Preparation method of low-grade copper sulfide collector

Abstract

The application discloses a preparation method of a low-grade copper sulfide collector, and belongs to the technical field of ore-dressing reagents. Xanthate a is dissolved in distilled water or anhydrous ethanol to prepare xanthate solution A. Halogen element simple substance and sodium hydroxide are added into the xanthate solution A to prepare a xanthate halide solution, and the molar ratio of xanthate, halogen element simple substance and sodium hydroxide is 0.8-1.2:0.8-1.2:0.1-0.3. Xanthate b is dissolved in distilled water or anhydrous ethanol to prepare xanthate solution B. The xanthate solution B is added into the xanthate halide solution, and the molar ratio of xanthate halide and xanthate is 1:1-1.1, until the reaction is completed. The obtained liquid is left to stand and separated, the organic phase is cleaned, dried, filtered, and the target low-grade copper sulfide collector is obtained. The preparation method synthesizes a novel collector with double active adsorption sites through a two-step series process, and the collector has stronger and more selective collecting capacity for low-grade copper sulfide ore.

Description

Technical Field

[0001] This invention belongs to the field of mineral processing reagents technology, specifically relating to a method for preparing a low-grade copper sulfide collector. Background Technology

[0002] With the continuous development and utilization of copper resources, easily beneficiated sulfide copper ore resources are becoming increasingly depleted. The remaining copper ores to be developed generally exhibit characteristics of low grade, fine grain size, and complex mineral composition. At the same time, the content of pyrite and other gangue minerals in the feed ore is relatively increasing, the symbiotic relationship between minerals is close, and the liberation difficulty is increased, which brings significant challenges to the flotation separation process.

[0003] In the flotation practice of low-grade copper sulfide ores, the collector is one of the key factors determining the separation index. Currently, concentrators commonly use traditional reagents for copper sulfide ore, mainly including butyl xanthate, butylammonium xanthate, and sulfur-nitrogen compounds. These collectors can achieve good results when processing easily beneficiated high-grade ores, but as the ore properties deteriorate, their insufficient selectivity and collecting ability become increasingly apparent. The collecting effect on copper minerals weakens, while non-selective adsorption increases, leading to a simultaneous decline in copper concentrate grade and recovery rate.

[0004] Existing research both domestically and internationally largely focuses on the modification and compounding of xanthates, nitric oxides, and sulfur-nitrogen compounds, with in-depth systematic studies of their corresponding ester derivatives. At the mechanism of action level, most explanations remain based on traditional chelate adsorption theory, and the understanding of the interaction between novel molecular structures and mineral surfaces is insufficient. Furthermore, to avoid the inadequacy of single-agent performance, multiple agents are often mixed and added, leading to complex preparation operations, high investment in on-site equipment, and inconvenience in transportation and inventory management, thus increasing operating costs.

[0005] In summary, given the increasing prevalence of low-grade, complexly distributed sulfide copper ore resources as the main raw material, there is an urgent need to develop a new type of copper collector with strong collecting ability and high selectivity. This collector aims to achieve simple addition and stable use without altering the existing flotation process, thereby meeting the actual production needs for efficient separation of low-grade copper ore. Summary of the Invention

[0006] The purpose of this invention is to provide a method for preparing a low-grade copper sulfide collector.

[0007] The objective of this invention is achieved as follows: the preparation method of the low-grade copper sulfide collector includes the following steps: Xanthate a is dissolved in distilled water or anhydrous ethanol to prepare xanthate solution A; Add a halogen element and sodium hydroxide to xanthate solution A to prepare a xanthate halide salt solution, wherein the molar ratio of xanthate: halogen element: sodium hydroxide is 0.8~1.2:0.8~1.2:0.1~0.3; Xanthate b is dissolved in distilled water or anhydrous ethanol to prepare xanthate solution B. Xanthate a and b can be the same or different salts. Add xanthate solution B to xanthate halide solution, wherein the molar ratio of xanthate halide to xanthate is 1:1~1.1; after the reaction is completed, let the resulting liquid stand and separate the liquids, and the resulting organic phase is the target low-grade copper sulfide collector.

[0008] Compared with the prior art, the technical solution described in this invention has the following advantages: 1. The preparation method described in this invention does not use direct esterification, but instead first synthesizes xanthate halide salts and then couples them with a second molecule of xanthate. This intermediate has both electrophilic and nucleophilic reactivity, providing a new path for constructing C–S–S–C or S–C–S bridging structures.

[0009] 2. Sodium hydroxide plays a dual role in the reaction system, acting as both a catalyst and a neutralizer. By neutralizing the generated hydrogen halides, it prevents the irreversible acidolysis of xanthate, protects the diester product from acid-catalyzed cracking, and maintains the weak alkalinity of the system, inhibiting the oxidation of thiosalts into disulfide byproducts.

[0010] 3. In the preparation method described in this invention, xanthates a and b can be the same or different salts, thereby enabling the synthesis of symmetrical or asymmetrical dixanthates, providing a pathway for the synthesis of molecularly customized collectors for different grades and gangue minerals.

[0011] 4. The preparation method described in this invention adopts a gradient temperature design of high-temperature activation and low-temperature coupling. The high-temperature section is mainly to overcome the energy barrier of the halogenation reaction, while the low-temperature section can avoid thermal decomposition or rearrangement of the diester product, thereby ensuring the stability of the ester bond.

[0012] 5. The post-processing technology designed in this invention further improves the purity and stability of the product. By allowing it to stand, washing it with water, and drying it, residual alkali metal halide salts and other unreacted impurities are removed, and trace amounts of salts are prevented from catalyzing the hydrolysis of diesters during storage, thus affecting the flotation effect. Attached Figure Description

[0013] Figure 1 This is a process flow diagram of the technical solution described in this invention. Detailed Implementation

[0014] The present invention will be further described below, but this is not intended to limit the invention in any way. Any modifications or substitutions made based on the teachings of the present invention shall fall within the scope of protection of the present invention.

[0015] The preparation method of the low-grade copper sulfide collector of the present invention includes the following steps: Xanthate a is dissolved in distilled water or anhydrous ethanol to prepare xanthate solution A; Add a halogen element and sodium hydroxide to xanthate solution A to prepare a xanthate halide salt solution, wherein the molar ratio of xanthate: halogen element: sodium hydroxide is 0.8~1.2:0.8~1.2:0.1~0.3, preferably 1:1:0.2; Xanthates undergo substitution reactions with elemental halogens, as shown in the following equation: ROCSSMe+X2→XROCSSMe+HX, where R is selected from C1-C5 alkyl groups, such as methyl, ethyl, propyl, butyl, isobutyl, pentyl, isopentyl, neopentyl, and X is one of Cl, Br, and I.

[0016] Xanthate b is dissolved in distilled water or anhydrous ethanol to prepare xanthate solution B. Xanthate a and b can be the same or different salts, preferably the same salt. Xanthate solution B is added to xanthate halide solution, wherein the molar ratio of xanthate halide to xanthate is 1:1 to 1.1, preferably 1:1.04; The reaction equations for xanthate halide salts and xanthate salts are as follows: XROCSSMe+R′OCSSMe→ R′OCSSROCSSMe+MeX, where R and R′ are selected from C1-C5 alkyl groups, such as methyl, ethyl, propyl, butyl, isobutyl, pentyl, isopentyl, neopentyl, X is one of Cl, Br, I, and Me is one of Na and K; After the reaction is complete, the resulting liquid is allowed to stand and separated. The organic phase is then purified to obtain a high-purity, low-grade copper sulfide collector.

[0017] The xanthate is selected from any one of methyl xanthate, ethyl xanthate, propyl xanthate, butyl xanthate, isobutyl xanthate, pentyl xanthate, isopentyl xanthate, and neopentyl xanthate.

[0018] The process conditions for dissolving xanthate are: temperature 50~80℃, time 30~60min, and stirring speed 250r / min.

[0019] The halogen element is selected from any one of Cl2, Br2, and I2.

[0020] The process conditions for the reaction of xanthate with elemental halogens are a temperature of 120~180℃ and a time of 120~200min.

[0021] The reaction conditions for xanthate and xanthate halide are a temperature of 25-50°C and a time of 120-200 min.

[0022] The settling time for separation is 5-6 hours.

[0023] The purification process specifically includes organic phase washing, drying, and filtration.

[0024] The cleaning refers to rinsing with distilled water at least 3 times.

[0025] The drying temperature is 50~80℃ and the drying time is 12~14h.

[0026] Example 1

[0027] Place 344.32g of sodium butylxanthate into a 1000ml beaker, add 300ml of distilled water, and heat in a water bath for 40 minutes at a stirring speed of 250r / min and a temperature of 60℃ to dissolve and prepare a sodium butylxanthate solution.

[0028] After dividing the solution into two equal parts, 160g of elemental bromine was added dropwise to one part at a rate of 2 drops / second, and then 39.99g of sodium hydroxide was added dropwise to the solution at a rate of 2 drops / second. The reaction was carried out for 200 minutes under the conditions of stirring speed of 250r / min and reaction temperature of 120℃ to obtain sodium butylxanthate bromide solution.

[0029] Another portion of sodium butyl xanthate solution was added to the sodium butyl xanthate bromide solution, and the reaction was carried out for 150 min at a stirring speed of 250 r / min and a reaction temperature of 50 °C.

[0030] The obtained liquid was transferred to a separatory funnel and allowed to stand for 5 hours before separation. The organic phase was then taken, washed three times with distilled water, filtered, and dried at 50°C for 13 hours. After filtration, the target low-grade copper sulfide collector was obtained with a purity of 57.43% and a yield of 66.87%.

[0031] Example 2

[0032] Place 256.28g of sodium ethyl xanthate into a 1000ml beaker, add 300ml of distilled water, and heat in a water bath at a stirring speed of 250r / min and a temperature of 70℃ for 35min to dissolve and prepare a sodium ethyl xanthate solution.

[0033] After dividing the solution into two equal parts, 160g of elemental bromine was added dropwise to one part at a rate of 2 drops / second, and then 39.99g of sodium hydroxide was added dropwise to the solution at a rate of 2 drops / second. The reaction was carried out for 180 minutes under the conditions of stirring speed of 250r / min and reaction temperature of 140℃ to obtain sodium ethyl xanthate bromide solution.

[0034] Another portion of sodium ethyl xanthate solution was added to the sodium ethyl xanthate bromide solution, and the reaction was carried out for 180 min at a stirring speed of 250 r / min and a reaction temperature of 40 °C.

[0035] The obtained liquid was transferred to a separatory funnel and allowed to stand for 6 hours before separation. The organic phase was then taken, washed three times with distilled water, filtered, and dried at 60°C for 12 hours. After filtration, the target low-grade copper sulfide collector was obtained with a purity of 56.89% and a yield of 65.76%.

[0036] Example 3

[0037] —Application Examples A copper mine has a raw ore copper grade of 0.48%. After grinding to a particle size of -0.074 mm (70%), a process flow of one roughing operation, two cleaning operations, and one scavenging operation is adopted. In the laboratory, after treating the copper ore with the collector prepared in Example 1, the copper recovery rate reached 82.87%, and the copper concentrate grade reached 22.45%. However, at the beneficiation site, after sulfidation with sodium sulfide and treatment with the collector prepared in Example 1, the copper recovery rate was 82.31%, and the copper concentrate grade was 19.87%.

Claims

1. A method for preparing a low-grade copper sulfide collector, characterized in that, The process includes the following steps: Xanthate a is dissolved in distilled water or anhydrous ethanol to prepare xanthate solution A; Add a halogen element and sodium hydroxide to xanthate solution A to prepare a xanthate halide salt solution, wherein the molar ratio of xanthate: halogen element: sodium hydroxide is 0.8~1.2:0.8~1.2:0.1~0.3; Xanthate b is dissolved in distilled water or anhydrous ethanol to prepare xanthate solution B. Xanthate a and b can be the same or different salts. Add xanthate solution B to xanthate halide solution, wherein the molar ratio of xanthate halide to xanthate is 1:1~1.1; after the reaction is completed, let the resulting liquid stand and separate the liquids, and the resulting organic phase is the target low-grade copper sulfide collector.

2. The method for preparing the low-grade copper sulfide collector according to claim 1, characterized in that, The xanthate is selected from any one of methyl xanthate, ethyl xanthate, propyl xanthate, butyl xanthate, isobutyl xanthate, pentyl xanthate, isopentyl xanthate, and neopentyl xanthate.

3. The method for preparing the low-grade copper sulfide collector according to claim 1, characterized in that, The process conditions for dissolving xanthate are: temperature 50~80℃, time 30~60min, and stirring speed 250r / min.

4. The method for preparing the low-grade copper sulfide collector according to claim 1, characterized in that, The halogen element is selected from any one of Cl2, Br2, and I2.

5. The method for preparing the low-grade copper sulfide collector according to claim 1, characterized in that, The process conditions for the reaction of xanthate with elemental halogens are a temperature of 120~180℃ and a time of 120~200min.

6. The method for preparing the low-grade copper sulfide collector according to claim 1, characterized in that, The reaction conditions for xanthate and xanthate halide are a temperature of 25-50°C and a time of 120-200 min.

7. The method for preparing the low-grade copper sulfide collector according to claim 1, characterized in that, The settling time for separation is 5-6 hours.

8. The method for preparing the low-grade copper sulfide collector according to claim 1, characterized in that, The method also includes a purification step, specifically organic phase washing, drying, and filtration.

9. The method for preparing the low-grade copper sulfide collector according to claim 8, characterized in that, The cleaning refers to rinsing with distilled water at least 3 times.

10. The method for preparing the low-grade copper sulfide collector according to claim 8, characterized in that, The drying temperature is 50~80℃ and the drying time is 12~14h.

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