Efficient combined collecting agent and beneficiation method for carlin type gold ore

Abstract

The invention discloses an efficient combined collecting agent for carlin type gold ore and a beneficiation method, and aims to solve the problems that the recovery rate is low and the separation efficiency is poor when a traditional collecting agent is used for recovering gold in the carlin type gold ore, ethylene diamine tetraacetic acid and sodium amyl xanthate are adopted as the efficient combined collecting agent; and hydrolysates which are non-selectively deposited on the surface of the mineral can be removed, the acting site of the collecting agent is recovered, selective adsorption of the collecting agent is promoted, and therefore the recovery rate and the separation efficiency of gold in the Carlin type gold ore are improved.

Description

Technical Field

[0001] The present invention relates to the technical field of mineral processing, and particularly relates to an efficient combined collector for Carlin-type gold ore and a beneficiation method thereof. Background Art

[0002] The gold in Carlin-type gold ore mainly exists in pyrite in the form of fine-grained invisible gold. At the same time, due to the impregnation of dolomite by ore-forming hydrothermal fluids during the geological ore-forming process, carbonates such as dolomite have become one of the main gangues in Carlin-type gold ore (Zhao Haiping, Liu Jingzhi, Hu Xueping, et al. Application of sodium aminophosphate in the efficient beneficiation of Carlin-type gold ore [J]. Nonferrous Metals Engineering, 2024, 14(6): 91-98.).

[0003] The industrial flotation results of Carlin-type gold ore show (Orlich J N, Kappes R D P, Gathje J C. Method for processing mineral material containing acid-consuming carbonate and precious metal in sulfide minerals. The United States: US9545636B2 [P], 2017-02-17.) that as the content of carbonate minerals such as dolomite in the raw ore gradually increases, the recovery rate of pyrite decreases from 51.3% to 36.7%; at the same time, as the content of pyrite in the raw ore increases from 1.2% to 3%, the floating ratio of dolomite in the concentrate increases from 8.6% to 18.7%. Theoretical research proves that during the flotation process, the alkaline environment created by dolomite promotes the oxidation of pyrite, and the acid released by the oxidation of pyrite in turn promotes the dissolution of dolomite. The Fe 2+ 、Fe 3+ 、Ca 2+ and Mg 2+ and their hydrolysis products non-selectively precipitate on the mineral surface, hindering the selective adsorption of the collector, thus deteriorating the flotation separation index of Carlin-type gold ore (Zhao H, Liu Z, Liu J, et al. Correlation of homogenization effect with flotation separation between oxidized pyrite and dolomite [J]. Minerals Engineering, 2024, 219.).

[0004] To reduce the influence of the interaction between pyrite and dolomite on the flotation of Carlin-type gold ores, early researchers conducted a large number of experimental explorations both in industry and in the laboratory. Among them, adding CuSO4 and N2 flotation are the most representative optimization methods. The experimental results show that adding CuSO4 has limited improvement on flotation indexes, and N2 flotation can economically increase the gold recovery rate, but this technology has not been widely applied because the improvement of flotation indexes of oxidized minerals by N2 flotation is not obvious, and due to the symbiosis of pyrite and dolomite, the alkaline environment created by dolomite promotes the oxidation of pyrite. Therefore, the research on the surface modification of oxidized minerals, especially the surfaces of pyrite and dolomite, is the key to improving the flotation separation efficiency of Carlin-type gold ores.

[0005] However, the surface modifiers currently disclosed on the market, such as aminophenylethane tetraacetic acid (BATPA) (Nesbitt H, Muir I. X-ray photoelectron spectroscopic study of a pristine pyrite surface reacted with water vapour and air[J]. Geochimica Et Cosmochimica Acta, 1994, 58(21):4667-79.), β-naphthalenesulfonic acid formaldehyde condensate (NSFC) (Yu J, Ge Y, Guo X, et al. The depression effect and mechanism of NSFC on dolomite in the flotation of phosphate ore[J]. Separation and Purification Technology, 2016, 161(88-95).), butyl xanthate + butylammonium dibutyl dithiophosphate (Ren Hui, Liu Jie, Wang Xun, et al. Experimental study on stage grinding-stage flotation of a gold mine in Inner Mongolia[J]. Conservation and Utilization of Mineral Resources, 2021, 41(2):106-111.), butyl xanthate + benzohydroxamic acid (Zhu Z, Nie G, Deng Q, et al. Flotation separation of pyrite and carbonate minerals from a carlin-type gold deposit in Guizhou by a new combined collector and its adsorption mechanism. Sci Rep 14, 27601(2024).), sodium carbonate + sodium hexametaphosphate + water glass + copper sulfate modifier (Chinese Patent Application CN103433143A), ethylenediamine phosphate + butylammonium dibutyl dithiophosphate + aniline dibutyl dithiophosphate + acetone (Chinese Patent Application CN107744884A) or xanthate + thionocarbamate collector (Huang Qingqi, Liao Xingjin, Wei Lianjun, et al. Experimental study on efficient flotation recovery of gold from carbonaceous Carlin-type gold ore in Guangxi[J]. Hunan Nonferrous Metals, 2022, 38(5):16-19.) have problems of low selectivity, poor recovery effect, serious slime and poor economy in the process of adjusting the surface properties of minerals for flotation of refractory Carlin-type gold ore (Sun H, Yang B, Zhu Z, et al.New insights into selective-depression mechanism of novel depressant EDTMPS on magnesite and quartz surfaces: Adsorption mechanism, DFT calculations, and adsorption model[J]. Minerals Engineering, 2021, 160(106660).), therefore, the high-efficiency recovery reagents for Carlin-type gold ores still need to be further optimized. Summary of the Invention

[0006] Aiming at the deficiencies of the prior art, the present invention aims to provide a high-efficiency combined collector for Carlin-type gold ores and a beneficiation method, which have the characteristics of improving the gold recovery rate of Carlin-type gold ores and the separation efficiency.

[0007] To achieve the above object, the present invention adopts the following technical solutions:

[0008] A high-efficiency combined collector for Carlin-type gold ores, characterized in that it comprises 15000 - 16400 parts of disodium ethylenediaminetetraacetate and 1700 - 2000 parts of sodium amyl xanthate by weight.

[0009] The present invention also provides a beneficiation method for recovering Carlin-type gold ores using the above high-efficiency combined collector, comprising the following steps:

[0010] S1. Crushing the raw ore;

[0011] S2. Mixing the ore crushed in step S1 with water, and then grinding to obtain a flotable product;

[0012] S3. Conducting three-stage all-open-circuit flotation on the flotable product obtained in step S2; before each stage of flotation, first add the above high-efficiency combined collector, stir and condition the pulp, and then conduct flotation to obtain concentrate and tailings; the tailings remaining after each stage of flotation enter the next stage of flotation, and the concentrates obtained from each stage of flotation are mixed to obtain the final concentrate, and the tailings remaining after the third stage of flotation are the final tailings; a foaming agent is also added after adding the high-efficiency combined collector before the first stage of flotation.

[0013] Further, in step S1, the raw ore is crushed to a particle size ≤ 2 mm.

[0014] Further, in step S2, the grinding is carried out in a ball mill with high-chromium media at a filling rate of 31%, and the grinding time is 11 minutes. The part with a particle size ≤ 30 μm in the obtained flotable product accounts for 86 - 92% of the total mass of the flotable product.

[0015] Further, in step S3, during each stage of flotation, the pulp mass concentration is 28-33%, and the pulp pH is maintained in an alkaline environment of 8-9.

[0016] Further, the total dosage of the high-efficiency combined collector in all stages of flotation includes 15000-16400 g / t of dry weight of the original ore for disodium ethylenediaminetetraacetate and 1700-2000 g / t of dry weight of the original ore for sodium amyl xanthate.

[0017] The beneficial effects of the present invention are as follows: Aiming at the problems of low recovery rate and poor separation efficiency when using traditional collectors to recover gold in Carlin-type gold ores, the present invention provides a high-efficiency combined collector. By using the high-efficiency combined collector of the present invention, the hydrolyzed products non-selectively deposited on the mineral surface can be removed, the action sites of the collector can be restored, and the selective adsorption of the collector can be promoted, thereby improving the recovery rate and separation efficiency of gold in Carlin-type gold ores. Specifically, disodium ethylenediaminetetraacetate has a strong complexing ability with Fe 2+ 、Fe 3+ 、Ca 2+ and Mg 2+ and their hydrolyzed products, and the complexed products are soluble in water, which can play a role in removing the hydrolyzed products on the mineral surface and provide action sites for the selective adsorption of the collector.

[0018] The combined collector in the present invention plays a good synergistic effect, and can achieve the goal of improving the recovery rate and separation efficiency of gold in the flotation process of Carlin-type gold ores. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1 It is a flowchart of the implementation of the methods of Examples 1-3 of the present invention. DETAILED DESCRIPTION OF THE INVENTION

[0020] The following will further describe the present invention in conjunction with the drawings. It should be noted that this embodiment is based on the present technical solution, and detailed implementation manners and specific operation processes are given, but the protection scope of the present invention is not limited to this embodiment.

[0021] Example 1

[0022] This example provides a beneficiation method for recovering Carlin-type gold ore using a high-efficiency combined collector. As Figure 1 shown, it includes the following steps:

[0023] S1. The original ore is crushed by a New Zealand crusher to a particle size ≤ 2 mm, and after being mixed evenly, it is reserved for use.

[0024] S2. Take 500 g of the uniformly mixed sample, mix it with 300 mL of water, and place it in a ball mill with high-chromium media (chromium content ≥ 30%) at a filling rate of 31%. Grind for 11 minutes to obtain a flotable product, and the portion with a particle size ≤ 30 μm in this flotable product accounts for 90% of the total amount of the flotable product.

[0025] S3. Conduct three-stage all-open-circuit flotation on the flotable product obtained in step S2. The tailings remaining from each stage of flotation enter the next stage of flotation. The concentrates obtained from each stage of flotation are mixed to obtain the final concentrate, and the tailings remaining after the third stage of flotation are the final tailings.

[0026] Before each stage of flotation, a high-efficiency combined collector is added in advance and stirred to condition the pulp. The high-efficiency combined collector added before the first stage of flotation contains 8000 g / t of sodium ethylenediaminetetraacetate and 900 g / t of sodium amyl xanthate based on the dry weight of the original ore, and the stirring and pulp conditioning time is 5 minutes. The dosages of the high-efficiency combined collector added in the second and third stages of flotation are the same, both including 3500 g / t of sodium ethylenediaminetetraacetate and 400 g / t of sodium amyl xanthate based on the dry weight of the original ore, and the stirring and pulp conditioning times are both 2 minutes. The flotation time for the first to third stages is 5 minutes each.

[0027] In each stage of flotation, the pulp pH is maintained in an alkaline environment of about 8.4, and the pulp mass concentration is about 29%.

[0028] In this embodiment, before the first stage of flotation, after adding the high-efficiency combined collector, foaming agent No. 2 oil is also added, with a dosage of 20 g / t of the dry weight of the original ore, and the pulp is stirred for 1 minute after adding the foaming agent.

[0029] In this embodiment, the total dosage of the high-efficiency combined collector for the three-stage flotation is 16700 g / t of the dry weight of the original ore, which includes 15000 g / t of sodium ethylenediaminetetraacetate and 1700 g / t of sodium amyl xanthate.

[0030] Example 2

[0031] The method of this embodiment is basically the same as that of Example 1, and the main difference is that the total dosage of the high-efficiency combined collector is 17900 g / t of the dry weight of the original ore, which includes 16000 g / t of sodium ethylenediaminetetraacetate and 1900 g / t of sodium amyl xanthate.

[0032] The dosage of the high-efficiency combined collector in the first stage of flotation is the same as that in Example 1, while the high-efficiency combined collector in the second and third stages both includes 4000 g / t of sodium ethylenediaminetetraacetate and 500 g / t of sodium amyl xanthate based on the dry weight of the original ore.

[0033] Example 3

[0034] The method of this embodiment is basically the same as that of Embodiment 1. The main difference is that the total dosage of the efficient combined collector is 18,400 g / t of the dry weight of the original ore, including 16,400 g / t of disodium ethylenediaminetetraacetate and 2,000 g / t of sodium amyl xanthate in the dry weight of the original ore.

[0035] The dosage of the efficient combined collector in the first-stage flotation is the same as that in Embodiment 1, while the efficient combined collector in the second-stage and third-stage flotation both contains 4,200 g / t of disodium ethylenediaminetetraacetate and 550 g / t of sodium amyl xanthate in the dry weight of the original ore.

[0036] Comparative Example 1

[0037] For a high-grade Carlin-type gold ore, the gold content in the original ore is about 4.52 g / t, and the MgO grade is about 2.86%. The characteristics of the ore are as follows: ① Most of the gold exists in pyrite in the form of fine-grained invisible gold and needs to be finely ground to obtain better dissociation; ② The main gangue is dolomite. During the oxidation process of pyrite, homogenization occurs with dolomite, resulting in non-selective precipitation of metal ions on the mineral surface, occupying the selective action sites of the collector. When using a conventional collector to float this Carlin-type gold ore, the separation efficiency of the concentrate is poor and the gold recovery rate is low.

[0038] Using the ore dressing method in Embodiment 1 to process the above ore, the obtained indexes are shown in Table 1.

[0039] Using the same above ore, replacing the efficient combined collector in the method of Embodiment 1 with a conventional collector sodium amyl xanthate for Comparative Experiment 1. The total dosage of sodium amyl xanthate is 5,000 g / t of the dry weight of the original ore (the dosages of sodium amyl xanthate in the first, second, and third-stage flotation processes are 2,500 g / t, 1,500 g / t, and 1,000 g / t respectively; the dosage of sodium amyl xanthate as a conventional collector is usually below 3,000 g / t of the dry weight of the original ore, and it is increased to 5,000 g / t in Comparative Experiment 1. Continuing to increase the dosage of sodium amyl xanthate has no effect on the data indexes).

[0040] The process indexes of Embodiment 1 and Comparative Experiment 1 are shown in Table 1 (using the MgO grade and recovery rate to replace the grade and recovery rate of gangue minerals such as dolomite):

[0041] Table 2

[0042]

[0043] As can be seen from Table 1, in Example 1, better ore dressing indexes were obtained. Compared with Comparative Experiment 1, the grade of Au in the concentrate increased by 7.78 g / t, and the recovery rate of Au increased by 39.33%. After the application of the high-efficiency combined collector, a good effect of doubling the grade and recovery rate of gold in the flotation concentrate was achieved. At the same time, after the application of the high-efficiency combined collector, the grade of MgO decreased by 0.52%, and the recovery rate of MgO decreased by 5.48%, which proved that the high-efficiency combined collector significantly improved the separation efficiency of the ore.

[0044] Comparative Example 2

[0045] For a certain low-grade Carlin-type gold ore, the gold content in the raw ore is about 1.25 g / t, and the MgO content is about 10.48%. The characteristics of the ore are as follows: ① Most of the gold exists in pyrite in the form of fine-grained invisible gold and needs to be finely ground to obtain better dissociation; ② The dolomite content is relatively high. The alkaline environment created by dolomite promotes the oxidation of pyrite. At the same time, Fe2+, Ca 2+ and Mg 2+ are non-selectively deposited on the surfaces of minerals such as pyrite and quartz, improving the floatability of gangue minerals such as quartz. As a result, when using a conventional collector to float this Carlin-type gold ore, the separation efficiency of the concentrate is poor and the recovery rate of gold is relatively low.

[0046] Using the ore dressing method in Example 2 to process the above ore, the obtained indexes are shown in Table 2.

[0047] Using the same ore above, replace the high-efficiency combined collector in the method of Example 2 with the conventional collector sodium amyl xanthate for Comparative Experiment 2. The total dosage of the conventional collector sodium amyl xanthate is 5000 g / t of the dry weight of the raw ore (the dosages of sodium amyl xanthate in the first, second, and third flotation processes are 2500 g / t, 1500 g / t, and 1000 g / t respectively. The dosage of sodium amyl xanthate as a conventional collector is usually below 3000 g / t of the dry weight of the raw ore. Increasing the dosage of sodium amyl xanthate further has no effect on the data indexes).

[0048] The process indexes of Example 2 and Comparative Experiment 2 are shown in Table 2 (using the grade and recovery rate of magnesium oxide to replace the grade and recovery rate of gangue minerals such as dolomite):

[0049] Table 2

[0050]

[0051]

[0052] As can be seen from Table 2, in Example 2, better ore dressing indexes were obtained. Compared with Comparative Experiment 2, the grade of Au in the concentrate increased by 1.50 g / t, and the recovery rate of Au increased by 21.08%. After the application of the high-efficiency combined collector, the expected goals of improving the grade and recovery rate of gold in the flotation concentrate were achieved. At the same time, after the application of the high-efficiency combined collector, the grade of MgO decreased by 3.67%, and the recovery rate of MgO decreased by 9.77%, which proved that the high-efficiency combined collector significantly improved the separation efficiency of the ore.

[0053] For those skilled in the art, various corresponding changes and deformations can be given according to the above technical solutions and concepts, and all these changes and deformations should be included in the protection scope of the claims of the present invention.

Claims

1. An efficient combined collector for Carlin-type gold ore, characterized in that, It includes 15000 - 16400 parts of disodium ethylenediaminetetraacetate and 1700 - 2000 parts of sodium amyl xanthate by weight.

2. A beneficiation method for recovering Carlin-type gold ore using the high-efficiency combined collector described in claim 1, characterized in that, It includes the following steps: S1. Crush the raw ore. S2. Take the crushed ore in step S1 and mix it with water, then carry out grinding to obtain a flotable product. S3. Conduct three-stage all-open-circuit flotation on the flotable product obtained in step S2; before each stage of flotation, first add the high-efficiency combined collector, stir and condition the pulp, and then carry out flotation to obtain concentrate and tailings; the tailings remaining after each stage of flotation enter the next stage of flotation, and the concentrates obtained from each stage of flotation are mixed to obtain the final concentrate, and the tailings remaining after the third stage of flotation are the final tailings; before the first stage of flotation, a frother is also added after adding the high-efficiency combined collector.

3. The method according to claim 2, wherein In step S1, the raw ore is crushed to a particle size ≤ 2 mm.

4. The method according to claim 2, wherein In step S2, the grinding is carried out in a ball mill with high-chromium media at a filling rate of 31%, and the grinding is carried out for 11 minutes. The part with a particle size ≤ 30 μm in the obtained flotable product accounts for 86 - 92% of the total mass of the flotable product.

5. The method according to claim 2, wherein In step S3, in each stage of flotation, the pulp mass concentration is 28 - 33%, and the pulp pH is maintained in an alkaline environment of 8 - 9.

6. The method according to claim 2, wherein The total dosage of the high-efficiency combined collector in all stages of flotation includes 15000 - 16400 g / t of the dry weight of the raw ore for disodium ethylenediaminetetraacetate and 1700 - 2000 g / t of the dry weight of the raw ore for sodium amyl xanthate.

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