Method for separating low-grade scheelite and fluorite ore

Abstract

The application provides a low-grade scheelite and fluorite ore beneficiation separation method. The preparation method adopts a scheelite-fluorite mixed flotation-scheelite-fluorite mixed concentrate reseparation process, through adopting a xanthate collector to preferentially remove pyrite, magnetic pyrite and other sulfide minerals, the interference of the sulfide minerals on subsequent scheelite-fluorite flotation is reduced; then through controlling the pH value of the scheelite-fluorite separation flotation slurry, and under the action of a special inhibitor, the scheelite-fluorite mixed concentrate is subjected to a reseparation process; in this way, the inhibition of fluorite in the traditional preferential flotation of scheelite and then fluorite process can be effectively reduced, and finally the efficient flotation of scheelite and fluorite ore is realized. Through controlling the pH value at 3-5 and adding an inhibitor SW, the argillaceous gangue such as calcite can be effectively inhibited, the floatability of scheelite is good, and the fluorite is basically not floated, so that higher-grade scheelite and fluorite concentrates can be obtained.

Description

Technical Field

[0001] This invention relates to the field of mineral processing technology, and in particular to a method for separating low-grade scheelite from fluorite. Background Technology

[0002] Scheelite and fluorite are both soluble salt minerals; the solubility of scheelite is 1.7 × 10⁻⁶. -5 mol / L, fluorite solubility 2.0 × 10⁻⁶ -4 mol / L, the Ca produced when they dissolve in aqueous solution 2+ The high concentration of corresponding anions leads to the adsorption and chemical reaction of the dissolved anions on the mineral surface, causing interconversion of the mineral surfaces. Furthermore, scheelite and fluorite both contain the same surface-active calcium particles, resulting in similar physicochemical properties on their surfaces. In addition, scheelite and fluorite are prone to over-grinding and sliming during grinding, making flotation separation difficult. For a long time, the flotation separation of calcium-bearing minerals has been a global challenge in mineral processing.

[0003] Currently, two main methods are used to achieve the flotation separation of low-grade scheelite and fluorite. One is the Petrov process, also known as the high-temperature thickening process. This involves concentrating the scheelite concentrate pulp to a concentration of over 50%, adding sodium hydroxide, sodium sulfide, and a large amount of water glass, then heating the pulp to over 90°C and holding it at that temperature for 1-2 hours. The pulp is then diluted for flotation separation of scheelite and gangue such as fluorite. In recent years, a metal-organic complex method using lead nitrate and benzo[a]hydroxyxamic acid has also been used, employing a room-temperature method to preferentially float scheelite followed by fluorite. However, the high-temperature thickening process requires heating with energy sources such as coal, natural gas, or electricity, resulting in high overall energy consumption, which contradicts current energy conservation and emission reduction policies. Furthermore, the high-temperature thickening process strongly suppresses fluorite, requiring activation before flotation recovery, resulting in a low fluorite recovery rate of only 20%-40%. The reagent cost of metal-organic complex flotation process is high, with a reagent cost of 60 to 80 yuan per ton of raw ore. The WO3 grade in scheelite flotation is only 20% to 30%, and the recovery rate is 65% to 75%, which cannot simultaneously guarantee the ideal effect of grade and recovery rate.

[0004] In view of this, it is necessary to design a beneficiation and separation method for low-grade scheelite and fluorite to solve the above problems. Summary of the Invention

[0005] In view of the shortcomings of the prior art, the purpose of this invention is to provide a method for separating low-grade scheelite and fluorite ore in beneficiation, which can simultaneously achieve efficient flotation of scheelite and fluorite ore, fully recover tungsten and fluorite resources in the mixed ore, and improve the beneficiation recovery rate.

[0006] To achieve the above objectives, the present invention provides a method for separating low-grade scheelite from fluorite ore through beneficiation, comprising the following steps:

[0007] S1. After crushing and grinding the target raw ore to a predetermined particle size, water is added to prepare a slurry of a predetermined concentration.

[0008] S2. The slurry is subjected to desulfurization roughing, desulfurization scavenging and desulfurization cleaning to obtain sulfur concentrate and desulfurization tailings;

[0009] S3. The desulfurized tailings obtained in step S2 are subjected to one roughing process of mixed scheelite and fluorite and two scavenging processes to obtain roughing concentrate and tailings.

[0010] S4. Perform three fine-selection processes on the rough concentrate obtained in step S3 to obtain a mixed concentrate of scheelite and fluorite.

[0011] S5. Adjust the pH value of the scheelite-fluorite mixed concentrate obtained in step S4 to a predetermined range;

[0012] S6. The mixed scheelite and fluorite concentrate processed in step S5 is subjected to one roughing separation, two fine scavenging separations, and three fine cleaning separations. The resulting flotation froth is the scheelite concentrate, and the flotation tailings are the fluorite concentrate.

[0013] Further, in step S2, the reagents added for the desulfurization roughing process include isoamyl xanthate at a dosage of 80-100 g / t and 2% thiocyanate at a dosage of 20-30 g / t. # Oil; the reagents added for the desulfurization scavenging include isoamyl xanthate at a dosage of 40-50 g / t and 2% thiocyanate at a dosage of 0-5 g / t. # Oil.

[0014] Further, in step S3, the reagents added for the roughing of the scheelite-fluorite mixed beneficiation include sodium carbonate at a dosage of 1000-2000 g / t, inhibitor SW at a dosage of 2000-3000 g / t, and paraffin soap oxide at a dosage of 300-400 g / t; the reagents added for scavenging I include paraffin soap oxide at a dosage of 100-150 g / t; and the reagents added for scavenging II include paraffin soap oxide at a dosage of 0-50 g / t.

[0015] Further, in step S4, the agent added for selection I includes the inhibitor SW at a dosage of 1000-1500 g / t; the agent added for selection II includes the inhibitor SW at a dosage of 750-1000 g / t; and the agent added for selection III includes the inhibitor SW at a dosage of 500-750 g / t.

[0016] Furthermore, in step S5, the predetermined range of pH value is 3 to 5.

[0017] Further, in step S6, the reagents added for the roughing and separation of scheelite and fluorite include water glass at a dosage of 2000-3000 g / t; the reagents added for finer separation I include water glass at a dosage of 1000-1500 g / t; the reagents added for finer separation II include the inhibitor SW at a dosage of 500-1000 g / t; and the reagents added for finer separation III include the inhibitor SW at a dosage of 0-500 g / t.

[0018] Furthermore, the inhibitor SW comprises a mixture of sulfuric acid (10% by mass), water glass (10% by mass), and gum arabic in a mass ratio of 4–6:8–12:1–2.

[0019] Furthermore, in step S1, the predetermined particle size of -0.074 mm accounts for 60-65%.

[0020] Furthermore, in step S1, the predetermined concentration of the slurry is 35-40%.

[0021] Furthermore, reagents used for pH adjustment include dilute sulfuric acid.

[0022] The beneficial effects of this invention are:

[0023] 1. This invention provides a method for separating low-grade scheelite and fluorite ore during beneficiation. The method employs a mixed flotation process of scheelite and fluorite followed by a re-separation process of the mixed concentrate. First, a xanthate collector is used to preferentially remove sulfide minerals such as pyrite and magnesia, reducing the interference of these sulfide minerals on subsequent scheelite and fluorite flotation. Then, by controlling the pH value of the scheelite and fluorite separation flotation pulp and under the action of a specially formulated inhibitor, the mixed concentrate of scheelite and fluorite is further separated. This effectively reduces the requirements of traditional methods involving preferential flotation of scheelite followed by flotation of fluorite. The method suppresses the growth of fluorite, ultimately achieving efficient flotation of both scheelite and fluorite. It can transform raw scheelite containing 0.27% WO3, 14.17% fluorite, 13.10% CaCO3, and 1.20% S into a scheelite concentrate containing 65.32% WO3 (78.44% recovery) and 2.23% CaF2; and a fluorite concentrate containing 94.46% CaF2 (80.89% recovery). Furthermore, this method has low energy consumption, low reagent costs, and significant economic benefits.

[0024] 2. The present invention provides a method for separating low-grade scheelite and fluorite ore through beneficiation. By controlling the pH value at 3-5 and adding an inhibitor SW, which is a mixture of 10% sulfuric acid, 10% water glass, and gum arabic in a mass ratio of 4-6:8-12:1-2, calcite and other argillaceous gangue can be effectively suppressed, ensuring that scheelite has good floatability while fluorite is basically non-floating. Therefore, it is beneficial to obtain higher-grade scheelite and fluorite concentrates in the future. Attached Figure Description

[0025] Figure 1 This is a schematic flowchart of a method for separating low-grade scheelite and fluorite ore in the beneficiation process provided by the present invention. Detailed Implementation

[0026] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be described in detail below with reference to the accompanying drawings and specific embodiments.

[0027] It should also be noted that, in order to avoid obscuring the present invention with unnecessary details, only the structures and / or processing steps closely related to the present invention are shown in the accompanying drawings, while other details that are not closely related to the present invention are omitted.

[0028] Additionally, it should be noted that the terms “comprising,” “including,” or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such process, method, article, or apparatus.

[0029] like Figure 1 As shown, a method for separating low-grade scheelite from fluorite ore includes the following steps:

[0030] S1. First, crush the target ore to -2mm, then grind it until 60-65% of the particles are -0.074mm in diameter, and then add water to make a slurry with a concentration of 35-40%.

[0031] S2. The slurry is fed into a flotation machine for desulfurization roughing, desulfurization scavenging and desulfurization cleaning (i.e. blank cleaning) to obtain sulfur concentrate and desulfurization tailings;

[0032] The reagents added for the desulfurization roughing process include isoamyl xanthate at a dosage of 80-100 g / t and 2% thiocyanate at a dosage of 20-30 g / t. # Oil; the reagents added for the desulfurization scavenging include isoamyl xanthate at a dosage of 40-50 g / t and 2% thiocyanate at a dosage of 0-5 g / t. # Oil;

[0033] S3. The desulfurized tailings obtained in step S2 are subjected to one roughing process of mixed scheelite and fluorite and two scavenging processes to obtain roughing concentrate and tailings.

[0034] The reagents added for the roughing stage of the scheelite-fluorite mixed beneficiation include sodium carbonate at a dosage of 1000-2000 g / t, inhibitor SW at a dosage of 2000-3000 g / t, and paraffin soap oxide at a dosage of 300-400 g / t; the reagents added for scavenging stage I include paraffin soap oxide at a dosage of 100-150 g / t; and the reagents added for scavenging stage II include paraffin soap oxide at a dosage of 0-50 g / t.

[0035] S4. Perform three fine-selection processes on the rough concentrate obtained in step S3 to obtain a mixed concentrate of scheelite and fluorite.

[0036] The agent added for selection I includes the inhibitor SW at a dosage of 1000-1500 g / t; the agent added for selection II includes the inhibitor SW at a dosage of 750-1000 g / t; and the agent added for selection III includes the inhibitor SW at a dosage of 500-750 g / t.

[0037] S5. Adjust the pH value of the scheelite-fluorite mixed concentrate obtained in step S4 to a predetermined range;

[0038] S6. The mixed scheelite and fluorite concentrate processed in step S5 is subjected to one roughing separation, two fine scavenging separations, and three fine cleaning separations. The flotation froth obtained is the scheelite concentrate, and the flotation tailings is the fluorite concentrate.

[0039] The reagents added for the roughing and separation of scheelite and fluorite include water glass at a dosage of 2000-3000 g / t; the reagents added for finer separation I include water glass at a dosage of 1000-1500 g / t; the reagents added for finer separation II include the inhibitor SW at a dosage of 500-1000 g / t; and the reagents added for finer separation III include the inhibitor SW at a dosage of 0-500 g / t.

[0040] This setup first uses xanthate collectors to preferentially remove sulfide minerals such as pyrite and magnesia, reducing the interference of these sulfide minerals on the subsequent flotation of scheelite and fluorite. Then, the scheelite-fluorite mixed concentrate is further separated, which effectively reduces the inhibition of fluorite in the traditional preferential flotation of scheelite followed by fluorite flotation. This allows for the efficient flotation of both scheelite and fluorite simultaneously. Moreover, this method has low energy consumption, low reagent costs, and significant economic benefits.

[0041] Specifically, in some embodiments of the present invention, in step S5, the predetermined range of pH value is 3 to 5.

[0042] This setup ensures that scheelite has good buoyancy while preventing fluorite from floating, thus achieving selective separation of scheelite and fluorite.

[0043] Specifically, in some embodiments of the present invention, the inhibitor SW comprises a mixture of sulfuric acid with a mass concentration of 10%, water glass with a mass concentration of 10%, and gum arabic in a mass ratio of 4-6:8-12:1-2.

[0044] With this setup, the inhibitor SW has a high selective inhibition effect on carbonates and other minerals, thus effectively suppressing argillaceous gangue such as calcite, which is beneficial for obtaining higher-grade scheelite and fluorite concentrates.

[0045] Specifically, in some embodiments of the present invention, the reagent used for pH adjustment includes dilute sulfuric acid.

[0046] The following describes the working principle of the beneficiation and separation method for low-grade scheelite and fluorite provided by this invention:

[0047] Example 1

[0048] This embodiment provides a method for separating low-grade scheelite from fluorite ore, including the following steps:

[0049] The target ore used in this embodiment is: scheelite containing 0.27% WO3, 14.17% fluorite, 13.10% CaCO3, and 1.20% S by mass percentage;

[0050] S1. First, crush the target ore to -2mm, then grind it until the particle size is -0.074mm accounting for 60%, and then add water to make a slurry with a concentration of 35%.

[0051] S2. The slurry is subjected to desulfurization roughing, desulfurization scavenging and desulfurization cleaning to obtain sulfur concentrate and desulfurization tailings;

[0052] The reagents added for the desulfurization roughing process include isoamyl xanthate at a dosage of 90 g / t and 25 g / t of 2 # Oil; the reagents added for the desulfurization scavenging include isoamyl xanthate at a dosage of 45 g / t and 2 g / t of 2 # Oil;

[0053] S3. The desulfurized tailings obtained in step S2 are subjected to one roughing process of mixed scheelite and fluorite and two scavenging processes to obtain roughing concentrate and tailings.

[0054] The reagents added for the roughing of the scheelite-fluorite mixed beneficiation include 1500 g / t of sodium carbonate, 2500 g / t of inhibitor SW, and 350 g / t of oxidized paraffin soap; the reagents added for scavenging I include 100 g / t of oxidized paraffin soap; and the reagents added for scavenging II include 25 g / t of oxidized paraffin soap.

[0055] S4. The rough concentrate obtained in step S3 is subjected to three fine-tuning processes to obtain a mixed concentrate of scheelite and fluorite, wherein the mixed concentrate of scheelite and fluorite contains 1.86% WO3 with a WO3 recovery rate of 86.10% and 92.06% CaF2 with a CaF2 recovery rate of 81.01%.

[0056] The agent added during the selection process I includes the inhibitor SW at a dosage of 1000 g / t; the agent added during the selection process II includes the inhibitor SW at a dosage of 750 g / t; and the agent added during the selection process III includes the inhibitor SW at a dosage of 700 g / t.

[0057] S5. The pH value of the scheelite-fluorite mixed concentrate obtained in step S4 is adjusted to 3 using dilute sulfuric acid.

[0058] S6. The mixed scheelite and fluorite concentrate processed in step S5 is subjected to one roughing separation, two fine scavenging separations, and three fine cleaning separations. The flotation froth obtained is the scheelite concentrate, and the flotation tailings is the fluorite concentrate.

[0059] The reagents added for the roughing and separation of scheelite and fluorite include 2500 g / t of water glass; the reagents added for finer separation I include 1200 g / t of water glass; the reagents added for finer separation II include 700 g / t of the inhibitor SW; and the reagents added for finer separation III include 200 g / t of the inhibitor SW.

[0060] The inhibitor SW is composed of sulfuric acid with a mass concentration of 10%, water glass with a mass concentration of 10%, and gum arabic mixed in a mass ratio of 5:10:1.

[0061] The scheelite concentrate obtained in this embodiment contains 65.32% WO3 with a recovery rate of 78.44% and 2.23% CaF2; the fluorite concentrate contains 94.46% CaF2 with a recovery rate of 80.89%.

[0062] Comparative Example 1

[0063] Comparative Example 1 provides a method for separating low-grade scheelite from fluorite ore. The difference from Example 1 is that the inhibitor SW in steps S3 and S4 is replaced with a water glass inhibitor.

[0064] The experimental procedures and reagents for other flotation applications are the same as in Example 1, and will not be repeated here.

[0065] In step S4, the scheelite-fluorite mixed concentrate contains 1.14% WO3 (87.29% recovery) and 57.49% CaF2 (82.81% recovery). The final scheelite concentrate contains 64.37% WO3 (79.78% recovery) and 2.60% CaF2; the fluorite concentrate contains 58.40% CaF2 (82.75% recovery).

[0066] Comparative Examples 2-4

[0067] Comparative Example 2 provides a method for separating low-grade scheelite from fluorite ore. The difference between this method and Example 1 is that the pH value in step S5 is different.

[0068] In Comparative Example 2, the pH value in step S5 was adjusted to 6;

[0069] In Comparative Example 3, the pH value in step S5 was adjusted to 8;

[0070] In Comparative Example 4, the pH value in step S5 was adjusted to 11.

[0071] The experimental procedures and reagents for other flotation applications are the same as in Example 1, and will not be repeated here.

[0072] Ultimately, Comparative Example 2 yielded scheelite concentrate containing 6.79% WO3 with a recovery rate of 83.87% and 81.14% CaF2; the fluorite concentrate contained 95.50% CaF2 with a recovery rate of 61.63%. Comparative Example 3 yielded scheelite concentrate containing 5.26% WO3 with a recovery rate of 84.45% and 88.73% CaF2; the fluorite concentrate contained 92.21% CaF2 with a recovery rate of 53.18%. Comparative Example 4 yielded scheelite concentrate containing 3.11% WO3 with a recovery rate of 85.20% and 92.45% CaF2; the fluorite concentrate contained 90.34% CaF2 with a recovery rate of 32.40%.

[0073] Comparative Example 5

[0074] This comparative example provides a method for separating low-grade scheelite from fluorite ore through beneficiation. The difference between this method and Example 1 is that the operation of step S5 is different.

[0075] In Comparative Example 5, step S5 adjusts the pH value of the scheelite-fluorite mixed concentrate obtained in step S4 to 11, heats the scheelite-fluorite mixed concentrate to 90°C and keeps it at that temperature for 2 hours while stirring, then cools it to room temperature before performing scheelite-fluorite separation and flotation.

[0076] The experimental procedures and reagents for other flotation applications are the same as in Example 1, and will not be repeated here.

[0077] Ultimately, the scheelite concentrate obtained in Comparative Example 5 contained 65.03% WO3 with a recovery rate of 76.41% and 4.50% CaF2; the fluorite concentrate contained 94.42% CaF2 with a recovery rate of 80.91%.

[0078] Comparative Example 6

[0079] This comparative example provides a method for separating low-grade scheelite from fluorite ore through beneficiation. The difference between this method and Example 1 is that the operation of step S5 is different.

[0080] In Comparative Example 6, step S5 adjusts the pH value of the scheelite-fluorite mixed concentrate obtained in step S4 to 3, heats the scheelite-fluorite mixed concentrate to 90°C and keeps it at that temperature for 2 hours while stirring, then cools it to room temperature before performing scheelite-fluorite separation and flotation.

[0081] The experimental procedures and reagents for other flotation applications are the same as in Example 1, and will not be repeated here.

[0082] Ultimately, the scheelite concentrate obtained in Comparative Example 6 contained 66.10% WO3 with a recovery rate of 79.21% and 1.92% CaF2; the fluorite concentrate contained 95.06% CaF2 with a recovery rate of 80.90%.

[0083] As can be seen, the pH value of the pulp is very important. When the pH value is controlled between 5 and 12, it is difficult to obtain high-grade scheelite concentrate by flotation at room temperature. Only by controlling the pH value of the scheelite-fluorite separation flotation pulp within the range of 3 to 5, and by using a specially formulated inhibitor SW, can the mixed scheelite-fluorite concentrate be further separated. This can effectively reduce the inhibition of fluorite in the traditional preferential flotation of scheelite followed by fluorite flotation, and ultimately achieve efficient flotation of both scheelite and fluorite. At the same time, this method can obtain high-grade scheelite concentrate and recovery rate without high-temperature treatment, and can effectively achieve flotation separation of scheelite and fluorite without high-temperature energy consumption.

[0084] In summary, this invention provides a method for separating low-grade scheelite and fluorite ore during beneficiation. It employs a mixed flotation process of scheelite and fluorite followed by a re-separation process using a mixed concentrate. First, a xanthate collector is used to preferentially remove sulfide minerals such as pyrite and magnesia, reducing the interference of these sulfide minerals on subsequent scheelite and fluorite flotation. Then, by controlling the pH of the scheelite and fluorite separation flotation pulp and using a specially formulated inhibitor, the mixed concentrate is further separated. This effectively reduces the inhibition of fluorite in traditional preferential flotation of scheelite followed by fluorite flotation, ultimately achieving efficient flotation of both scheelite and fluorite ore simultaneously. By controlling the pH value at 3-5 and adding a depressant SW (composed of 10% sulfuric acid, 10% water glass, and gum arabic in a mass ratio of 4-6:8-12:1-2), calcite and other argillaceous gangues can be effectively suppressed, ensuring good floatability of scheelite while fluorite is essentially non-floatable. This is beneficial for obtaining higher-grade scheelite and fluorite concentrates. The preparation and flotation application of this composite depressant are simple, low-cost, and do not involve complex operations, resulting in significant economic benefits and facilitating industrial-scale promotion.

[0085] The above embodiments are only used to illustrate the technical solutions of the present invention and are not intended to limit it. Although the present invention has been described in detail with reference to preferred embodiments, those skilled in the art should understand that modifications or equivalent substitutions can be made to the technical solutions of the present invention without departing from the spirit and scope of the technical solutions of the present invention.

Claims

1. A method for separating low-grade scheelite from fluorite ore during beneficiation, characterized in that, Includes the following steps: S1. After crushing and grinding the target raw ore to a predetermined particle size, water is added to prepare a slurry of a predetermined concentration. S2. The slurry is subjected to desulfurization roughing, desulfurization scavenging and desulfurization cleaning to obtain sulfur concentrate and desulfurization tailings; S3. The desulfurized tailings obtained in step S2 are subjected to one roughing process of mixed scheelite and fluorite and two scavenging processes to obtain roughing concentrate and tailings. S4. Perform three fine-selection processes on the rough concentrate obtained in step S3 to obtain a mixed concentrate of scheelite and fluorite. S5. Adjust the pH value of the scheelite-fluorite mixed concentrate obtained in step S4 to a predetermined range; S6. The mixed scheelite and fluorite concentrate processed in step S5 is subjected to one roughing separation, two fine scavenging separations, and three fine cleaning separations. The flotation froth obtained is the scheelite concentrate, and the flotation tailings is the fluorite concentrate. In step S5, the predetermined range of pH value is 3 to 5; In step S6, the reagents added for the roughing and separation of scheelite and fluorite include water glass at a dosage of 2000-3000 g / t, and the reagents added for the finer separation I include water glass at a dosage of 1000-1500 g / t. The agents added for Refinement II include inhibitor SW at a dosage of 500–1000 g / t; the agents added for Refinement III include inhibitor SW at a dosage of 0–500 g / t. The inhibitor SW comprises sulfuric acid with a mass concentration of 10%, water glass with a mass concentration of 10%, and gum arabic mixed in a mass ratio of 4-6:8-12:1-2.

2. The method for separating low-grade scheelite and fluorite ore according to claim 1, characterized in that: In step S2, the reagents added for the desulfurization roughing process include 80-100 g / t of isoamyl xanthate and 20-30 g / t of No. 2 oil; the reagents added for the desulfurization scavenging process include 40-50 g / t of isoamyl xanthate and 0-5 g / t of No. 2 oil.

3. The method for separating low-grade scheelite and fluorite ore according to claim 1, characterized in that: In step S3, the reagents added for the roughing of the mixed scheelite and fluorite include sodium carbonate at a dosage of 1000-2000 g / t, inhibitor SW at a dosage of 2000-3000 g / t, and paraffin soap oxide at a dosage of 300-400 g / t; the reagents added for scavenging I include paraffin soap oxide at a dosage of 100-150 g / t; and the reagents added for scavenging II include paraffin soap oxide at a dosage of 0-50 g / t.

4. The method for separating low-grade scheelite and fluorite ore according to claim 3, characterized in that: In step S4, the agent added for selection I includes the inhibitor SW at a dosage of 1000-1500 g / t; the agent added for selection II includes the inhibitor SW at a dosage of 750-1000 g / t; and the agent added for selection III includes the inhibitor SW at a dosage of 500-750 g / t.

5. The method for separating low-grade scheelite and fluorite ore according to claim 1, characterized in that: In step S1, the predetermined particle size of -0.074 mm accounts for 60 to 65%.

6. The method for separating low-grade scheelite and fluorite ore according to claim 1, characterized in that: In step S1, the predetermined concentration of the slurry is 35-40%.

7. The method for separating low-grade scheelite and fluorite ore according to claim 1, characterized in that: Reagents used for pH adjustment include dilute sulfuric acid.

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