise optimization of copper-gold flotation behavior by selectively regulating the interface of copper-gold sulfide minerals treated with organosulfur inhibitors. While maintaining the flotation activity of gold minerals, it can effectively suppress the non-selective flotation of non-target copper minerals or gangue, thereby significantly improving the recovery rate and grade of gold concentrate. This method forms discontinuous oxidizing active sites through a mild oxidizing medium and is supplemented by synergistic regulation with copper ions, achieving a directional enhancement of the affinity between gold and mineral interfaces. This avoids the side effects that may occur during traditional strong oxidation or high-concentration heavy metal activation processes, such as excessive mineral oxidation, competitive adsorption of collectors, and loss of impurity copper. At the same time, the process conditions of this application are mild and easy to operate, and can be directly embedded into existing flotation processes, making it easy to scale up for industrial applications. More importantly, this method is applicable to different types of associated copper-gold ore systems. Whether it is copper sulfide type, sulfide-oxidation mixed type, or complex gangue-enriched deposits, it can achieve stable and efficient gold recovery, showing strong versatility and practical value, and providing a new technical approach for the high-selectivity flotation of associated copper-gold ore.

[0050] In some embodiments, the copper sulfide gold-bearing ore includes at least one of chalcopyrite, bornite, and chalcocite;

[0051] And / or, the organosulfur inhibitors include sodium thioglycolate;

[0052] And / or, the organosulfur inhibitor forms a sulfur-containing organic adsorption layer in the copper sulfide gold-bearing ore and the gold-bearing interface.

[0053] In some embodiments, the solid content of the slurry is 20%-40%;

[0054] Optionally, the solid content of the slurry can be any value between 20%, 25%, 30%, 35%, 40%, or 20-40%.

[0055] Preferably, the solid content of the slurry is 25-35%;

[0056] And / or, 75%-85% of the slurry has a fineness of -0.074 mm.

[0057] Optionally, the pulp fineness of -0.074 mm can be any value between 75%, 80%, 85%, or 75-85%.

[0058] It is important to note that by using this grinding system, while ensuring that the solid content of the slurry is 20%-40% and the fineness of the slurry is -0.074mm, 75%-85% of the slurry is basically liberated as individual copper sulfide minerals (chalcopyrite, bornite, chalcocite, etc.) are present, over-grinding that causes mud formation is avoided, thus providing a stable and controllable slurry system for subsequent interface control treatment.

[0059] Preferably, the mild oxidation medium includes ozone nanobubble water, which performs interfacial selective oxidation treatment on the slurry. The introduction time of ozone nanobubbles is controlled to be about 5 minutes, so as to induce the formation of dispersed oxidation active sites at the gold-bearing interface without destroying the overall floatability of the mineral.

[0060] In some embodiments, the copper ion regulating component includes at least one of a soluble copper salt, a complexed copper ion release system, and a solid-phase copper ion release system.

[0061] It is important to note that solid-phase copper ion slow-release systems include systems that can induce localized dissolution and release of copper ions from the surface of copper sulfide minerals under the influence of slurry chemical conditions, including pH control, redox potential control, or interfacial selective oxidation treatment; all three types of agents essentially provide copper ions and have the same effect; Cu 2+ It can form a Cu2S or Cu(I)-S active layer on the mineral surface, thereby enhancing the adsorption capacity of the collector; that is, it plays the role of providing copper ions.

[0062] The soluble copper salt includes at least one of copper sulfate, copper nitrate, and copper chloride;

[0063] Preferably, the soluble copper salt includes copper sulfate, with an addition amount of 50 g / t and a stirring time of 4 min, thereby promoting the directional adsorption or complexation of copper ions at the gold-loaded active sites and enhancing the interfacial interaction between gold and the collector.

[0064] The complexed copper ion release system includes at least one of copper citrate, copper tartrate, and copper ethylenediaminetetraacetate.

[0065] The solid-phase copper ion slow-release system includes at least one of cuprous oxide, basic copper carbonate, and copper-containing mineral powder; the solid-phase copper ion slow-release system gradually releases copper ions in the slurry system through dissolution or interfacial reaction.

[0066] In some embodiments, the copper ion regulating component, by mass parts, comprises:

[0067] 100 parts soluble copper salt, 0-30 parts complexed copper ion release system and 0-20 parts solid phase copper ion sustained release system.

[0068] Optionally, the copper ion regulating component, by mass parts, can be any value between 0, 5, 10, 15, 20, 25, 30 or 0-30 for the complexed copper ion release system, and any value between 0, 5, 10, 15, 20 or 0-20 for the solid-phase copper ion sustained-release system.

[0069] Preferably, the copper ion regulating component comprises, by mass, 100 parts of soluble copper salt, 0-30 parts of complexed copper ion release system, and 0-20 parts of solid-phase copper ion sustained-release system.

[0070] It should be noted that the copper ion regulating component, by mass, includes: 100 parts soluble copper salt, 15 parts complexed copper ion release system and 8 parts solid-phase copper ion sustained-release system.

[0071] By combining soluble copper salts, complexed copper ion release systems, and solid-phase copper ion release systems, copper ion sources with different release rates are formed in the slurry. Soluble copper salts enable rapid release of copper ions, the complexed copper system provides slow release regulation, and the solid-phase copper source provides continuous trace replenishment, thus constructing a gradient copper ion release mechanism of "rapid release-slow regulation-continuous replenishment." This multi-source copper ion system generates a synergistic regulatory effect at the gold-loaded interface, enabling copper ions to continuously participate in the interfacial activation process. Without disrupting the overall inhibition state of the copper minerals, it enhances the interfacial interaction between gold and the collector, exhibiting a significant synergistic enhancement effect.

[0072] In some embodiments, the mild oxidizing medium includes ozone and / or hydrogen peroxide.

[0073] It should be noted that both ozone and hydrogen peroxide are precursors for the controlled release of high-valence oxides, which are chemical precursors that can gradually generate high-valence oxides or strong oxide species in the reaction system.

[0074] In some embodiments, the mild oxidizing medium includes ozone and / or hydrogen peroxide.

[0075] It should be noted that both ozone and hydrogen peroxide are precursors for the controlled release of high-valence oxides, which are chemical precursors that can gradually generate high-valence oxides or strong oxide species in the reaction system.

[0076] In some embodiments, the pH value of the first reaction is 6.5-8;

[0077] Optionally, the pH value of the first reaction can be 6.5, 7, 7.5, 8, or any value between 6.5 and 8;

[0078] It is important to note that controlling the slurry pH in the first reaction stage (ozone nanobubble treatment stage) within the range of 6.5-8 is based on a comprehensive analysis of the interfacial chemical properties of copper sulfide gold-bearing minerals and the kinetic characteristics of the ozone oxidation reaction. Under these pH conditions, ozone can maintain a relatively stable molecular state in the aqueous system while also moderately decomposing near the mineral interface to generate small amounts of reactive oxygen species (such as ·OH and O2). -(etc.), thus forming a mild and controllable oxidation environment. In this environment, ozone preferentially acts on the adsorption layer formed by organic sulfur inhibitors on the mineral surface and its adjacent areas, causing local oxidation or destruction of the bond structure of the inhibitor molecules, thereby achieving selective destruction and reconstruction of the inhibitor layer on the mineral surface.

[0079] Meanwhile, under weakly neutral to slightly alkaline conditions, the main crystal faces of copper sulfide minerals are not prone to vigorous oxidation reactions, and it is difficult for a continuous and dense oxide film to form on the mineral surface. Therefore, significant changes in the overall floatability of the mineral can be avoided. At this time, ozone oxidation mainly concentrates on areas with thinner inhibitory layer coverage or more active interfacial structures, causing discontinuously distributed oxidation active sites to form on the mineral surface, thereby achieving selective oxidation of the gold-supported interface. These locally formed oxidation active sites facilitate the re-exposure of the gold or gold-copper interface that was originally covered by the inhibitor, promoting the exposure and reconstruction of active sites at the gold-supported interface.

[0080] Through the above-mentioned effects, while maintaining the overall stability of the copper mineral's suppressed state, the shielding effect of organic sulfur inhibitors on the gold-supported interface can be effectively weakened. This provides favorable conditions for the subsequent directional adsorption or complexation of copper ions at the interface, thereby further promoting the formation of interfacial bridging structures between gold and the collector, and improving the flotation responsiveness of gold in the suppressed system. Therefore, controlling the pH in the first reaction stage within the range of 6.5-8 is beneficial for achieving selective oxidation regulation and interfacial activity recovery of the suppressed gold-supported interface by ozone nanobubbles, thus significantly improving the gold flotation recovery effect and the stability of the flotation process.

[0081] And / or, the time for the first reaction is 3-8 minutes;

[0082] Optionally, the time for the first reaction can be any value between 3 min, 4 min, 5 min, 6 min, 7 min, 8 min, or 3-8 min;

[0083] And / or, the flow rate of ozone in the mildly oxidizing medium is 0.2-0.6 L / min, and the amount of hydrogen peroxide is 80-150 g / t slurry;

[0084] Optionally, the ozone flow rate can be any value between 0.2 L / min, 0.3 L / min, 0.4 L / min, 0.5 L / min, 0.6 L / min or 0.2-0.6 L / min, and the hydrogen peroxide dosage can be any value between 80 g / t slurry, 90 g / t slurry, 100 g / t slurry, 110 g / t slurry, 120 g / t slurry, 130 g / t slurry, 140 g / t slurry, 150 g / t slurry or 80-150 g / t slurry.

[0085] And / or, the ozone is prepared into ozone micro-nano bubble water for use.

[0086] It is important to note that compared with directly introducing ozone gas, using ozone micro-nano bubbles to treat the slurry can improve the dissolution efficiency and utilization rate of ozone in the slurry, making the oxidation more concentrated at the mineral interface, thereby achieving mild and selective oxidation of the mineral surface. While destroying the inhibition layer, it avoids excessive oxidation or passivation of the mineral surface and improves the adsorption efficiency of flotation reagents on the target mineral surface.

[0087] In some embodiments, the pH value of the second reaction is 7-9;

[0088] Optionally, the pH value of the second reaction can be any value between 7, 8, 9, or 7-9;

[0089] It is important to note that the second reaction stage involves adding copper ions to the pulp to regulate the composition and then performing flotation separation. In this invention, the pulp pH is controlled within the range of 7-9 during this stage, primarily based on a comprehensive consideration of factors such as the form of copper ions in the aqueous system, the interfacial reaction characteristics of copper sulfide gold-bearing minerals, and the behavior of the collector. Within this pH range, copper ions in the pulp mainly exist as free Cu. 2+ and small amounts of hydrolyzed forms (such as CuOH) + The presence of these substances (such as copper sulfide minerals) allows them to maintain good migration ability while possessing moderate surface reactivity. This facilitates directional adsorption or complexation at the active sites on the gold-loaded interface formed after selective oxidation in the first reaction stage, thereby constructing local copper active centers near the gold-copper sulfide mineral interface. This interface structure enhances the chemical interaction between the collector molecules and the gold-loaded interface, increases the interfacial affinity between gold and the collector, and promotes the entry of gold contained in copper sulfide minerals into the foam product along with the copper minerals.

[0090] Meanwhile, under weakly alkaline conditions, organic sulfur inhibitors (such as sodium thioglycolate) in the pulp system can still maintain their inhibitory effect on the surface of the copper sulfide mineral matrix, thereby preventing non-selective overall activation of copper ions across the entire mineral surface and ensuring that the flotation process mainly regulates the gold-bearing interface region. In other words, under this pH condition, copper ions are more likely to be preferentially adsorbed at the highly reactive interface sites formed after mild oxidation treatment, rather than forming a large-area activation layer on the overall crystal surface of the mineral.

[0091] Furthermore, when the pH is above 9, copper ions are prone to further hydrolysis, generating precipitates or colloidal species such as Cu(OH)2. This not only reduces the utilization efficiency of effective copper ions but may also form a deposition layer on the mineral surface that is unfavorable for collector adsorption. Conversely, when the pH is below 7, the activity of copper ions in the slurry system is too high, easily leading to over-activation on the mineral surface and weakening the selectivity of the inhibitor system. Therefore, controlling the pH in the second reaction stage within the range of 7-9 is beneficial for maintaining the overall stability of the slurry system while ensuring that copper ions have appropriate interfacial reactivity.

[0092] In summary, by controlling the pH of the second reaction stage within the range of 7-9, the directional regulation and selective adsorption of copper ions at the active sites of the gold-supported interface can be achieved. Without disrupting the overall inhibition state of the mineral, the interfacial interaction between gold and the collector is enhanced, thereby effectively improving the flotation recovery of gold in copper sulfide minerals.

[0093] And / or, the second reaction takes 3-5 minutes;

[0094] Optionally, the time for the second reaction can be any value between 3 min, 4 min, 5 min, or 3-5 min;

[0095] And / or, the amount of copper ions in the copper ion regulating component is 20-80 g / t slurry.

[0096] Optionally, the amount of copper ions in the copper ion regulating component can be 20 g / t slurry, 30 g / t slurry, 40 g / t slurry, 50 g / t slurry, 60 g / t slurry, 70 g / t slurry, 80 g / t slurry, or any value between 20 and 80 g / t slurry.

[0097] In some embodiments, the collector includes at least one of xanthate, pyridine, and thiol collectors;

[0098] And / or, the foaming agent is No. 2 oil.

[0099] In some embodiments, the flotation includes coarse flotation, fine flotation, and sweep flotation;

[0100] Preferably, the flotation process is “one stage roughing + two stages scavenging + three stages cleaning”, with collectors added during the scavenging stage and inhibitors added during the cleaning stage;

[0101] In the roughing process, the amount of collector used is 80-120 g / t slurry, the amount of frother used is 20-40 g / t slurry, and the roughing time is 8-10 min.

[0102] Optionally, during the roughing process, the amount of collector can be 80 g / t pulp, 90 g / t pulp, 100 g / t pulp, 110 g / t pulp, 120 g / t pulp, or any value between 80 and 120 g / t pulp; the amount of frother can be 20 g / t pulp, 30 g / t pulp, 40 g / t pulp, or any value between 20 and 40 g / t pulp; and the roughing time can be 8 min, 9 min, 10 min, or any value between 8 and 10 min.

[0103] The purification process also includes the addition of an inhibitor, which includes water glass, at a dosage of 100-250 g / t slurry, and the purification time is 6-12 min.

[0104] Optionally, during the refining process, the amount of inhibitor can be 100 g / t slurry, 150 g / t slurry, 200 g / t slurry, 250 g / t slurry, or any value between 100 and 250 g / t slurry, and the refining time can be any value between 6 min, 7 min, 8 min, 9 min, 10 min, 11 min, 12 min, or 6-12 min;

[0105] The scavenging process also includes the addition of a collector and a frother. During the scavenging process, the amount of the collector is 10-30 g / t of slurry, the amount of the frother is 5-10 g / t of slurry, and the scavenging time is 4-6 min.

[0106] Optionally, during the scavenging process, the amount of collector can be any value between 10 g / t slurry, 20 g / t slurry, 30 g / t slurry, or 10-30 g / t slurry; the amount of frother can be any value between 5 g / t slurry, 6 g / t slurry, 7 g / t slurry, 8 g / t slurry, 9 g / t slurry, 10 g / t slurry, or 5-10 g / t slurry; and the scavenging time can be any value between 4 min, 5 min, 6 min, or 4-6 min.

[0107] It should be noted that this application adopts a process structure of "interface control pretreatment + conventional flotation recovery". The interface control step is set as a flotation pretreatment unit, which can be directly connected with the existing associated copper and gold ore flotation process without the need to add complex or special equipment, and has good process compatibility and engineering applicability.

[0108] Compared with existing technologies, the advantages of this application are as follows: Under the action of organosulfur inhibitors, the flotation behavior of gold hosted in copper sulfide minerals is directionally restored by selectively controlling the interface on the surface of copper sulfide gold-bearing minerals. This method avoids the interference of traditional strong oxidation or excessive copper ion activation on the overall separation behavior of copper minerals. While maintaining the stability of the copper minerals' inhibited state, it effectively enhances the interfacial affinity between gold and the collector, thereby significantly improving the gold flotation recovery rate and recovery stability. The process conditions are mild, and the process structure is highly compatible with conventional flotation processes, showing good prospects for industrial application.

[0109] The implementation schemes of this application will be described in detail below with reference to specific embodiments. However, those skilled in the art will understand that the following embodiments are only for illustrating this application and should not be regarded as limiting the scope of this application. Unless otherwise specified in the embodiments, conventional conditions or conditions recommended by the manufacturer shall apply. Reagents or instruments used without specified manufacturers are all conventional products that can be purchased commercially.

[0110] Example 1

[0111] This embodiment provides a flotation method for copper sulfide gold-bearing ores based on the synergistic effect of interfacial selective oxidation and copper ions. This embodiment uses a copper sulfide-type associated gold deposit in Hubei Province. The ore exhibits significant inhibition characteristics after treatment with sodium mercaptoacetate before flotation. The main copper minerals in the ore are chalcopyrite and a small amount of bornite, with a total content of approximately 15%-20%; the gold grade of the original ore is approximately 2-4 g / t. Gold mainly exists in the form of fine or micro-fine grains on the surface, in fractures, and between crystals of chalcopyrite, with some gold forming a close symbiotic relationship with copper sulfides. Gangue minerals are mainly quartz and sericite. Under conventional flotation conditions, the addition of sodium mercaptoacetate forms a stable mercapto complex inhibition layer on the surface of the copper minerals, leading to a significant decrease in the interaction ability between the copper sulfide gold-bearing minerals and xanthates, black dyes, or thiols as collectors, resulting in a significant reduction in the gold flotation recovery rate. The specific preparation method is as follows:

[0112] S1: Grinding and Slurry Preparation: The above-mentioned associated copper-gold ore is crushed and then ground to control the grinding fineness to be approximately -0.074 mm (approximately 83%), and a grinding slurry is prepared with a solids content of approximately 28%.

[0113] S2: Sodium mercaptoacetate inhibition treatment: Add 80g / t sodium mercaptoacetate as an inhibitor to the grinding slurry and stir for a certain period of time to allow sodium mercaptoacetate to form an inhibition layer on the surface of the copper mineral and gold-bearing interface;

[0114] S3: Interface Selective Oxidation Pretreatment: After the inhibition treatment is completed, ozone nanobubble water is added to the slurry as a mild oxidation medium. The ozone flow rate is 0.3L / min. Interface selective oxidation treatment is performed on the surface of the inhibited minerals. The ozone nanobubble introduction time is controlled at about 4min. The pH of the slurry is controlled at 7.5 (the pH value is adjusted by adding sodium carbonate).

[0115] S4: Copper ion synergistic regulation treatment: After interfacial selective oxidation treatment, a copper ion regulating component is added to the slurry. The copper ion regulating component is a copper sulfate solution, and its addition amount is controlled at approximately 50 g / t (based on Cu). 2+ (Calculation), stirring time is about 4 minutes, and the pH of the slurry is controlled at 8;

[0116] S5: Flotation Recovery of Gold Concentrate: After completing the interface control treatment, flotation operation is carried out without changing the conventional flotation process structure: Xanthate collector (butyl xanthate) is added to the pulp at a dosage of about 100 g / t, and frother (2# oil) at a dosage of about 30 g / t. After stirring, roughing flotation is carried out for 8 minutes to obtain roughing tailings and roughing concentrate. The roughing tailings are subjected to two scavenging processes. In each scavenging process, the dosage of collector is 20 g / t pulp and the dosage of frother is 8 g / t pulp. Each scavenging process lasts for 6 minutes. The roughing concentrate is subjected to three cleaning processes. During the cleaning process, an appropriate amount of inhibitor water glass is added at a dosage of 180 g / t pulp. Each cleaning process lasts for 8 minutes to finally obtain gold-bearing concentrate.

[0117] The process flow of this flotation method for copper sulfide gold-bearing ores based on the synergistic effect of interfacial selective oxidation and copper ions is as follows: Figure 1 As shown.

[0118] Under the above conditions, compared with the suppressed system without interface control treatment, the flotation recovery rate of gold was significantly improved, while the overall flotation behavior of copper minerals remained stable, without obvious overactivation. Under the above conditions, the gold concentrate recovery rate in this embodiment can reach 92%, and the copper loss rate is ≤5%.

[0119] Example 2

[0120] The difference from Example 1 is that in step S3, hydrogen peroxide solution is added to the slurry as a mild oxidizing medium at a dosage of 120 g / t.

[0121] Example 3

[0122] The difference from Example 1 is that in step S4, a copper ion regulating component is added to the slurry. The copper ion regulating component, by mass, includes:

[0123] 100 parts soluble copper salt, 15 parts complexed copper ion release system and 10 parts solid-phase copper ion release system.

[0124] Among them, the soluble copper salt is copper sulfate; the complexed copper ion release system is copper citrate; and the solid-phase copper ion slow-release system is copper oxide.

[0125] Comparative Example 1

[0126] The difference from Example 1 is that step S3 is not performed, that is, a mild oxidizing medium is not added, and the slurry obtained in step S2 is subjected to step S4 and subsequent processing.

[0127] Comparative Example 2

[0128] The difference from Example 1 is that step S4 is not performed, that is, copper ion control components are not added, and the slurry obtained in step S3 is subjected to step S5 and subsequent processing.

[0129] Comparative Example 3

[0130] The difference from Example 1 is that steps S3 and S4 are not performed, that is, a mild oxidizing medium and copper ion regulating components are not added, and the slurry obtained in step S2 is subjected to step S5 and subsequent processing.

[0131] Comparative Example 4

[0132] The difference from Example 1 is that the order of steps S3 and S4 is changed, that is, copper ion regulating components are added first, and then mild oxidation medium is added.

[0133] Comparative Example 5

[0134] The difference from Example 1 is that when ozone nanobubbles are introduced in step S3, the pH of the slurry is controlled to be 5.7.

[0135] Comparative Example 6

[0136] The difference from Example 1 is that the pH of the slurry is controlled at 10.8 during the reaction in step S4.

[0137] The gold concentrate and copper loss prepared in the above examples and comparative examples were tested, and the specific test data are shown in Table 1:

[0138] Table 1 Gold concentrate recovery rate and copper loss

[0139]

[0140] Note: Copper loss refers to the percentage of copper metal entering the tailings during the flotation process relative to the total copper metal in the original ore. It characterizes the degree of copper mineral loss during flotation, and its calculation formula is: Copper loss (%) = Copper metal in tailings / Copper metal in original ore × 100%; where: the copper metal in the tailings is obtained by chemical analysis of the flotation tailings sample. The lower the copper loss value, the better the recovery effect of copper minerals during the flotation process and the higher the process selectivity.

[0141] analyze:

[0142] As can be seen from the above tests and the test results in Table 1, all embodiments of the present invention exhibit high gold concentrate recovery rates. Among them, the gold recovery rate of Example 1 reaches 92%, and the copper loss is controlled within 5%. This indicates that the interface control method combining mild oxidation treatment with copper ion regulation can significantly improve the flotation recovery effect of gold hosted in copper sulfide minerals.

[0143] In contrast, the gold recovery rates of each comparative example were significantly lower than those of Example 1, indicating that the interface control system proposed in this invention has a significant advantage in improving gold flotation recovery.

[0144] Comparative Example 1 (without oxidation step): Comparative Example 1 did not undergo the mild oxidation treatment in step S3. Copper ion regulating components were directly added to the suppressed slurry system. Because the mineral surface was still covered by the organic sulfur inhibition layer formed by sodium mercaptoacetate, the active sites at the gold-carrying interface were difficult to expose. Copper ions could not effectively adsorb or complex at the interface, resulting in a weak interfacial interaction between gold and the collector, ultimately leading to a significant decrease in gold recovery.

[0145] Comparative Example 2 (without copper ion regulation): Comparative Example 2 underwent only mild oxidation treatment without the addition of copper ion regulation components. Although mild oxidation can weaken the covering effect of inhibitors on the mineral surface and expose some interfacial active sites to some extent, the lack of synergistic regulation by copper ions makes it difficult to form an effective chemical bridging structure at the gold-supported interface, thus limiting the improvement in gold flotation response.

[0146] Comparative Example 3 (No Oxidation + No Copper Ions): Comparative Example 3 was neither lightly oxidized nor had any copper ion regulating components added. At this time, the mineral surface still maintained a complete inhibition layer structure, and the active sites of the gold-carrying interface were severely masked. The collector could not effectively act on the gold-related interface, so the gold recovery rate was the lowest.

[0147] Comparative Example 4 (in reverse order): In Comparative Example 4, copper ions were added first to regulate the composition before mild oxidation treatment. Since copper ions were added before the formation of oxidative active sites on the mineral surface, they are prone to non-selective adsorption or hydrolysis reactions in the slurry, making it difficult to achieve directional regulation of the gold-carrying interface; the subsequent oxidation treatment may also destroy the structure of the adsorbed copper ions, thereby weakening the overall regulation effect.

[0148] Comparative Example 5 (pH too low during oxidation stage): When the slurry pH drops to 5.7 in step S3, the decomposition behavior of ozone in water changes, the proportion of active oxygen species in the system increases, which easily leads to a strong oxidation reaction on the mineral surface. This may form an oxide film on the mineral surface that is not conducive to the adsorption of the collector, thereby reducing the interface regulation effect.

[0149] Comparative Example 6 (pH too high in the copper ion stage): When the pulp pH rises to 10.8 in step S4, copper ions are prone to hydrolysis and form precipitates such as Cu(OH)2, thereby reducing the utilization efficiency of effective copper ions and potentially forming a deposit layer on the mineral surface, hindering the adsorption of the collector, and ultimately leading to a decrease in gold recovery rate.

[0150] In summary, this invention, through an interface regulation strategy of "mild oxidation treatment + synergistic regulation of copper ions," achieves the exposure and reconstruction of active sites on the gold-bearing interface without disrupting the overall inhibition state of the mineral, thereby significantly improving the flotation recovery effect of gold hosted in copper sulfide minerals.

[0151] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of this application, and are not intended to limit them. Although this application has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some or all of the technical features therein. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of this application.

[0152] Furthermore, those skilled in the art will understand that although some embodiments herein include certain features included in other embodiments but not others, combinations of features from different embodiments are intended to be within the scope of this application and form different embodiments. For example, any of the claimed embodiments can be used in any combination. The information disclosed in this background section is intended only to enhance the understanding of the general background of this application and should not be construed as an admission or in any way implying that such information constitutes prior art known to those skilled in the art.

Claims

1. A flotation method for copper sulfide gold-bearing ores based on the synergistic effect of interfacial selective oxidation and copper ions, characterized in that, include: The slurry of copper-gold sulfide ore treated with organosulfur inhibitors and a mild oxidation medium are first mixed and first reacted to obtain an oxidized slurry. The oxidized slurry and the copper ion regulating component are subjected to a second mixing and a second reaction to obtain a copper ion regulated slurry. The copper ion-modified slurry, collector, and frother are then mixed and floated to obtain a gold-bearing concentrate.

2. The flotation method for copper sulfide gold-bearing ores based on the synergistic effect of interfacial selective oxidation and copper ions according to claim 1, characterized in that, The copper sulfide gold-bearing ore includes at least one of chalcopyrite, bornite, and chalcocite. And / or, the organosulfur inhibitors include sodium thioglycolate; And / or, the organosulfur inhibitor forms a sulfur-containing organic adsorption layer in the copper sulfide gold-bearing ore and the gold-bearing interface.

3. The flotation method for copper sulfide gold-bearing ores based on the synergistic effect of interfacial selective oxidation and copper ions according to claim 1, characterized in that, The solid content of the slurry is 20%-40%; And / or, 75%-85% of the slurry has a fineness of -0.074 mm.

4. The flotation method for copper sulfide gold-bearing ores based on the synergistic effect of interfacial selective oxidation and copper ions according to claim 1, characterized in that, The copper ion regulating component includes at least one of soluble copper salt, complexed copper ion release system, and solid-phase copper ion release system. The soluble copper salt includes at least one of copper sulfate, copper nitrate, and copper chloride; The complexed copper ion release system includes at least one of copper citrate, copper tartrate, and copper ethylenediaminetetraacetate. The solid-phase copper ion slow-release system includes at least one of cuprous oxide, basic copper carbonate, and copper-containing mineral powder.

5. The flotation method for copper sulfide gold-bearing ores based on the synergistic effect of interfacial selective oxidation and copper ions according to claim 4, characterized in that, The copper ion regulating component, by mass parts, includes: 100 parts soluble copper salt, 0-30 parts complexed copper ion release system and 0-20 parts solid phase copper ion release system.

6. The flotation method for copper sulfide gold-bearing ores based on the synergistic effect of interfacial selective oxidation and copper ions according to claim 1, characterized in that, The mild oxidizing medium includes ozone and / or hydrogen peroxide.

7. The flotation method for copper sulfide gold-bearing ores based on the synergistic effect of interfacial selective oxidation and copper ions according to claim 6, characterized in that, The pH value of the first reaction is 6.5-8; And / or, the time for the first reaction is 3-8 minutes; And / or, the flow rate of ozone in the mildly oxidizing medium is 0.2-0.6 L / min, and the amount of hydrogen peroxide is 80-150 g / t slurry; And / or, the ozone is prepared into ozone micro-nano bubble water for use.

8. The flotation method for copper sulfide gold-bearing ores based on the synergistic effect of interfacial selective oxidation and copper ions according to claim 1, characterized in that, The pH value of the second reaction is 7-9; And / or, the second reaction takes 3-5 minutes; And / or, the amount of copper ions in the copper ion regulating component is 20-80 g / t slurry.

9. The flotation method for copper sulfide gold-bearing ores based on the synergistic effect of interfacial selective oxidation and copper ions according to claim 1, characterized in that, The collector includes at least one of xanthate collectors, nitric acid collectors, and thiol collectors; And / or, the foaming agent is No. 2 oil.

10. The flotation method for copper sulfide gold-bearing ores based on the synergistic effect of interfacial selective oxidation and copper ions according to any one of claims 1-9, characterized in that, The flotation process includes roughing, cleaning, and sweeping. In the roughing process, the amount of collector used is 80-120 g / t slurry, the amount of frother used is 20-40 g / t slurry, and the roughing time is 8-10 min. The purification process also includes the addition of an inhibitor, which includes water glass, at a dosage of 100-250 g / t slurry, and the purification time is 6-12 min. The scavenging process also includes the addition of a collector and a frother. During the scavenging process, the amount of the collector is 10-30 g / t of slurry, the amount of the frother is 5-10 g / t of slurry, and the scavenging time is 4-6 min.

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