N-substituted carbamoyl xanthate flotation collectors and methods of making and using same

Abstract

The present application belongs to the technical field of mineral flotation, and particularly relates to N-substituted carbamoyl xanthate flotation collector and preparation method and application. Halogenated acyl compound is used as bridging structure, and fatty amine and xanthate are introduced into two ends thereof. Compared with the prior art, the present application has the beneficial effects that the flotation collector molecule of the present application contains two functional groups of amide group and xanthate group, and the synergistic effect of the two functional groups makes the collector molecule form stable adsorption on the surface of chalcopyrite, compared with the traditional flotation collector Z-200 or xanthate, the recovery rate of the flotation collector of the present application on chalcopyrite is better under the same low dosage condition. The flotation collector of the present application can realize efficient flotation of chalcopyrite under the natural pH condition of ore pulp; a one-pot two-step method is used, and water is used as solvent, so that the use of organic solvent is avoided; the reaction condition is mild, the operation process is less, and the product yield can be up to 94% or more, which is beneficial to industrial production.

Description

Technical Field

[0001] This invention belongs to the field of mineral flotation technology, specifically relating to N-substituted carbamoyl xanthate flotation collectors, their preparation methods, and applications. Background Technology

[0002] Copper, as an important metal in the national economy, is widely used in industries such as electronics, defense, construction, and machinery. It mainly comes from copper sulfide ores, especially chalcopyrite, which often occurs in association with pyrite. Due to the similar natural floatability of chalcopyrite and pyrite, their flotation separation has always been a technical challenge in the field of mineral processing.

[0003] Currently, the mainstream industrial method for flotation separation of chalcopyrite and pyrite is the "high alkalinity + xanthate / thiocarbamate flotation collector" process. This involves using a large amount of lime to suppress pyrite under high alkalinity conditions (pH > 11) in the pulp, while simultaneously using traditional xanthate or thiocarbamate flotation collectors for copper mineral flotation. O-isopropyl-N-ethylthiocarbamate (Z-200) is a commonly used representative flotation collector in copper-sulfur separation. However, this technical approach has significant drawbacks: (i) Existing flotation collectors have insufficient selectivity, which affects the comprehensive recovery of resources. Traditional xanthate-based flotation collectors have strong collecting ability but poor selectivity. They also exhibit strong non-selective adsorption of pyrite, making it difficult to improve the grade of copper concentrate.

[0004] (ii) The high-alkali lime process brings serious economic and environmental burdens. Pipelines are severely scaled, and equipment maintenance costs increase significantly; the high-alkali environment inhibits the recovery of associated precious metals such as gold and silver, further exacerbating the waste of valuable minerals; the high-alkalinity tailings water increases the environmental management pressure and overall operating costs of the concentrator.

[0005] To address the two major pain points mentioned above, researchers have explored various xanthate-based flotation collectors. However, the molecular design of existing xanthate-based flotation collectors is mostly limited to single-end modification of xanthic acid groups, and there is still a lack of ability to introduce auxiliary functional groups with cooperative coordination capabilities into the molecule. In addition, other types of sulfide mineral flotation collectors, such as thiourethanes and thioureas, although each has its own characteristics, generally suffer from complex synthetic routes, the need for organic solvents, and high production costs, which limit their large-scale industrial application.

[0006] In view of this, the present invention is hereby proposed. Summary of the Invention

[0007] One objective of this invention is to provide an N-substituted carbamoyl xanthate flotation collector and its preparation method. A haloacyl compound is used as a crosslinking structure, with aliphatic amines and xanthates introduced to its two ends, respectively. This flotation collector molecule contains both amide and xanthate functional groups, which can synergistically chelate copper, gold, and silver ions on the mineral surface, achieving stronger collecting ability and higher selectivity under low alkalinity conditions. The preparation method employs a one-pot, two-step process with mild reaction conditions, simple operation, and water as a solvent, making it environmentally friendly. This effectively solves the technical defects of existing xanthate-based collectors, such as insufficient selectivity and complex synthesis steps.

[0008] The second objective of this invention is to provide the application of the aforementioned N-substituted carbamoyl xanthate flotation collector in the flotation of copper sulfide ores. Addressing the process bottleneck of existing technologies requiring high alkalinity of the slurry to suppress pyrite, this invention's flotation collector achieves highly efficient and selective separation of chalcopyrite and pyrite in low alkalinity slurries, fundamentally solving a series of problems associated with high-alkali lime processes, such as pipe scaling, high equipment maintenance costs, and difficulties in tailings water treatment.

[0009] The technical solution adopted in this invention is as follows: an N-substituted carbamoyl xanthate flotation collector, comprising compounds represented by the following general formula (I): ; In general formula (Ⅰ), for alkyl; For H or alkyl; for Straight-chain or branched alkyl or The alkenyl group.

[0010] Preferably, the for Alkyl, the For H or Alkyl, the for Straight-chain or branched alkyl groups.

[0011] The method for preparing the N-substituted carbamoyl xanthate flotation collector of the present invention involves sequentially reacting a fatty amine and xanthate with a haloacyl compound via a nucleophilic substitution reaction to obtain the N-substituted carbamoyl xanthate flotation collector.

[0012] Preferably, the haloacyl compound has the structure of formula (II), where X is any one of fluorine, chlorine, bromine or iodine; the aliphatic amine is selected as a primary or secondary amine; and the xanthate has the structure of formula (III), where Me is a metal element, such as sodium or potassium. ; .

[0013] Preferably, the preparation method of the N-substituted carbamoyl xanthate flotation collector includes the following steps: S1. Add chloroacetyl chloride to an aqueous solution of aliphatic amine at a temperature of -10 to 10°C for 1 to 5 hours to obtain the first reaction solution; S2. Add the aqueous solution of xanthate to the first reaction solution, and react at a temperature of 15~40℃ for 2~7 hours to obtain the second reaction solution; S3. Separate the target product from the second reaction solution.

[0014] Preferably, the temperature of the first step aliphatic amine substitution reaction is -10~10℃, and the reaction time is 1~5 hours; the temperature of the second step xanthate substitution reaction is 15~40℃, and the reaction time is 2~7 hours; the molar ratio of haloacyl compound, aliphatic amine and xanthate is 1:(1~1.1):(1~1.1).

[0015] Preferably, an acid-binding agent is added in the first step of the reaction, and the molar ratio of the haloacyl compound to the acid-binding agent in the reaction is 1:(1~1.1).

[0016] The application of the flotation collector described in this invention, or the flotation collector prepared by the preparation method described in this invention, in the flotation of copper sulfide ore.

[0017] Preferably, the flotation collector is suitable for the flotation separation of chalcopyrite and pyrite in low-alkalinity slurry.

[0018] Preferably, the flotation collector is suitable for a pulp pH of 4-10 during the flotation process.

[0019] Compared with the prior art, the beneficial effects of the present invention are as follows: (1) Excellent selectivity: The flotation collector of this invention contains two functional groups, amide and xanthate groups. Their synergistic effect allows the collector molecules to form stable adsorption on the surface of chalcopyrite, while also exhibiting a certain enrichment effect on precious metals such as gold and silver, and a very weak adsorption effect on pyrite. Single-mineral flotation results show that the pyrite recovery rate is consistently below 3% under the natural pH conditions of the pulp, indicating that this flotation collector has excellent selectivity. Compared with traditional flotation collectors Z-200 or xanthates, under the same low dosage conditions, the flotation collector of this invention has a better recovery rate for chalcopyrite.

[0020] (2) Low alkalinity adaptability: The flotation collector of the present invention can achieve efficient flotation of chalcopyrite under the natural pH conditions of the slurry. A low dose (3mg / L DBA-Bu) can achieve a recovery rate of 97.98%, which greatly reduces the consumption of alkaline adjusters such as lime, and reduces reagent costs and environmental burden.

[0021] (3) The synthesis process is green and simple: a one-pot two-step method is adopted, with water as the solvent, avoiding the use of organic solvents; the reaction conditions are mild, the operation steps are few, and the product yield can reach more than 94%, which is conducive to industrial production. Attached Figure Description

[0022] Figure 1 This is a comparison chart of the flotation performance of collectors DBA-Bu, butyl xanthate, and Z-200 under the same conditions.

[0023] Figure 2 The image shows the infrared spectrum of EA-Bu in Example 1.

[0024] Figure 3 The image shows the infrared spectrum of DEA-Bu in Example 2.

[0025] Figure 4 The infrared spectrum of BA-Bu in Example 3 is shown.

[0026] Figure 5 The infrared spectrum of DBA-Bu in Example 4 is shown.

[0027] Figure 6 This is a high-resolution liquid chromatography-mass spectrum of EA-Bu in Example 1.

[0028] Figure 7 This is a high-resolution liquid chromatography-mass spectrum of DEA-Bu in Example 2.

[0029] Figure 8 This is the high-resolution liquid chromatography-mass spectrum of BA-Bu in Example 3.

[0030] Figure 9 This is a high-resolution liquid chromatography-mass spectrum of DBA-Bu in Example 4. Detailed Implementation

[0031] To facilitate understanding of the present invention, the present invention will be described more fully and in detail below with reference to preferred embodiments, but the scope of protection of the present invention is not limited to the following specific embodiments.

[0032] Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0033] Unless otherwise specified, all reagents and raw materials used in this invention are commercially available products or products that can be prepared by known methods.

[0034] An N-substituted carbamoyl xanthate flotation collector, comprising compounds represented by the following general formula (Ⅰ): ; In general formula (Ⅰ), for alkyl; For H or alkyl; for Straight-chain or branched alkyl or The alkenyl group.

[0035] In some embodiments, the for Alkyl, the For H or Alkyl, the for Straight-chain or branched alkyl groups.

[0036] In some embodiments, the for Alkyl, the For H or Alkyl, the for Straight-chain or branched alkyl groups.

[0037] The method for preparing the N-substituted carbamoyl xanthate flotation collector of the present invention involves sequentially reacting a fatty amine and a xanthate (sodium or potassium) with a haloacyl compound via a substitution reaction to obtain the N-substituted carbamoyl xanthate flotation collector. The haloacyl compound has the structure of Formula II, where X is any one of fluorine, chlorine, bromine, or iodine, preferably chlorine; the fatty amine is selected as a primary or secondary amine; the xanthate has the structure of Formula III, where Me is any one of the primary metallic elements sodium or potassium, preferably sodium. ; .

[0038] The preparation steps are as follows: The first step is the substitution reaction of aliphatic amines. The haloacyl compound is added to the aqueous solution of the aliphatic amine, the temperature is -10~10℃, and the reaction time is 1~5 hours to obtain the first reaction solution. The second step is the xanthate substitution reaction, in which an aqueous solution of xanthate is added to the first reaction solution, the temperature is 15~40℃, and the reaction time is 2~7 hours, to obtain the second reaction solution; The third step is to separate the oily substance, i.e., the target product, from the second reaction solution.

[0039] In the aforementioned reaction, the molar ratio of the raw material haloacyl compound, fatty amine, and xanthate is 1:(1~1.1):(1~1.1). An acid-binding agent is required in the first step of the reaction, and the molar ratio of the haloacyl compound to the acid-binding agent is 1:(1~1.1). Examples of acid-binding agents include sodium hydroxide, sodium bicarbonate, sodium carbonate, and triethylamine, with sodium carbonate being preferred.

[0040] The flotation collector described in this invention, or the flotation collector prepared by the method described in this invention, is particularly suitable for the selective separation of chalcopyrite and pyrite in the flotation of copper sulfide ores. The flotation collector is suitable for a pulp pH of 4-10 during the flotation process. The dosage of the flotation collector described in this invention is 0.1-5 mg / L. During the flotation process, methyl isobutyl methanol (MIBC) or pine oil is used as a frother, preferably MIBC, and the dosage of the frother in the pulp is 5-20 mg / L.

[0041] Example 1: Preparation of the collector N-ethylcarbamoyl xanthate butyl ester (EA-Bu) In a three-necked flask equipped with a stirrer, add 2.25 g of ethylamine and 25 mL of distilled water, then cool to 0°C in an ice bath with stirring. Next, add 5.30 g of sodium carbonate as an acid-binding agent and stir until completely dissolved. This process requires strict sealing of the container to prevent ethylamine volatilization and reduced yield. Then, slowly add 5.65 g of chloroacetyl chloride dropwise at 0°C. After the addition is complete, maintain the temperature at 0°C and continue the reaction for 2 hours. No separation of the intermediate is necessary after the first step.

[0042] An aqueous solution of 8.61 g of sodium butyl xanthate was added to the reaction solution obtained in the first step, and the mixture was then kept at 30 °C for 5 hours. After the reaction was completed, the mixture was cooled to room temperature, allowed to stand and separate into layers, and the upper layer of pale yellow oily liquid was obtained, which was the target product EA-Bu, with a yield of approximately 83%.

[0043] Example 2: Preparation of the collector N,N-diethylcarbamoyl xanthate butyl ester (DEA-Bu) In a three-necked flask equipped with a stirrer, 3.66 g of diethylamine and 30 mL of distilled water were added, and the mixture was then placed in an ice bath and cooled to 0°C with stirring. Subsequently, 5.30 g of sodium carbonate was added as an acid-binding agent, and the mixture was stirred until completely dissolved. This process required strict sealing of the container to prevent diethylamine volatilization and reduced yield. Then, 5.65 g of chloroacetyl chloride was slowly added dropwise at 0°C, and the reaction was continued at 0°C for 2 hours after the addition was complete. After the reaction was complete, an aqueous solution of 8.61 g of sodium butyl xanthate was added to the three-necked flask, and the reaction was then maintained at 30°C for 4 hours. After the reaction was complete, the mixture was cooled to room temperature, allowed to stand, and separated into layers. The upper layer, a pale yellow oily liquid, was obtained, which was the target product DEA-Bu, with a yield of approximately 86%.

[0044] Example 3: Preparation of the collector N-butylcarbamoyl xanthate (BA-Bu) In a three-necked flask equipped with a stirrer, 3.66 g of n-butylamine and 30 mL of distilled water were added, and the mixture was then placed in an ice bath and cooled to 0°C with stirring. Subsequently, 5.30 g of sodium carbonate was added as an acid-binding agent, and the mixture was stirred until completely dissolved. Then, 5.65 g of chloroacetyl chloride was slowly added dropwise at 0°C, and the reaction was continued at 0°C for 2 hours after the addition was complete. After the first step, an aqueous solution of 8.61 g of sodium butyl xanthate was added to the three-necked flask, and the reaction was continued at 30°C for 4 hours. After the reaction was completed, the mixture was cooled to room temperature, allowed to stand, and separated into layers. The upper layer, a yellow oily liquid, was obtained, which was the target product BA-Bu, with a yield of approximately 89%.

[0045] Example 4: Preparation of the collector N,N-dibutylcarbamoyl xanthate (DBA-Bu) In a three-necked flask equipped with a stirrer, 6.46 g of di-n-butylamine and 30 mL of distilled water were added and the flask was cooled in an ice bath. 5.30 g of sodium carbonate was added and stirred until completely dissolved. Then, 5.65 g of chloroacetyl chloride was slowly added dropwise, maintaining the temperature below 5°C during the addition. After the addition was complete, the reaction was maintained at 0°C for 2 hours. After the first step, an aqueous solution of 8.61 g of sodium butyl xanthate was added to the three-necked flask, and the reaction was maintained at 30°C for 4 hours. After the reaction was completed, the mixture was cooled to room temperature, allowed to stand, and separated into layers. The upper layer, a yellow, viscous, oily liquid, was obtained, which was the target product DBA-Bu, with a yield of approximately 94%.

[0046] Example 5: Preparation of several other collectors Following the preparation methods described in Examples 1-4, the functional groups at both ends are derived from different aliphatic amines (ethylamine, diethylamine, butylamine, dibutylamine) and xanthates (ethyl xanthate, isopropyl xanthate, butyl xanthate, pentyl xanthate, etc.). During the preparation process, thin-layer chromatography (TLC) was used to monitor the raw materials and products in real time. The collectors prepared in this invention are all insoluble in water but soluble in common solvents such as methanol, acetone, and ethyl acetate, and are stable at room temperature and in the dark.

[0047] The collector is any one of the following compounds: ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; .

[0048] The above-mentioned collectors, when used in the dosage range of 3~5 mg / L, achieve a flotation recovery rate of over 80% for chalcopyrite and a flotation recovery rate of less than 3% for pyrite; they exhibit excellent selectivity.

[0049] The chemical structures of all products were determined by infrared spectroscopy and high-resolution liquid chromatography-mass spectrometry. Among them, Figure 2 and Figure 6 The structure of the collector EA-Bu in Example 1 was determined; Figure 3 and Figure 7 The structure of the collector DEA-Bu in Example 2 was determined; Figure 4 and Figure 8 The structure of the collector BA-Bu in Example 3 was determined; Figure 5 and Figure 9 The structure of the collector DBA-Bu in Example 4 was determined.

[0050] Application Example 1: Micro-flotation experiment of collector EA-Bu on chalcopyrite The raw material for the micro-flotation experiment was chalcopyrite, the purity of which was confirmed by elemental analysis (chalcopyrite: Cu 33.28%, Fe 32.14%, S 33.21%). The ore was crushed and sieved, and the -74 to +38 μm particle size was used for later use.

[0051] For each flotation experiment, 2.0 g of a single mineral was weighed and placed in a 30 mL XFGC type hanging flotation cell. The mixture was stirred at 1758 r / min for 2 min to ensure thorough dispersion. The collector EA-Bu (0.1~5 mg / L) of this invention was added, and the mixture was stirred for 2 min. Then, the frother MIBC (5 mg / L) was added, and the mixture was stirred for 2 min, followed by manual skimming of the foam for 3 min. After flotation, the foam product and the product in the cell were dried and weighed separately, and the recovery rate was calculated. Each experiment was repeated three times, and the average value was taken.

[0052] The results showed that, under the natural pH of the slurry (range of 4-10 in random sampling), the recovery rate of chalcopyrite was 82.00% when the amount of collector EA-Bu was 4 mg / L.

[0053] Application Example 2: Micro-flotation Experiment of Pyrite Using Collector EA-Bu The raw material for the micro-flotation experiment was pyrite, the purity of which was confirmed by elemental analysis (pyrite: Fe 44.42%, S 51.35%). The ore was crushed and sieved, and the -74 to +38 μm particle size was used for later use.

[0054] For each flotation experiment, 2.0 g of a single mineral was weighed and placed in a 30 mL XFGC type hanging flotation cell. The mixture was stirred at 1758 r / min for 2 min to ensure thorough dispersion. The collector EA-Bu (0.1~5 mg / L) of this invention was added, and the mixture was stirred for 2 min; then the frother MIBC (5 mg / L) was added, and the mixture was stirred for 2 min, followed by manual skimming of the foam for 3 min. After flotation, the foam product and the product in the cell were dried and weighed separately, and the recovery rate was calculated. Each experiment was repeated three times, and the average value was taken.

[0055] The results showed that, under the natural pH of the slurry, the recovery rate of pyrite was 2.35% when the amount of collector EA-Bu was 4 mg / L.

[0056] Application Example 3: Micro-flotation experiment of collector DEA-Bu on chalcopyrite The raw materials and equipment used in the micro-flotation experiment were the same as those in Application Example 1. Under the conditions of stirring speed of 1758 r / min, pine oil dosage of 8 mg / L, natural pH of slurry, and collector DEA-Bu dosage of 4 mg / L, the recovery rate of chalcopyrite was 85.99%.

[0057] Application Example 4: Micro-flotation Experiment of Pyrite Using Collector DEA-Bu The raw materials and equipment used in the micro-flotation experiment were the same as those in Application Example 2. Under the conditions of stirring speed of 1758 r / min, pine oil dosage of 8 mg / L, natural pH of slurry, and collector DEA-Bu dosage of 4 mg / L, the recovery rate of pyrite was 2.16%.

[0058] Application Example 5: Microflotation Experiment of Collector BA-Bu on Chalcopyrite The raw materials and equipment used in the micro-flotation experiment were the same as those in Application Example 1. Under the conditions of stirring speed of 1758 r / min, frother MIBC dosage of 10 mg / L, natural pH of slurry, and collector BA-Bu dosage of 3 mg / L, the recovery rate of chalcopyrite was 95.44%.

[0059] Application Example 6: Micro-flotation Experiment of Pyrite Using Collector BA-Bu The raw materials and equipment used in the micro-flotation experiment were the same as those in Application Example 2. Under the conditions of stirring speed of 1758 r / min, frother MIBC dosage of 10 mg / L, natural pH of slurry, and collector BA-Bu dosage of 3 mg / L, the recovery rate of pyrite was 2.41%.

[0060] Application Example 7: Microflotation Experiment of Collector DBA-Bu on Chalcopyrite The raw materials and equipment used in the micro-flotation experiment were the same as those in Application Example 1. Under the conditions of stirring speed of 1758 r / min, frother MIBC dosage of 10 mg / L, natural pH of slurry, and collector DBA-Bu dosage of 3 mg / L, the recovery rate of chalcopyrite was 97.98%.

[0061] Application Example 8: Microflotation Experiment of Pyrite Using Collector DBA-Bu The raw materials and equipment used in the micro-flotation experiment were the same as those in Application Example 2. Under the conditions of stirring speed of 1758 r / min, frother MIBC dosage of 10 mg / L, natural pH of slurry, and collector DBA-Bu dosage of 3 mg / L, the recovery rate of pyrite was 1.83%.

[0062] Application Example 9: Flotation Experiment of Collector DBA-Bu in Actual Gold-Silver-Copper-Sulfur Ores The raw material for the flotation experiment was a gold, silver, copper and sulfur ore. The main element grades were confirmed by analysis (Cu 0.75%, Au 0.21g / t, Ag 3.75g / t, S 4.82%). The ore was crushed and screened, and the grinding fineness was -200 mesh 70%.

[0063] For each flotation experiment, 400g of mineral sample was weighed and placed in a 1L PK / FD II type single-cell flotation machine. The sample was stirred for 2 minutes at 1758 r / min to ensure thorough dispersion. Then, 30g / t of collector DBA-Bu was added and stirred for 3 minutes; followed by 20g / t of frother MIBC and stirring for 3 minutes. Aeration and frothing were then performed for 5 minutes. After flotation, the froth product and the product in the cell were filtered, dried, and weighed separately, and the recovery rate was calculated. Each experiment was repeated three times, and the average value was taken.

[0064] Experimental results show that, under the natural pH of the pulp (4-10), the copper concentrate obtained by flotation has a Cu grade of 11.36% (recovery rate 84.31%), an Au grade of 0.85 g / t (recovery rate 44.20%), and an Ag grade of 43.20 g / t (recovery rate 58.87%). The Cu grade is significantly increased (15 times), the Ag grade is also significantly increased (11 times), and the Au grade is also somewhat increased (4 times). This indicates that the flotation collector of this invention, while achieving highly efficient flotation of chalcopyrite, also has a certain enrichment effect on gold and silver.

[0065] It should be noted that the units used for copper grade, gold grade, and silver grade are not consistent in usage. They usually retain their industry-standard units, i.e., Cu grade is usually used as a percentage, while gold and silver grades are usually used as g / t. However, they can be compared uniformly through conversion (1% = 10000 g / t).

[0066] Examples 1-5 illustrate the green and simple synthesis process of the flotation collector of the present invention: a one-pot two-step method is adopted, using water as a solvent, avoiding the use of organic solvents; the reaction conditions are mild, the operation steps are few, and the product yield can reach more than 94%, which is conducive to industrial production.

[0067] Application Examples 1-8 show that the single mineral flotation results indicate that: (1) The flotation collector of the present invention has low alkalinity adaptability and can achieve efficient flotation of chalcopyrite under the natural pH conditions of the pulp. A low dose (3 mg / L DBA-Bu) can achieve a recovery rate of 97.98%, which greatly reduces the consumption of alkaline adjusters such as lime, and reduces reagent costs and environmental burden. (2) The flotation collector of the present invention has outstanding selectivity and extremely weak adsorption on pyrite. Under the natural pH conditions of the pulp, the pyrite recovery rate is always below 3%, indicating that the flotation collector has excellent selectivity. Therefore, the application of the flotation collector described in the present invention or the flotation collector prepared by the preparation method described in the present invention in the flotation of copper sulfide ore is particularly suitable for the selective separation of chalcopyrite and pyrite, and can be carried out under the natural pH conditions of the pulp.

[0068] Comparative Example 1: Microflotation experiment using conventional flotation collector butyl xanthate. Under the same flotation conditions, conventional butyl xanthate was used instead of the collector of the present invention for single mineral flotation.

[0069] Comparative Example 2: Microflotation experiment of conventional collector Z-200. Under the same flotation conditions, Z-200 was used instead of the collector of the present invention for single mineral flotation.

[0070] The flotation performance comparison results of collectors DBA-Bu, butyl xanthate, and Z-200 under the same conditions are as follows: Figure 1 As shown in the figure, within the dosage range of less than 5 mg / L, the collecting ability for chalcopyrite is: collector DBA-Bu > butyl xanthate > Z-200, and the difference between the three narrows with increasing dosage. For pyrite, the collecting ability is: butyl xanthate > Z-200 > collector DBA-Bu. However, the recovery rate of pyrite by DBA-Bu is much lower than that of traditional butyl xanthate, and the collecting ability of collector DBA-Bu for pyrite remains essentially unchanged with increasing dosage; this indicates that the collector of this invention has superior selectivity. This comparison fully demonstrates that the flotation collector of this invention has significant advantages in terms of reagent dosage and pulp pH. Compared with traditional flotation collectors Z-200 or xanthate, under the same low dosage conditions, the flotation collector of this invention has a better recovery rate for chalcopyrite.

[0071] Mechanism Explanation: Unlike traditional flotation collectors such as butyl xanthate (which uses a single xanthate group to provide a chelating site) and Z-200 (which uses a thiocarbamate group to provide a chelating site), the flotation collector of this invention contains both amide and xanthate functional groups. The xanthate group provides a sulfur atom as a coordination site, while the amide group provides a carbonyl oxygen atom as a coordination site. Furthermore, the two groups are linked by a rotatable flexible connection via a methylene group, facilitating synergistic chelation and co-coordination between the two functional groups, resulting in stable adsorption of the collector molecule on the chalcopyrite surface. In addition, the sulfur atom of the xanthate group preferentially coordinates with copper ions, while the oxygen atom of the amide group has weak coordination ability with iron ions. Therefore, stable dual-site adsorption cannot be formed on the pyrite surface. Thus, the flotation collector of this invention exhibits outstanding selectivity for chalcopyrite and pyrite, achieving high selectivity even under natural pH conditions. Flotation is carried out under natural pH conditions, requiring little or no lime, which fundamentally solves the scaling problem. At the same time, the low alkalinity is conducive to the flotation and recovery of precious metals such as gold and silver.

[0072] The technical features of the above embodiments can be combined in any way. For the sake of brevity, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

Claims

1. The application of N-substituted carbamoyl xanthate flotation collectors, characterized in that, Application of N-substituted carbamoyl xanthate flotation collectors in the flotation of copper sulfide ores, with pulp pH ranging from 4 to 10 during the flotation process. The N-substituted carbamoyl xanthate flotation collector is represented by a compound of the following general formula (I): ； In general formula (Ⅰ), for alkyl; For H or alkyl; for Straight-chain or branched alkyl or The alkenyl group.

2. The application of the N-substituted carbamoyl xanthate flotation collector according to claim 1, characterized in that, The for Alkyl, the For H or Alkyl, the for Straight-chain or branched alkyl groups.

3. The application of the N-substituted carbamoyl xanthate flotation collector according to claim 1, characterized in that, The N-substituted carbamoyl xanthate flotation collector is used for the flotation separation of chalcopyrite and pyrite in low-alkalinity slurry.

Images