Copper sulfide ore flotation combined inhibitor and application thereof

Abstract

The invention discloses a copper sulfide ore flotation combined inhibitor and application thereof, and belongs to the technical field of mineral flotation inhibitors. The combined inhibitor is formed by mixing sodium pyrosulfite, 1, 2, 4-triazole sodium and sodium thiophosphate, and the mass ratio of the sodium pyrosulfite to the 1, 2, 4-triazole sodium to the sodium thiophosphate is 2: 2: 1. The combined inhibitor can be applied to flotation of copper sulphide ore, and the specific method comprises the steps that the combined inhibitor is added into ore pulp obtained after ore grinding so as to preferentially inhibit iron sulphide minerals, copper concentrate is obtained through one-time roughing, two-time concentration and two-time scavenging in cooperation with a collecting agent and a foaming agent, and efficient separation of copper ore and pyrite is achieved. The combined inhibitor can effectively replace traditional lime, overcomes the defects of foam stickiness, pipeline equipment scaling corrosion, tailing water pollution and the like caused by a lime high-alkali method, and achieves environment-friendly and efficient recovery of copper sulphide ore resources.

Description

Technical Field

[0001] The present invention relates to the technical field of mineral flotation inhibitors, and in particular to a copper sulfide ore flotation combined inhibitor and application thereof. Background Art

[0002] Copper, with its exceptional ductility and excellent thermal and electrical conductivity, plays an irreplaceable role in key sectors such as electrical engineering, light industry, machinery manufacturing, construction, and defense. Copper sulfide ores account for over 75% of proven copper resources. Therefore, the efficient and clean utilization of these ores is crucial for ensuring a stable supply of copper resources. In copper sulfide ores, copper minerals (such as chalcopyrite, chalcocite, and bornite) often coexist closely with large amounts of iron sulfide minerals (primarily pyrite, followed by pyrrhotite and marcasite). During flotation, the similar natural floatability of these two minerals makes their selective separation a long-standing technical challenge. To ensure the purity and quality of copper concentrate, the currently widely used process both domestically and internationally utilizes lime (CaO) as a depressant for iron sulfide minerals in a highly alkaline slurry (typically pH greater than 12) to effectively separate copper concentrate from pyrite.

[0003] The use of lime as an inhibitor in traditional processes presents significant drawbacks. First, from a production perspective, the high-temperature calcination of limestone is a typically energy-intensive and carbon-intensive process, placing a heavy burden on the environment. Second, its practical application presents multiple challenges. Lime requires the preparation of lime milk before use, which is not only cumbersome but also poses safety risks due to strong alkaline contact. Lime easily scales, leading to frequent pipe blockages and equipment corrosion, increasing maintenance costs and impacting production stability. The amount of lime added directly impacts the stability of industrial production indicators but is difficult to precisely control. More importantly, excessive lime use increases the viscosity of the flotation froth, reducing separation efficiency and compromising concentrate filtration. It also leads to an abnormally high pH value in the tailings water (often exceeding 10), seriously compromising wastewater discharge standards. Furthermore, a highly alkaline environment inhibits the leaching and recovery of associated precious metals such as gold and silver, resulting in a waste of resources.

[0004] To improve the flotation environment for separating copper concentrate from pyrite, some mineral processing researchers have conducted extensive research on copper-sulfur separation inhibitors. For example, some researchers have explored the use of strong oxidants such as calcium hypochlorite and potassium permanganate as alternatives to lime. However, these methods also face challenges such as easy agent failure, high storage and operation risks, poor adaptability to complex slurry environments, and large fluctuations in production indicators, making them difficult to promote and apply in large-scale industrial production.

[0005] Therefore, developing a new and efficient iron sulfide mineral inhibitor that can replace lime is a key technical problem that needs to be solved urgently in the current copper-sulfur ore beneficiation field. Summary of the Invention

[0006] To address a series of problems in copper-sulfur separation technology, such as environmental pollution, scaling and corrosion of equipment and pipelines, sticky foam, and poor mineral processing indicators, caused by the reliance on the lime high-alkali method, the present invention provides a highly efficient and environmentally friendly lime-free combined inhibitor and its application, which can effectively separate copper minerals from pyrite minerals under natural pH conditions.

[0007] The combined inhibitor of the present invention is composed of a mixture of sodium pyrosulfite, 1,2,4-triazole sodium and sodium thiophosphate; the mass ratio of the sodium pyrosulfite, 1,2,4-triazole sodium and sodium thiophosphate is 2:2:1.

[0008] The copper sulfide ore flotation combined depressant of the present invention can be used in the flotation of copper sulfide ore, and the flotation of the copper sulfide ore is carried out in a slurry environment with a natural pH value without adding lime.

[0009] The flotation of copper sulfide ore of the present invention comprises the following steps: (1) Grind the copper-sulfur ore to prepare ore slurry.

[0010] (2) Adding a dispersant, a combined inhibitor, a collector and a frother to the ore pulp in sequence for roughing to obtain copper roughing concentrate and copper roughing tailings.

[0011] (3) The copper rougher concentrate is subjected to two rounds of concentration, with combined inhibitors added in each concentration operation to obtain the final copper concentrate. The middlings produced in the two concentration operations are returned to the previous operation in sequence.

[0012] (4) The copper roughing tailings are scavenged twice, and a collector is added in each scavenging operation to obtain the final tailings. The intermediate ore produced in the two scavenging operations is returned to the previous operation in sequence.

[0013] Preferably, in step (2) of the present invention, the dispersant is water glass; the collecting agent is diethyl thiocarb; and the foaming agent is 2# oil.

[0014] Preferably, in step (2) of the present invention, the amount of the dispersant is 1000-1500 g / t; the amount of the combined inhibitor is 400-800 g / t; the amount of the collector is 40-60 g / t; and the amount of the foaming agent is 15-25 g / t.

[0015] Preferably, in step (3) of the present invention, the amount of the combined inhibitor added in the first concentration is 200-400 g / t, and the amount of the combined inhibitor added in the second concentration is 100-200 g / t.

[0016] Preferably, in step (3) of the present invention, a foaming agent needs to be added during the first concentration, and the amount of the foaming agent added is 8-12 g / t.

[0017] Preferably, in step (4) of the present invention, the amount of collector used in the first sweep is 20-30 g / t; and the amount of collector used in the second sweep is 10-15 g / t.

[0018] Preferably, in step (4) of the present invention, a foaming agent needs to be added during the first scanning, and the amount of the foaming agent added is 8-12 g / t.

[0019] Mechanism of the present invention: The combined inhibitor of the present invention is composed of a mixture of sodium metabisulfite, 1,2,4-triazole sodium and sodium thiophosphate. The synergistic effect of sodium metabisulfite, 1,2,4-triazole sodium and sodium thiophosphate is utilized to form a dense and stable hydrophilic inhibitory film on the surface of pyrite. The sodium metabisulfite regulates the slurry into a reducing environment, hindering the oxidation of the pyrite surface to form hydrophobic elemental sulfur. At the same time, the SO3 formed by the oxidation of sodium metabisulfite is 2- The ion itself can be chemically adsorbed on the Fe site on the surface of pyrite, making the pyrite surface hydrophilic; 1,2,4-triazole sodium, through the nitrogen atom on its ring, undergoes a strong chelation reaction with the exposed Fe site on the surface of pyrite, forming a stable chemical adsorption layer, which effectively hinders the chemical adsorption of the collector ethylthiocyanate on the Fe site on the surface of pyrite; the S atoms and P atoms in sodium thiophosphate can also bond with the Fe site on the surface of pyrite to form a hydrophilic adsorption layer. The combined inhibitor of the present invention forms a denser and more solid hydrophilic inhibition layer when adsorbed on the surface of pyrite than a single component, and has strong adaptability to changes in the surface properties of pyrite. At the same time, the combined inhibitor has a weak interaction with the surface of chalcopyrite, and the collector ethylthiocyanate can still stably chemically adsorb on the Cu site on the surface of chalcopyrite to form a hydrophobic film, thereby achieving efficient separation of copper concentrate and pyrite.

[0020] Beneficial effects of the present invention: (1) High efficiency and environmental protection: The combined inhibitor proposed in the present invention does not contain highly toxic components. Its application can completely replace lime, fundamentally avoiding problems such as high-alkali wastewater pollution and pipeline scaling, and realizing green and clean production in the flotation process of copper sulfide ore.

[0021] (2) Strong selectivity and excellent indicators: This combined inhibitor has excellent selective inhibition ability for pyrite and other pyrite minerals, while having little effect on the floatability of copper minerals such as chalcopyrite. It can significantly improve the grade and recovery rate of copper concentrate and effectively reduce the mutual inclusion of copper and sulfur.

[0022] (3) Simplified process and reduced costs: The present invention does not require the preparation of lime milk, which simplifies the process flow and reduces equipment maintenance costs and safety risks. The inhibitor itself is used in small amounts, the cost is low, and the overall economic benefits are significant.

[0023] (4) Wide applicability: The method of the present invention can achieve excellent copper-sulfur separation effect under natural pH conditions. The process conditions are mild and easy to control. It can be widely used for the efficient separation of copper-sulfur co-existing ores of different properties. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] Figure 1 Schematic diagram of the flotation process used in the embodiments and comparative examples of the present invention. DETAILED DESCRIPTION

[0025] The present invention is further described in detail below with reference to the accompanying drawings and specific embodiments, but the protection scope of the present invention is not limited to the contents described above.

[0026] The combined inhibitor used in the examples and comparative examples of the present invention was prepared by uniformly mixing sodium metabisulfite, sodium 1,2,4-triazole, and sodium thiophosphate in a mass ratio of 2:2:1.

[0027] Example 1 The flotation method used in this example is based on a copper sulfide ore from Jiangxi Province. The ore contains 0.704% copper (Cu) and 9.58% sulfur (S). The specific steps of the flotation process are as follows: (1) Grinding: Grind the raw ore so that the proportion of particles with a diameter of -0.074 mm in the slurry reaches 70%, and adjust the slurry mass concentration to 30%.

[0028] (2) Roughing: 1200 g / t of water glass, 600 g / t of combined inhibitor, 50 g / t of ethyl dithiocarbamate and 20 g / t of No. 2 oil are added to the slurry in sequence, based on the dry weight of each ton of raw ore. Then, a roughing operation is carried out to obtain copper roughing concentrate and copper roughing tailings.

[0029] (3) Concentration: The copper rougher concentrate is subjected to two rounds of concentrating. In the first round, 300 g / t of combined depressant and 10 g / t of frother 2 oil are added per ton of dry weight of the raw ore. In the second round, 150 g / t of combined depressant is added. The middlings from the two rounds of concentrating are returned to the previous level in sequence to obtain copper concentrate.

[0030] (4) Scavenging: The copper roughing tailings are scavenged twice. In the first scavenging, 25g / t of ethyl thiocyanate and 10g / t of frother 2 oil are added per ton of dry weight of the original ore; in the second scavenging, 12g / t of ethyl thiocyanate is added; the intermediate ore from the two scavengings is returned to the previous level operation in turn, and the tailings are finally obtained.

[0031] The results of the flotation closed-circuit test of this embodiment are shown in Table 1.

[0032] Example 2 The process flow and reagent types of this example are the same as those of Example 1, except that the ore sample processed in this example is a low-grade copper-sulfur ore from Sichuan, with a raw ore content of 0.27% Cu and 4.14% S. The reagent dosages were adjusted as follows: in the roughing stage, 1500 g / t of water glass, 800 g / t of combined depressant, 60 g / t of ethyl sulfide and nitrogen, and 25 g / t of No. 2 oil were used; in the first concentrating stage, 400 g / t of combined depressant, 12 g / t of No. 2 oil were used, and in the second concentrating stage, 200 g / t of combined depressant were used; in the first scavenging stage, 30 g / t of ethyl sulfide and nitrogen, 12 g / t of No. 2 oil were used, and in the second scavenging stage, 15 g / t of ethyl sulfide and nitrogen were used. The results of the closed-circuit flotation test of this example are shown in Table 1.

[0033] Example 3 The process flow and reagent types of this example are the same as those of Example 1, except that the ore sample processed in this example is a copper sulfide ore from Yunnan, with a raw ore content of 0.35% Cu and 6.31% S. The reagent dosages were adjusted as follows: in the roughing stage, 1500 g / t of water glass, 800 g / t of combined depressant, 60 g / t of EDTA, and 25 g / t of 2# oil were used; in the first cleaning stage, 400 g / t of combined depressant, 12 g / t of 2# oil were used, and in the second cleaning stage, 200 g / t of combined depressant was used; in the first scavenging stage, 30 g / t of EDTA, 12 g / t of 2# oil were used, and in the second scavenging stage, 15 g / t of EDTA. The results of the closed-circuit flotation test of this example are shown in Table 1.

[0034] Example 4 The process flow and reagent types of this example are the same as those of Example 1, except that the ore sample processed in this example is a copper sulfide ore from Guangxi, with a raw ore content of 0.95% Cu and 6.20% S. The reagent dosages were adjusted as follows: 1000 g / t of water glass and 400 g / t of combined depressant in the roughing stage; 40 g / t of ethyl sulfide and nitrogen and 15 g / t of secondary oil; 200 g / t of combined depressant and 8 g / t of secondary oil in the first cleaning stage, and 100 g / t of combined depressant in the second cleaning stage; 20 g / t of ethyl sulfide and nitrogen and 8 g / t of secondary oil in the first scavenging stage, and 10 g / t of ethyl sulfide and nitrogen in the second scavenging stage. The results of the closed-circuit flotation test of this example are shown in Table 1.

[0035] Example 5 The process flow, reagent types, and dosages of this example are identical to those of Example 1, except that the ore sample processed in this example is a copper sulfide ore from Guizhou, with a raw ore content of 1.43% Cu and 10.62% S. The reagent dosages were adjusted as follows: 1000 g / t of water glass and 400 g / t of combined depressant in the roughing stage; 40 g / t of ethyl sulfide and nitrogen and 15 g / t of secondary oil; 200 g / t of combined depressant and 8 g / t of secondary oil in the first cleaning stage, and 100 g / t of combined depressant in the second cleaning stage; 20 g / t of ethyl sulfide and nitrogen and 8 g / t of secondary oil in the first scavenging stage, and 10 g / t of ethyl sulfide and nitrogen in the second scavenging stage. The results of the closed-circuit flotation test of this example are shown in Table 1.

[0036] Comparative Example 1 This comparative example is intended for comparison with Example 1. The process flow and reagent types used in this comparative example are identical to those in Example 1. The difference is that this comparative example does not use the combined depressant of the present invention, but instead employs conventional lime (CaO) as a depressant. The CaO dosage is: 1000 g / t in the roughing stage, 500 g / t in the first cleaning stage, and 250 g / t in the second cleaning stage. The closed-circuit flotation test results for this comparative example are shown in Table 1.

[0037] Comparative Example 2 This comparative example is intended for comparison with Example 2. The process flow and reagent types used in this comparative example are the same as those in Example 2. The difference is that this comparative example does not use the combined depressant of the present invention, but instead uses conventional lime (CaO) as a depressant. The amount of CaO used is the same as in Comparative Example 1. The results of the closed-circuit flotation test for this comparative example are shown in Table 1.

[0038] Comparative Example 3 This comparative example is intended for comparison with Example 2. The process flow and reagent types used in this comparative example are the same as those in Example 2. The difference is that this comparative example does not use the combined depressant of the present invention, but instead uses conventional lime (CaO) as a depressant. The amount of CaO used is the same as in Comparative Example 1. The results of the closed-circuit flotation test for this comparative example are shown in Table 1.

[0039] Comparative Example 4 This comparative example is intended for comparison with Example 2. The process flow and reagent types used in this comparative example are the same as those in Example 2. The difference is that this comparative example does not use the combined depressant of the present invention, but instead uses conventional lime (CaO) as a depressant. The amount of CaO used is the same as in Comparative Example 1. The results of the closed-circuit flotation test for this comparative example are shown in Table 1.

[0040] Comparative Example 5 This comparative example is intended for comparison with Example 2. The process flow and reagent types used in this comparative example are the same as those in Example 2. The difference is that this comparative example does not use the combined depressant of the present invention, but instead uses conventional lime (CaO) as a depressant. The amount of CaO used is the same as in Comparative Example 1. The results of the closed-circuit flotation test for this comparative example are shown in Table 1.

[0041] Table 1 According to the results of Example 1 and Comparative Example 1, after using the combined depressant of the present invention, the copper grade of the copper concentrate reached 22.14%, and the copper recovery rate reached 91.83%. In contrast, when using traditional lime (CaO) as a depressant, the copper grade of the copper concentrate was only 19.36%, and the copper recovery rate was only 89.10%. This demonstrates that for the same ore, the combined depressant of the present invention can achieve higher copper grades while maintaining higher copper recovery rates compared to traditional lime. For various types of copper sulfide ores from different sources and grades, the combined depressant of the present invention consistently achieved copper recoveries exceeding 90%. This fully demonstrates the excellent ore adaptability and universal superiority of the depressant of the present invention. Based on the S grade data of the copper concentrate, the S grade of the copper concentrate in all examples was significantly lower than that of the corresponding comparative examples, and the depressant can be applied to the flotation of different types of copper sulfide ores. This demonstrates that the combined depressant of the present invention has stronger inhibition ability for iron sulfide minerals, better selectivity, and wider applicability, effectively reducing sulfur incorporation into copper concentrate, thereby improving the quality of the copper concentrate.

[0042] In summary, the combined inhibitor and its application method for copper-sulfur separation under lime-free conditions provided by the present invention can effectively replace the traditional lime-based high-alkali process. This method not only avoids the various drawbacks associated with the use of lime but also exhibits superior separation performance. It can improve the grade of copper concentrates for copper sulfide ores of varying properties, offering significant technical advantages and broad prospects for industrial application.

[0043] While various embodiments of the present invention have been described above, the foregoing description is intended to be illustrative, non-exhaustive, and not limited to the disclosed embodiments. Many modifications and variations will be apparent to those skilled in the art without departing from the scope and spirit of the described embodiments. The terminology used herein is selected to best explain the principles of the embodiments, their practical applications, or improvements to existing technologies, or to enable others skilled in the art to understand the embodiments disclosed herein.

Claims

1. A combined depressant for flotation of copper sulfide ore, characterized in that: The combined inhibitor is composed of a mixture of sodium pyrosulfite, 1,2,4-triazole sodium and sodium thiophosphate; the mass ratio of the sodium pyrosulfite, 1,2,4-triazole sodium and sodium thiophosphate is 2:2:

1.

2. The use of the copper sulfide ore flotation combined depressant according to claim 1 in the flotation of copper sulfide ore, characterized in that: The copper sulfide ore flotation is carried out in a slurry environment with a natural pH value without adding lime.

3. The use of the copper sulfide ore flotation combined depressant according to claim 2 in the flotation of copper sulfide ore, characterized in that: The copper sulfide ore flotation comprises the following steps: (1) Grinding copper-sulfur ore to prepare ore pulp; (2) Adding dispersant, combined depressant, collector and frother to the slurry in sequence for roughing to obtain coarse concentrate and coarse tailings; (3) The copper rougher concentrate is subjected to two rounds of beneficiation, with combined depressants added in each beneficiation operation to obtain copper concentrate, wherein the middlings produced in each beneficiation operation are returned to the previous operation in sequence; (4) The coarse tailings are scavenged twice, and a collector is added in each scavenging operation to obtain the final tailings. The medium ore produced in each scavenging operation is returned to the previous level operation in turn.

4. The use of the copper sulfide ore flotation combined depressant according to claim 3 in the flotation of copper sulfide ore, characterized in that: In step (2), the dispersant is water glass; the collecting agent is diethyl thiocyanate; and the foaming agent is 2# oil.

5. The use of the copper sulfide ore flotation combined depressant according to claim 3 in the flotation of copper sulfide ore, characterized in that: In step (2), the amount of the dispersant is 1000-1500 g / t; the amount of the combined inhibitor is 400-800 g / t; the amount of the collector is 40-60 g / t; and the amount of the foaming agent is 15-25 g / t.

6. Use of the copper sulfide ore flotation combined depressant according to claim 3 in the flotation of copper sulfide ore, characterized in that: In step (3), the amount of combined inhibitor added in the first concentration is 200-400 g / t, and the amount of combined inhibitor added in the second concentration is 100-200 g / t.

7. Use of the copper sulfide ore flotation combined depressant according to claim 3 in the flotation of copper sulfide ore, characterized in that: In step (3), a foaming agent needs to be added in the first selection, and the amount of the foaming agent added is 8~12g / t.

8. Use of the copper sulfide ore flotation combined depressant according to claim 3 in the flotation of copper sulfide ore, characterized in that: In step (4), the amount of collector used in the first sweep is 20-30 g / t; the amount of collector used in the second sweep is 10-15 g / t.

9. The use of the copper sulfide ore flotation combined depressant according to claim 3 in the flotation of copper sulfide ore, characterized in that: In step (4), a foaming agent needs to be added during the first sweep, and the amount of the foaming agent added is 8-12 g / t.

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