Flotation reagent and beneficiation method for fine-grained oxidized gold ore

Abstract

The application relates to the technical field of mineral processing, in particular to a flotation reagent for fine-grained oxidized gold ore and a beneficiation method, wherein the flotation reagent is obtained by compounding component A, component B and component C; the component A comprises at least one of sodium polysulfide such as sodium tetrasulfide and sodium pentasulfide; the component B comprises at least one of ammonium chloride, ammonium sulfate, sodium hydrosulfide, sodium carbonate and copper sulfate; and the component C comprises at least one of 8-hydroxyquinoline and 8-aminoquinoline. The flotation reagent can produce a synergistic effect with other reagents, and realizes rapid and efficient activation of gold in oxidized gold ore with poor floatability.

Description

Technical Field

[0001] This application relates to the field of mineral processing technology, specifically to flotation reagents and beneficiation methods for fine-grained oxidized gold ore. Background Technology

[0002] As a key strategic mineral resource, gold (Au) not only has financial and monetary attributes, but is also widely used in industries such as instrumentation and electronics, instrument manufacturing, chemical equipment, medical, communications, and aerospace.

[0003] Gold ore beneficiation typically selects a suitable recovery process based on the ore properties, often employing flotation, gravity separation, or a combined process. Gravity separation recovers coarse-grained gold or gold associated with carrier minerals with high sulfide density, while flotation primarily recovers fine-grained native gold or gold from other fine-grained carrier minerals. Commonly used collectors in flotation include ethyl xanthate, butyl xanthate, pentyl xanthate, and butylammonium black, while common activators include sodium sulfide, copper sulfate, and ammonium chloride. However, for oxidized gold ores, the oxidation of primary pyrite to form a large amount of porous limonite, with fine-grained and submicroscopic gold embedded in the iron oxide lattice and fractures, makes conventional single copper salts or ammonium salts ineffective in activating the carrier minerals. Furthermore, the dosage of sodium sulfide is extremely difficult to control; insufficient dosage results in poor activation, while excessive dosage can combine with gold to form fine Au₂S precipitates, rendering the gold minerals unfloatable. Excessive reagents can also consume dissolved oxygen in the pulp, greatly reducing the interaction between the collector and gold minerals, and affecting the Au grade and recovery rate of the flotation gold concentrate.

[0004] Therefore, a new flotation reagent for fine-grained oxidized gold ore is needed to achieve rapid and efficient activation of oxidized gold ore. Summary of the Invention

[0005] The purpose of this application is to overcome the shortcomings of the prior art and provide flotation reagents and beneficiation methods for fine-grained oxidized gold ores. These flotation reagents can synergistically interact with other reagents to achieve rapid and efficient activation of gold in oxidized gold ores with poor floatability.

[0006] The objective of this invention is achieved through the following technical solution: On the one hand, this application provides a flotation reagent, which is obtained by compounding component A, component B and component C; Component A includes at least one of polysulfides such as sodium tetrasulfide and sodium pentasulfide; Component B includes at least one of ammonium chloride, ammonium sulfate, sodium hydrosulfide, sodium carbonate, and copper sulfate. Component C includes at least one of 8-hydroxyquinoline and 8-aminoquinoline.

[0007] Furthermore, the weight ratio of component A, component B and component C is (65~76):(17~25):(3~15).

[0008] On the other hand, this application provides a method for beneficiating fine-grained oxidized gold ore using the above-mentioned flotation reagents, comprising the following steps: S1. Grinding: Add the flotation reagent to the fine-grained oxidized gold ore and grind it to -0.075 mm with a content of 80%~95% to obtain the ground ore sample; S2. Roughing: The raw ore sample after grinding is first stirred and slurryed, and then pH adjuster, inhibitor, collector and frother are added in sequence. Then roughing operation is carried out to obtain rough gold concentrate and rough tailings. S3. Scavenging I: The roughing tailings are stirred and slurry adjusted for the second time, and then the flotation reagents, collectors and frothers are added in sequence to carry out scavenging I operation to obtain scavenging I concentrate and scavenging I tailings. The scavenging I concentrate is returned to S2. S4. Scavenging II: The tailings from scavenging I are subjected to a third stirring and slurry preparation, and a collector and a frother are added to carry out scavenging II operation to obtain scavenging II concentrate and scavenging II tailings. The scavenging II concentrate is returned to S3. S5. Refinement: The roughed gold concentrate is subjected to a fourth stirring and slurry adjustment, and an inhibitor is added for refinement operation I to obtain refinement I concentrate and refinement I tailings. The refinement I tailings are returned to S2. The refinement I concentrate is then subjected to refinement operation II without the addition of any reagents to obtain refinement II concentrate and refinement II tailings. The refinement II tailings are returned to refinement operation I. The refinement II concentrate is then subjected to refinement operation III without the addition of any reagents to obtain refinement III concentrate and refinement III tailings. The refinement III concentrate is used as the final gold concentrate, and the refinement III tailings are returned to refinement operation II.

[0009] Furthermore, the fine-grained oxidized gold ore includes gold mineral particles with 90% being less than 30 μm and gold contained in sulfide-encapsulated containers accounting for ≤20%.

[0010] Furthermore, the pH adjuster includes at least one of sodium carbonate, sodium hexametaphosphate, sodium polyphosphate, and ammonium aminophosphate.

[0011] Furthermore, the inhibitor includes at least one of the following agents: water glass, sodium hexametaphosphate, sodium polyphosphate, sodium aminophosphate, etc.

[0012] Furthermore, the collector comprises xanthate and black powder in a weight ratio of 3:1, wherein the xanthate comprises one of butyl xanthate, Y89, and isopentyl xanthate, and the black powder comprises one of butylamine black powder, aniline black powder, or other black powder esters.

[0013] Furthermore, the foaming agent includes one of No. 2 oil and methyl isobutyl methanol.

[0014] Furthermore, in S1, the amount of flotation reagent used is 40~200 g / t based on the weight of the raw ore.

[0015] Furthermore, in S2, the concentration of the slurry after the first stirring and conditioning is 30%~45%.

[0016] Furthermore, in S2, the amount of pH adjuster used is 300~1000 g / t based on the weight of the raw ore sample after grinding.

[0017] Furthermore, in S2, the amount of the inhibitor used is 150~300 g / t based on the weight of the raw ore sample after grinding.

[0018] Furthermore, in S2, the amount of collector used is 80~250g / t based on the weight of the raw ore sample after grinding.

[0019] Furthermore, in S2, the amount of foaming agent used is 0~80g / t based on the weight of the raw ore sample after grinding.

[0020] Furthermore, in S3, the concentration of the slurry after the second stirring and conditioning is 30%~45%.

[0021] Furthermore, in S3, the amount of activator used is 10~50 g / t based on the weight of the roughing tailings.

[0022] Furthermore, in S3, based on the weight of the roughing tailings, the amount of collector used is 20~60 g / t, and the amount of frother used is 0~20 g / t.

[0023] Furthermore, in S4, the concentration of the slurry after the third stirring and conditioning is 30%~45%.

[0024] Furthermore, in S4, the amount of collector used is 10~30 g / t based on the weight of the tailings from the scavenging I process.

[0025] Furthermore, in S4, the amount of frother used is 0~10 g / t based on the weight of the tailings from the scavenging I process.

[0026] Furthermore, in S5, the concentration of the slurry after the fourth stirring and conditioning is 15%~30%.

[0027] Furthermore, in S5, the amount of the inhibitor used is 0~100 g / t based on the weight of the rough gold concentrate.

[0028] The beneficial effects of this application are: 1. This application adds flotation reagents with activating capabilities in advance during the grinding stage, which enhances the surface of freshly liberated particles and their timely interaction with the activator, reduces the influence of gangue minerals covering freshly liberated gold-bearing particles, and can effectively improve the flotation efficiency of gold minerals.

[0029] 2. The flotation reagents provided in this application adopt a combination of multiple reagents, which avoids the prominent problems of difficulty in controlling the dosage and short effective action time caused by using a single reagent such as sodium sulfide. It maximizes the synergistic effect between reagents and can effectively activate fine gold minerals and a small amount of gold minerals hosted in sulfides. It effectively solves the problem of low Au recovery rate of fine particles and achieves high-efficiency recovery of Au in ore.

[0030] 3. The flotation reagents added during the grinding and dissociation stage of this application can achieve the effect of simultaneous dissociation and activation. Combined with the subsequent addition of pH adjusters and inhibitors, and the use of middlings sequential return, the flotation effect can be effectively improved, the impact of primary and secondary slime generated by fine grinding can be reduced, and the efficient recovery of gold can be achieved. Attached Figure Description

[0031] Figure 1 A process flow diagram for beneficiation of fine-grained oxidized gold ore for this application. Detailed Implementation

[0032] The technical solution of this application is described in further detail below with reference to the accompanying drawings, but the scope of protection of this invention is not limited to the following description.

[0033] Example 1

[0034] The candidate ore in this embodiment is a domestic oxidation-type gold mine with an Au grade of 1.82 g / t. The gold in the ore mainly exists in the form of independent gold minerals (83%), which are native gold and silver gold minerals. It is mainly embedded in the intergranular limonite and in the fissures and cavities of limonite filled with clay minerals. The visible gold grain size is 1~25 μm, and the remaining 12% of the gold is hosted in sulfides or encapsulated by sulfides.

[0035] In this embodiment, the flotation reagents are a combination of sodium tetrasulfide, ammonium chloride, and 8-hydroxyquinoline in a weight ratio of 71:18:11.

[0036] Follow these steps for mineral processing: S1. Grinding: Add flotation reagent at a dosage of 150 g / t to the raw ore and grind it using a rod mill until the -0.075 mm content is 85%, to obtain the ground raw ore sample; S2. Roughing: The raw ore sample after grinding is slurry adjusted to a slurry concentration of 35%. Then, based on the weight of the raw ore sample after grinding, 800 g / t of pH adjuster Na2CO3, 230 g / t of inhibitor Na2SiO3, 200 g / t of collector (butyl xanthate and butylammonium black powder in a weight ratio of 3:1) and 40 g / t of frother No. 2 oil are added sequentially. Roughing is then carried out in a flotation machine to obtain rough gold concentrate and rough tailings. S3. Scavenging I: The roughing tailings are slurryed to a slurry concentration of 40%, and then, based on the weight of the roughing tailings, 40 g / t of flotation reagent, 50 g / t of collector (butyl xanthate and butyl ammonium black powder in a weight ratio of 3:1) and 10 g / t of frother No. 2 oil are added sequentially to carry out scavenging I operation, to obtain scavenging I concentrate and scavenging I tailings. The scavenging I concentrate is returned to S2. S4. Scavenging II. The tailings from Scavenging I are slurryed to a slurry concentration of 40%. Based on the weight of the tailings from Scavenging I, 25 g / t of collector (butyl xanthate and butyl ammonium black powder in a weight ratio of 3:1) and 5 g / t of frother No. 2 oil are added to carry out Scavenging II operation to obtain Scavenging II concentrate and Scavenging II tailings. The Scavenging II concentrate is returned to S3, and the Scavenging II tailings are used as the final flotation gold tailings. S5. Refinement. The rough gold concentrate is slurryed to a slurry concentration of 20%. 80 g / t of Na2SiO3 (a depressant) is added based on the weight of the rough gold concentrate to perform Refinement I, yielding Refinement I concentrate and Refinement I tailings. The Refinement I tailings are returned to S2. The Refinement I concentrate is then subjected to Refinement II without the addition of any reagents, yielding Refinement II concentrate and Refinement II tailings. The Refinement II tailings are returned to Refinement I. The Refinement II concentrate is then subjected to Refinement III without the addition of any reagents, yielding Refinement III concentrate and Refinement III tailings. The Refinement III concentrate is used as the final gold concentrate, and the Refinement III tailings are returned to Refinement II.

[0037] The gold concentrate and gold tailings obtained in this embodiment were analyzed and characterized by chemical dissolution and atomic absorption spectrometry, and the experimental indicators are shown in Table 1.

[0038] Table 1 Test Indicators for Gold Concentrate and Gold Tailings

[0039] Example 2

[0040] The candidate ore in this embodiment is a domestic oxidation-type gold mine with an Au grade of 1.8 g / t. The gold in the ore mainly exists in the form of independent gold minerals, which are native gold and silver gold minerals. It is mainly embedded in the intergranular limonite and in the fissures and cavities of limonite filled with clay minerals. The visible gold grain size is 1~25 μm, and the remaining 10% of the gold is hosted in sulfides or encapsulated by sulfides.

[0041] The flotation reagents in this embodiment are a 1:1 mixture of sodium tetrasulfide and sodium pentasulfide in a weight ratio of 75:19:6, copper sulfate, and 8-aminoquinoline.

[0042] Follow these steps for mineral processing: S1. Grinding: Add flotation reagent at a dosage of 180 g / t to the raw ore and grind it using a rod mill until the content of -0.075 mm is 88%, to obtain the ground raw ore sample; S2. Roughing: The raw ore sample after grinding is slurry adjusted to a slurry concentration of 35%. Then, based on the weight of the raw ore sample after grinding, 900 g / t of pH adjuster Na2CO3, 200 g / t of inhibitor Na2SiO3, 160 g / t of collector (Y89 and butyl ammonium black powder in a weight ratio of 3:1) and 40 g / t of frother No. 2 oil are added in sequence. Then, roughing is carried out in a flotation machine to obtain rough gold concentrate and rough tailings. S3. Scavenging I: The roughing tailings are slurryed to a slurry concentration of 35%, and then, based on the weight of the roughing tailings, 45 g / t of flotation reagent, 40 g / t of collector (Y89 and butyl ammonium black reagent in a weight ratio of 3:1) and 10 g / t of frother 2# oil are added sequentially to carry out scavenging I operation, to obtain scavenging I concentrate and scavenging I tailings. The scavenging I concentrate is returned to S2. S4. Scavenging II. The tailings from Scavenging I are slurryed to a slurry concentration of 35%. Based on the weight of the tailings from Scavenging I, 20 g / t of collector (Y89 and butyl ammonium black powder in a weight ratio of 3:1) and 5 g / t of frother 2# oil are added to carry out Scavenging II operation to obtain Scavenging II concentrate and Scavenging II tailings. The Scavenging II concentrate is returned to S3, and the Scavenging II tailings are used as the final flotation gold tailings. S5. Refinement. The rough gold concentrate is slurryed to a slurry concentration of 16%. 60 g / t of Na2SiO3 (a depressant) is added by weight of the rough gold concentrate to perform Refinement I, yielding Refinement I concentrate and Refinement I tailings. The Refinement I tailings are returned to S2. The Refinement I concentrate is then subjected to Refinement II without the addition of any reagents, yielding Refinement II concentrate and Refinement II tailings. The Refinement II tailings are returned to Refinement I. The Refinement II concentrate is then subjected to Refinement III without the addition of any reagents, yielding Refinement III concentrate and Refinement III tailings. The Refinement III concentrate is used as the final gold concentrate, and the Refinement III tailings are returned to Refinement II.

[0043] The gold concentrate and gold tailings obtained in this embodiment were analyzed and characterized by chemical dissolution and atomic absorption spectrometry, and the experimental indicators are shown in Table 2.

[0044] Table 2 Test Indicators for Gold Concentrate and Gold Tailings

[0045] Comparative Example 1 The same raw ore as in Example 1 was used, and mineral processing was carried out according to the method of Example 1; however, the difference between Comparative Example 1 and Example 1 is as follows: The flotation reagents are a combination of sodium tetrasulfide and 8-hydroxyquinoline in a weight ratio of 71:11.

[0046] The gold concentrate and gold tailings obtained in this embodiment were analyzed and characterized by chemical dissolution and atomic absorption spectrometry, and the experimental indicators are shown in Table 3.

[0047] Table 3 Test Indicators for Gold Concentrate and Gold Tailings

[0048] Comparative Example 2 The same raw ore as in Example 1 was used for beneficiation, and the beneficiation process was carried out according to the method of Example 1; however, the difference between Comparative Example 2 and Example 1 is as follows: The flotation reagents are a combination of sodium pentasulfide and sodium hydrosulfide in a weight ratio of 75:21.

[0049] The gold concentrate and gold tailings obtained in this embodiment were analyzed and characterized by chemical dissolution and atomic absorption spectrometry, and the experimental indicators are shown in Table 4.

[0050] Table 4 Test Indicators for Gold Concentrate and Gold Tailings

[0051] Comparative Example 3 The same raw ore as in Example 1 was used for beneficiation, and the beneficiation process was carried out according to the method of Example 1; however, the difference between Comparative Example 3 and Example 1 is as follows: The flotation reagents are a combination of copper sulfate and 8-hydroxyquinoline in a weight ratio of 66:8.

[0052] The gold concentrate and gold tailings obtained in this embodiment were analyzed and characterized by chemical dissolution and atomic absorption spectrometry, and the experimental indicators are shown in Table 5.

[0053] Table 5 Test Indicators for Gold Concentrate and Gold Tailings

[0054] Comparative Example 4 The same raw ore as in Example 1 was used for beneficiation, and the beneficiation process was carried out according to the method of Example 1; however, the difference between Comparative Example 4 and Example 1 is as follows: The flotation reagent is sodium sulfide, a conventional activator.

[0055] The gold concentrate and gold tailings obtained in this embodiment were analyzed and characterized by chemical dissolution and atomic absorption spectrometry, and the experimental indicators are shown in Table 6.

[0056] Table 6 Test Indicators for Gold Concentrate and Gold Tailings

[0057] As shown in Tables 1 and 2, Examples 1 and 2 of this application employed a closed-circuit test process involving one roughing, two scavenging, three cleaning, and sequential return of middlings. This yielded a gold concentrate with an Au grade of 28-29 g / t and an Au recovery rate of approximately 84%. The Au content in the flotation tailings was 0.29 g / t, with an Au loss rate of approximately 16%. The flotation reagents and beneficiation method provided effectively solved the problem of low recovery rates for fine and micro-fine gold oxide particles, achieving efficient gold recovery from the ore. As shown in Tables 1, 3, and 4, compared to Comparative Examples 1 and 2, the gold grade of the gold concentrate in Example 1 increased by approximately 7 g / t, and the gold recovery rate increased by 4%-6%. As shown in Tables 1 and 5, compared to Comparative Example 3, the gold grade of the gold concentrate in Example 1 increased by 6 g / t, and the gold recovery rate increased by approximately 8%. As shown in Table 6, compared to Comparative Example 4, the gold grade of the gold concentrate in Example 1 increased by 5.5%. The gold recovery rate of the gold concentrate increased by about 9% with g / t, which shows that the process and reagents of this invention have a significant effect on improving gold grade and gold recovery rate compared with the existing conventional activator sodium sulfide.

[0058] Based on the above analysis, it can be seen that this application mainly utilizes the synergistic effect between components A, B, and C in the gold ore activator, which has a good activation effect on the gold-bearing minerals and helps to enhance the interaction between the gold minerals and subsequent collectors, thereby achieving effective recovery of gold mineral particles and significantly improving the Au grade and Au recovery rate of gold concentrate.

[0059] The above description is merely a preferred embodiment of this application. It should be understood that this application is not limited to the forms disclosed herein and should not be construed as excluding other embodiments. It can be used in various other combinations, modifications, and environments, and can be altered within the scope of the concept described herein through the above teachings or the technology or knowledge in related fields. Modifications and variations made by those skilled in the art that do not depart from the spirit and scope of this invention should be within the protection scope of the appended claims.

Claims

1. A flotation reagent, characterized in that, The flotation reagent is obtained by compounding component A, component B and component C; Component A includes at least one of sodium tetrasulfide and sodium pentasulfide; Component B includes at least one of ammonium chloride, ammonium sulfate, sodium hydrosulfide, sodium carbonate, and copper sulfate. Component C includes at least one of 8-hydroxyquinoline and 8-aminoquinoline.

2. The flotation reagent according to claim 1, characterized in that, The weight ratio of component A, component B and component C is (65~76):(17~25):(3~15).

3. A method for beneficiating fine-grained oxidized gold ore using the flotation reagents as described in claims 1-2, characterized in that, Includes the following steps: S1. Grinding: Add the flotation reagent to the fine-grained oxidized gold ore and grind it to -0.075 mm with a content of 80%~95% to obtain the ground ore sample; S2. Roughing: The raw ore sample after grinding is first stirred and slurryed, and then pH adjuster, inhibitor, collector and frother are added in sequence. Then roughing operation is carried out to obtain rough gold concentrate and rough tailings. S3. Scavenging I: The roughing tailings are stirred and slurry adjusted for the second time, and then the flotation reagents, collectors and frothers are added in sequence to carry out scavenging I operation to obtain scavenging I concentrate and scavenging I tailings. The scavenging I concentrate is returned to S2. S4. Scavenging II. The tailings from scavenging I are subjected to a third stirring and slurry preparation, and a collector and a frother are added to carry out scavenging II operation to obtain scavenging II concentrate and scavenging II tailings. The scavenging II concentrate is returned to S3. S5. Refinement. The roughed gold concentrate is subjected to a fourth stirring and slurry adjustment, and an inhibitor is added for refinement operation I to obtain refinement I concentrate and refinement I tailings. The refinement I tailings are returned to S2. The refinement I concentrate is then subjected to refinement operation II without the addition of any reagents to obtain refinement II concentrate and refinement II tailings. The refinement II tailings are returned to refinement operation I. The refinement II concentrate is then subjected to refinement operation III without the addition of any reagents to obtain refinement III concentrate and refinement III tailings. The refinement III concentrate is used as the final gold concentrate, and the refinement III tailings are returned to refinement operation II.

4. The method according to claim 3, characterized in that, The fine-grained oxidized gold ore includes gold minerals in which 90% of the gold mineral particles are less than 30 μm and the gold contained in sulfide inclusions is ≤20%.

5. The method according to claim 3, characterized in that, The pH adjuster includes at least one of sodium carbonate, sodium hexametaphosphate, sodium polyphosphate, and ammonium aminophosphate. And / or, the inhibitor includes at least one of the following agents: water glass, sodium hexametaphosphate, sodium polyphosphate, sodium aminophosphate, etc. And / or, the collector comprises xanthate and black powder in a weight ratio of 3:1, wherein the xanthate comprises one of butyl xanthate, Y89, and isopentyl xanthate, and the black powder comprises one of butylamine black powder, aniline black powder, or other black powder esters; And / or, the foaming agent includes one of No. 2 oil and methyl isobutyl methanol.

6. The method according to claim 5, characterized in that, In S1, the amount of flotation reagent used is 40~200 g / t based on the weight of the raw ore.

7. The method according to claim 5, characterized in that, In S2, the concentration of the slurry after the first stirring and conditioning is 30%~45%; And / or, in S2, the amount of pH adjuster used is 300~1000 g / t based on the weight of the raw ore sample after grinding; And / or, in S2, the amount of the inhibitor used is 150~300 g / t based on the weight of the raw ore sample after grinding; And / or, in S2, the amount of collector used is 80~250 g / t based on the weight of the raw ore sample after grinding; And / or, in S2, the amount of the frother used is 0~80 g / t based on the weight of the raw ore sample after grinding.

8. The method according to claim 5, characterized in that, In S3, the slurry concentration after the second stirring and conditioning is 30%~45%; And / or, in S3, the amount of activator used is 10~50 g / t based on the weight of the roughing tailings; And / or, in S3, the amount of collector used is 20~60 g / t and the amount of frother used is 0~20 g / t, based on the weight of the roughing tailings.

9. The method according to claim 5, characterized in that, In S4, the concentration of the slurry after the third stirring and conditioning is 30%~45%; And / or, in S4, the amount of collector used is 10~30 g / t based on the weight of the tailings from the scavenging I process; And / or, in S4, the amount of frother used is 0~10 g / t based on the weight of the tailings from the scavenging I process.

10. The method according to claim 5, characterized in that, In S5, the concentration of the slurry after the fourth stirring and conditioning is 15%~30%; And / or, in S5, the amount of the inhibitor used is 0~100 g / t based on the weight of the rough gold concentrate.

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