A mineral processing method for flotation recovery of pyrite from low-alkalinity high-sulfur copper tailings

Abstract

The present invention relates to mineral separation technology and relates to a flotation beneficiation method for recovering pyrite from low-alkalinity, high-sulfur copper tailings. This method first subjects the low-alkalinity, high-sulfur copper tailings to primary classification. The primary classification sediment enters a roughing agitator, where water is added for slurry adjustment. Subsequently, a composite collector and frother are added to produce a high-sulfur-grade sulfur concentrate (1) through a process of one roughing, two sweeping, and two refining. The overflow from the primary classification undergoes secondary classification. The secondary classification sediment enters a fine mixing tank, where water is added for slurry adjustment. Subsequently, a composite collector and frother are added to produce a one roughing, two sweeping, and two refining process. This produces a high-sulfur-grade sulfur concentrate (2). The fine sulfur roughing concentrate and fine scavenging concentrate (I) enter a fine sulfur concentrate (I). The overflow from the secondary classification enters a thickener, where a flocculant is added to adjust the underflow concentration of the thickener to 30% to 35%, before returning to the fine sulfur scavenging (I) process. This method offers the advantages of low cost and wide applicability, enabling efficient flotation recovery of pyrite.

Description

Technical Field

[0001] The invention belongs to mineral separation technology and relates to a mineral separation method for recovering pyrite from low-alkalinity and high-sulfur copper tailings by flotation. Background Art

[0002] Pyrite, an important chemical raw material, is widely used in the production of chemical products such as sulfuric acid and sulfur. During the sorting process of non-ferrous metal sulfide ores, pyrite is often suppressed and left in the tailings to improve the grade and recovery rate of the main metal. The suppressed or removed iron sulfide minerals are often stored in tailings ponds along with other gangue minerals, or enriched to obtain sulfur concentrate and then sent to sulfuric acid plants. The long-term storage of iron sulfide minerals in tailings ponds can have a serious impact on the ecological environment around the mining area. For example, sulfur-containing tailings are prone to produce acid mine drainage due to long-term natural oxidation, resulting in abnormal water pH and increased heavy metal ion concentrations. In addition, excessively high sulfur content in tailings can easily cause spontaneous combustion due to localized high temperatures caused by sulfur oxidation, posing a significant safety risk. Therefore, improving the beneficiation recovery rate of co-existing iron sulfide minerals and reducing the sulfur content in tailings are of great significance to environmental protection and resource recycling.

[0003] Due to its low economic value, the industry often uses lime as a pyrite inhibitor to recover other high-priced metals under high-alkaline conditions, and pyrite is often left in the tailings. The high-alkalinity copper-sulfur separation process will cause the associated precious metals to be suppressed by high alkalinity, which is detrimental to the equipment and the environment. In addition, a large amount of sulfuric acid needs to be added as an activator during the sulfur recovery stage, and the pH value of the mineral processing wastewater is relatively high. With the increasingly stringent environmental protection policies, the low-alkalinity copper-sulfur separation process has gradually replaced the high-alkalinity copper-sulfur separation process. For this reason, it is urgent to design a mineral processing method for flotation recovery of pyrite from low-alkalinity, high-sulfur copper tailings, so as to further improve the economic, social and ecological benefits of mines and promote the green and high-quality development of mines. Summary of the Invention

[0004] The present invention discloses a beneficiation method for recovering pyrite from low-alkalinity and high-sulfur copper tailings by flotation, so as to solve any of the above and other potential problems in the prior art.

[0005] In order to solve the above technical problems, a flotation beneficiation method for recovering pyrite from low-alkalinity and high-sulfur copper tailings is provided. The flotation beneficiation method specifically comprises the following steps:

[0006] S1) the low-alkalinity high-sulfur copper tailings to be treated are subjected to a primary classification, the primary classification sand is sent to a roughing mixing tank, water is added to prepare the slurry, and then a composite collector and a frother are added to obtain a high-sulfur grade sulfur concentrate 1 and tailings 1 under the conditions of one roughing, two sweeping and two refining;

[0007] S2) the overflow from the primary classification is subjected to secondary classification, the secondary classification sediment is fed into a fine particle mixing tank, water is added to prepare the slurry, and then a composite collector and a foaming agent are added to perform a one coarse, two sweep, and two fine operations to obtain a high-sulfur grade sulfur concentrate 2 and a tailing 2;

[0008] S3) The secondary overflow is then sent to the thickener, where flocculants are added to control the underflow concentration, and then pumped to the sand box of the fine sulfur sweep I flotation machine to complete the recovery.

[0009] Furthermore, the fine sulfur roughing concentrate and fine-grained sweep I concentrate in S2) enter the fine sulfur concentrate I.

[0010] Furthermore, it is characterized in that the primary classification pressure in S1) is 0.11-0.15 MPa.

[0011] Furthermore, the crude sulfur sweep I and crude sulfur refinement I tail in S1) are returned to the primary classification sand settling tank, a water replenishment point is set in the sand settling tank, and the slurry in the sand settling tank is transported to the crude sulfur stirring tank through a pipeline, and the slurry concentration value of the crude sulfur stirring tank is 42% to 50%;

[0012] Furthermore, the secondary classification sand settling in S2) is transported to the fine sulfur stirring tank through a pipeline, and the slurry concentration in the coarse sulfur stirring tank is 30% to 35%.

[0013] Furthermore, the amount of composite collector for crude sulfur selection in S1) and S2) is 25-30 g / t, the amount of foaming agent is 5-10 g / t, the amount of composite collector for crude sulfur sweep I is 10-15 g / t, the amount of composite collector for crude sulfur sweep II is 5-10 g / t, the amount of composite collector for crude sulfur refinement II is 3-5 g / t, the amount of collector for fine sulfur sweep I is 15-20 g / t, and the amount of collector for fine sulfur sweep II is 5-10 g / t.

[0014] Furthermore, the composite collector comprises ethylthiocyanate, isobutyl xanthate and isopentyl xanthate, and the mass ratio of the three is 2:5:3;

[0015] The composite collector is added at a mass concentration of 5%;

[0016] The foaming agent used is 2# oil.

[0017] Furthermore, the amount of flocculant in S3) is 5 to 15 g / t, and the underflow concentration is adjusted to 30% to 35%;

[0018] The flocculant is polyacrylamide.

[0019] Furthermore, the sulfur recovery rate of the mineral processing method reaches 90.44%, and the sulfur grade in the sulfur concentrate product reaches 46.36%.

[0020] A sulfur concentrate is obtained by adopting the above-mentioned mineral processing method.

[0021] The beneficial effects of the present invention are: due to the adoption of the above technology, the method of the present invention utilizes a composite collector to simultaneously improve the grade of the product, greatly improving the sulfur recovery rate, and at the same time has the advantages of low cost and wide applicability, and can achieve efficient flotation recovery of pyrite. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the present invention will be further described below with reference to the accompanying drawings.

[0023] Figure 1 The present invention is a process flow chart of a mineral processing method for recovering pyrite by flotation from low-alkalinity and high-sulfur copper tailings. DETAILED DESCRIPTION

[0024] The technical solution of the present invention will be further described below with reference to specific embodiments of the present invention.

[0025] like Figure 1 As shown, the present invention provides a flotation beneficiation method for recovering pyrite from low-alkalinity high-sulfur copper tailings, which is characterized in that the low-alkalinity high-sulfur copper tailings are subjected to a primary classification, and the primary classification sand is discharged into a roughing mixing barrel to obtain a high-sulfur grade sulfur concentrate 1 under the conditions of one roughing, two sweeping and two refining; the overflow of the primary classification is subjected to a secondary classification, and the secondary classification sand is discharged to perform a one roughing, two sweeping and two refining operation to obtain a high-sulfur grade sulfur concentrate 2, wherein the fine sulfur roughing concentrate and the fine-grained sweep I concentrate are discharged into the fine sulfur concentrate I; the overflow of the secondary classification is discharged into a thickener, and is concentrated and dehydrated and returned to the fine sulfur sweep I.

[0026] Preferably, the primary classification pressure is 0.11-0.15 MPa.

[0027] Preferably, the crude sulfur sweep I and the crude sulfur refine I tail are returned to the primary classification sand settling tank, a water replenishment point is set in the sand settling tank, the slurry in the sand settling tank is transported to the crude sulfur stirring tank through a pipeline, and the slurry concentration in the crude sulfur stirring tank is 42% to 50%; the secondary classification sand is transported to the fine sulfur stirring tank through a pipeline, and the slurry concentration in the crude sulfur stirring tank is 30% to 35%.

[0028] Preferably, sulfur concentrate 1 and tailings 1 are obtained in the process of one coarse, two sweeps and two refineries in the first classification and sedimentation; sulfur concentrate 2 and tailings 2 are obtained in the process of one coarse, two sweeps and two refineries in the second classification and sedimentation, wherein the fine sulfur roughing concentrate and the fine sulfur sweep I concentrate enter the fine sulfur refinement; the overflow from the second classification is dehydrated and concentrated to 30% to 35% through a thickener, and then returned to the fine particle sweep I.

[0029] Preferably, the composite collector used is ethylthiocyanate, isobutyl xanthate and isopentyl xanthate, and the addition mass ratio is 2:5:3; the foaming agent used is 2# oil, and the flocculant is polyacrylamide, wherein the amount of crude sulfur composite collector is 25-30 g / t, the amount of foaming agent is 5-10 g / t, the amount of crude sulfur sweep I composite collector is 10-15 g / t, the amount of crude sulfur sweep II composite collector is 5-10 g / t, the amount of crude sulfur fine II composite collector is 3-5 g / t, the amount of fine sulfur rough selection composite collector is 15-20 g / t, the amount of foaming agent is 3-5 g / t, the amount of fine sulfur sweep I composite collector is 15-20 g / t, the amount of fine sulfur sweep II composite collector is 5-10 g / t, and the amount of thickener flocculant is 5-15 g / t.

[0030] Preferably, the low-alkalinity, high-sulfur copper tailings are copper tailings separated by a low-alkalinity copper-sulfur separation process.

[0031] Example 1

[0032] The mineral raw material is high-sulfur copper tailings from a copper concentrator in Jiangxi Province, with a pH value of 8-9.5 and a sulfur grade of 8-12%. The gangue minerals are mainly quartz and aluminosilicate. The dosage of the reagents is shown in Table 1. The test is an industrial field commissioning.

[0033] Table 1 Example 1 Dosage

[0034]

[0035] The specific steps are as follows:

[0036] (1) The high-sulfur copper tailings are classified once through a φ300 cyclone with a classification pressure of 0.13 MPa. Collectors and frothers are added in sequence. The roughing operation time is 6 minutes, followed by two scavenging operations with each scavenging time of 6 minutes, and two concentrating operations with each concentrating time of 4 minutes. Sulfur concentrate 1 and tailings 1 are obtained. The intermediate products are returned in sequence. The return points of scavenging I and concentrating I are the first classification sand settling tanks.

[0037] (2) The overflow from the primary classification is passed through a φ150 hydrocyclone for secondary classification at a classification pressure of 0.15 MPa. Collectors and frothers are added in sequence. The roughing operation time is 6 minutes, followed by two scavenging operations, each of which takes 6 minutes. Two concentrating operations, each of which takes 4 minutes, are performed to obtain sulfur concentrate 2 and tailings 2. Among them, the fine sulfur roughing concentrate and fine sulfur scavenging I concentrate enter the fine sulfur concentrating process, and the remaining intermediate products are returned in sequence. The return point of the fine sulfur concentrate I tailings is the secondary classification sand settling tank.

[0038] (3) The secondary overflow enters the φ18m thickener, and the underflow concentration is controlled at 30% to 35%, and is pumped to the sand box of the fine sulfur sweep I flotation machine.

[0039] (4) Table 2 shows the flotation product indicators of Example 1.

[0040] Table 2 Flotation product indicators of Example 1

[0041] Operational Products Yield / % grade / % Recovery rate / % sulfur concentrate 17.85 46.36 90.44 tailings 82.15 1.07 9.56 raw ore 100.00 9.15 100.00

[0042] From the results in Table 2, it can be seen that the sulfur recovery rate of the high-sulfur copper tailings reached 90.44% after secondary classification and coarse and fine separation, which achieved a relatively high sulfur recovery rate. The sulfur grade in the sulfur concentrate product reached 46.36%, and high-quality concentrate indicators were obtained.

[0043] Example 2

[0044] The mineral raw materials used in this example are the same as those in Example 1, and the dosage of the reagents is shown in Table 3. The test is an industrial field test.

[0045] Table 3 Example 2 dosage

[0046]

[0047] The specific steps are as follows:

[0048] (1) The high-sulfur copper tailings are classified once through a φ300 cyclone with a classification pressure of 0.12 MPa. Collectors and frothers are added in sequence. The roughing operation time is 5 minutes, followed by two scavenging operations with each scavenging operation time of 5 minutes, and two concentrating operations with each concentrating operation time of 4 minutes. Sulfur concentrate 1 and tailings 1 are obtained. The intermediate products are returned in sequence. The return points of scavenging I and tailings I are the first classification sand settling tank.

[0049] (2) The overflow from the primary classification is passed through a φ150 hydrocyclone for secondary classification at a classification pressure of 0.15 MPa. Collectors and frothers are added in sequence. The roughing operation time is 5 minutes, followed by two scavenging operations, each of which takes 5 minutes. The concentrating operations are then repeated twice, each of which takes 4 minutes. Sulfur concentrate 2 and tailings 2 are obtained. Among them, the fine sulfur roughing concentrate and the fine sulfur scavenging I concentrate are fed into the fine sulfur concentrating process, and the remaining intermediate products are returned in sequence. The return point of the fine sulfur concentrate I tailings is the secondary classification sand settling tank.

[0050] (3) The secondary overflow enters the φ18m thickener, and the underflow concentration is controlled at 30% to 35%, and is pumped to the sand box of the fine sulfur sweep I flotation machine.

[0051] (4) Table 4 shows the flotation product indicators of Example 1.

[0052] Table 4 Flotation product indicators of Example 2

[0053] Operational Products Yield / % grade / % Recovery rate / % sulfur concentrate 18.27 45.84 91.53 tailings 81.73 0.95 8.47 raw ore 100.00 9.15 100.00

[0054] From the results in Table 4, it can be seen that the sulfur recovery rate of the high-sulfur copper tailings reached 91.53% after secondary classification and coarse and fine separation, which achieved a relatively high sulfur recovery rate. The sulfur grade in the sulfur concentrate product reached 45.84%, and high-quality concentrate indicators were obtained.

[0055] Example 3

[0056] The mineral raw materials used in this example are the same as those in Example 1, and the dosage of the reagents is shown in Table 5. The test is an industrial field test.

[0057] Table 5 Example 2 dosage

[0058]

[0059] The specific steps are as follows:

[0060] (1) The high-sulfur copper tailings are classified once through a φ300 cyclone with a classification pressure of 0.12 MPa. Collectors and frothers are added in sequence. The roughing operation time is 6 minutes, followed by two scavenging operations with each scavenging time of 6 minutes, and two concentrating operations with each concentrating time of 5 minutes. Sulfur concentrate 1 and tailings 1 are obtained. The intermediate products are returned in sequence. The return points of scavenging I and tailings I are the first classification sand settling tank.

[0061] (2) The overflow from the primary classification is passed through a φ150 hydrocyclone for secondary classification at a classification pressure of 0.15 MPa. Collectors and frothers are added in sequence. The roughing operation time is 6 minutes, followed by two scavenging operations, each of which takes 6 minutes. Two concentrating operations, each of which takes 5 minutes, are performed to obtain sulfur concentrate 2 and tailings 2. Among them, the fine sulfur roughing concentrate and the fine sulfur scavenging I concentrate are fed into the fine sulfur concentrating process, and the remaining intermediate products are returned in sequence. The return point of the fine sulfur concentrate I tailings is the secondary classification sand settling tank.

[0062] (3) The secondary overflow enters the φ18m thickener, and the underflow concentration is controlled at 30% to 35%, and is pumped to the sand box of the fine sulfur sweep I flotation machine.

[0063] (4) Table 6 shows the flotation product indicators of Example 1.

[0064] Table 6 Flotation product indicators of Example 3

[0065] Operational Products Yield / % grade / % Recovery rate / % sulfur concentrate 18.71 45.13 92.28 tailings 81.29 0.87 7.72 raw ore 100.00 9.15 100.00

[0066] From the results in Table 6, it can be seen that the sulfur recovery rate of the high-sulfur copper tailings reached 92.28% after secondary classification and coarse and fine separation, which achieved a relatively high sulfur recovery rate. The sulfur grade in the sulfur concentrate product reached 45.13%, and high-quality concentrate indicators were obtained.

[0067] The above is a detailed description of a flotation beneficiation method for recovering pyrite from low-alkalinity, high-sulfur copper tailings provided in the examples of this application. The description of the above examples is only intended to help understand the method and core concept of this application; at the same time, those skilled in the art will find that the specific implementation methods and application scopes may vary based on the concept of this application. In summary, the contents of this specification should not be construed as limiting this application.

[0068] For example, certain words are used in the specification and claims to refer to specific components. Those skilled in the art should understand that hardware manufacturers may use different nouns to refer to the same component. This specification and claims do not use differences in names as a way to distinguish components, but use differences in the functions of components as the criteria for distinction. For example, "including" and "comprising" mentioned throughout the specification and claims are open-ended terms, so they should be interpreted as "including / including but not limited to". "Approximately" means that within an acceptable error range, those skilled in the art can solve the technical problems within a certain error range and basically achieve the technical effects. The subsequent description in the specification is a preferred embodiment of the present application, but the description is for the purpose of illustrating the general principles of the present application, and is not used to limit the scope of the present application. The scope of protection of the present application shall be as defined in the attached claims.

[0069] It should also be noted that the terms "include," "comprises," or any other variations thereof are intended to encompass non-exclusive inclusion, such that a product or system comprising a series of elements includes not only those elements but also other elements not explicitly listed, or elements inherent to such product or system. In the absence of further limitations, an element defined by the phrase "comprises a..." does not exclude the presence of other identical elements in the product or system comprising the element.

[0070] It should be understood that the term "and / or" as used herein is merely a description of the relationship between associated objects, indicating that three possible relationships exist. For example, "A and / or B" can represent: A exists alone, A and B exist simultaneously, or B exists alone. Furthermore, the character " / " in this document generally indicates that the associated objects are in an "or" relationship.

[0071] The above description shows and describes several preferred embodiments of the present application. However, as previously mentioned, it should be understood that the present application is not limited to the form disclosed herein and should not be construed as excluding other embodiments. Instead, the present application can be used in various other combinations, modifications, and environments and can be modified within the scope of the application concept described herein through the above teachings or technology or knowledge in the relevant field. Modifications and variations made by those skilled in the art that do not depart from the spirit and scope of the present application should be protected by the claims appended hereto.

Claims

1. A mineral processing method for recovering pyrite by flotation from low-alkalinity, high-sulfur copper tailings, characterized in that: The mineral processing method specifically comprises the following steps: S1) The low-alkalinity, high-sulfur copper tailings to be treated are subjected to a primary classification, and the sand is settled in the primary classification and enters a roughing mixing tank, where water is added to prepare the slurry, and then a composite collector and a frother are added to obtain a high-sulfur grade sulfur concentrate 1 and tailings 1 under the conditions of one roughing, two sweeping and two refining; S2) The overflow from the primary classification is subjected to secondary classification, and the sediment from the secondary classification enters a fine-grain mixing tank, where water is added to prepare the slurry. Subsequently, a composite collector and a foaming agent are added to perform a one-coarse, two-sweep, and two-fine operation to obtain a high-sulfur-grade sulfur concentrate 2 and tailings 2; S3) The secondary overflow is then sent to the thickener, where flocculants are added to control the underflow concentration, and then pumped to the sand box of the fine sulfur sweep I flotation machine to complete the recovery; The amount of the composite collector for crude sulfur selection in S1) and S2) is 25-30 g / t, the amount of the foaming agent is 5-10 g / t, the amount of the composite collector for crude sulfur sweep I is 10-15 g / t, the amount of the composite collector for crude sulfur sweep II is 5-10 g / t, the amount of the composite collector for crude sulfur refinement II is 3-5 g / t, the amount of the collector for fine sulfur sweep I is 15-20 g / t, and the amount of the collector for fine sulfur sweep II is 5-10 g / t; The composite collector comprises ethylthiocyanate, isobutyl xanthate and isopentyl xanthate, and the mass ratio of the three is 2:5:3; The composite collector is added at a mass concentration of 5%; The foaming agent used is 2# oil.

2. The mineral processing method according to claim 1, characterized in that: The fine sulfur roughing concentrate and fine-grained sweeping concentrate in S2) enter the fine sulfur concentrate I.

3. The mineral processing method according to claim 1, characterized in that: The primary classification pressure in S1) is 0.11-0.15 MPa.

4. The mineral processing method according to claim 1, characterized in that: The crude sulfur sweep I and crude sulfur refinement I tail in S1) are returned to the primary classification sand settling tank, a water replenishment point is set in the sand settling tank, and the slurry in the sand settling tank is transported to the crude sulfur stirring tank through a pipeline. The slurry concentration in the crude sulfur stirring tank is 42%~50%.

5. The mineral processing method according to claim 1, characterized in that: The secondary classification sand in S2) is transported to the fine sulfur mixing tank through a pipeline, and the slurry concentration in the coarse sulfur mixing tank is 30%~35%.

6. The mineral processing method according to claim 1, characterized in that: The dosage of the flocculant in S3) is 5-15 g / t, and the underflow concentration is adjusted to 30%-35%; The flocculant is polyacrylamide.

7. The mineral processing method according to claim 1, characterized in that: The sulfur recovery rate of the mineral processing method reaches 90.44%, and the sulfur grade in the sulfur concentrate product reaches 46.36%.

8. A sulfur concentrate, characterized in that: The sulfur concentrate is obtained by the mineral processing method according to any one of claims 1 to 7.

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