Copper-molybdenum bulk concentrate flotation separation method and used combined inhibitor

Abstract

The invention discloses a flotation separation method for copper-molybdenum bulk concentrate and a combined inhibitor used in the flotation separation method. The combined inhibitor comprises dithionite and thiobarbituric acid. The method comprises the following steps: adding dithionite into copper-molybdenum bulk concentrate pulp to carry out reagent removal treatment, then adding thiobarbituric acid to inhibit chalcopyrite, and then adding a molybdenite collecting agent and a foaming agent to carry out flotation, so as to obtain molybdenum concentrate and copper concentrate. The combined inhibitor is non-toxic and environment-friendly, the excellent inhibition effect on the chalcopyrite can be achieved through the synergistic effect of the two inhibitors under the condition of low dosage, and the recovery rate of molybdenum and the molybdenum-copper separation effect are remarkably improved.

Description

Technical Field

[0001] The invention relates to a flotation separation method for a copper-molybdenum mixed concentrate and a combined depressant used therein, belonging to the technical field of copper-molybdenum sulfide mineral separation. Background Art

[0002] Copper and molybdenum are both metal materials with important practical value. The high electrical and thermal conductivity of copper makes it widely used in electrical, construction, manufacturing and other fields. Molybdenum is an important strategic reserve resource. Due to its excellent high temperature and corrosion resistance, it is widely used in the manufacture of high-temperature equipment and electronic components, providing key support for aerospace and other fields. However, due to the close association of copper and molybdenum minerals and similar floatability, the separation of copper and molybdenum minerals has always been a major problem that plagues mineral sorting.

[0003] At present, there are two process flows for the separation of copper-molybdenum mixed concentrates at home and abroad: copper suppression and molybdenum flotation and molybdenum suppression and copper flotation. Since molybdenum ore has good natural floatability, the copper suppression and molybdenum flotation process is basically adopted in practice. Commonly used copper suppression agents can be divided into: (1) Inorganic inhibitors. Commonly used agents include cyanide and Knox agents. The principle of this type of inhibitor is that after the agent is dissolved in water, the dissociated ions are adsorbed on the surface of the copper mineral, increasing the hydrophilicity of the copper mineral surface, but it has no obvious effect on molybdenite. Although this inhibitor has the advantages of good inhibitory effect and low dosage, its application is limited due to its own toxicity and great pollution to the environment. (2) Organic inhibitors, sodium thioacetic acid (HSCH 2 COONa) is a new type of organic inhibitor in copper separation in recent years. The -HS group and -COOH group in its molecule are adsorbed on the surface of copper minerals to form a hydrophilic film, which increases the hydrophilicity of the copper mineral surface. However, the high cost of sodium thioglycolate has always restricted its promotion. (3) Oxidants. Commonly used oxidants include hydrogen peroxide, sodium hypochlorite and potassium permanganate. In the flotation process, the strong reducing property and easy oxidation property of xanthate are used to oxidize the xanthate adsorbed on the surface of copper minerals through oxidants to generate non-collectible perxanthate Cu(C 2 H 5 OCSSO) 2 , thus achieving the effect of inhibiting copper. However, due to its strong oxidizing property, it is easy to corrode, the cost of the agent is high, and some of them are toxic. The method and location of adding the oxidant need to be studied.

[0004] Due to many problems in the existing copper-molybdenum separation methods and reagents, the sorting effect of copper-molybdenum mixed concentrate in my country is not good. Therefore, it is urgent to find a depressant and flotation separation process with few types of reagents, low toxicity, low dosage and strong selectivity. Summary of the invention

[0005] In view of the shortcomings in the prior art, the first object of the present invention is to provide a combined inhibitor for flotation separation of copper-molybdenum mixed concentrate. The combined inhibitor has a small number of reagents and only contains low-toxic and harmless dithionite and thiobarbituric acid. The synergistic effect of the two can achieve excellent inhibitory effect on chalcopyrite at a lower dosage, significantly improving the recovery rate of molybdenum and the molybdenum-copper separation effect.

[0006] The second object of the present invention is to provide a method for flotation separation of copper-molybdenum mixed concentrate. The process reasonably sets the addition order of dithionite and thiobarbituric acid in the combined inhibitor, and adopts a hydrocarbon collector with a good collection effect on molybdenite. Under the condition of low dosage of reagents, the recovery rate of molybdenum and the effect of molybdenum-copper separation are significantly improved. The whole process is low-toxic, environmentally friendly and has a simple process.

[0007] In order to achieve the above-mentioned object, the present invention provides a combined depressant for flotation separation of copper-molybdenum mixed concentrate, wherein the combined depressant comprises dithionite and thiobarbituric acid; the mass ratio of the dithionite and thiobarbituric acid is (0.2-1): (0.5-2).

[0008] In the technical solution of the present invention, dithionite and thiobarbituric acid have good synergistic effects, which are mainly manifested in that: dithionite has strong reducing properties, which can reduce hydrophobic substances such as elemental sulfur and polysulfide on the surface of chalcopyrite, and realize the effective desorption of neutral oil collectors used in the flotation separation process of the chalcopyrite surface and copper-molybdenum mixed concentrate; and the molecular structure of thiobarbituric acid is a resonance isomer. Due to the strong electron-pulling effect of the double carbon group, the double bonds between the nitrogen atom and the sulfur atom can be transformed into each other, so that thiobarbituric acid has There are multiple structural formulas, so thiobarbituric acid has both thiol and carbon-nitrogen double bond functional groups, as well as carbon-sulfur double bonds and amino groups; the combined action of multiple functional groups can selectively form a strong chelate with the surface of chalcopyrite, and the inhibitory effect is significantly stronger than that of traditional inhibitors such as sodium thioglycolate. At the same time, the combination of thiol and amino groups can enhance the adaptability of the agent; more importantly, dithionite can also reduce part of the divalent copper ions present in the ore pulp, eliminate the effect of divalent copper ions and thiobarbituric acid, significantly enhance the inhibitory effect, and reduce the dosage of thiobarbituric acid.

[0009] The dosage of dithionite and thiobarbituric acid in the present invention also has a direct impact on the separation effect. If the mass ratio of dithionite is too low, it will lead to insufficient drug removal, affecting the subsequent inhibitory effect of thiobarbituric acid on chalcopyrite. If the mass ratio is too high, it will cause the surface of chalcopyrite to be excessively reduced, which is also not conducive to the effect of thiobarbituric acid.

[0010] As a preferred solution, the combined inhibitor is calculated per ton of copper-molybdenum mixed concentrate, and the dosage of dithionite and thiobarbituric acid in the flotation separation of copper-molybdenum mixed concentrate is 0.2-1.0 kg and 0.5-2.0 kg respectively. The combined inhibitor used in the roughing separation of the present invention is low in dosage and has a good inhibitory effect.

[0011] As a preferred solution, the dithionite is sodium dithionite and / or potassium dithionite.

[0012] The present invention also provides a flotation separation method for a copper-molybdenum mixed concentrate, which comprises adding dithionite to the copper-molybdenum mixed concentrate pulp for drug removal, then adding thiobarbituric acid to inhibit chalcopyrite, and then adding a molybdenite collector and a frother to carry out flotation to obtain a molybdenum concentrate and a copper concentrate.

[0013] The flotation separation method for the copper-molybdenum mixed concentrate of the present invention is to first inhibit chalcopyrite and increase its hydrophilicity through the synergistic effect of the combined inhibitor, and then select a collector and a frother that can increase the surface hydrophobicity of molybdenite and stabilize the foam. Due to the synergistic effect of the combined inhibitor, efficient selective separation of copper ore and molybdenum ore can be achieved under low-alkali conditions, and the recovery rate of molybdenum concentrate is improved.

[0014] The inventors found that in the separation method of the present invention, dithionite must be added first for drug removal, and then thiobarbituric acid is added to achieve the best copper-molybdenum separation effect; if sodium dithionite and thiobarbituric acid are added at the same time, the inhibitory effect on copper is significantly weakened, and the obtained molybdenum concentrate has a lower grade and a higher copper content, while the copper concentrate grade and copper recovery rate are reduced; and if thiobarbituric acid is added first and then dithionite, the adsorption of thiobarbituric acid on the mineral surface will be destroyed by dithionite, thereby affecting its inhibitory effect on chalcopyrite. In addition, the drug removal effect of dithionite may affect the adsorption of subsequent flotation reagents, thereby affecting the selectivity and efficiency of flotation.

[0015] As a preferred solution, the flotation comprises one roughing selection, at least one cleaning selection and at least one scavenging selection.

[0016] The dosage of the agent in the present invention is relative to the dosage of the original ore.

[0017] As a preferred solution, the reagent system for rough selection is: 0.2-1.0 kg / t of dithionite, 0.5-2.0 kg of thiobarbituric acid, 0.1-1 kg / t of collector, and 50-200 g / t of foaming agent.

[0018] As a preferred solution, the concentrate obtained after the roughing is a molybdenum rough concentrate, and the tailings are a copper rough concentrate; the molybdenum rough concentrate is subjected to concentrating, and the final concentrated concentrate is a molybdenum concentrate; the copper rough concentrate is subjected to scavenging, and the scavenging tailings are a copper concentrate.

[0019] As a preferred solution, only a collector is added during the scavenging process, and the amount of the collector is 0.1 to 0.5 times the amount used in the roughing process.

[0020] As a preferred solution, only thiobarbituric acid inhibitor is added during the selection process, and the amount used is 0.01 to 0.5 times the amount used in the roughing selection, and the amount of inhibitor used in the Nth selection is less than the amount used in the N-1th selection. In the combined inhibitor of the present invention, since the main function of dithionite is drug removal, the agent on the surface of the mineral can be removed by adding it in the roughing selection. In the subsequent selection process, only thiobarbituric acid needs to be added to further inhibit chalcopyrite to achieve deep flotation; and as the number of selections increases, the content of impurity minerals in the concentrate decreases, so the amount of inhibitor used gradually decreases.

[0021] As a preferred solution, the copper-molybdenum mixed concentrate is a copper-molybdenum mixed concentrate obtained by flotation of molybdenum-containing copper ore or copper-molybdenum ore using a neutral oil collector; wherein the copper content is 2 to 30 wt%; and the molybdenum content is 0.2 to 50 wt%.

[0022] As a preferred solution, the copper-molybdenum mixed concentrate slurry concentration is 10-40%.

[0023] As a preferred solution, the collector is at least one of diesel and kerosene.

[0024] As a preferred solution, the foaming agent is at least one of No. 2 oil and MIBC.

[0025] In the molybdenite collection process of the present invention, the diesel and kerosene used are hydrocarbon oil collectors, which can form an oil film on the surface of the molybdenite, increase the hydrophobicity of the surface of the molybdenite, so that the molybdenite can adhere to the surface of the bubble and be carried by the bubble to the surface of the slurry to form mineralized foam, and then separate from other minerals; and No. 2 oil can further promote the diffusion of air in the slurry to form foam with suitable size, good toughness and stable performance, provide a carrier for the flotation of molybdenite, and significantly improve the molybdenite collection effect.

[0026] Compared with the prior art, the present invention has the following beneficial effects:

[0027] First, through the strong reducing property of dithionite, the elemental sulfur, polysulfide and other hydrophobic substances on the surface of chalcopyrite are reduced, thereby achieving effective desorption of the chalcopyrite surface and the neutral oil collector.

[0028] Secondly, dithionite can also reduce some of the divalent copper ions present in the ore pulp, eliminate the effect of divalent copper ions and thiobarbituric acid, enhance the effect of thiobarbituric acid, and reduce the dosage of thiobarbituric acid.

[0029] Thirdly, thiobarbituric acid contains thiol and amino groups in its molecular structure, which can form a strong chelate with the surface of chalcopyrite. Its inhibitory effect is significantly stronger than that of traditional inhibitors such as sodium thioglycolate. At the same time, the combination of thiol and amino groups can enhance the adaptability of the agent, and it can flexibly respond to various types of copper-molybdenum mixed concentrates.

[0030] Fourthly, dithionite and thiobarbituric acid have almost no inhibitory effect on molybdenite, and the agents have good selectivity.

[0031] Fifthly, the combined inhibitor is non-toxic and environmentally friendly, which is beneficial to the subsequent wastewater treatment or reuse of the ore dressing plant and well protects the ecological benefits around the ore dressing plant. BRIEF DESCRIPTION OF THE DRAWINGS

[0032] Figure 1 The present invention is a process flow chart for a small-scale closed-circuit test of copper-molybdenum flotation separation. DETAILED DESCRIPTION

[0033] The following specific examples are intended to further illustrate the content of the present invention, but are not intended to limit the scope of protection of the claims of the present invention. The pharmaceutical agents used without indicating the manufacturer are all conventional products that can be purchased commercially.

[0034] The dosage of the reagents in the examples of the present invention and the comparative examples is relative to the dosage of the original ore, and the slurry concentration is the mass concentration.

[0035] Example 1

[0036] The test raw material comes from a copper-molybdenum mixed concentrate obtained by flotation using diesel as a collector from a molybdenum-containing copper mine. The copper content is 23.07% and the molybdenum content is 1.19%. The process mineralogy research results show that the main metal minerals in the sample are chalcopyrite, molybdenite and a small amount of pyrite. A combined inhibitor for flotation separation of copper-molybdenum mixed concentrate provided by the present invention is used to conduct a laboratory small-scale closed-circuit test on the ore sample. The specific steps of the test are as follows:

[0037] 1) adding 800 g / t of sodium dithionite to the copper-molybdenum mixed concentrate pulp (pulp concentration is 25%) for drug removal, and then sequentially adding 1500 g / t of thiobarbituric acid as an inhibitor, 300 g / t of kerosene as a collector, and 100 g / t of No. 2 oil as a frother, and performing a roughing;

[0038] 2) The rough tailings after roughing are subjected to two scavengings, 150g / t of kerosene is added in scavenging 1, and 75g / t of kerosene is added in scavenging 2. The scavenging tailings are used as copper concentrate;

[0039] 3) The coarse concentrate after roughing is subjected to three rounds of concentration, wherein 500 g / t of thiobarbituric acid is added in concentration 1, 200 g / t of thiobarbituric acid is added in concentration 2, and 100 g / t of thiobarbituric acid is added in concentration 3. The concentrated ore is used as molybdenum concentrate.

[0040] The test results are shown in Table 1.

[0041] It can be seen from the test results that the present invention provides a combined depressant for flotation separation of copper-molybdenum mixed concentrate. In a small-scale closed-circuit test in a laboratory, a molybdenum grade of 49.58% and a copper content of only 1.41% in the molybdenum concentrate can be obtained, and a molybdenum recovery rate of 95.07%; a copper concentrate with a copper grade of 23.58% contains only 0.060% molybdenum and a copper recovery rate of 99.86%.

[0042] Table 1

[0043]

[0044] Example 2

[0045] The test raw material comes from a copper-molybdenum mixed concentrate obtained by flotation using kerosene as a collector from a copper-molybdenum ore. The copper content is 11.20% and the molybdenum content is 22.99%. The process mineralogy research results show that the main metal minerals in the sample are chalcopyrite, molybdenite and pyrite. A combined inhibitor for flotation separation of a copper-molybdenum mixed concentrate provided by the present invention is used to conduct a laboratory small-scale closed-circuit test on the ore sample. The specific steps of the test are as follows:

[0046] 1) adding 500 g / t of sodium dithionite to the copper-molybdenum mixed concentrate pulp (pulp concentration is 20%) for drug removal, and then adding 1000 g / t of thiobarbituric acid as an inhibitor, 800 g / t of kerosene as a collector, and 150 g / t of MIBC as a frother to perform a roughing operation;

[0047] 2) The rough tailings after roughing are subjected to two scavengings. In scavenging 1, 400 g / t of kerosene is added, and in scavenging 2, 200 g / t of kerosene is added. The scavenging tailings are used as copper concentrate;

[0048] 3) The coarse concentrate after roughing is subjected to three rounds of concentration, wherein 400 g / t of thiobarbituric acid is added in concentration 1, 200 g / t of thiobarbituric acid is added in concentration 2, and 100 g / t of thiobarbituric acid is added in concentration 3. The concentrated ore is used as molybdenum concentrate.

[0049] The test results are shown in Table 2.

[0050] It can be seen from the test results that the present invention provides a combined depressant for flotation separation of copper-molybdenum mixed concentrate. In a small-scale closed-circuit test in a laboratory, a molybdenum grade of 50.66% and a copper content of only 0.28% in the molybdenum concentrate can be obtained, and a molybdenum recovery rate of 99.50%; a copper concentrate with a copper grade of 20.19% contains only 0.21% molybdenum and a copper recovery rate of 98.87%.

[0051] Table 2

[0052]

[0053]

[0054] Example 3

[0055] The test raw material comes from a copper-molybdenum mixed concentrate obtained by flotation using heavy oil as a collector from a molybdenum-containing copper mine. The copper content is 21.71% and the molybdenum content is 0.83%. The process mineralogy research results show that the main metal minerals in the sample are chalcopyrite, molybdenite and a small amount of pyrite. A combined inhibitor for flotation separation of copper-molybdenum mixed concentrate provided by the present invention is used to conduct a laboratory small-scale closed-circuit test on the ore sample. The specific steps of the test are as follows:

[0056] 1) adding 600 g / t of sodium dithionite to the copper-molybdenum mixed concentrate pulp (pulp concentration is 30%) for drug removal, and then sequentially adding 1200 g / t of thiobarbituric acid as an inhibitor, 200 g / t of kerosene as a collector, and 50 g / t of No. 2 oil as a frother, and performing a roughing;

[0057] 2) The rough tailings after roughing are subjected to two scavengings, with 100 g / t of kerosene added in scavenging 1 and 50 g / t of kerosene added in scavenging 2. The scavenging tailings are used as copper concentrate;

[0058] 3) The coarse concentrate after roughing is subjected to three rounds of concentration, wherein 400 g / t of thiobarbituric acid is added in concentration 1, 200 g / t of thiobarbituric acid is added in concentration 2, and 100 g / t of thiobarbituric acid is added in concentration 3. The concentrated ore is used as molybdenum concentrate.

[0059] The test results are shown in Table 3.

[0060] It can be seen from the test results that the present invention provides a combined depressant for flotation separation of copper-molybdenum mixed concentrate. In a small-scale closed-circuit test in a laboratory, a molybdenum grade of 48.70% and a copper content of only 1.58% in the molybdenum concentrate can be obtained, and a molybdenum recovery rate of 94.91%; a copper concentrate with a copper grade of 22.04% contains only 0.043% molybdenum and a copper recovery rate of 99.88%.

[0061] Table 3

[0062]

[0063]

[0064] Comparative Example 1

[0065] For the ore sample in Example 1, while keeping the process structure and the total dosage of the reagent unchanged, thiobarbituric acid was replaced with sodium thioglycolate, and a small-scale closed-circuit laboratory test was carried out on the ore. The specific steps of the test are as follows:

[0066] 1) adding 800 g / t of sodium dithionite to the copper-molybdenum mixed concentrate pulp (pulp concentration is 25%) for drug removal, and then sequentially adding 1500 g / t of sodium thioglycolate as an inhibitor, 300 g / t of kerosene as a collector, and 100 g / t of No. 2 oil as a frother to perform a roughing operation;

[0067] 2) The rough tailings after roughing are subjected to two scavengings, 150g / t of kerosene is added in scavenging 1, and 75g / t of kerosene is added in scavenging 2. The scavenging tailings are used as copper concentrate;

[0068] 3) The coarse concentrate after roughing is subjected to three rounds of concentration, wherein 500 g / t of sodium thioglycolate is added in concentration 1, 200 g / t of sodium thioglycolate is added in concentration 2, and 100 g / t of sodium thioglycolate is added in concentration 3. The concentrated ore is used as molybdenum concentrate.

[0069] The test results are shown in Table 4.

[0070] From the test results, it can be seen that after the combined inhibitor removes thiobarbituric acid, the laboratory small closed-circuit test can obtain a molybdenum concentrate with a molybdenum grade of 48.44%, a molybdenum recovery rate of 90.48%, and a copper content of 3.81%; the copper grade in the copper concentrate is 23.51%, the molybdenum content is 0.12%, and the copper recovery rate is 99.62%. By comparison, it is found that after the inhibitor is replaced by sodium thioglycolate from thiobarbituric acid, the molybdenum concentrate obtained has a lower grade, a higher copper content, and a significantly lower molybdenum recovery rate.

[0071] Table 4

[0072]

[0073] Comparative Example 2

[0074] For the ore sample in Example 1, under the condition of maintaining the process structure and the total dosage of the reagent, the sodium dithionite in the combined inhibitor provided by the present invention was removed, and a laboratory small-scale closed-circuit test was carried out on the ore. The specific steps of the test are as follows:

[0075] 1) Adding 1500 g / t of thiobarbituric acid as an inhibitor, 300 g / t of kerosene as a collector, and 100 g / t of No. 2 oil as a frother to the copper-molybdenum mixed concentrate slurry (slurry concentration of 25%), and performing a roughing operation;

[0076] 2) The rough tailings after roughing are subjected to two scavengings, 150g / t of kerosene is added in scavenging 1, and 75g / t of kerosene is added in scavenging 2. The scavenging tailings are used as copper concentrate;

[0077] 3) The coarse concentrate after roughing is subjected to three rounds of concentration, wherein 500 g / t of thiobarbituric acid is added in concentration 1, 200 g / t of thiobarbituric acid is added in concentration 2, and 100 g / t of thiobarbituric acid is added in concentration 3. The concentrated ore is used as molybdenum concentrate.

[0078] The test results are shown in Table 5.

[0079] From the test results, it can be seen that after the combined inhibitor removes sodium dithionite, the laboratory small closed-circuit test can obtain a molybdenum concentrate with a molybdenum grade of 25.95%, a molybdenum recovery rate of 81.76%, and a copper content of 7.56%; the copper grade in the copper concentrate is 23.64%, the molybdenum content is 0.22%, and the copper recovery rate is 98.80%. By comparison, it is found that the inhibitory effect of the combined inhibitor on copper is significantly weakened after sodium dithionite is removed, and the obtained molybdenum concentrate has a lower grade and a higher copper content; the copper recovery rate of the copper concentrate is reduced.

[0080] Table 5

[0081]

[0082] Comparative Example 3

[0083] For the ore sample in Example 1, under the condition of maintaining the process structure and the total dosage of the reagent, the sodium dithionite in the combined inhibitor provided by the present invention was replaced with sodium sulfide, and a laboratory small-scale closed-circuit test was carried out on the ore. The specific steps of the test are as follows:

[0084] 1) adding 800 g / t of sodium sulfide to the copper-molybdenum mixed concentrate pulp (pulp concentration is 25%) for drug removal, and then sequentially adding 1500 g / t of thiobarbituric acid as an inhibitor, 300 g / t of kerosene as a collector, and 100 g / t of No. 2 oil as a frother, and performing a roughing operation;

[0085] 2) The rough tailings after roughing are subjected to two scavengings, 150g / t of kerosene is added in scavenging 1, and 75g / t of kerosene is added in scavenging 2. The scavenging tailings are used as copper concentrate;

[0086] 3) The coarse concentrate after roughing is subjected to three rounds of concentration, wherein 500 g / t of thiobarbituric acid is added in concentration 1, 200 g / t of thiobarbituric acid is added in concentration 2, and 100 g / t of thiobarbituric acid is added in concentration 3. The concentrated ore is used as molybdenum concentrate.

[0087] The test results are shown in Table 6.

[0088] From the test results, it can be seen that after sodium dithionite is replaced with sodium sulfide, the laboratory small closed-circuit test can obtain a molybdenum concentrate with a molybdenum grade of 32.48%, a molybdenum recovery rate of 86.18%, and a copper content of 4.08%; the copper grade in the copper concentrate is 23.55%, the molybdenum content is 0.16%, and the copper recovery rate is 99.47%. By comparison, it is found that the inhibitory effect on copper is significantly weakened after sodium dithionite is replaced with sodium sulfide, and the obtained molybdenum concentrate has a lower grade and a higher copper content, and the molybdenum recovery rate will also be significantly reduced; the copper concentrate grade and copper recovery rate are both reduced.

[0089] Table 6

[0090]

[0091] Comparative Example 4

[0092] For the ore sample in Example 1, under the condition of maintaining the process structure and the total dosage of the reagent, the sequential addition of sodium dithionite and thiobarbituric acid was changed to simultaneous addition, and a laboratory small-scale closed-circuit test was carried out on the ore. The specific steps of the test are as follows:

[0093] 1) adding 800 g / t of sodium dithionite and 1500 g / t of thiobarbituric acid to the copper-molybdenum mixed concentrate slurry (slurry concentration is 25%), then adding 300 g / t of kerosene as a collector and 100 g / t of No. 2 oil as a frother to perform a roughing operation;

[0094] 2) The rough tailings after roughing are subjected to two scavengings, 150g / t of kerosene is added in scavenging 1, and 75g / t of kerosene is added in scavenging 2. The scavenging tailings are used as copper concentrate;

[0095] 3) The coarse concentrate after roughing is subjected to three rounds of concentration, wherein 500 g / t of thiobarbituric acid is added in concentration 1, 200 g / t of thiobarbituric acid is added in concentration 2, and 100 g / t of thiobarbituric acid is added in concentration 3. The concentrated ore is used as molybdenum concentrate.

[0096] The test results are shown in Table 7.

[0097] From the test results, it can be seen that after changing the sequential addition of sodium dithionite and thiobarbituric acid to simultaneous addition, the laboratory small closed-circuit test can obtain a molybdenum concentrate with a molybdenum grade of 30.82%, a molybdenum recovery rate of 83.68%, and a copper content of 5.65%; the copper grade in the copper concentrate is 23.70%, the molybdenum content is 0.20%, and the copper recovery rate is 99.21%. By comparison, it is found that the inhibitory effect on copper is significantly weakened after changing the sequential addition of sodium dithionite and thiobarbituric acid to simultaneous addition, and the obtained molybdenum concentrate has a lower grade and a higher copper content; the copper recovery rate of the copper concentrate is reduced.

[0098] Table 7

[0099]

[0100] Comparative Example 5

[0101] For the ore sample in Example 1, under the condition of maintaining the process structure and the total dosage of the reagent, the mass ratio of sodium dithionite and thiobarbituric acid reagent was changed from 0.8:1.5 to 0.1:2.1, and a laboratory small closed-circuit test was carried out on the ore. The specific steps of the test are as follows:

[0102] 1) adding 100 g / t of sodium dithionite to the copper-molybdenum mixed concentrate pulp (pulp concentration is 25%) for drug removal, and then sequentially adding 2100 g / t of thiobarbituric acid as an inhibitor, 300 g / t of kerosene as a collector, and 100 g / t of No. 2 oil as a frother, and performing a roughing;

[0103] 2) The rough tailings after roughing are subjected to two scavengings, 150g / t of kerosene is added in scavenging 1, and 75g / t of kerosene is added in scavenging 2. The scavenging tailings are used as copper concentrate;

[0104] 3) The coarse concentrate after roughing is subjected to three rounds of concentration, wherein 500 g / t of thiobarbituric acid is added in concentration 1, 200 g / t of thiobarbituric acid is added in concentration 2, and 100 g / t of thiobarbituric acid is added in concentration 3. The concentrated ore is used as molybdenum concentrate.

[0105] The test results are shown in Table 8.

[0106] From the test results, it can be seen that by changing the mass ratio of sodium dithionite and thiobarbituric acid from 0.8:1.5 to 0.1:2.1, a small-scale closed-circuit test in the laboratory can obtain a molybdenum concentrate with a molybdenum grade of 40.53%, a molybdenum recovery rate of 89.39%, and a copper content of 3.06%; the copper grade in the copper concentrate is 23.48%, the molybdenum content is 0.13%, and the copper recovery rate is 99.65%. By comparison, it is found that after changing the mass ratio of sodium dithionite and thiobarbituric acid from 0.8:1.5 to 0.1:2.1, due to incomplete drug removal, the inhibitory effect on copper is significantly weakened, and the obtained molybdenum concentrate has a lower grade and a higher copper content; the copper concentrate grade and copper recovery rate are both reduced.

[0107] Table 8

[0108]

[0109] Comparative Example 6

[0110] For the ore sample in Example 1, under the condition of maintaining the process structure and the total dosage of the reagent, the mass ratio of sodium dithionite and thiobarbituric acid reagent was changed from 0.8:1.5 to 1.6:0.7, and a laboratory small closed-circuit test was carried out on the ore. The specific steps of the test are as follows:

[0111] 1) adding 1600 g / t of sodium dithionite to the copper-molybdenum mixed concentrate pulp (pulp concentration is 25%) for drug removal, and then sequentially adding 700 g / t of thiobarbituric acid as an inhibitor, 300 g / t of kerosene as a collector, and 100 g / t of No. 2 oil as a frother, and performing a roughing;

[0112] 2) The rough tailings after roughing are subjected to two scavengings, 150g / t of kerosene is added in scavenging 1, and 75g / t of kerosene is added in scavenging 2. The scavenging tailings are used as copper concentrate;

[0113] 3) The coarse concentrate after roughing is subjected to three rounds of concentration, wherein 500 g / t of thiobarbituric acid is added in concentration 1, 200 g / t of thiobarbituric acid is added in concentration 2, and 100 g / t of thiobarbituric acid is added in concentration 3. The concentrated ore is used as molybdenum concentrate.

[0114] The test results are shown in Table 9.

[0115] From the test results, it can be seen that by changing the mass ratio of sodium dithionite and thiobarbituric acid from 0.8:1.5 to 1.6:0.7, the laboratory small closed-circuit test can obtain a molybdenum concentrate with a molybdenum grade of 31.29%, a molybdenum recovery rate of 82.94%, and a copper content of 5.22%; the copper grade in the copper concentrate is 23.52%, the molybdenum content is 0.21%, and the copper recovery rate is 99.28%. By comparison, it is found that after changing the mass ratio of sodium dithionite and thiobarbituric acid from 0.8:1.5 to 1.6:0.7, on the one hand, due to the excessive reduction of the slurry, on the other hand, due to the decrease in the dosage of thiobarbituric acid, the inhibition effect on copper is significantly weakened, and the obtained molybdenum concentrate grade is lower and the copper content is higher; the copper concentrate grade and copper recovery rate are both reduced.

[0116] Table 9

[0117]

Claims

1. A combined depressant for flotation separation of copper-molybdenum mixed concentrate, characterized in that: The combined inhibitor comprises dithionite and thiobarbituric acid; the mass ratio of the dithionite to thiobarbituric acid is (0.2-1): (0.5-2).

2. The combined depressant for flotation separation of copper-molybdenum mixed concentrate according to claim 1, characterized in that: The combined inhibitor is calculated per ton of copper-molybdenum mixed concentrate, and the dosage of dithionite and thiobarbituric acid in the flotation separation and roughing of the copper-molybdenum mixed concentrate is 0.2-1.0 kg and 0.5-2.0 kg respectively.

3. A flotation separation method for a copper-molybdenum mixed concentrate according to claim 1 or 2, characterized in that: Add dithionite to the copper-molybdenum mixed concentrate slurry for drug removal, then add thiobarbituric acid to inhibit chalcopyrite, and then add molybdenite collector and frother for flotation to obtain molybdenum concentrate and copper concentrate; The mass ratio of the dithionite to thiobarbituric acid is (0.2-1):(0.5-2).

4. A flotation separation method for copper-molybdenum mixed concentrate according to claim 3, characterized in that: The flotation comprises one roughing process, at least one cleaning process and at least one scavenging process.

5. A flotation separation method for copper-molybdenum mixed concentrate according to claim 4, characterized in that: The reagent system of the rough selection is: 0.2-1.0 kg / t of dithionite, 0.5-2.0 kg of thiobarbituric acid, 0.1-1 kg / t of collector, and 50-200 g / t of foaming agent; The concentrate obtained after the roughing is a molybdenum rough concentrate, and the tailings are a copper rough concentrate; the molybdenum rough concentrate is subjected to concentrating, and the final concentrated concentrate is a molybdenum concentrate; the copper rough concentrate is subjected to scavenging, and the scavenging tailings are a copper concentrate.

6. A flotation separation method for copper-molybdenum mixed concentrate according to claim 5, characterized in that: During the scavenging process, only the collector is added, and the amount of the collector is 0.1 to 0.5 times the amount used in the roughing process; During the selection process, only thiobarbituric acid inhibitor is added, and the amount used is 0.01 to 0.5 times the amount used in the rough selection, and the amount of the inhibitor used in the Nth selection is less than that used in the N-1th selection.

7. A flotation separation method for copper-molybdenum mixed concentrate according to claim 3, characterized in that: The copper-molybdenum mixed concentrate is a copper-molybdenum mixed concentrate obtained by flotation of molybdenum-containing copper ore or copper-molybdenum ore using a neutral oil collector; wherein the copper content is 2-30wt%; and the molybdenum content is 0.2-50wt%.

8. A flotation separation method for copper-molybdenum mixed concentrate according to claim 6, characterized in that: The copper-molybdenum mixed concentrate slurry concentration is 10-40%.

9. A flotation separation method for copper-molybdenum mixed concentrate according to claim 3 or 5, characterized in that: The collector is at least one of diesel and kerosene; The foaming agent is at least one of No. 2 oil and MIBC.

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