Combined collectors, flotation reagents and methods for floating scheelite

Abstract

The present application belongs to the field of flotation, and particularly relates to a combined collector for flotation of scheelite, a flotation reagent and a method. The combined collector comprises component A and component B; the component A comprises a compound with the structure of formula 1; the component B comprises a compound with the structure of formula 2; and in the combined collector, the weight content of the component A is greater than or equal to 40%. According to the method, a scheelite concentrate with a high WO3 grade can be obtained through one stage of cleaning, the WO3 enrichment ratio is greater than 10, and the flotation recovery rate is high. The combined collector provided by the present application has simple components and is environmentally friendly, the loss rate of scheelite in the flotation tailings is low, and efficient flotation of scheelite and flotation separation between scheelite and calcium-containing gangue minerals can be realized.

Description

Technical Field

[0001] The invention relates to the technical field of mineral processing and beneficiation, in particular to the application of a composite in the normal-temperature flotation of scheelite. Background Art

[0002] Scheelite (CaWO4) is widely distributed in Hunan, Jiangxi, Fujian, and other regions. However, its ore grade is generally low, its mineral composition is complex, and it is often associated with other minerals such as fluorite, calcite, apatite, and quartz, making it a difficult ore to select. Therefore, the mining and utilization of scheelite resources has become increasingly important.

[0003] As mentioned above, scheelite often presents a complex co-existence relationship with calcium-containing gangue minerals such as fluorite (CaF2), calcite (CaCO3), apatite (Ca5(PO4)3OH), etc., and these calcium-containing minerals have similar surface physical and chemical properties, similar Ca active sites, and similar floatability. Therefore, achieving efficient flotation separation between scheelite and these calcium-containing gangue minerals, especially fluorite and calcite, is the focus and difficulty of current scheelite flotation research.

[0004] To address this global challenge, research on flotation collectors with both strong capture capacity and good selectivity is crucial. Fatty acid collectors have long been widely used in scheelite flotation due to their strong capture capacity, but their selectivity is relatively poor. Consequently, their flotation performance is generally poor in scheelite deposits with high calcium gangue mineral content. Chelating collectors offer superior selectivity and are commonly used in the flotation of scheelite and wolframite, achieving good flotation performance. However, the complex synthesis steps and high reagent costs of chelating collectors make their use in scheelite flotation difficult. Therefore, selecting a collector with both high selectivity and strong capture capacity is crucial for scheelite flotation. However, research has shown that a single collector often struggles to achieve both high selectivity and strong capture capacity. Therefore, the use of a combination of different collectors, due to the synergistic effects between the collectors, can not only enhance their capture capacity but also significantly increase their selectivity. This is crucial for the efficient and clean flotation separation of scheelite.

[0005] Therefore, there is a need in the art for a composite reagent with strong collecting ability and high selectivity for scheelite flotation to achieve efficient flotation separation between scheelite and calcium-containing gangue minerals such as calcite and fluorite. Summary of the Invention

[0006] To address the difficulty in separating scheelite from calcium-containing gangue minerals due to the inability of existing flotation collectors to achieve both high collection capacity and selectivity when flotating scheelite, the present invention provides a combined scheelite flotation collector (also known as a composite collector) with a simple composition, strong selectivity, and high collection capacity. This collector significantly improves the flotation recovery rate and grade of scheelite, and effectively reduces the content of calcium-containing gangue minerals such as calcite and fluorite in the coarse concentrate.

[0007] Another object of the present invention is to provide an application case of a composite reagent comprising the combined collector in the selective separation of scheelite and calcium-containing gangue.

[0008] A combined collector comprises component A and component B; component A comprises a compound having a structure of formula 1; component B comprises a compound having a structure of formula 2;

[0009]

[0010] R1 is an alkyl group; M is H, K or Na, and n is an integer from 2 to 6;

[0011] The Ar is an aromatic group;

[0012] In the combined collector, the weight content of component A is ≥40%.

[0013] The present invention innovatively discovered that the combination of free NH groups at positions 3 and above in Formula 1 and their monoacylated structures can achieve synergy, improving their capture and selectivity for scheelite. Furthermore, the combination of the arylmethyl structure, trisubstituted number, and P=O structure in Formula 2 can also achieve synergy, optimizing their capture and selectivity for scheelite. Furthermore, the combination of Formulas 1 and 2, based on the intramolecular synergy, can also achieve targeted intermolecular enhancement, further synergistically improving the flotation capacity and selectivity of scheelite.

[0014] In the present invention, in the formula 1, R1 is C 10 ~C 20 The alkyl group may further be a straight-chain alkyl group; the n may further be 2 to 3.

[0015] In the present invention, in Formula 2, Ar is a phenyl group or an alkyl-substituted phenyl group.

[0016] In the present invention, the separation effect can be significantly improved by controlling the ratio of each agent in the combined collector, and the separation effect between scheelite and calcium-containing gangue, especially fluorite, can be further improved;

[0017] Preferably, the weight content of component A in the combined collector is 40-75%, preferably 50-70%. The inventors have found through experiments that, under the synergistic effect of the reagents of Formulas 1 and 2, by adding an auxiliary collector such as sodium oleate, the collector's selectivity can be further improved while maintaining the collector's selectivity.

[0018] In the present invention, the ratio of component A to component B may be 2 to 3:1.

[0019] The combined collector further comprises component C, which includes oleic acid and its salts.

[0020] In the combined collector, the weight content of component C is ≤25%, preferably 5-25%, and more preferably 10-20%.

[0021] The present invention further provides a composite flotation reagent comprising the combined collector of the present invention.

[0022] The composite pharmaceutical composition of the present invention comprises an inhibitor;

[0023] The inhibitor may be a conventional calcium-containing gangue inhibitor, for example, at least one of sodium fluorosilicate and water glass.

[0024] The present invention also provides a method for flotation of scheelite, comprising mixing an ore to be selected containing scheelite with a flotation agent for flotation to obtain scheelite concentrate; the flotation agent comprises the combined collector of the present invention.

[0025] The flotation agent is the flotation agent described in the present invention;

[0026] Preferably, the minerals to be selected further include gangue minerals, and the gangue minerals include calcium-containing gangue;

[0027] Preferably, the calcium-containing gangue includes at least one of calcite and fluorite.

[0028] In the present invention, the amount of the combined collector used in the flotation stage is 300-1500 g / t, further 500-1200 g / t, and further 600-1000 g / t, taking into account the effect and composition. In the present invention, the amount of the combined collector used in the roughing flotation can be 300-600 g / t.

[0029] Preferably, the amount of the inhibitor is 1500 to 4500 g / t, preferably 2000 to 4000 g / t.

[0030] Preferably, the pH in the flotation stage is 7 to 10.5, preferably 7.5 to 8.5.

[0031] Preferably, the pulp temperature during flotation operation is -5 to 40°C; further preferably, it can be 20 to 30°C.

[0032] At the same time, the present invention provides a process for flotation separation of calcium-containing scheelite, which adopts the flotation agent for flotation separation and obtains high-grade scheelite concentrate through two rounds of concentration. The calcium gangue content, especially fluorite content, in the concentrate is low.

[0033] Beneficial effects:

[0034] 1. The combination of free NH at positions 3 and above in Formula 1 and its monoacylated structure can achieve synergy, improving its capture ability and selectivity in scheelite. In addition, the combination of the arylmethyl structure, the number of trisubstituted groups, and the P=O structure in Formula 2 can achieve synergy, optimizing its capture ability and selectivity in scheelite. Further, the combination of Formulas 1 and 2 can achieve intermolecular targeted enhancement based on intramolecular synergy, further synergistically improving the flotation ability and selectivity of scheelite.

[0035] The combined collector of the present invention has both strong collecting ability and strong selectivity. It has poor collecting ability for calcium-containing gangue minerals, especially fluorite. It can effectively solve the problems of poor selectivity of traditional fatty acid collectors, large amounts of fluorite and calcite mixed in the concentrate, resulting in low WO3 grade and unsatisfactory flotation indicators.

[0036] 2. The combined collector provided by the present invention is used in the flotation of scheelite. It has good flotation effects under neutral and alkaline pulp conditions, has a wide tolerance to pulp pH, and is insensitive to changes in flotation pulp temperature. The flotation indicators are better at lower temperatures.

[0037] 3. The combined collector provided by the present invention has the advantages of good flotation effect, strong collecting ability, strong reagent selectivity and no pollution. BRIEF DESCRIPTION OF THE DRAWINGS

[0038] Figure 1 The XRD analysis results of the mineral composition of the scheelite ore used in the present invention are as follows;

[0039] Figure 2 This is a flow chart of the closed-circuit flotation test of the present invention. DETAILED DESCRIPTION

[0040] Example 1:

[0041] 1. Select the raw scheelite ore from a certain place for flotation experiment, Figure 1Table 1 shows the semi-quantitative analysis results of XRD of scheelite ore. The main useful minerals in the ore are scheelite, chalcopyrite, etc., of which the WO3 content is 0.50%. The main gangue minerals are quartz, pyroxene, (clinopyroxene, sodium) feldspar, mica, chlorite, amphibole, calcite, fluorite, etc., of which the fluorite content is about 6.13% and the calcite content is about 7.44%.

[0042] Table 1 Relative composition of raw ore minerals

[0043] mineral Chlorite talc amphibole Mica quartz calcite content(%) 7.95 5.78 7.87 5.96 16.33 7.44 mineral Scheelite fluorite pyroxene feldspar other content(%) 0.67 6.13 16.79 23.30 1.78

[0044] 2. Crushing and screening the raw ore, crushing the raw ore to less than -2mm, and fully mixing it and then bagging it for storage. Use a laboratory small ball mill to put 700g of raw ore and 350g of tap water into it, and grind the ore to -200 mesh (-74μm) accounting for 76%;

[0045] 3. Flotation process Figure 2 , pour the slurry into a 1.5L aerated flotation machine, adjust the slurry pH to about 8.0 (±0.1), then add 3.0kg / t sodium fluorosilicate as a depressant, and the slurry mixing time is 3 minutes; finally, add a combined collector (or a single collector for comparison), the collector dosage is 400g / t, the slurry mixing time is 3 minutes, the roughing time is 8 minutes, and only the combined collector is added in the scavenging stage, the dosage of the combined collector is half of that in the previous stage, the scavenging operation is performed 3 times, the middling products obtained by flotation are returned in sequence, and the obtained coarse concentrate is subjected to a single beneficiation to obtain tungsten concentrate;

[0046] In this case, the collector selected in formula 1 has n=2 and R1 is n-dodecyl C 12 H 25 , M is H. It should be noted that M in the flotation stage can be partially or completely converted into a salt form (M is K or Na) according to the control of pH in the flotation stage. The formula 2 refers to a collector of formula 2 in which Ar is a phenyl group.

[0047] The flotation temperature is 25-30°C.

[0048] 6. Weigh the flotation products, then assay the flotation products to measure the grade of WO3 in each flotation product, and calculate the recovery rate, yield and grade of each flotation product.

[0049] The composition of the collectors and the flotation results of each experimental group in Example 1 are shown in Table 1:

[0050] Table 1

[0051]

[0052]

[0053] Note: In Table 1, the total amount of collector used in each experimental group is the same;

[0054] Contrast formula a:

[0055] Contrast formula b: n = 2;

[0056] Contrast formula c:

[0057] Contrast formula d: The structure is similar to Formula 1, R1 and M are the same as Formula 1 in this case, and n=1;

[0058] Contrast formula e:

[0059] Formula 1A: Formula 1 wherein R1 is n-hexadecyl, n=3, and M is Na;

[0060] As shown in the table above, the WO3 grade of the raw ore is 0.500%. By comparing Group A and Group B, it can be seen that the combination of Formula 1 and Formula 2 in the combined collector has a strong inhibitory effect on calcite and fluorite in the raw ore, but the flotation recovery rate of tungsten ore is relatively high. As a preferred method, when the weight ratio of Formula 1 and Formula 2 collectors is 2-3:1, the effect is the best, and the grade and recovery rate of the flotation concentrate are both high;

[0061] By comparing Group A, Group B and Comparative Groups 1, 2 and 3, it can be seen that when Formula 1, Formula 2 and auxiliary collector act alone, the flotation effect is poor, and the grade and recovery rate of scheelite concentrate are both low;

[0062] By comparing Group A, Group B and Comparative Group 4, it can be seen that the weight content of Formula 1 in the combined collector must be no less than 40%. When the content of Formula 1 collector is low, the flotation index is poor.

[0063] By comparing group B with comparison groups 5 to 9, it can be seen that the combined control of the structures of formula 1 and formula 2 is the key to determining the strong capture ability and selectivity of the combined collector.

[0064] Example 2

[0065] The flotation method of Example 2 is the same as that of Example 1, with the main difference being the addition of an auxiliary collector, sodium oleate. The other flotation conditions are the same as those of Example 1. The flotation results are shown below (Table 2):

[0066] Table 2

[0067]

[0068]

[0069] As shown in the table above, by comparing Group A of Example 1 and Group A of Example 2, it can be seen that after the auxiliary collector sodium oleate is added, the WO3 grade in the flotation concentrate is significantly increased by about 1.5%, and the calcite and fluorite contents in the concentrate are significantly reduced (both ≥ 1.4%). While ensuring the selectivity of the reagent, the collection capacity of the combined collector is significantly increased, and the WO3 recovery rate is increased by more than 10%;

[0070] By comparing groups A to C of Example 2, when the weight content of sodium oleate is low, the recovery rate of the flotation concentrate decreases by about 5%, and the grade decreases slightly, indicating that the optimal weight content range of sodium oleate is 5 to 25%, and further 10 to 20%; when the dosage of sodium oleate is too high, the synergistic effect between the reagents deteriorates, and at this time, the grade and recovery rate of WO3 in the flotation concentrate are both reduced.

[0071] Example 3

[0072] The flotation method of Example 3 is consistent with that of Examples 1 and 2, and the weight ratio of the combined collector used is consistent with that of Group A of Example 2. The main difference is that the flotation index difference is determined by changing the flotation pH, the amount of inhibitor, the amount of combined collector, etc. The final flotation results of each group are shown in Table 3:

[0073] Table 3

[0074]

[0075]

[0076] Note: The dosage of inhibitors and collectors in Table 3 refers to the dosage of reagents in the roughing process. The dosage of combined collectors in other flotation processes is reduced by half step by step according to the method of Example 1.

[0077] The above embodiments are intended only to illustrate the technical solutions of the present invention and are not intended to limit the present invention. It should be noted that the above preferred embodiments should not be considered as limiting the present invention, and the scope of protection of the present invention should be based on the scope defined in the claims. It will be apparent to those skilled in the art that various improvements and modifications can be made without departing from the spirit and scope of the present invention, and such improvements and modifications should also be considered within the scope of protection of the present invention.

Claims

1. A combined collector, characterized in that: Comprising component A and component B; component A comprises a compound having a structure of formula 1; component B comprises a compound having a structure of formula 2; Formula 1 Formula 2 R1 is an alkyl group; M is H, K or Na, and n is an integer of 2 to 6; The Ar is an aromatic group; In the combined collector, the weight content of component A is ≥40%.

2. The combined collector according to claim 1, wherein In the formula 1, R1 is C 10 ~C 20 wherein n is 2 or 3.

3. The combined collector according to claim 1, wherein In the formula 2, Ar is a phenyl group or an alkyl-substituted phenyl group.

4. The combined collector according to claim 1, wherein In the combined collector, the weight content of component A is 40-75%.

5. The combined collector according to claim 4, wherein In the combined collector, the weight content of component A is 50-70%.

6. The combined collector according to any one of claims 1 to 5, wherein The invention also comprises component C, which comprises oleic acid and its salt.

7. The combined collector according to claim 6, wherein In the combined collector, the weight content of component C is ≤25%.

8. The combined collector according to claim 7, wherein In the combined collector, the weight content of component C is 5-25%.

9. The combined collector according to claim 8, wherein In the combined collector, the weight content of component C is 10-20%.

10. A composite flotation reagent comprising a collector and a depressant, characterized in that: The collector comprises the combined collector according to any one of claims 1 to 9.

11. The composite flotation reagent according to claim 10, characterized in that: The inhibitor includes at least one of sodium fluorosilicate and water glass.

12. A method for flotation of scheelite, comprising mixing a mineral to be selected including scheelite with a flotation agent and performing flotation to obtain scheelite concentrate; characterized in that: The flotation reagent comprises the combined collector according to any one of claims 1 to 9.

13. The method for flotation of scheelite according to claim 12, wherein: The flotation agent is the flotation agent according to any one of claims 10 to 11.

14. The method for flotation of scheelite according to claim 13, wherein: The minerals to be selected also include gangue minerals, and the gangue minerals include calcium-containing gangue.

15. The method for flotation of scheelite according to claim 14, wherein: The calcium-containing gangue includes at least one of calcite and fluorite.

16. The method according to claim 13, wherein During the flotation stage, the dosage of the combined collector is 300~1500g / t.

17. The method according to claim 16, wherein During the flotation stage, the dosage of the combined collector is 500~1200g / t.

18. The method according to claim 16, wherein During the flotation stage, the dosage of the combined collector is 600~1000g / t.

19. The method according to claim 13, wherein During the flotation stage, the dosage of inhibitor is 1500~4500g / t.

20. The method according to claim 19, wherein During the flotation stage, the dosage of inhibitor is 2000~4000g / t.

21. The method according to claim 13, wherein The pH value in the flotation stage is 7~10.

5.

22. The method according to claim 21, wherein The pH value in the flotation stage is 7.5~8.5.

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