A combined collector for a copper-sulfur flotation system and application thereof

Abstract

The application discloses a combined collector of copper-sulfur flotation system and application thereof, and belongs to the technical field of flotation separation of non-ferrous metal sulfide ore. The application comprises the following steps: adding sodium carbonate into the ore pulp in the ore grinding stage to adjust the weak alkaline environment of the ore pulp and improve the subsequent flotation conditions; in the copper-sulfur separation stage, sodium percarbonate and water glass are used as the weak depressor of pyrite to reduce the floatability of the pyrite through the synergistic effect of oxidation and dispersion, and dimethylthionine acetate and dimethylphenyl dithiophosphoric acid are used as the combined collector of chalcopyrite to realize the selective collection of chalcopyrite and complete the copper-sulfur separation; in the sulfur separation stage, only a small amount of copper sulfate is needed to activate the pyrite, and then the combined xanthate of ethyl xanthate, butyl xanthate and amyl xanthate is used for collection, so that the pyrite is recycled to the maximum extent, the reagent waste is reduced, and the resource utilization rate is improved. The method has the advantages of good selectivity, high separation efficiency and strong applicability, and is suitable for efficient step-by-step recovery of copper-sulfur minerals.

Description

Technical Field

[0001] This invention relates to a combined collector for a copper-sulfur flotation system and its application, specifically relating to the field of mineral separation technology. Background Technology

[0002] Chalcopyrite and pyrite often coexist in copper-sulfur ores, and their surface properties are similar. Conventional collectors tend to act on both minerals simultaneously, making copper-sulfur separation difficult. Current production methods typically use lime as a pyrite depressant, utilizing a highly alkaline environment to alter the surface state of pyrite, promote the formation of ferric hydroxides, and enhance its hydrophilicity, thereby reducing pyrite floatability. While this method can achieve copper-sulfur separation to some extent, it often requires a large amount of lime, resulting in excessively high slurry pH, introducing a large amount of calcium ions, affecting the slurry's hydrochemical environment, and increasing the difficulty of subsequent process control.

[0003] After copper-sulfur separation, sulfur beneficiation of the pyrite-containing product is usually required to recover sulfur resources. Traditional processes typically involve acidifying the high-alkali slurry with sulfuric acid to break down the strong inhibition caused by lime, restoring the floatability of the pyrite surface, and then using xanthate collectors for recovery. This process suffers from high acid and alkali reagent consumption, high production costs, significant equipment corrosion, and complex procedures. Furthermore, while using strong inhibitors in copper-sulfur separation can reduce pyrite flotation to some extent, it can weaken the connection between copper-sulfur separation and subsequent sulfur beneficiation. If pyrite is excessively inhibited, the subsequent sulfur beneficiation stage requires large amounts of sulfuric acid for activation and a strong collector regime, potentially leading to increased reagent consumption, process complexity, and fluctuations in sulfur concentrate quality.

[0004] Therefore, the existing copper-sulfur flotation process urgently needs a technical solution that has a milder and more controllable inhibitory effect on pyrite and facilitates subsequent sulfur recovery, so as to reduce the amount of lime and sulfuric acid used, reduce reagent consumption and process complexity, and improve the comprehensive recovery efficiency of copper and sulfur resources. Summary of the Invention

[0005] The purpose of this invention is to address the problems in existing copper-sulfur flotation processes, such as high lime consumption, excessive suppression in the initial stage, large consumption of sulfuric acid and activators in subsequent sulfur removal, complex processes, and easy waste of sulfur resources. This invention provides a combined collector for a copper-sulfur flotation system and its application. This method constructs a mild and controllable reagent regime to moderately suppress pyrite in the copper-sulfur separation stage while selectively collecting chalcopyrite. This ensures preferential flotation of chalcopyrite while avoiding irreversible or excessive suppression of pyrite. Furthermore, only a small amount of copper sulfate is needed in the subsequent sulfur removal stage to restore the floatability of pyrite, thereby reducing the amount of lime and sulfuric acid used and improving the overall recovery efficiency of copper and sulfur resources.

[0006] To achieve the above objectives, the present invention employs the following technical solution: The primary copper-sulfide ore is crushed, and sodium carbonate is added during the grinding stage to obtain a slurry for flotation. A combination of depressants, sodium percarbonate and water glass, and a combination of collectors, dimethylacetate thiophene and xylenol dithiophosphate, are added to perform a roughing, scavenging, and cleaning flotation operation to obtain copper concentrate and copper tailings. Then, a small amount of copper sulfate, a combination of xanthate, and 2... # The oil, similarly, undergoes a roughing, scavenging, and cleaning flotation process to obtain sulfur concentrate and tailings.

[0007] The combined inhibitors of the present invention, sodium percarbonate and water glass, have a mass ratio of 1:1; the combined collectors, dimethylacetate thiophene and xylenol dithiophosphate, also have a mass ratio of 1:1; the combined xanthate is composed of ethyl xanthate, butyl xanthate and pentyl xanthate, wherein the mass ratio is 3:5:2.

[0008] The application of a combined collector in a copper-sulfur flotation system includes the following steps: (1) The copper-sulfur ore is crushed, sodium carbonate is added during the grinding stage, and then the slurry is adjusted to obtain the slurry to be floated. (2) The slurry obtained after step (1) is subjected to flotation operation with one roughing, two scavenging and two cleaning processes by adding a combination of inhibitors and a combination of collectors to obtain copper concentrate and copper tailings. (3) Add copper sulfate, combined xanthate and 2 to the copper tailings in step (2). # The oil undergoes a flotation process involving roughing, scavenging, and cleaning to obtain sulfur concentrate and final tailings. Preferably, in step (1), 80-85% of the particles are ground to a fineness of -0.074mm, the concentration of the slurry to be floated is 30%-35%, and the amount of sodium carbonate used is 550-600g / t.

[0009] Preferably, in step (2), the combined inhibitor is sodium percarbonate and water glass, wherein the mass ratio of sodium percarbonate and water glass is 1:1; the combined collector dimethylacetate thiophene and xylenol dithiophosphate are also in a mass ratio of 1:1; in step (3), the combined xanthate is composed of ethyl xanthate, butyl xanthate and pentyl xanthate, wherein the mass ratio is 3:5:2.

[0010] Preferably, in step (2), the amount of combined depressant used in the copper roughing operation is 1100-1200 g / t, and the amount of combined collector used is 130-140 g / t; the amount of combined depressant used in copper cleaning I is 500-550 g / t, and copper cleaning II is blank flotation; the amount of combined collector used in copper scavenging I is 40-50 g / t, and the amount of combined collector used in copper scavenging II is 20-25 g / t.

[0011] Preferably, in step (3), the amount of copper sulfate used in the sulfur roughing operation is 40-50 g / t, and the amount of combined xanthate is 100-110 g / t. # The oil dosage is 20-30 g / t; sulfur refining I and sulfur refining II are blank flotation; the copper sulfate dosage in sulfur scavenging I is 20-30 g / t, and the combined xanthate dosage is 50-65 g / t. # The dosage of oil is 10-15 g / t, the dosage of copper sulfate for sulfur scavenging II is 10-15 g / t, and the dosage of combined xanthate is 25-30 g / t. # The amount of oil used is 5-7g / t.

[0012] Preferably, in steps (2) and (3), the combined collector is combined with 2 # Oil is added directly by weighing, while the remaining reagents are prepared as a 5% aqueous solution and added. Each roughing operation takes 3-4 minutes, each scavenging operation takes 4-5 minutes, and each fine cleaning operation takes 2-3 minutes. The intermediate mineral products are returned step by step to form a closed loop.

[0013] The principle of this invention is as follows: This invention achieves stepwise flotation of copper-sulfur minerals based on the overall concept of "weakly alkaline environment regulation, mild inhibition of pyrite, synergistic collection of chalcopyrite, and low-dose activation and recovery of pyrite".

[0014] Sodium carbonate is added during the grinding stage to create a suitable weakly alkaline environment in the slurry, reducing the interference of hard water ions and impurity ions on the mineral surface and flotation reagents, while also improving the dispersion of the slurry. During the copper-sulfur separation stage, sodium percarbonate releases peroxide species into the slurry and gently oxidizes the pyrite surface, forming hydrophilic oxygen-containing iron and oxygen-containing sulfur species. Water glass further adsorbs onto the oxidation and hydroxylation sites on the pyrite surface, enhancing its hydrophilicity and dispersibility, and reducing the covering of slime on the chalcopyrite surface, thereby decreasing the floatability of pyrite.

[0015] The structure of dimethylsulfonyl acetate contains both a positively charged dimethylsulfonyl group and a negatively charged carboxylate group, classifying it as an amphoteric compound. The carboxylate group of dimethylsulfonyl acetate adsorbs onto the copper active sites on the chalcopyrite surface, forming a polar pre-adsorption layer. Meanwhile, the dimethylsulfonyl group alters the local charge and hydration state at the mineral interface, providing favorable conditions for the subsequent approach and enrichment of xylenol dithiophosphate.

[0016] Xylenol dithiophosphate participates in the collection of ore in the form of dithiophosphate ions. The sulfur atoms in its dithiophosphate groups can coordinate with the copper active sites on the surface of chalcopyrite, while the xylenol groups are arranged to the outside of the aqueous phase, providing hydrophobicity.

[0017] When both collectors are present, dimethylacetate thiophene also plays a role in interface regulation and pre-assembly: on the one hand, its carboxylate group binds to the active sites on the chalcopyrite surface; on the other hand, its positively charged sulfonium group may electrostatically attract the negatively charged dithiophosphate group, thereby increasing the local concentration of xylenol dithiophosphate on the chalcopyrite surface. As a result, xylenol dithiophosphate is more likely to undergo directional adsorption in the pre-adsorption region formed by dimethylacetate thiophene, forming an arrangement structure where "polar groups are close to the mineral surface and hydrophobic xylenol groups face the aqueous phase," thus making the collecting film on the chalcopyrite surface more continuous, dense, and stable.

[0018] Since the copper stage employs a mild and reversible inhibition method on pyrite, the sulfur beneficiation stage after copper-sulfur separation does not require extensive acidification or strong de-inhibition. Only a small amount of copper sulfate needs to be added to activate the pyrite, allowing copper ions to be adsorbed or deposited on the pyrite surface, restoring its adsorption capacity for xanthate collectors. Subsequently, a combination xanthate consisting of ethyl xanthate, butyl xanthate, and pentyl xanthate in a mass ratio of 3:5:2 is used to efficiently collect the activated pyrite, thereby achieving further recovery of sulfur resources.

[0019] The beneficial effects of this invention are: (1) This invention uses sodium carbonate to regulate the slurry environment, avoiding the high alkalinity and calcium ion interference caused by the large amount of lime used in traditional processes. Sodium percarbonate and water glass are used to mildly and synergistically inhibit pyrite, reducing the possibility of irreversible strong inhibition of pyrite. Water glass can also disperse ore slime, reduce ore slime covering and foam entrainment, which is beneficial to improving the quality of copper concentrate.

[0020] (2) Dimethylacetic acid thiophene has a synergistic collecting effect with xylenol dithiophosphoric acid, which can improve the selectivity of chalcopyrite and the efficiency of copper-sulfur separation.

[0021] (3) Since pyrite retains good reactivation properties, only a small amount of copper sulfate is needed to complete the activation during the sulfur beneficiation stage, reducing the amount of activator used. This invention reduces the use of large amounts of lime and sulfuric acid, thereby reducing acid-base neutralization, equipment corrosion, wastewater treatment, and overall production costs.

[0022] (4) This invention realizes the stepwise recovery of copper concentrate and sulfur concentrate, reduces resource waste, and has the advantages of reasonable process connection, mild reagent system and high comprehensive utilization rate. Attached Figure Description

[0023] Figure 1 The above are process flow diagrams for embodiments 1, 2, and 3 of the present invention. Detailed Implementation

[0024] The present invention will be further described in detail below with reference to specific embodiments, but the scope of protection of the present invention is not limited to the content described.

[0025] Examples 1, 2, and 3: Mineral raw materials: The ore is derived from primary copper-sulfur ore from a mining area in Henan Province. The main useful element in the ore is Cu, with a content of 0.84%. The associated beneficial component is sulfur, which can be comprehensively recovered during the beneficiation process. The main useful metallic minerals are chalcopyrite and pyrite. The gangue minerals are mainly quartz, followed by chlorite and muscovite, with small amounts of feldspar and calcite. Copper in the ore mainly exists in the form of copper sulfide, with a relatively low content of copper oxide.

[0026] like Figure 1 As shown, the specific steps are as follows: (1) The actual copper-sulfur ore was crushed, sodium carbonate was added and the ore was ground. After grinding, the ore was classified so that the particle size was -0.074 mm, accounting for 80%-85% (80% in Example 1, 82% in Example 2, and 85% in Example 3). The slurry was then adjusted so that the concentration of the ore slurry to be floated was 30%-35% (30% in Example 1, 33% in Example 2, and 35% in Example 3). The amount of sodium carbonate used was 550-600 g / t (550 g / t in Example 1, 580 g / t in Example 2, and 600 g / t in Example 3). (2) The slurry from step (1) is introduced into the flotation machine and combined inhibitors and combined collectors are added for the copper roughing operation stage, wherein the amount of combined inhibitors is 1100-1200 g / t and the amount of combined collectors is 130-140 g / t. (3) The copper roughing concentrate from step (2) is subjected to two cleaning operations to obtain the final copper concentrate, wherein the amount of combined depressant used in cleaning I is 500-550 g / t, and cleaning II is blank flotation; (4) The copper roughing tailings in step (2) are subjected to two scavenging operations to obtain copper tailings, wherein the amount of scavenging I combined collector is 40-50g / t and the amount of scavenging II combined collector is 20-25g / t. (5) Add copper sulfate, combined xanthate, and 2 to the copper tailings in step (4). # During the sulfur roughing stage of oil processing, the dosage of copper sulfate is 40-50 g / t, and the dosage of combined xanthate is 100-110 g / t. # The amount of oil used is 20-30g / t; (6) Perform two blank cleaning operations on the sulfur roughing concentrate from step (5) to obtain the final sulfur concentrate; (7) The tailings from the sulfur roughing process in step (5) are subjected to two scavenging operations to obtain tailings, wherein the amount of copper sulfate used in sulfur scavenging I is 20-30 g / t, and the amount of combined xanthate used is 50-65 g / t. #The dosage of oil is 10-15 g / t, the dosage of copper sulfate for sulfur scavenging II is 10-15 g / t, and the dosage of combined xanthate is 25-30 g / t. # The amount of oil used is 5-7g / t; (8) The combined inhibitors in steps (2) and (3) are sodium percarbonate and water glass, wherein the mass ratio of sodium percarbonate to water glass is 1:1; the combined collectors dimethylacetate thiophene and xylenol dithiophosphate are also in a mass ratio of 1:1; the combined xanthates in steps (5) and (7) are composed of ethyl xanthate, butyl xanthate and pentyl xanthate, wherein the mass ratio is 3:5:2; (9) The combined collector in steps (2) and (3), and the 2 in steps (5) and (7) # Oil is added directly by weighing, while the remaining reagents are prepared as a 5% aqueous solution and added. Each roughing operation takes 3-4 minutes, each scavenging operation takes 4-5 minutes, and each fine cleaning operation takes 2-3 minutes. The intermediate mineral products are returned step by step to form a closed loop.

[0027] In Examples 1, 2, and 3, the dosage of each reagent was appropriately adjusted according to changes in ore properties. The reagent addition method and operation process remained consistent throughout. The operation flow diagram is shown below. Figure 1 As shown in Table 1, the dosage details of the drugs are shown in Table 2, and the product indicators are shown in Table 2.

[0028] Table 1. Detailed dosage of pharmaceuticals in Examples 1, 2, and 3.

[0029] Table 2 Product Indicators for Examples 1, 2 and 3

[0030] The closed-circuit test results of Examples 1, 2, and 3 show that the copper-sulfur separation concept proposed in this invention, which involves "weakly alkaline environment control, mild inhibition of pyrite, synergistic collection of chalcopyrite, and low-dose activation and recovery of pyrite," effectively achieves efficient separation of chalcopyrite and pyrite. The copper concentrate product has a copper grade greater than 15%, a copper recovery rate greater than 79%, and a sulfur grade less than 36%; the sulfur concentrate product has a sulfur grade greater than 49% and a sulfur recovery rate greater than 53%. These results demonstrate that the synergistic effect of dimethylacetate thiophene and xylenol dithiophosphate used in this invention effectively achieves efficient separation of chalcopyrite and pyrite under weakly alkaline slurry and mild inhibition conditions.

[0031] Comparative Example 1: The ore sample treatment in this embodiment is the same as in Example 1, except that the collector for chalcopyrite in the copper beneficiation stage is a single dimethylacetic acid thiophene. Other process conditions remain unchanged, with the specific operational variables as follows: (1) The collector for chalcopyrite in the copper beneficiation stage is thiamethoxam dimethylacetate; (2) The dosage of copper roughing operation stage is 130g / t, the dosage of copper scavenging I is 40g / t, and the dosage of copper scavenging II is 20g / t.

[0032] The product specifications of Comparative Example 1 are shown in Table 3.

[0033] Comparative Example 2: The ore sample treatment in this embodiment is the same as in Example 1, except that the copper beneficiation stage uses traditional lime as the pyrite depressant. Other process conditions remain unchanged, with the specific operational variables as follows: (1) Lime is used as the inhibitor for pyrite in the copper beneficiation stage; (2) The dosage of copper roughing operation stage is 6000g / t, the dosage of copper cleaning I is 4000g / t, the dosage of copper cleaning II is 0g / t, and it is blank flotation.

[0034] The product specifications of Comparative Example 2 are shown in Table 3.

[0035] Comparative Example 3: The ore sample processed in this embodiment is the same as in Example 1, except that the chalcopyrite collector used in the copper beneficiation stage is a single butyl xanthate. Other process conditions remain unchanged, with the specific operational variables as follows: (1) The collector for chalcopyrite in the copper beneficiation stage is a single butyl xanthate; (2) The dosage of copper roughing operation stage is 100g / t, the dosage of copper scavenging I is 40g / t, and the dosage of copper scavenging II is 20g / t.

[0036] The product specifications of Comparative Example 3 are shown in Table 3.

[0037] Comparative Example 4: The ore sample treatment in this embodiment is the same as in Example 1, except that: in the copper beneficiation stage, the chalcopyrite collector is a single butyl xanthate, and the pyrite inhibitor is a single lime; in the sulfur beneficiation stage, sulfuric acid is used as the activator. Other process conditions remain unchanged, and the specific operational variables are as follows: (1) In the copper beneficiation stage, the collector for chalcopyrite is a single butyl xanthate, and the inhibitor for pyrite is a single lime. (2) The amount of lime used in the copper roughing operation stage is 6000 g / t, and the amount of butyl xanthate used is 100 g / t; (3) The amount of lime used in copper beneficiation I is 4000 g / t, and the amount of lime used in copper beneficiation II is 0 g / t, which is a blank flotation.

[0038] (4) The dosage of copper scavenging I butyl xanthate is 40 g / t, and the dosage of copper scavenging II butyl xanthate is 20 g / t.

[0039] (5) In the sulfur selection stage, sulfuric acid is used as an acidifying agent or depressant to adjust the pH of the slurry to 6-7, and no copper sulfate activator is added.

[0040] The product specifications of Comparative Example 4 are shown in Table 3.

[0041] Table 3 Comparative Product Indicators of Examples 1, 2, 3 and 4

[0042] Examples 1 to 3 used the same primary copper-sulfide ore and conducted closed-circuit flotation tests under different grinding fineness, pulp concentration, and sodium carbonate dosage conditions. The results showed that the copper concentrate obtained in Examples 1 to 3 had a copper grade of 15.19%–15.23% and a copper recovery rate of 79.85%–80.14%; the sulfur concentrate obtained had a sulfur grade of 49.15%–49.21% and a sulfur recovery rate of 53.51%–53.86%, and the copper grade in the sulfur concentrate was only 0.26%–0.29%, indicating that the method of the present invention has good stability and repeatability.

[0043] Compared with Comparative Examples 1 to 4, Example 1 achieved a better overall separation effect between copper concentrate and sulfur concentrate. When using dimethylacetate alone, although the sulfur grade and sulfur recovery rate of the sulfur concentrate were high, the copper grade and copper recovery rate of the sulfur concentrate were significantly increased, and copper mineral entrainment was severe. When lime was used as a pyrite inhibitor, the copper recovery rate of the copper concentrate was significantly reduced, and the copper entrainment in the sulfur concentrate increased. When using butyl xanthate alone, the copper grade of the copper concentrate decreased, the sulfur entrainment increased, and the sulfur concentrate recovery rate decreased. When using the traditional process of lime, butyl xanthate, and sulfuric acid acidification and inhibition, the overall indicators of both copper concentrate and sulfur concentrate decreased, and the sulfur loss in the final tailings increased.

[0044] The above results indicate that the technical effect of this invention does not stem from a single agent, but rather from the mild synergistic inhibition of pyrite by sodium percarbonate and water glass, and the synergistic selective collection of chalcopyrite by dimethylacetate thiophene and xylenol dithiophosphate. The former maintains pyrite in a moderately and reversibly inhibited state, requiring only a small amount of copper sulfate for subsequent activation; the latter enhances the selective collection ability of chalcopyrite, reducing the amount of chalcopyrite entering the sulfur concentrate. Therefore, this invention achieves a high-grade and high-recovery sulfur concentrate while ensuring a high copper recovery rate, realizing efficient stepwise recovery of copper and sulfur resources.

Claims

1. A combined collector for a copper-sulfur flotation system, characterized in that, The combined collector is dimethylacetylthiophene and xylenol dithiophosphate, wherein the mass ratio of dimethylacetylthiophene to xylenol dithiophosphate is 1:

1.

2. The application of the combined collector in the copper-sulfur flotation system according to claim 1, characterized in that, The specific steps are as follows: (1) The copper-sulfur ore is crushed, sodium carbonate is added during the grinding stage, and then the slurry is adjusted to obtain the slurry to be floated. (2) Add a combination of inhibitors and a combination of collectors to the slurry to be floated in step (1) and carry out a flotation operation of one roughing, two scavenging and two cleaning to obtain copper concentrate and copper tailings. (3) Add copper sulfate, combined xanthate and 2 to the copper tailings from step (2). # The oil undergoes a flotation process involving roughing, scavenging, and cleaning to obtain sulfur concentrate and final tailings.

3. The application of the combined collector in the copper-sulfur flotation system according to claim 2, characterized in that: In step (1), grinding to a particle fineness of -0.074mm accounts for 80-85%, the concentration of the pulp to be floated is 30%-35%, and the amount of sodium carbonate used is 550-600g / t.

4. The application of the combined collector in the copper-sulfur flotation system according to claim 2, characterized in that: In step (2), the combined inhibitor is sodium percarbonate and water glass, with a mass ratio of 1:1; the combined collector is dimethylacetate thiatin and xylenol dithiophosphate, with a mass ratio of 1:1; in step (3), the combined xanthate is composed of ethyl xanthate, butyl xanthate and pentyl xanthate, with a mass ratio of 3:5:

2.

5. The application of the combined collector in the copper-sulfur flotation system according to claim 2, characterized in that: In step (2), the dosage of combined depressant in copper roughing is 1100-1200 g / t, and the dosage of combined collector is 130-140 g / t; the dosage of combined depressant in copper cleaning I is 500-550 g / t, and copper cleaning II is blank flotation; the dosage of combined collector in copper scavenging I is 40-50 g / t, and the dosage of combined collector in copper scavenging II is 20-25 g / t.

6. The application of the combined collector in the copper-sulfur flotation system according to claim 2, characterized in that: In step (3), the amount of copper sulfate used in the sulfur roughing operation is 40-50 g / t, and the amount of combined xanthate used is 100-110 g / t. # The oil dosage is 20-30 g / t; sulfur refining I and sulfur refining II are blank flotation; the copper sulfate dosage in sulfur scavenging I is 20-30 g / t, and the combined xanthate dosage is 50-65 g / t. # The dosage of oil is 10-15 g / t, the dosage of copper sulfate for sulfur scavenging II is 10-15 g / t, and the dosage of combined xanthate is 25-30 g / t. # The amount of oil used is 5-7g / t.

7. The application of the combined collector in the copper-sulfur flotation system according to claim 2, characterized in that: In steps (2) and (3), the combined collector and 2 # Oil is added directly by weighing, while the remaining reagents are prepared as a 5% aqueous solution and added. Each roughing operation takes 3-4 minutes, each scavenging operation takes 4-5 minutes, and each fine cleaning operation takes 2-3 minutes. The intermediate mineral products are returned step by step to form a closed loop.

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