Beneficiation method for recovering scheelite from low-grade tailings

Abstract

The invention provides a beneficiation method for recovering scheelite from low-grade tailings, and belongs to the technical field of ore separation processes. According to the method, the tungsten-containing tailings which are low in grade, low in value and difficult to recover are converted into valuable and easy-to-recover ore resources at low cost through the magnetic separation / centrifugal machine reselection combined physical mineral separation technology, and the reagent cost of subsequent flotation is greatly reduced. Then carrying out a flotation test, and discarding tailings of flotation middlings by adopting a centrifugal machine so as to remove gangue which is easy to float and argillization and avoid continuous circulation and accumulation of the gangue in a closed circuit to influence the floating of target minerals and the quality of concentrate; meanwhile, a nontoxic and environment-friendly gangue inhibitor CD-6 is adopted and matched with a CK-3 composite collecting agent, efficient separation of gangue minerals and tungsten minerals is achieved, finally, comprehensive recycling of extremely-low-grade tungsten-containing tailing resources is achieved, and a new effective method is provided for development and utilization of similar tungsten-containing tailing resources.

Description

Technical Field

[0001] This invention relates to the field of ore separation technology, specifically to a beneficiation method for recovering scheelite from low-grade tailings. Background Technology

[0002] Tungsten, as an important strategic metal, is widely used in cemented carbide, special steel, and the electronics industry. my country's tungsten resources are mainly composed of scheelite, which is increasingly characterized by being low-grade, fine-grained, and complex. There are huge reserves of ultra-low-grade ore and tailings with WO3 < 0.3%. However, the comprehensive recovery of such ores faces the following problems: low efficiency of single gravity separation, insufficient selectivity of conventional flotation, and high flotation costs.

[0003] For the flotation research and industrial practice of fine-grained tungsten minerals, the main methods currently include selective flocculation flotation, shear flocculation flotation, carrier flotation, and oil agglomeration flotation.

[0004] While the comprehensive utilization rate of valuable metals in tailings has improved with the iterative upgrading of mineral processing technology, bottlenecks such as "low recovery rate, high cost, complex process, and difficulty in implementation" remain prominent. Therefore, there is an urgent need to develop new, efficient, low-cost, and easily industrialized processes and methods to promote the efficient utilization of valuable tailings resources in China. Summary of the Invention

[0005] In view of the technical problems existing in the background art, this application provides a mineral processing method for recovering scheelite from low-grade tailings, aiming to solve the problem of recycling and utilizing existing extremely low-grade tungsten tailings resources.

[0006] This application provides a mineral processing method for recovering scheelite from low-grade tailings, comprising the following steps: S1. Prepare the tailings slurry by mixing it with other materials to obtain a slurry. S2. The slurry is subjected to strong magnetic separation to obtain magnetic concentrate and magnetic tailings; S3. The magnetic tailings are graded and screened into three particle sizes: +0.074mm, -0.074mm +0.038mm, and -0.038mm. Then, centrifuge gravity separation tests are conducted on each size. The centrifuge concentrates of the three particle sizes are combined into tungsten rough concentrate, and the centrifuge tailings are combined into tailings 2. S4. The tungsten rough concentrate is subjected to a closed-circuit test of tungsten ambient temperature flotation, consisting of one roughing, two scavenging, and two cleaning processes, to obtain ambient temperature tungsten concentrate and tailings 3 and 4. Among them, the tailings from the first cleaning process and the concentrate from the first scavenging process are fed into a centrifuge for gravity separation and desliming. The gravity separation tailings are tailings 4. The gravity separation concentrate is returned to the roughing process, and the tailings from the second cleaning process and the concentrate from the second scavenging process are returned sequentially. S5. After concentrating the tungsten concentrate at room temperature, a closed-circuit test of tungsten heating and beneficiation is carried out, consisting of one roughing, two scavenging, and two beneficiation processes, to obtain tungsten concentrate and tailings 5; wherein, tailings from beneficiation process one, tailings from beneficiation process two, concentrate from scavenging process one, and concentrate from scavenging process two are returned in sequence.

[0007] In some embodiments, in step S4, instead of using the method of sequential return of middlings from the tailings and concentrate from the scavenging process, the concentrate is deslimed using a vertical centrifuge and then returned to the roughing process.

[0008] In some embodiments, in step S1, the WO3 grade of the tailings to be processed is 0.01-0.08%.

[0009] In some embodiments, in step S4, the modifier used for roughing is sodium carbonate, with a dosage of 100-1000 g / t; the inhibitor used for roughing is CD-6; the collector used for roughing is CK-3, with a dosage of 50-500 g / t.

[0010] In some embodiments, the CD-6 inhibitor is composed of water glass, tannic acid, modified starch, and hydroxyethylidene diphosphonic acid in a mass ratio of 7:1:1:1.

[0011] In some embodiments, CK-3 is composed of oxidized paraffin soap, modified oleic acid, octyl hydroxamic acid, and diesel oil in a mass ratio of 4:3:2:1.

[0012] In some embodiments, in step S1, the concentration of the slurry is 20-40%.

[0013] In some embodiments, in step S5, the room-temperature tungsten concentrate is concentrated into a slurry with a mass concentration of 40-60%.

[0014] In some embodiments, in step S2, the magnetic field strength of the strong magnetic separation is 0.6-2T.

[0015] In some embodiments, in step S3, the centrifuge is a vertical centrifuge with a centrifugal force of 80-600G and a backwash water volume of 2-10L / min.

[0016] This application also provides a mineral processing method for recovering scheelite from low-grade tailings, comprising the following steps: A1. The tailings to be processed are screened into three particle sizes: +0.074mm, -0.074mm +0.038mm, and -0.038mm. Then, centrifuge gravity separation tests are conducted on each size. The concentrate obtained from the first centrifuge gravity separation is then subjected to centrifuge gravity separation tests again. Finally, the centrifuge concentrates of the three particle sizes are combined into tungsten gravity separation rough concentrate, and the centrifuge tailings are combined into tailings 1. The tungsten gravity separation rough concentrate enters the flotation desulfurization process. A2. The tungsten gravity separation rough concentrate is subjected to a desulfurization process consisting of one roughing, two scavenging, and two cleaning processes to obtain sulfur concentrate and sulfur tailings. A3. The sulfur tailings II are subjected to a closed-circuit test of tungsten ambient temperature flotation consisting of one roughing, two scavenging, and two cleaning processes to obtain tungsten concentrate II and tailings 3' and 4'. Among them, the tailings from the first cleaning process and the concentrate from the first scavenging process are fed into a centrifuge for gravity separation and desliming. The gravity separation tailings are tailings 4'. The gravity separation concentrate is returned to the roughing process, and the tailings from the second cleaning process and the concentrate from the second scavenging process are returned sequentially. A4. After the tungsten concentrate is concentrated, a closed-circuit test of tungsten heating and beneficiation is carried out, consisting of one roughing, two scavenging, and two beneficiation processes, to obtain tungsten concentrate and tailings 5'; wherein, tailings from beneficiation process one, tailings from beneficiation process two, concentrate from scavenging process one, and concentrate from scavenging process two are returned in sequence.

[0017] The effective effects of this invention are as follows: In the technical solution of this application embodiment, the low-grade, low-value, and difficult-to-recover tungsten-containing tailings are first disposed of in advance by physical separation method of magnetic separation / centrifugal gravity separation, so as to turn them into easily recoverable and valuable ore. Then, flotation test is carried out on them to realize the comprehensive recovery and utilization of extremely low-grade tungsten-containing tailings resources, providing a new and effective method for the development and utilization of similar tungsten-containing tailings resources.

[0018] 1) This application first utilizes a combined physical beneficiation process of magnetic separation / centrifugal gravity separation to transform low-grade, low-value, and difficult-to-recover tungsten-bearing tailings into valuable and easily recoverable ore resources at low cost, significantly reducing the reagent costs of subsequent flotation. The application employs the non-toxic and environmentally friendly gangue inhibitor CD-6, combined with the CK-3 composite collector, to achieve efficient separation of gangue minerals and tungsten minerals.

[0019] 2) In this application, the tailings of the flotation mineral are removed by centrifuge, which can remove the easily floatable muddy gangue and prevent it from continuously circulating and accumulating in the closed circuit, which would ultimately affect the flotation of the target mineral and the quality of the concentrate.

[0020] 3) This invention effectively solves the problem of recycling and utilizing extremely low-grade tungsten-bearing tailings resources, and provides a new and effective method for the development and utilization of similar tungsten-bearing resources, which is suitable for widespread application.

[0021] The above description is only an overview of the technical solution of this application. In order to better understand the technical means of this application and to implement it in accordance with the contents of the specification, and to make the above and other objects, features and advantages of this application more obvious and understandable, the following are specific embodiments of this application. Attached Figure Description

[0022] To more clearly illustrate the technical solutions of this application, the accompanying drawings used in this application will be briefly described below. Obviously, the drawings described below are merely some embodiments of this application. For those skilled in the art, other drawings can be obtained from these drawings without any creative effort.

[0023] Figure 1 This is a flowchart illustrating Embodiment 1 of this application.

[0024] Figure 2 This is a flowchart illustrating Embodiment 2 of this application.

[0025] Figure 3 This is a flowchart illustrating Comparative Example 1 of this application.

[0026] Figure 4 This is a flowchart illustrating Comparative Example 2 of this application. Detailed Implementation

[0027] The embodiments of the technical solution of this application will now be described in detail with reference to the accompanying drawings. These embodiments are only used to more clearly illustrate the technical solution of this application and are therefore merely examples, and should not be used to limit the scope of protection of this application.

[0028] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application pertains; the terminology used herein is for the purpose of describing particular embodiments only and is not intended to limit the application; the terms “comprising” and “having”, and any variations thereof, in the specification, claims, and foregoing description of the drawings are intended to cover non-exclusive inclusion.

[0029] In this document, the term "embodiment" means that a particular feature, structure, or characteristic described in connection with an embodiment may be included in at least one embodiment of this application. The appearance of this phrase in various places throughout the specification does not necessarily refer to the same embodiment, nor is it a separate or alternative embodiment mutually exclusive with other embodiments. It will be explicitly and implicitly understood by those skilled in the art that the embodiments described herein can be combined with other embodiments.

[0030] In the description of the embodiments in this application, the term "and / or" is merely a description of the relationship between related objects, indicating that three relationships can exist. For example, A and / or B can represent: A existing alone, A and B existing simultaneously, and B existing alone. Additionally, the character " / " in this document generally indicates that the preceding and following related objects have an "or" relationship.

[0031] This application provides a mineral processing method for recovering scheelite from low-grade tailings, comprising the following steps: S1. Adjust the tailings (raw ore) to obtain a raw ore slurry with a concentration of 20-40%; The WO3 grade of the tailings to be processed is 0.01-0.08%.

[0032] S2. The slurry is subjected to strong magnetic separation to obtain magnetic concentrate and magnetic tailings; The magnetic field strength of the strong magnetic separator is 0.6-2T.

[0033] S3. The magnetic tailings are graded and screened into three particle sizes: +0.074mm, -0.074mm +0.038mm, and -0.038mm. Then, centrifuge gravity separation tests are conducted on each size. The centrifuge concentrates of the three particle sizes are combined into tungsten rough concentrate, and the centrifuge tailings are combined into tailings 2. The centrifuge is a vertical centrifuge with a centrifugal force of 80-600G and a backwash water volume of 2-10L / min.

[0034] S4. The tungsten rough concentrate is subjected to a closed-circuit test of tungsten ambient temperature flotation, consisting of one roughing, two scavenging, and two cleaning processes, to obtain ambient temperature tungsten concentrate and tailings 3 and 4. Among them, the tailings from the first cleaning process and the concentrate from the first scavenging process are fed into a centrifuge for gravity separation and desliming. The gravity separation tailings are tailings 4. The gravity separation concentrate is returned to the roughing process, and the tailings from the second cleaning process and the concentrate from the second scavenging process are returned sequentially. In this process, the tailings from the first beneficiation stage and the concentrate from the first scavenging stage do not use the method of sequential return of middlings. Instead, they are deslimed using a vertical centrifuge, and the centrifuged concentrate is then returned to the roughing stage.

[0035] The modifier used in the roughing process is sodium carbonate, with a dosage of 100-1000 g / t; the inhibitor used in the roughing process is CD-6; and the collector used in the roughing process is CK-3, with a dosage of 50-500 g / t.

[0036] CD-6 inhibitors are formulated from water glass, tannic acid, modified starch, and hydroxyethylidene diphosphonic acid in a mass ratio of 7:1:1:1.

[0037] CK-3 is a compound made of oxidized paraffin soap, modified oleic acid, octyl hydroxamic acid and diesel oil in a mass ratio of 4:3:2:1.

[0038] In this application, the non-toxic and environmentally friendly gangue inhibitor CD-6, combined with the CK-3 composite collector, was used to achieve efficient separation of gangue minerals and tungsten minerals.

[0039] S5. After concentrating the tungsten concentrate at room temperature, a closed-circuit test of tungsten heating and beneficiation is carried out, consisting of one roughing, two scavenging, and two beneficiation processes, to obtain tungsten concentrate and tailings 5; wherein, tailings from beneficiation process one, tailings from beneficiation process two, concentrate from scavenging process one, and concentrate from scavenging process two are returned in sequence.

[0040] Specifically, after concentrating the tungsten concentrate at room temperature into a slurry with a mass concentration of 40-60%, a closed-circuit test of tungsten heating and beneficiation is conducted, consisting of one roughing, two scavenging, and two beneficiation processes.

[0041] This application also provides a mineral processing method for recovering scheelite from low-grade tailings, comprising the following steps: A1. The tailings to be processed are screened into three particle sizes: +0.074mm, -0.074mm +0.038mm, and -0.038mm. Then, centrifuge gravity separation tests are conducted on each size. The concentrate obtained from the first centrifuge gravity separation is then subjected to centrifuge gravity separation tests again. Finally, the centrifuge concentrates of the three particle sizes are combined into tungsten gravity separation rough concentrate, and the centrifuge tailings are combined into tailings 1. The tungsten gravity separation rough concentrate enters the flotation desulfurization process. A2. The tungsten gravity separation rough concentrate is subjected to a desulfurization process consisting of one roughing, two scavenging, and two cleaning processes to obtain sulfur concentrate and sulfur tailings. A3. The sulfur tailings II are subjected to a closed-circuit test of tungsten ambient temperature flotation consisting of one roughing, two scavenging, and two cleaning processes to obtain tungsten concentrate II and tailings 3' and 4'. Among them, the tailings from the first cleaning process and the concentrate from the first scavenging process are fed into a centrifuge for gravity separation and desliming. The gravity separation tailings are tailings 4'. The gravity separation concentrate is returned to the roughing process, and the tailings from the second cleaning process and the concentrate from the second scavenging process are returned sequentially. A4. After the tungsten concentrate is concentrated, a closed-circuit test of tungsten heating and beneficiation is carried out, consisting of one roughing, two scavenging, and two beneficiation processes, to obtain tungsten concentrate and tailings 5'; wherein, tailings from beneficiation process one, tailings from beneficiation process two, concentrate from scavenging process one, and concentrate from scavenging process two are returned in sequence.

[0042] The following are some specific embodiments. It should be noted that the embodiments described below are exemplary and are only used to explain this application, and should not be construed as limiting this application. Where specific techniques or conditions are not specified in the embodiments, they shall be performed in accordance with the techniques or conditions described in the literature in this field or according to the product instructions. Reagents or instruments whose manufacturers are not specified are all conventional products that can be obtained commercially.

[0043] Example 1 This embodiment takes a copper-zinc-iron tailings mine in Inner Mongolia as the research object. The test ore sample is the magnetic separation tailings of the concentrator. The tailings contain 0.042% WO3, and the proportion of -0.038mm particle size is 43.87%. The gangue minerals in the ore include grossular, andradite, almandine, spessartine, quartz, orthoclase, plagioclase, albite, diopside, andradite, triclinic manganese pyroxene, rhodonite, aegirine, heliotropium, tremolite, etc. Among them, the most abundant is garnet minerals, with a content of 45.09%. The calcium-containing minerals that affect tungsten flotation include grossular, andradite, diopside, rhodonite, andradite, wollastonite, calcite, fluorite, apatite, etc.

[0044] This embodiment provides a mineral processing method for recovering scheelite from low-grade tailings, and the mineral processing flow chart is shown below. Figure 1 As shown, the specific steps include the following: (1) Take copper-zinc-iron tailings with a WO3 grade of 0.042%, add water to adjust the slurry mass concentration to 30%, and carry out high-gradient magnetic separation. Set the magnetic field background intensity to 1.2T to obtain strong magnetic concentrate (WO3 grade 0.014%). Figure 1 Tailings 1) and magnetic separation tailings (WO3 grade 0.063%) were selected, and the magnetic separation tailings were put into a graded centrifugal gravity separation test.

[0045] (2) The magnetic separation tailings were separated into three particle sizes of +0.074mm, -0.074+0.038mm and -0.038mm by a vibrating screen and then subjected to centrifugal gravity separation tests. The centrifugal concentrates of the three particle sizes were combined into tungsten gravity separation rough concentrate (WO3 grade 0.21%), and the centrifugal tailings were combined into tailings 2 (WO3 grade 0.027%). The tungsten gravity separation rough concentrate was then fed into the tungsten ambient temperature flotation process.

[0046] (3) Tungsten ambient temperature flotation process: Adjust the tungsten gravity separation rough concentrate slurry mass concentration to 32% for tungsten roughing operation. Add 250 g / t of sodium carbonate modifier, stir for 3 min, add 125 g / t of CD-6 inhibitor, stir for 3 min, add 100 g / t of CK-3, stir for 3 min, and then perform aeration flotation to obtain tungsten flotation rough concentrate and tailings.

[0047] Tungsten flotation rough concentrate enters tungsten ambient temperature cleaning operation 1, where 30 g / t of inhibitor CD-6 is added and stirred thoroughly for 3 min, followed by aeration flotation for 2 min to obtain tungsten concentrate one and middlings one; tungsten concentrate one enters tungsten ambient temperature cleaning operation 2, where 15 g / t of inhibitor CD-6 is added and stirred thoroughly for 3 min, followed by aeration flotation for 2 min to obtain tungsten concentrate two and middlings two.

[0048] Tailings 1 enters the first tungsten scavenging operation (tungsten scavenging 1), where 25 g / t of collector CK-3 is added and stirred thoroughly for 3 minutes, followed by aeration flotation for 2 minutes to obtain scavenging concentrate 1 and tailings 2; tailings 2 enters the second tungsten scavenging operation (tungsten scavenging 2), where 12 g / t of collector CK-3 is added and stirred thoroughly for 3 minutes, followed by aeration flotation for 2 minutes to obtain scavenging concentrate 2 and tailings 3.

[0049] During the closed-loop flotation process, the middlings concentrate and the scavenger concentrate are combined and fed into the centrifugal concentrator for gravity separation. The centrifugal concentrate is returned to the tungsten roughing operation, and the centrifugal tailings are called tailings 4. The middlings concentrate is returned to the tungsten ambient temperature cleaning operation 1 in sequence, and the scavenger concentrate is returned to the tungsten scavenger operation 1 in sequence.

[0050] (4) Tungsten heating and refining process: The tungsten concentrate obtained from the ambient temperature flotation is fed into the tungsten heated beneficiation feed. First, the slurry is concentrated to a mass concentration of 50%, then 250 g / t of inhibitor CD-6 is added and stirred thoroughly. After heating to 90°C and holding for 1 hour, heated roughing and cleaning (tungsten roughing) is carried out. After aeration flotation for 3 minutes, tungsten rough concentrate and tungsten rough tailings are obtained.

[0051] Tungsten concentrate roughing material enters tungsten heated beneficiation 1, where 50 g / t of inhibitor CD-6 is added and stirred thoroughly for 3 minutes, followed by aeration flotation for 2 minutes to obtain tungsten heated concentrate one and tungsten heated middlings one; tungsten heated concentrate one enters tungsten heated beneficiation 2, where 20 g / t of inhibitor CD-6 is added and stirred thoroughly for 3 minutes, followed by aeration flotation for 2 minutes to obtain tungsten concentrate and tungsten heated middlings two.

[0052] Tungsten heating middlings 1 are returned sequentially to tungsten heating roughing, and tungsten heating middlings 2 are returned sequentially to tungsten heating cleaning 1.

[0053] Tungsten concentrate and rough tailings 1 enters tungsten heated scavenging beneficiation beneficiation beneficiation 1 (tungsten concentrate scavenging 1), 2 g / t of collector CK-3 is added, and the mixture is stirred thoroughly for 3 min, followed by aeration flotation for 2 min, yielding tungsten heated scavenging beneficiation beneficiation beneficiation 1 concentrate and tungsten concentrate and rough tailings 2; tungsten concentrate and rough tailings 2 enters tungsten heated scavenging beneficiation beneficiation beneficiation beneficiation 2 (tungsten concentrate scavenging 2), 1 g / t of collector CK-3 is added, and the mixture is stirred thoroughly for 3 min, followed by aeration flotation for 2 min, yielding tungsten heated scavenging benefici Figure 1 Tailings 5); The concentrate from the tungsten heated scavenging process 1 is returned sequentially to the tungsten heated roughing process, and the concentrate from the tungsten heated scavenging process 2 is returned sequentially to the tungsten scavenging process 1.

[0054] In this embodiment, the CD-6 inhibitor is composed of water glass, tannic acid, modified starch, and hydroxyethylidene diphosphonic acid in a mass ratio of 7:1:1:1, and the collector CK-3 is composed of oxidized paraffin soap, modified oleic acid, octyl hydroxamic acid, and diesel oil in a mass ratio of 4:3:2:1.

[0055] Example 2 This embodiment takes a molybdenum tailings mine in Henan Province as the research object. The tailings contain 0.02% WO3, and the gangue minerals are mainly pyroxene, epidote, biotite, and potassium feldspar, with small amounts of montmorillonite, calcite, and chlorite.

[0056] This embodiment provides a mineral processing method for recovering scheelite from low-grade tailings, and the mineral processing flow chart is shown below. Figure 2 As shown, there are no magnetic minerals in the tailings, so no magnetic separation was performed; the specific steps include the following: (1) The molybdenum tailings with a WO3 grade of 0.02% were separated into three particle sizes of +0.074mm, -0.074+0.038mm and -0.038mm by a vibrating screen and then subjected to centrifugal gravity separation tests. The concentrate obtained from the first centrifugal gravity separation was subjected to centrifugal gravity separation tests again. Finally, the centrifugal concentrates of the three particle sizes were combined into tungsten gravity separation rough concentrate (WO3 grade 0.32%), and the centrifugal tailings were combined into tailings 1' (WO3 grade 0.01%). The tungsten gravity separation rough concentrate entered the flotation desulfurization process.

[0057] (2) Desulfurization process: Adjust the tungsten gravity separation rough concentrate slurry concentration to 38%, add 5 g / t copper sulfate activator, stir for 3 min, add 8 g / t butyl xanthate, stir for 3 min, add pine oil, stir for 1 min, and then aerate and float for 3 min to obtain sulfur rough concentrate and sulfur tailings.

[0058] The sulfur crude concentrate enters the sulfur beneficiation process 1, is stirred for 1 minute, and then aerated and floated for 2 minutes to obtain sulfur concentrate 1 and sulfur middlings 1; sulfur concentrate 1 enters the sulfur beneficiation process 2, is stirred for 1 minute, and then aerated and floated for 2 minutes to obtain sulfur concentrate 2 and sulfur middlings 2.

[0059] Sulfur tailings 1 enters the first sulfur scavenging operation (sulfur scavenging 1), 2g / t butyl xanthate is added, stirred for 3 minutes, and then aerated and floated for 2 minutes to obtain sulfur scavenging 1 concentrate and sulfur tailings 2; sulfur tailings 2 enters the second sulfur scavenging operation (sulfur scavenging 2), 1g / t butyl xanthate is added, stirred for 3 minutes, and then aerated and floated for 2 minutes to obtain sulfur scavenging 2 concentrate and sulfur tailings 2.

[0060] (3) Tungsten ambient temperature flotation process: Add 50 g / t of sodium carbonate modifier to the second sulfur tailings for tungsten roughing operation. After stirring for 3 minutes, add 28 g / t of CD-6 inhibitor, stir for 3 minutes, add 21 g / t of CK-3, stir for 3 minutes, and then perform aeration flotation to obtain tungsten flotation rough concentrate and tailings one.

[0061] The tungsten flotation rough concentrate is fed into the tungsten ambient temperature beneficiation process 1. 7 g / t of the inhibitor CD-6 is added and stirred thoroughly for 3 min, followed by aeration flotation for 2 min to obtain tungsten concentrate 1 and middlings 1. Tungsten concentrate No. 1 enters the tungsten ambient temperature beneficiation process 2, 3g / t of inhibitor CD-6 is added and stirred thoroughly for 3min, followed by aeration flotation for 2min to obtain tungsten concentrate No. 2 and middlings No. 2.

[0062] Tailings 1 enters the first tungsten scavenging operation (tungsten scavenging 1), where 5 g / t of collector CK-3 is added and stirred thoroughly for 3 minutes, followed by aeration flotation for 2 minutes to obtain scavenging concentrate 1 and tailings 2; tailings 2 enters the second tungsten scavenging operation (tungsten scavenging 2), where 2 g / t of collector CK-3 is added and stirred thoroughly for 3 minutes, followed by aeration flotation for 2 minutes to obtain scavenging concentrate 2 and tailings 3'.

[0063] During closed-loop flotation, the middlings and scavenging concentrates from the first flotation stage are combined and fed into a centrifugal concentrator for gravity separation. The centrifugal concentrate is returned to the tungsten roughing stage, and the centrifugal tailings are... Figure 2 The tailings 4' and the middle ore 2 are returned to the tungsten ambient temperature beneficiation 1 operation in sequence, and the scavenging concentrate 2 is returned to the tungsten scavenging 1 operation in sequence.

[0064] (4) Tungsten heating and refining process.

[0065] The tungsten concentrate obtained from the ambient temperature flotation is fed into the tungsten heated beneficiation feed. First, the slurry is concentrated to a mass concentration of 50%, then 55 g / t of inhibitor CD-6 is added and stirred thoroughly. After heating to 90 degrees Celsius and holding for 1 hour, heated fine and rough beneficiation (tungsten fine beneficiation) is carried out. After aeration flotation for 3 minutes, tungsten fine concentrate and tungsten fine tailings are obtained.

[0066] Tungsten concentrate roughing material enters tungsten heated cleaning process 1, where 14 g / t of CD-6 inhibitor is added and the mixture is stirred thoroughly for 3 minutes, followed by aeration flotation for 2 minutes to obtain tungsten heated concentrate one and tungsten heated middlings one. Tungsten heated concentrate one enters tungsten heated cleaning process 2, where 7 g / t of CD-6 inhibitor is added and the mixture is stirred thoroughly for 3 minutes, followed by aeration flotation for 2 minutes to obtain tungsten concentrate and tungsten heated middlings two. Tungsten heated middlings one is returned sequentially to tungsten heated roughing process, and tungsten heated middlings two is returned sequentially to tungsten heated cleaning process 1.

[0067] Tungsten concentrate and rough tailings 1 enters tungsten heated scavenging beneficiation beneficiation beneficiation 1 (tungsten concentrate scavenging 1), 1 g / t of collector CK-3 is added, and the mixture is stirred thoroughly for 3 min, followed by aeration flotation for 2 min, yielding tungsten heated scavenging beneficiation beneficiation beneficiation 1 concentrate and tungsten concentrate and rough tailings 2; tungsten concentrate and rough tailings 2 enters tungsten heated scavenging beneficiation beneficiation beneficiation beneficiation 2 (tungsten concentrate scavenging 2), 0.5 g / t of collector CK-3 is added, and the mixture is stirred thoroughly for 3 min, followed by aeration flotation for 2 min, yielding tungsten heated scavenging beneficiation beneficiation beneficiation beneficiation 2 concentrate and tungsten concentrate and rough tailings 3 ( Figure 2 (5' of tailings).

[0068] The concentrate from the tungsten heated scavenging process 1 is returned sequentially to the tungsten heated roughing process, and the concentrate from the tungsten heated scavenging process 2 is returned sequentially to the tungsten scavenging process 1.

[0069] Comparative Example 1 Comparative Example 1 provides a beneficiation method for recovering scheelite from low-grade tailings. The difference from Example 1 is that, in the flotation process, a centrifuge is not used for tailings removal during middlings extraction; instead, a sequential return method is used. The beneficiation process flow is as follows: Figure 3 As shown in Table 1, the experimental results are as follows.

[0070] Comparative Example 2 Comparative Example 1 provides a beneficiation method for recovering scheelite from low-grade tailings. The difference from Example 2 is that, in the middlings flotation process, a centrifuge is not used for tailings removal; instead, a sequential return method is employed. The beneficiation process flow is as follows: Figure 4 As shown in Table 1, the experimental results are as follows.

[0071] Comparative Example 3 Comparative Example 3 provides a beneficiation method for recovering scheelite from low-grade tailings. The difference from Example 1 is that the tungsten collector CK-3 is replaced with a commonly used tungsten collector 731. The test results are shown in Table 1.

[0072] Comparative Example 4 Comparative Example 4 provides a beneficiation method for recovering scheelite from low-grade tailings. The difference from Example 1 is that the gangue inhibitor CD-6 is replaced with a commonly used gangue inhibitor, water glass. The test results are shown in Table 1.

[0073] Table 1. Test results of Examples 1-2 and Comparative Examples 1-4 Comparing Example 1 and Comparative Example 1, it can be seen that for copper-zinc-iron tailings, compared with the method of desliming the middlings in tungsten flotation and then returning them, the yield of tungsten concentrate obtained by sequentially returning the middlings in tungsten flotation increased by 0.003%, the WO3 grade decreased by 14.16%, and the WO3 recovery rate decreased by 5.74%. This phenomenon indicates that the slime contained in the middlings accumulates continuously in the closed-loop circulation, which has a significant interference and inhibitory effect on the effective flotation of tungsten minerals.

[0074] Comparing Example 2 with Comparative Example 2, it can be seen that for molybdenum tailings, compared with the method of desliming the middlings in tungsten flotation using a centrifuge and then returning the middlings, the yield of tungsten concentrate obtained by sequentially returning the middlings in tungsten flotation increased by 0.004%, the WO3 grade decreased by 9.65%, and the WO3 recovery rate decreased by 5.155%. This also shows that the slime contained in the middlings accumulates continuously in the closed-loop circulation, which has a significant interference and inhibitory effect on the effective flotation of tungsten minerals.

[0075] Comparing Example 1 and Comparative Example 3, it can be seen that compared with the traditional tungsten collector 731, the WO3 grade of the tungsten concentrate obtained by using the tungsten collector CK-3 of the present invention is increased by 7.8%, and the WO3 recovery rate is increased by 8.354%. This result fully demonstrates that CK-3 has better selectivity while having strong collecting ability.

[0076] Comparing Example 1 and Comparative Example 4, it can be seen that, compared with conventional tungsten gangue inhibitor water glass, the WO3 grade of tungsten concentrate obtained by using the gangue inhibitor CD-6 of the present invention is increased by 4.63%, and the WO3 recovery rate is increased by 4.433%. This result fully demonstrates that CD-6 has a highly efficient inhibitory effect on gangue.

[0077] It should be noted that this application is not limited to the above-described embodiments. The above embodiments are merely examples, and any embodiments with the same structure and effect as the technical concept within the scope of this application are included in the technical scope of this application. Furthermore, various modifications that can be conceived by those skilled in the art to the embodiments, and other ways of constructing by combining some of the constituent elements of the embodiments, without departing from the spirit of this application, are also included in the scope of this application.

Claims

1. A beneficiation method for recovering scheelite from low-grade tailings, characterized by, Comprising the following steps: S1. Slurry preparation is performed on the tailings to be treated to obtain a slurry; S2. The slurry is subjected to high-intensity magnetic separation to obtain a magnetic concentrate and a magnetic tailings; S3. The magnetic tailings are classified into three particle sizes of +0.074 mm, -0.074+0.038 mm, and -0.038 mm, and then subjected to centrifuge reselection tests, respectively, the centrifuge concentrates of the three particle sizes are combined as a tungsten rough concentrate, and the centrifuge tailings are combined as tailings 2; S4. The tungsten rough concentrate is subjected to a tungsten normal-temperature flotation closed-circuit test of one roughing, two scavengings, and two cleanings to obtain a normal-temperature tungsten concentrate and tailings 3 and 4; wherein, the tailings of the first cleaning and the concentrate of the first scavenging enter a centrifuge for reselection desliming, the tailings of the reselection are tailings 4, the concentrate of the reselection returns to the roughing, and the tailings of the second cleaning and the concentrate of the second scavenging return in sequence; S5. The normal-temperature tungsten concentrate is concentrated and then subjected to a tungsten heated cleaning closed-circuit test of one roughing, two scavengings, and two cleanings to obtain a tungsten concentrate and tailings 5; wherein, the tailings of the first cleaning, the tailings of the second cleaning, the concentrate of the first scavenging, and the concentrate of the second scavenging return in sequence.

2. The mineral processing method for recovering scheelite from low-grade tailings according to claim 1, characterized by, In step S4, the tailings of the first cleaning and the concentrate of the first scavenging do not return in sequence with middlings, but are deslimed by a vertical centrifuge and then the centrifuge concentrate returns to the roughing.

3. The mineral processing method for recovering scheelite from low-grade tailings according to claim 1, characterized by, In step S1, the tailings to be treated have a WO3 grade of 0.01-0.08%.

4. The mineral separation method for recovering scheelite from low-grade tailings according to claim 1, characterized by, In step S4, the adjusting agent used in the roughing is sodium carbonate, and the amount used is 100-1000 g / t; the depressant used in the roughing is CD-6, and the collector used in the roughing is CK-3, and the amount of the collector used is 50-500 g / t.

5. The mineral separation method for recovering scheelite from low-grade tailings according to claim 4, characterized by, The CD-6 depressant is compounded by water glass, tannic acid, modified starch, and hydroxyethylidene diphosphonic acid at a mass ratio of 7:1:1:

1.

6. The mineral separation method for recovering scheelite from low-grade tailings according to claim 4, characterized by, The CK-3 is compounded by oxidized paraffin soap, modified oleic acid, octyl hydroxamic acid, and diesel oil at a mass ratio of 4:3:2:

1.

7. The mineral separation method for recovering scheelite from low-grade tailings according to claim 1, characterized by, In step S5, the normal-temperature tungsten concentrate is concentrated to a slurry with a mass concentration of 40-60%.

8. The mineral processing method for recovering scheelite from low-grade tailings according to claim 1, characterized by, In step S2, the magnetic field strength of the high-intensity magnetic separation is 0.6-2 T.

9. The mineral processing method for recovering scheelite from low-grade tailings according to claim 1, characterized by, In step S3, the centrifuge is a vertical centrifuge, the centrifugal force is 80-600 G, and the backflush water amount is 2-10 L / min.

10. A beneficiation process for recovering scheelite from low grade tailings, characterized by, Comprising the following steps: A1. The tailings to be treated are classified into three particle sizes of +0.074 mm, -0.074+0.038 mm, and -0.038 mm, and then subjected to centrifuge reselection tests, respectively, the concentrate obtained by the first centrifuge reselection is subjected to centrifuge reselection tests again, and finally the centrifuge concentrates of the three particle sizes are combined as a tungsten reselection rough concentrate, and the centrifuge tailings are combined as tailings 1, which enters a flotation desulfurization process; A2. The tungsten reselection rough concentrate is subjected to a desulfurization process of one roughing, two scavengings, and two cleanings to obtain a sulfur concentrate and sulfur tailings two; A3. The sulfur tailings two are subjected to a tungsten normal-temperature flotation closed-circuit test of one roughing, two scavengings, and two cleanings to obtain a tungsten concentrate two and tailings 3' and 4'; wherein, the tailings of the first cleaning and the concentrate of the first scavenging enter a centrifuge for reselection desliming, the tailings of the reselection are tailings 4', the concentrate of the reselection returns to the roughing, and the tailings of the second cleaning and the concentrate of the second scavenging return in sequence; A4. After the tungsten concentrate is twice concentrated, a tungsten heated cleaning closed-circuit test is carried out once rough selection, twice scavenging, and twice cleaning, to obtain a tungsten concentrate and a tailing 5'; wherein the tailings of the first cleaning, the tailings of the second cleaning, the concentrate of the first scavenging, and the concentrate of the second scavenging are sequentially returned.

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