Beneficiation method of cobalt ore

Abstract

The invention discloses a cobalt ore beneficiation method, which belongs to the technical field of copper-cobalt ore flotation, and comprises the following specific steps: step 1, adding a sample into water, continuously stirring, standing, filtering, repeating for three times, and taking an obtained filter cake as flotation feed ore; 2, an inhibitor, a collecting agent and a foaming agent are used for conducting preferential flotation on the pretreated cobalt ore sample, and copper concentrate and tailings are obtained; 3, the tailings are subjected to ore grinding for 3-16 min, and the granularity of the minerals is refined to be-0.045 mm 88%; fourthly, an activating agent and a collecting agent are used for conducting re-flotation on tailings obtained after ore grinding, and cobalt concentrate and tailings are obtained; 5, chemical multi-element analysis and size fraction screen analysis are conducted on the obtained copper concentrate and cobalt concentrate, and the quality and grade of products are inspected; according to the method, minerals are easy to separate, the flotation effect is good, and the cobalt recovery rate and the concentrate grade are effectively improved.

Description

Technical Field

[0001] The present invention relates to a mineral processing method, in particular to a mineral processing method for cobalt ore, and belongs to the technical field of flotation of copper-cobalt ore. Background Art

[0002] Cobalt is an important rare metal, mainly used in the manufacture of superalloys, catalysts, battery materials, etc. The distribution of cobalt ore resources is uneven, mainly concentrated in countries such as the Congo, Australia, Cuba, and Zambia. Cobalt resources in China are relatively scarce and mainly rely on imports. Therefore, it is of great significance to improve the recovery rate of cobalt ore beneficiation.

[0003] At present, the main mineral processing methods for cobalt ore include flotation, magnetic separation, gravity separation, etc. Flotation is the most widely used mineral processing method, with advantages such as large processing capacity, high efficiency, and strong adaptability. However, there are still some problems in the current flotation of cobalt ore. For example, the symbiotic relationship between cobalt minerals and other minerals is complex, and the separation is difficult. The floatability of some cobalt minerals is poor, and an activator needs to be added for flotation. Problems such as excessive foaming and unstable concentrate quality are prone to occur during the flotation process. Specifically, in cobalt ore, the symbiotic relationship between cobalt minerals and other minerals is complex, such as chalcopyrite, pyrite, pyrrhotite, etc. These minerals have similar floatability to cobalt minerals and are difficult to separate, resulting in low recovery rate of cobalt and low concentrate grade. Some cobalt minerals, such as cobalt ore, cobaltite, etc., have poor floatability and need to add an activator for flotation. Moreover, the selectivity of the activator is limited, and it is easy to activate other minerals, affecting the concentrate grade.

[0004] In order to improve the recovery rate of cobalt and the concentrate grade, a large amount of reagents such as collectors, inhibitors, and activators need to be added. This not only increases the production cost but also pollutes the environment. The use effect of some reagents is greatly affected by factors such as pulp pH value, temperature, and stirring speed. Strict control of operating conditions is required to ensure the flotation effect, which also increases the operation difficulty and production cost.

[0005] Moreover, some flotation methods need to add toxic and harmful reagents, such as cyanides and heavy metals. These reagents will enter the wastewater and waste residues during the flotation process, polluting the environment. The foam generated during the flotation process will also pollute the environment, such as affecting the ecological balance of water bodies.

[0006] At present, for the flotation method of carbonaceous copper-cobalt ore in Patent CN103480500A, the raw materials are ground, slurried, reagents are added, and finally flotation is carried out to obtain copper-cobalt concentrate and tailings. The process is simple. The original ore has a copper grade of 1.53%, a cobalt grade of 0.15%, and a carbon grade of 5.89%. The copper-cobalt concentrate has a copper grade of 22.47% and a cobalt grade of 2.08%. The copper recovery rate is 94.21%, and the cobalt recovery rate is 90.52%. During the flotation process, non-target minerals, especially magnetic minerals, will appear and easily interfere with the subsequent flotation process. The cobalt recovery rate and concentrate grade both need to be improved.

[0007] Therefore, developing a beneficiation method for cobalt ore that can overcome the above defects has become an urgent technical problem for those skilled in the art. Summary of the Invention

[0008] The technical problem to be solved by the present invention is to overcome the shortcomings of the prior art and provide a beneficiation method for cobalt ore, which has easy separation of minerals, good flotation effect, and can effectively improve the cobalt recovery rate and concentrate grade.

[0009] To solve the above technical problems, the present invention provides a beneficiation method for cobalt ore, which specifically includes the following steps:

[0010] Step 1: Washing

[0011] Add the sample to water, continuously stir, then let it stand and filter. Repeat three times. The obtained filter cake is used as the flotation feed to remove oxidized minerals and harmful ions.

[0012] Step 2: Preferential copper flotation (one roughing, five cleanings, two scavengings)

[0013] Use inhibitors, collectors, and frothers to conduct preferential flotation on the pretreated cobalt ore sample to obtain copper concentrate and tailings.

[0014] The dosage of the inhibitor is 3 - 9 kg, the dosage of the collector is 30 - 50 g / t, and the dosage of the frother No. 2 oil is 30 - 50 g / t.

[0015] Step 3: Grinding of copper flotation tailings

[0016] Grind the tailings for 3 - 16 minutes to refine the mineral particle size to -0.045 mm 88% (indicating particles with a particle size less than 0.045 mm, and 88% means that in the grinding process, particles with a particle size less than 0.045 mm account for 88% of the total mass).

[0017] Step 4: Re-flotation of cobalt (one roughing, four cleanings, two scavengings)

[0018] Use activators and collectors to conduct re-flotation on the ground tailings to obtain cobalt concentrate and tailings.

[0019] The dosage of the activator is 0 - 3500 g / t, and the dosage of the collector is 150 - 450 g / t;

[0020] Step Five: Conduct chemical multi-element analysis and particle size screening on the obtained copper concentrate and cobalt concentrate to inspect the quality and grade of the products.

[0021] The further limited technical solution of the present invention is:

[0022] Further, in the beneficiation method of the aforementioned cobalt ore, the inhibitor in Step Two is lime, and the dosage of lime is 7 kg / t.

[0023] In the beneficiation method of the aforementioned cobalt ore, the collector in Step Two is C330, and the dosage of C330 is 40 g / t.

[0024] In the beneficiation method of the aforementioned cobalt ore, the frother in Step Two is No. 2 oil, and the dosage of No. 2 oil is 40 g / t.

[0025] In the beneficiation method of the aforementioned cobalt ore, the activator in Step Four is sulfuric acid, and the dosage of sulfuric acid is 2000 g / t.

[0026] In the beneficiation method of the aforementioned cobalt ore, the collector in Step Four is butyl xanthate, and the dosage of butyl xanthate is 350 g / t.

[0027] In the beneficiation method of the aforementioned cobalt ore, the pulp pH value in Step Two is 9.5 - 12.

[0028] In the beneficiation method of the aforementioned cobalt ore, the pulp pH value in Step Four is 4 - 7.

[0029] In the beneficiation method of the aforementioned cobalt ore, the tailings are ground for 10 min in Step Three.

[0030] The beneficial effects of the present invention are:

[0031] The present invention adopts a closed-circuit process of "cobalt-copper concentrate - washing - preferential copper flotation (using a one-roughing, five-cleaning, and two-scavenging process in the prior art) - grinding of copper flotation tailings (-0.045 mm 88%) and then cobalt flotation (using a one-roughing, four-cleaning, and two-scavenging process in the prior art)". Calculated based on the flotation feed after washing, copper concentrate with a yield of 5.72%, copper grade of 21.52%, and copper recovery rate of 72.37% and cobalt concentrate with a yield of 59.98%, cobalt grade of 1.06%, and cobalt recovery rate of 94.66% can be obtained; calculated based on the copper-cobalt concentrate, the copper concentrate yield is 4.32% and the copper recovery rate is 43.39%, and the cobalt concentrate yield is 45.29% and the cobalt recovery rate is 78.35%.

[0032] In the present invention, preferential flotation can effectively remove most non-target minerals, especially magnetic minerals, thereby reducing the interference in the subsequent flotation process, improving the selectivity of cobalt mineral flotation. By optimizing the types and dosages of inhibitors, collectors, and activators, the flotation efficiency of cobalt minerals and the concentrate grade can be further improved. By grinding the tailings, the particle size of the minerals can be refined, and the floatability of cobalt minerals can be improved, thereby obtaining a higher recovery rate of cobalt concentrate. Finally, by removing oxidized minerals and harmful ions through the initial washing step, the interference in the flotation process can be reduced, and the flotation efficiency can be improved. In the present invention, lime is used to adjust the high pH value to inhibit gangue and pyrite, and C330 is used to selectively collect copper minerals; subsequently, sulfuric acid is used to adjust the low pH value to activate cobalt minerals and inhibit gangue, and butyl xanthate is used to collect cobalt minerals, forming a step-by-step separation logic of first inhibition and then activation to reduce the mutual interference between copper and cobalt minerals; after sulfuric acid activates the surface of cobalt minerals, butyl xanthate can effectively combine with cobalt ions to improve the collection efficiency; the collection selectivity of C330 for copper minerals under high pH conditions complements the inhibitory effect of lime.

[0033] The stable bubbles generated by No. 2 oil used in the present invention provide a floating carrier for the minerals after the action of the collector. The size and stability of the bubbles affect the entrainment efficiency of the minerals and jointly determine the recovery rate and grade of the flotation product with the collector.

[0034] Through the precise regulation of the pH value by lime and sulfuric acid in the present invention, combined with the targeted collection of C330 and butyl xanthate, the step-by-step preferential flotation of copper and cobalt minerals is realized. While sulfuric acid activates cobalt minerals, the inhibitory effect of lime residue is eliminated, forming an antagonistic-synergistic effect between the reagents. The selected lime, sulfuric acid, and butyl xanthate are all commonly used reagents in mineral processing, with low cost, easy availability, and clear action mechanisms, facilitating parameter adjustment in industrial production. BRIEF DESCRIPTION OF THE DRAWINGS

[0035] Figure 1 It is a flow chart of the test on the types and dosages of copper-selective inhibitors in the examples of the present invention;

[0036] Figure 2 It is a flow chart of the test on the types of copper-selective collectors in the examples of the present invention;

[0037] Figure 3 It is a flow chart of the test on the dosages of copper-selective collectors in the examples of the present invention;

[0038] Figure 4 It is a flow chart of the test on the dosages of copper-selective frothers in the examples of the present invention;

[0039] Figure 5 It is a flow chart of the test on the grinding time of cobalt-selective in the examples of the present invention;

[0040] Figure 6It is the flow chart of the cobalt activator dosage test in the embodiment of the present invention;

[0041] Figure 7 It is the flow chart of the cobalt collector dosage test in the embodiment of the present invention;

[0042] Figure 8 It is the schematic diagram of particle size sieving analysis of copper concentrate, cobalt concentrate and tailings obtained from the closed-circuit process of copper-cobalt concentrate in the embodiment of the present invention. Specific embodiments

[0043] Next, the technical solutions in the embodiments of the present invention will be clearly and completely described in conjunction with the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts shall fall within the protection scope of the present invention.

[0044] Example 1

[0045] In this embodiment, the type of copper depressant is determined

[0046] The sample is washed and then subjected to a flotation test. The washing steps are as follows: Add 1 kg of the sample to 7 L of water, continuously stir for 30 s, then let it stand for 20 min and filter. Repeat this three times, and the obtained filter cake is used as the flotation feed.

[0047] The on-site copper-cobalt concentrate sample is subjected to the test of the type and dosage of copper depressant. Among them, the dosage of collector C330 is 40 g / t, and the dosage of foaming agent No. 2 oil is 40 g / t. The test flow is as attached Figure 1 shown, and the test results are shown in Table 1.

[0048] Table 1 Test results of the type and dosage of copper depressant (%)

[0049]

[0050]

[0051] The test results show that with the increase of the lime dosage, the copper grade of the concentrate first increases and then decreases, and the combination of sodium sulfide and lime cannot significantly improve the separation effect; therefore, lime is selected as the depressant, and its appropriate dosage is 7 kg / t. At this time, the concentrate with the best operation yield of 19.06%, copper grade of 7.23%, and copper operation recovery rate of 79.21% can be obtained.

[0052] Example 2

[0053] In this embodiment, the type of copper collector is determined

[0054] The field copper-cobalt concentrate samples were tested for the types of copper collectors. The dosage of each collector was 40 g / t, the dosage of the inhibitor lime was 7 kg / t, and the dosage of the foaming agent No. 2 oil was 40 g / t. The test flow is as attached Figure 2 as shown, and the test results are shown in Table 2.

[0055] Table 2 Test Results of Copper Collector Types (%)

[0056]

[0057] The test results show that among the three copper collectors, the separation index of ethyl xanthate is the worst. Although the copper recovery rate of C330 is slightly lower than that of Z200, its copper grade in the concentrate is the highest. Considering comprehensively, C330 was selected as the copper collector for this ore, obtaining better copper grade and copper recovery rate in the concentrate.

[0058] The field copper-cobalt concentrate samples were tested for the dosage of copper collector C330. The dosage of the inhibitor lime was 7 kg / t, and the dosage of the foaming agent No. 2 oil was 40 g / t. The test flow is as attached Figure 3 as shown, and the test results are shown in Table 3.

[0059] Table 3 Test Results of Copper Collector Dosage (%)

[0060]

[0061] The test results show that as the dosage of the copper collector increases, the concentrate yield is higher, the copper grade is lower, and the copper recovery rate is higher. Considering comprehensively, the dosage of the copper collector was selected as 40 g / t.

[0062] Example 3

[0063] Determination of the Dosage of Copper Foaming Agent

[0064] The field copper-cobalt concentrate samples were tested for the dosage of copper foaming agent No. 2 oil. The dosage of the collector C330 was 40 g / t, and the dosage of the inhibitor lime was 7 kg / t. The test flow is as attached Figure 4 as shown, and the test results are shown in Table 4.

[0065] Table 4 Test Results of Copper Foaming Agent Dosage (%)

[0066]

[0067] The test results show that as the dosage of the foaming agent increases, the concentrate yield is higher, the copper grade is lower, and the copper recovery rate is higher. Considering comprehensively, the dosage of the foaming agent was selected as 40 g / t.

[0068] Example 4

[0069] Determination of Cobalt Grinding Time

[0070] The copper rougher tailings were ground to different times respectively and then subjected to one roughing and two cleaning cobalt flotation tests to determine the appropriate grinding time. Sulfuric acid was used as the activator for cobalt and the pulp pH value was adjusted to 5.5. The dosage of butyl xanthate as the collector was 450 g / t, and the dosage of No. 2 oil as the frother was 40 g / t. The test flow is as shown in the appendix Figure 5 and the test results are shown in Table 5.

[0071] Table 5 Test results of cobalt flotation grinding time (%)

[0072]

[0073] [[ID=...]]The test results show that increasing the grinding time will improve the dissociation degree of minerals. Therefore, within a certain time, with the extension of the grinding time, both the concentrate yield and the cobalt grade of the concentrate will increase. If the grinding time is too long, it will cause the useful minerals to slime and be lost in the tailings. Therefore, the grinding time was selected as 10 min, and at this time, a concentrate with a yield of 50.50%, a cobalt grade of 1.05%, and a cobalt recovery rate of 76.23% can be obtained.

[0074] Example 5

[0075] Determination of the dosage of cobalt flotation activator

[0076] The copper rougher tailings were ground for 10 min and then subjected to the cobalt flotation roughing test to determine the appropriate dosage of the activator. During the test, the dosage of butyl xanthate was 350 g / t, and the dosage of No. 2 oil was 40 g / t. The test flow is as shown in the appendix Figure 6 and the test results are shown in Table 6.

[0077] Table 6 Test results of cobalt flotation activator dosage (%)

[0078]

[0079] The test results show that with the increase of the sulfuric acid dosage, the concentrate yield increases, and the cobalt grade of the concentrate decreases slightly. Considering comprehensively, the sulfuric acid dosage was selected as 2000 g / t.

[0080] Example 6

[0081] Determination of the dosage of cobalt flotation collector

[0082] The copper rougher tailings were ground for 10 min and then subjected to the cobalt flotation roughing test to determine the appropriate dosage of butyl xanthate. During the test, the sulfuric acid dosage was 2000 g / t, and the dosage of No. 2 oil was 40 g / t. The test flow is as shown in the appendix Figure 7 and the test results are shown in Table 7.

[0083] Table 7 Test results of cobalt flotation collector dosage (%)

[0084]

[0085]

[0086] The test results show that with the increase of the collector dosage, the concentrate yield increases while the cobalt grade in the concentrate decreases. Considering comprehensively, when the dosage of butyl xanthate is 350 g / t, all data are better.

[0087] Example 7

[0088] On the basis of Examples 1 - 6, in this example, a closed-circuit flotation test is carried out using the cobalt ore beneficiation method. The specific cobalt ore beneficiation method is as follows:

[0089] Step 1: Add 1 kg of the sample to 7 L of water, stir continuously for 30 s, then let it stand for 20 min and filter. Repeat three times. The obtained filter cake is used as the flotation feed to remove oxidized minerals and harmful ions.

[0090] Step 2: Use lime as the depressant with a dosage of 7 kg / t, C330 as the collector with a dosage of 40 g / t, and No. 2 oil as the frother with a dosage of 40 g / t. Conduct preferential flotation on the pretreated cobalt ore to obtain copper concentrate and tailings. The pulp pH value is 9.5 - 12.

[0091] Step 3: Grind the tailings for 10 min to refine the mineral particle size to 88 wt% with a particle size of -0.045 mm.

[0092] Step 4: Use sulfuric acid as the activator with a dosage of 2000 g / t and butyl xanthate as the collector with a dosage of 350 g / t. Conduct re-flotation on the ground tailings to obtain cobalt concentrate and tailings. The pulp pH value is 4 - 7.

[0093] Step 5: Conduct chemical multi-element analysis and particle size screening on the obtained copper concentrate and cobalt concentrate to inspect the quality and grade of the products.

[0094] The results of the closed-circuit flotation test on the on-site copper-cobalt concentrate samples are shown in Tables 8 and 9.

[0095] Table 8 Results of the closed-circuit flotation test based on the flotation feed (excluding the wash liquid) (%)

[0096]

[0097]

[0098] Table 9 Results of the closed-circuit flotation test based on the copper-cobalt concentrate (including the wash liquid) (%)

[0099]

[0100] The test results show that through the closed-circuit process of "cobalt-copper concentrate - washing - preferential copper flotation (one roughing, five cleanings, two scavengings) - grinding of copper flotation tailings (-0.045mm 88%) and then cobalt flotation (one roughing, four cleanings, two scavengings)" of the present invention, based on the flotation feed after washing, copper concentrate with a yield of 5.72%, copper grade of 21.52%, and copper recovery rate of 72.37% and cobalt concentrate with a yield of 59.98%, cobalt grade of 1.06%, and cobalt recovery rate of 94.66% can be obtained; if calculated based on copper-cobalt concentrate, the yield of copper concentrate is 4.32%, the copper recovery rate is 43.39%, the yield of cobalt concentrate is 45.29%, and the cobalt recovery rate is 78.35%.

[0101] Chemical multi-element analysis was carried out on the copper concentrate and cobalt concentrate obtained from the closed-circuit process of on-site copper-cobalt concentrate, and the results are shown in Tables 10 and 11.

[0102] Table 10 Results of multi-element analysis of copper concentrate (%)

[0103] Analysis item Cu As Pb + Zn MgO Bi + Sb Content 21.52 0.17 0.12 1.63 0.20 Industry standard for third-grade products ≥20 ≤0.20 ≤8 ≤3 ≤0.4

[0104] Table 11 Results of multi-element analysis of cobalt (sulfur) concentrate (%)

[0105] Analysis item Co Cu TS ES As P Pb + Zn Mn <![CDATA[SiO2]]> Content 1.06 0.67 47.65 45.95 0.287 0.005 0.03 0.008 2.40 LJK-43 standard - - - ≥43 ≤0.05 ≤0.05 ≤1.00 - -

[0106] Analysis shows that: the copper concentrate product obtained from the test meets the industry standard of grade three; except for the excessive As in the obtained cobalt (sulfur) concentrate, other components meet the standard of sulfur concentrate grade LJK-43.

[0107] Table 12 Results of particle size screening analysis of copper concentrate (%)

[0108]

[0109] Table 13 Results of particle size screening analysis of cobalt concentrate (%)

[0110]

[0111]

[0112] Table 14 Results of particle size screening analysis of tailings (%)

[0113]

[0114] As Figure 8 shown in the closed-circuit process of on-site copper-cobalt concentrate, particle size screening analysis was carried out on the obtained copper concentrate, cobalt concentrate, and tailings, and the results are shown in Tables 12 to 14. Analysis shows that: the copper and cobalt grades of the coarse and fine particle sizes in the concentrate are not much different; the copper and cobalt grades of the fine particle size in the tailings are significantly higher than those of the coarse particle size, indicating that the metals in the tailings are mainly lost in the fine particle size.

[0115] In addition to the above embodiments, the present invention may have other embodiments. Any technical solutions formed by equivalent substitution or equivalent transformation shall fall within the protection scope claimed by the present invention.

Claims

1. A beneficiation method for cobalt ore, characterized in that, Specifically, it includes the following steps: Step 1: Add the sample into water, stir continuously, then let it stand and filter. Repeat this three times. The obtained filter cake is used as the flotation feed; Step 2: Use an inhibitor, a collector, and a frother to preferentially float the pretreated cobalt ore sample to obtain copper concentrate and tailings; The dosage of the inhibitor is 3 - 9 kg, the dosage of the collector is 30 - 50 g / t, and the dosage of the frother No. 2 oil is 30 - 50 g / t; Step 3: Grind the tailings for 3 - 16 min to refine the mineral particle size to 88% of -0.045 mm; Step 4: Use an activator and a collector to re - float the ground tailings to obtain cobalt concentrate and tailings; The dosage of the activator is 0 - 3500 g / t, and the dosage of the collector is 150 - 450 g / t; Step 5: Conduct chemical multi - element analysis and particle size screening on the obtained copper concentrate and cobalt concentrate to inspect the quality and grade of the products.

2. The ore dressing method of cobalt ore according to claim 1, characterized in that: The inhibitor in Step 2 is lime, and the dosage of the lime is 7 kg / t.

3. The beneficiation method of cobalt ore according to claim 1, characterized in that: The collector in Step 2 is C330, and the dosage of the C330 is 40 g / t.

4. The beneficiation method of cobalt ore according to claim 1, wherein: The frother in Step 2 is No. 2 oil, and the dosage of the No. 2 oil is 40 g / t.

5. The beneficiation method of cobalt ore according to claim 1, characterized in that: The activator in Step 4 is sulfuric acid, and the dosage of the sulfuric acid is 2000 g / t.

6. The beneficiation method of cobalt ore according to claim 1, characterized in that: The collector in Step 4 is butyl xanthate, and the dosage of the butyl xanthate is 350 g / t.

7. The ore dressing method of cobalt ore according to claim 1, characterized in that: The pulp pH value in Step 2 is 9.5 - 12.

8. The beneficiation method of cobalt ore according to claim 1, characterized in that: The pulp pH value in Step 4 is 4 - 7.

9. The beneficiation method of cobalt ore according to claim 1, characterized in that: In Step 3, the tailings are ground for 10 min.

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