Beneficiation method of fluorite ore

Abstract

The present disclosure relates to the technical field of fluorite beneficiation, and provides a fluorite ore beneficiation method, which comprises the following steps: crushing raw ore to obtain crushed ore; first grading the crushed ore to obtain first oversize and first undersize; sorting the first oversize to obtain metallurgical-grade fluorite lump ore and sorting tailings, wherein the sorting comprises at least one of color selection and photoelectric selection; combining the first undersize and the sorting tailings to perform first grinding to obtain mixed materials; second grading the mixed materials to obtain second oversize and second undersize; gravity separating the second oversize to obtain gravity separation concentrate and gravity separation tailings; combining the second undersize and the gravity separation concentrate to perform second grinding to obtain floating material; and floating the floating material to obtain flotation fluorite concentrate and flotation tailings. The above beneficiation method can simultaneously obtain metallurgical-grade fluorite lump ore and high-quality acid-grade fluorite concentrate from fluorite ore with a CaF2 grade of not more than 45% (or even less than 30%).

Description

Technical Field

[0001] This disclosure relates to the field of fluorite beneficiation technology, and for example to a method for beneficiating fluorite ore. Background Technology

[0002] Fluorite is a very important non-metallic mineral resource, with applications spanning traditional and emerging industries such as metallurgy, chemicals, refrigeration, nuclear energy, and fluorochemicals. Among these, fluorochemicals and metallurgy are the primary consumer sectors. Currently, approximately 63% of China's fluorite products are used in the fluorochemical industry, followed by about 23% in the metallurgical industry. While China's fluorite resources are relatively abundant, the average CaF2 grade in single fluorite ores is only about 35%–40% of the total proven resources. Of this, high-grade ores with a CaF2 grade of at least 60% (i.e., metallurgical-grade fluorite lumps) account for only 20% of the total single fluorite ores, and high-grade rich ores with a CaF2 grade of at least 80% (i.e., high-grade fluorite lumps) account for less than 10% of the total single fluorite ores.

[0003] Currently, the main beneficiation methods for obtaining metallurgical-grade fluorite lumps are high-pressure water jet washing and manual sorting. These methods rely on simple tools such as water tanks and hoppers, as well as a large amount of manual labor, resulting in low production efficiency. Furthermore, after manual sorting to remove high-grade fluorite lumps, the fluorite content in the remaining ore is significantly reduced (e.g., by 20%), making it difficult to obtain high-quality acid-grade fluorite concentrate with a CaF2 content of not less than 97% through direct flotation. However, fluorochemical-grade acid-grade fluorite concentrate must be obtained through flotation, and with years of mining, the flotation grade of fluorite has been decreasing, making it increasingly difficult to obtain high-quality acid-grade fluorite concentrate using only a single flotation process.

[0004] Chinese patent document CN202210687338.8, application date 20220616, entitled "A Method for Beneficiating Fluorite Ore", discloses a beneficiation method comprising: (1) crushing and screening fluorite ore; (2) adding 10-40mm ore obtained by screening in step (1) to a photoelectric concentrator for photoelectric beneficiation to obtain a first fluorite concentrate and a first photoelectric beneficiation tailings; (3) adding the first photoelectric beneficiation tailings to a photoelectric concentrator for photoelectric beneficiation to obtain a second photoelectric beneficiation concentrate and a second photoelectric beneficiation tailings; (4) mixing the second photoelectric beneficiation concentrate and <10mm ore obtained by screening in step (1) and then crushing and screening; (5) adding <3mm ore obtained by screening in step (4) to a mill for grinding; (6) performing flotation operations on the ground product including at least one fluorite roughing, at least one fluorite cleaning and at least one fluorite scavenging to obtain a second fluorite concentrate.

[0005] The combined photoelectric and flotation beneficiation method described in the aforementioned patent literature can be used for beneficiating medium- and low-grade fluorite ore (CaF2 grade not less than 30%), and can simultaneously obtain metallurgical-grade fluorite lumps and acid-grade fluorite concentrate. However, the aforementioned patent literature has not yet provided a solution for beneficiating fluorite ore with a CaF2 grade of less than 30% to simultaneously obtain metallurgical-grade fluorite lumps and acid-grade fluorite concentrate, and to maximize the yield of acid-grade fluorite concentrate as well as the recovery rate and grade of CaF2.

[0006] In summary, there is an urgent need for a beneficiation method that can simultaneously obtain metallurgical-grade fluorite lumps and acid-grade fluorite concentrate from medium- and low-grade fluorite ores with a CaF2 grade of no more than 45% (or even less than 30%), and can maximize the yield of acid-grade fluorite concentrate as well as the recovery rate and grade of CaF2, in order to solve the problem of insufficient rich fluorite resources in China and maximize the recovery of resources. Summary of the Invention

[0007] The purpose of this disclosure is to overcome the shortcomings of the prior art and provide a beneficiation method for fluorite ore, so as to not only obtain metallurgical-grade fluorite lumps (CaF2 grade of 60% to 80%) and high-quality acid-grade fluorite concentrate (CaF2 grade of not less than 97%) from medium- and low-grade fluorite ore with a CaF2 grade of not more than 45% (or even less than 30%), but also to maximize the yield of high-quality acid-grade fluorite concentrate and the recovery rate and grade of CaF2, so as to solve the problem of insufficient rich fluorite resources in China and maximize the recovery of resources.

[0008] The purpose of this disclosure is achieved through the following technical solution:

[0009] On the one hand, a method for beneficiating fluorite ore is provided. The method includes: crushing the raw ore to obtain crushed ore; performing a first classification on the crushed ore to obtain a first oversize and a first undersize; separating the first oversize to obtain metallurgical-grade fluorite lumps and separation tailings, wherein the separation includes at least one of color sorting and photoelectric sorting; combining the first undersize and the separation tailings, and performing a first grinding to obtain a mixture; performing a second classification on the mixture to obtain a second oversize and a second undersize; performing gravity separation on the second oversize to obtain gravity concentrate and gravity tailings; combining the second undersize and the gravity concentrate, and performing a second grinding to obtain a flotation feed; and performing flotation on the flotation feed to obtain flotation fluorite concentrate and flotation tailings.

[0010] It is readily understood that the phrase "the sorting includes at least one of color sorting and photoelectric sorting" as stated above means that the sorting includes only color sorting; or, the sorting includes only photoelectric sorting; or, the sorting includes both color sorting and photoelectric sorting. This disclosure does not impose any limitations on this.

[0011] It is worth noting that in the above embodiments, by first sorting the first oversize obtained from the crushing and first grading of the raw ore, the metallurgical-grade fluorite lumps (i.e., particle ore) can be preferentially selected, thereby effectively alleviating the problem of insufficient rich fluorite resources in China; secondly, by continuing to combine the first undersize and the sorting tailings obtained from the crushing and first grading of the raw ore with the sorting of the first oversize, and then sequentially performing the first grinding and second grading, and further processing the obtained second undersize... Gravity separation is used to remove the gravity tailings, and then the gravity concentrate is combined with the second undersize for the second grinding. This effectively increases the CaF2 content in the feed material obtained after the second grinding compared to the CaF2 content in the original ore, thereby significantly reducing the operational pressure of flotation. Based on this, by performing flotation on the feed material, the goal is to maximize the yield of high-quality acid-grade fluorite concentrate, as well as the recovery rate and grade of CaF2, while obtaining high-quality acid-grade fluorite concentrate (i.e., the flotated fluorite concentrate).

[0012] It should be noted that the principle of flotation includes: utilizing the different hydrophilicity and hydrophobicity of various minerals with water, and using the action of air bubbles in water to combine mineral particles with air bubbles, thereby achieving the separation of various minerals.

[0013] In some embodiments, the grade of CaF2 in the ore is no greater than 45%.

[0014] In some examples, the CaF2 grade in the ore is less than 30%.

[0015] Based on this, it is easy to understand that the mineral processing method provided in this disclosure is applicable to medium- and low-grade fluorite ores with a CaF2 grade of no more than 45% (or even less than 30%).

[0016] In some embodiments, the sorting includes only color sorting. This allows for the simultaneous acquisition of metallurgical-grade fluorite ore and high-quality acid-grade fluorite concentrate, while minimizing the yield of the high-quality acid-grade fluorite concentrate and the recovery rate and grade of CaF2, thereby reducing beneficiation costs.

[0017] In some embodiments, the color sorting is performed using a color sorter.

[0018] In the above embodiments, the principle of using the color sorter for color sorting includes: utilizing the differences in color, texture, shape, luster, and quality of the ores in the first sieve oversize to separate fluorite minerals from gangue minerals (e.g., silicate minerals such as quartz and feldspar, carbonate minerals such as calcite and dolomite, and sulfate minerals such as barite and celestite).

[0019] In some examples, the operating conditions of the color sorter include: a sensitivity of 5 to 100 values, a cleaning time of 1 to 60 seconds, and a cleaning cycle of 5 to 30 minutes.

[0020] In the above example, by limiting the operating conditions of the color sorter, the separation effect of fluorite minerals and gangue minerals can be further improved.

[0021] In some embodiments, the photoelectric selection is performed using an X-ray photoelectric selector.

[0022] In the above embodiments, the principle of using the X-ray photoelectric separator for photoelectric separation includes: using multi-energy X-ray full-particle-size scanning of the ore in the first sieve, collecting the X-ray attenuation information of the ore, establishing a multi-energy spectral ore identification model, judging the material composition and content in the ore through multi-material decomposition calculation, and then identifying fluorite minerals and gangue minerals by setting a separation threshold, thereby separating them to obtain the metallurgical grade fluorite lump ore and the separation tailings.

[0023] In some examples, the operating conditions of the X-ray photoelectric separator include: a jet pressure of 0.01 to 0.05 MPa and a conveyor belt speed of 1 to 5 m / s.

[0024] In the above example, by limiting the operating conditions of the X-ray photoelectric separator, the separation effect of fluorite minerals and gangue minerals can be further improved.

[0025] In some embodiments, the gravity separation employs a heavy medium cyclone separator; wherein the operating conditions of the heavy medium cyclone separator include: a feed pressure of 0.1–0.5 MPa and a medium density of 1.5–2.5 g / cm³. 3 .

[0026] In the above embodiments, by using the heavy medium cyclone to perform gravity separation on the material over the second sieve and controlling the operating conditions of the heavy medium cyclone, the content of CaF2 in the feed material can be further increased, thereby further reducing the operating pressure of the flotation, which is conducive to further improving the yield of high-quality acid-grade fluorite concentrate and the recovery rate and grade of CaF2.

[0027] Furthermore, it should be noted that after the gravity separation, the tailings can be obtained through a first filtration separation. In this case, the beneficiation water generated by the first filtration separation can be returned to the steps corresponding to the second classification and the gravity separation for recycling, thereby achieving the effect of saving resources.

[0028] In some embodiments, the maximum particle size of the crushed ore is 60-80 mm, and the maximum particle size of the first undersize material is 10-30 mm.

[0029] It should be noted that the particle size of the first oversize material can be derived from the defined particle size of the crushed ore (i.e., the maximum particle size of the crushed ore) and the particle size of the first undersize material (i.e., the maximum particle size of the first undersize material).

[0030] For example, when the particle size of the crushed ore is -80mm (i.e., the maximum particle size of the crushed ore is 80mm) and the particle size of the first undersize is -30mm (i.e., the maximum particle size of the first undersize is 30mm), the particle size of the first oversize is +30 to -80mm.

[0031] In the above embodiments, by limiting the particle size of the crushed ore and the particle size of the first undersize, the metallurgical grade fluorite ore obtained by the sorting of the first oversize can meet the product particle size requirements.

[0032] In some embodiments, the maximum particle size of the mixture is 3 to 6 mm, and the maximum particle size of the second sieve undersize is 0.5 to 1 mm.

[0033] It should be noted that the particle size of the second oversize material can be derived from the defined particle size of the mixture (i.e., the maximum particle size of the mixture) and the particle size of the second undersize material (i.e., the maximum particle size of the second undersize material).

[0034] For example, when the particle size of the mixture is -3 mm (i.e., the maximum particle size of the mixture is 3 mm) and the particle size of the second undersize is -1 mm (i.e., the maximum particle size of the second undersize is 1 mm), the particle size of the second oversize is +1 to -3 mm.

[0035] In the above embodiments, by limiting the particle size of the mixture, not only can the working efficiency of the second grinding and the flotation be significantly improved, but the energy consumption of the second grinding can also be greatly reduced; at the same time, by limiting the particle size of the second undersize, the second oversize can meet the requirements of the gravity separation for ore particle size.

[0036] In some embodiments, the first grading is a dry grading. For example, the dry grading is a vibrating screen dry grading.

[0037] In the above embodiments, since the first grading is the dry grading, the first oversize material obtained does not need to undergo the steps of concentration, filtration and dehydration before the sorting, thereby achieving the effect of simplifying the workflow.

[0038] In some embodiments, the second grading is a wet grading.

[0039] In the above embodiments, the minerals undergoing the second classification (i.e., the mixture) have a small particle size, and in this case, the wet classification can improve the screening efficiency.

[0040] In some embodiments, the first grinding process is a high-pressure roller mill.

[0041] In the above embodiments, by combining the first undersize material and the sorted tailings for high-pressure roller milling, effective liberation of fluorite minerals and gangue minerals can be achieved.

[0042] In some examples, the pressure of the high-pressure roller mill is 5 to 20 MPa.

[0043] In the above example, by limiting the pressure of the high-pressure roller mill, it is possible to ensure that the resulting mixture has an ideal particle size.

[0044] In some embodiments, the second grinding process is ball milling.

[0045] In some embodiments, the weight percentage of minerals with a particle size of -0.074 mm in the feed material is 55% to 85%.

[0046] In the above embodiments, by limiting the content of minerals with a particle size of -0.074mm, it is possible to prevent them from being unable to effectively dissociate due to excessively low content, thereby affecting the grade of the flotation fluorite concentrate. On the other hand, it is possible to prevent the ore from being over-grinded due to excessively high content, thereby affecting the recovery rate of the flotation fluorite concentrate and increasing energy consumption.

[0047] In some embodiments, the reagents used in the flotation include collectors, and also include at least one of activators, modifiers and inhibitors.

[0048] In some examples, the collector includes at least one of sodium alkyl sulfate, alkyl sulfonate, oleic acid, and sodium oleate.

[0049] It should be noted that the amount of collector used can be selectively set according to actual needs (e.g., the number of roughing stages required in the flotation process), and this disclosure does not impose any limitations on this. For example, the amount of collector used is 1000-1500 g / t of raw ore.

[0050] In some examples, the activator includes at least one of aluminum sulfate and ferrous sulfate.

[0051] It should be noted that the amount of activator can be selectively set according to actual needs (e.g., the need for a certain floatation effect on the activated mineral), and this disclosure does not impose any limitations on this. For example, the amount of activator is 100-500 g / t of raw ore.

[0052] In some examples, the modifier includes at least one of sodium carbonate, sodium hydroxide, and sulfuric acid.

[0053] It should be noted that the dosage of the modifier can be selectively set according to actual needs (e.g., the pH requirement for the flotation), and this disclosure does not impose any limitations on it. For example, the dosage of the modifier is 200–1500 g / t of raw ore.

[0054] In some examples, the inhibitor includes at least one of water glass, acidified water glass, starch, tannin, tannin, humic acid, and sodium naphthalenesulfonate.

[0055] It should be noted that the dosage of the inhibitor can be selectively set according to actual needs (e.g., the required recovery rate and grade of CaF2 in the flotation fluorite concentrate), and this disclosure does not impose any limitations on this. For example, the dosage of the inhibitor is 500–3000 g / t of raw ore.

[0056] In some embodiments, the flotation includes at least two coarse flotations, at least two sweep flotations, and at least seven fine flotations.

[0057] Furthermore, it should be noted that after the flotation, the flotation fluorite concentrate and the flotation tailings can be obtained separately through a second filtration. In this case, the beneficiation water generated by the second filtration can be returned to the steps corresponding to the second grinding and the flotation for recycling, thereby achieving the effect of saving resources.

[0058] In some embodiments, the CaF2 grade in the metallurgical-grade fluorite block ore is 60% to 80%.

[0059] Based on this, it is easy to understand that the metallurgical-grade fluorite ore obtained by the beneficiation method provided in this disclosure meets the requirements for the grade of CaF2.

[0060] In some embodiments, the grade of CaF2 in the gravity separation tailings is no greater than 5%.

[0061] Based on this, it is easy to understand that since the grade of CaF2 in the gravity separation tailings is low, the grade of CaF2 in the gravity separation concentrate is high, which is beneficial to increasing the CaF2 content in the feed material.

[0062] In some embodiments, the CaF2 grade in the flotation fluorite concentrate is not less than 97%.

[0063] Based on this, it is easy to understand that the flotation fluorite concentrate obtained by the beneficiation method provided in this disclosure meets the requirements for the CaF2 grade of high-quality acid-grade fluorite concentrate.

[0064] The beneficial effects of this disclosure are:

[0065] This disclosure discloses a beneficiation method for fluorite ore. Firstly, by separating the material oversize from the first screen, metallurgical-grade fluorite lumps can be preferentially selected, effectively alleviating the shortage of rich fluorite resources in China. Secondly, by combining the first undersize and the sorting tailings for sequential grinding and classification, and then subjecting the resulting second undersize to gravity separation to remove the gravity separation tailings, and finally combining the gravity separation concentrate with the second undersize for the second grinding, the CaF2 content in the flotation material can be effectively increased compared to the CaF2 content in the original ore, thereby significantly reducing the operational pressure of flotation. Based on this, by performing flotation on the flotation material, the method ultimately achieves the goal of maximizing the yield of high-quality acid-grade fluorite concentrate, as well as the recovery rate and grade of CaF2, while obtaining high-quality acid-grade fluorite concentrate. Attached Figure Description

[0066] Figure 1 This is a flowchart illustrating a fluorite ore beneficiation method according to some embodiments of the present disclosure;

[0067] Figure 2 This is a flowchart of another fluorite ore beneficiation method provided according to some embodiments of the present disclosure. Detailed Implementation

[0068] The technical solutions in some embodiments of this disclosure will be clearly and completely described below. Obviously, the described embodiments are only some embodiments of this disclosure, and not all embodiments. Based on the embodiments provided in this disclosure, all other embodiments obtained by those skilled in the art are within the scope of protection of this disclosure.

[0069] Hereinafter, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature.

[0070] In describing some embodiments, the expressions "at least one of A, B and C" and "at least one of A, B or C" may be used, both of which have the same meaning and include the following combinations of A, B and C: only A, only B, only C, a combination of A and B, a combination of A and C, a combination of B and C, and a combination of A, B and C.

[0071] In describing some embodiments, the expression "A and / or B" may be used. It is readily understood that "A and / or B" includes the following three combinations: A only, B only, and a combination of A and B.

[0072] Example 1

[0073] A beneficiation method for fluorite ore, such as Figure 1 As shown, it includes S1 to S8.

[0074] S1. The raw ore (CaF2 grade of 28.82%) is crushed using a jaw crusher to obtain crushed ore with a particle size of -60mm.

[0075] S2. The crushed ore is dry-classified by vibrating screen to obtain the first oversize material with a particle size of +30 to -60 mm and the first undersize material with a particle size of -30 mm.

[0076] S3. A color sorter is used to color sort the material on the first screen to obtain metallurgical-grade fluorite ore (CaF2 grade of 60.15%) and sorted tailings. The operating conditions of the color sorter include: sensitivity of 25 values, cleaning time of 5 seconds, and cleaning cycle of 5 minutes.

[0077] S4. Combine the first screened material and the sorted tailings, and use a high-pressure roller mill to grind them at a working pressure of 10MPa to obtain a mixture with a particle size of -3mm.

[0078] S5. Perform wet classification on the mixture to obtain the second sieve oversize with a particle size of +0.5 to -3 mm and the second sieve undersize with a particle size of -0.5 mm.

[0079] S6. The material over the second screen is subjected to gravity separation using a heavy media hydrocyclone, followed by a first filtration separation to obtain gravity concentrate and gravity tailings (CaF2 grade 4.65%). The operating conditions of the heavy media hydrocyclone include: feed pressure of 0.2 MPa and media density of 2.1 g / cm³. 3 .

[0080] In S6, the mineral processing water produced by the first filtration separation is returned to the steps corresponding to wet classification and gravity separation for recycling.

[0081] S7. Combine the second screening undersize and gravity concentrate, and ball mill them to obtain the feed material (CaF2 grade is 35.86%); wherein, in the feed material, the weight percentage of minerals with a particle size of -0.074mm is 80%.

[0082] S8. The feed material is floated using a collector (oleic acid) with a mass concentration of 2% and an inhibitor (water glass) with a mass concentration of 5%, followed by a second filtration separation to obtain flotation fluorite concentrate (CaF2 grade of 97.12%) and flotation tailings (CaF2 grade of 5.69%).

[0083] In S8, the mineral processing water produced by the second filtration separation is returned to the corresponding steps of ball milling and flotation for recycling.

[0084] In S8, flotation includes two roughing stages, two scavenging stages, and eight cleaning stages. Specifically, in the first roughing stage, the dosage of depressant is 1000 g / t of raw ore, and the dosage of collector is 800 g / t of raw ore; in the second roughing stage, no depressant is used, and the dosage of collector is 200 g / t of raw ore; in the two scavenging stages, neither depressant nor collector is used; in the eight cleaning stages, no collector is used, and the dosages of depressant are 500 g / t of raw ore, 200 g / t of raw ore, 100 g / t of raw ore, 50 g / t of raw ore, 50 g / t of raw ore, 50 g / t of raw ore, 50 g / t of raw ore, and 50 g / t of raw ore, respectively.

[0085] Example 2

[0086] A beneficiation method for fluorite ore, such as Figure 2 As shown, it includes S1 to S8.

[0087] S1. The raw ore (CaF2 grade of 32.28%) is crushed using a jaw crusher to obtain crushed ore with a particle size of -65mm.

[0088] S2. The crushed ore is dry-classified by vibrating screen to obtain the first oversize material with a particle size of +25 to -65 mm and the first undersize material with a particle size of -25 mm.

[0089] S3. An X-ray photoelectric separator is used to perform photoelectric separation on the material on the first screen to obtain metallurgical-grade fluorite lump ore (CaF2 grade of 66.42%) and sorting tailings. The operating conditions of the X-ray photoelectric separator include: air pressure of 0.02 MPa and conveyor belt speed of 2 m / s.

[0090] S4. Combine the first screened material and the sorted tailings, and use a high-pressure roller mill to grind them at a working pressure of 8MPa to obtain a mixture with a particle size of -6mm.

[0091] S5. Perform wet classification on the mixture to obtain the second sieve oversize with a particle size of +0.5 to -6 mm and the second sieve undersize with a particle size of -0.5 mm.

[0092] S6. The material over the second screen is subjected to gravity separation using a heavy media hydrocyclone, followed by a first filtration separation to obtain gravity concentrate and gravity tailings (CaF2 grade 4.52%). The operating conditions of the heavy media hydrocyclone include: feed pressure of 0.15 MPa and media density of 2.2 g / cm³. 3 .

[0093] In S6, the mineral processing water produced by the first filtration separation is returned to the steps corresponding to wet classification and gravity separation for recycling.

[0094] S7. Combine the second screening undersize and gravity concentrate, and ball mill them to obtain the feed material (CaF2 grade is 38.87%); wherein, in the feed material, the weight percentage of minerals with a particle size of -0.074mm is 72%.

[0095] S8. The feed material is floated using a 5% (w / w) modifier (sodium carbonate), a 2% (w / w) collector (sodium oleate), and a 5% (w / w) depressant (water glass), followed by a second filtration separation to obtain flotation fluorite concentrate (CaF2 grade of 97.51%) and flotation tailings (CaF2 grade of 6.16%).

[0096] In S8, the mineral processing water produced by the second filtration separation is returned to the corresponding steps of ball milling and flotation for recycling.

[0097] In S8, flotation includes two roughing stages, three scavenging stages, and eight cleaning stages. Specifically, in the first roughing stage, the dosage of modifier is 500 g / t of raw ore, the dosage of depressant is 500 g / t of raw ore, and the dosage of collector is 800 g / t of raw ore. In the second roughing stage, no modifier or depressant is used, and the dosage of collector is 400 g / t of raw ore. In the three scavenging stages, no modifier, depressant, or collector is used. In the eight cleaning stages, no modifier or collector is used, and the dosages of depressant are 200 g / t of raw ore, 100 g / t of raw ore, 100 g / t of raw ore, 50 g / t of raw ore, 50 g / t of raw ore, 50 g / t of raw ore, 50 g / t of raw ore, and 50 g / t of raw ore, respectively.

[0098] Example 3

[0099] A beneficiation method for fluorite ore, such as Figure 2 As shown, it includes S1 to S8.

[0100] S1. The raw ore (CaF2 grade of 35.05%) is crushed using a jaw crusher to obtain crushed ore with a particle size of -70mm.

[0101] S2. The crushed ore is dry-classified by vibrating screen to obtain the first oversize material with a particle size of +15 to -70 mm and the first undersize material with a particle size of -15 mm.

[0102] S3. An X-ray photoelectric separator is used to perform photoelectric separation on the material on the first screen to obtain metallurgical-grade fluorite lump ore (CaF2 grade of 70.53%) and sorting tailings. The operating conditions of the X-ray photoelectric separator include: air pressure of 0.015 MPa and conveyor belt speed of 3 m / s.

[0103] S4. Combine the first screened material and the sorted tailings, and use a high-pressure roller mill to grind them at a working pressure of 6MPa to obtain a mixture with a particle size of -6mm.

[0104] S5. Perform wet classification on the mixture to obtain the second sieve oversize with a particle size of +0.5 to -6 mm and the second sieve undersize with a particle size of -0.5 mm.

[0105] S6. The material over the second screen is subjected to gravity separation using a heavy media hydrocyclone, followed by a first filtration separation to obtain gravity concentrate and gravity tailings (CaF2 grade 4.85%). The operating conditions of the heavy media hydrocyclone include: feed pressure of 0.12 MPa and media density of 2.1 g / cm³. 3 .

[0106] In S6, the mineral processing water produced by the first filtration separation is returned to the steps corresponding to wet classification and gravity separation for recycling.

[0107] S7. Combine the second screening undersize and gravity concentrate, and ball mill them to obtain the feed material (CaF2 grade is 42.33%); wherein, in the feed material, the weight percentage of minerals with a particle size of -0.074mm is 68%.

[0108] S8. The feed material is floated using a 5% (w / w) modifier (sodium carbonate), a 2% (w / w) collector (sodium oleate), and a 5% (w / w) inhibitor (water glass and tannin), followed by a second filtration separation to obtain flotation fluorite concentrate (CaF2 grade of 97.61%) and flotation tailings (CaF2 grade of 6.95%).

[0109] In S8, the mineral processing water produced by the second filtration separation is returned to the corresponding steps of ball milling and flotation for recycling.

[0110] In S8, flotation includes two roughing stages, three scavenging stages, and seven cleaning stages. Specifically, in the first roughing stage, the dosage of modifier is 600 g / t of raw ore, the dosage of water glass as a depressant is 1000 g / t of raw ore, the dosage of tannin as a depressant is 500 g / t of raw ore, and the dosage of collector is 1000 g / t of raw ore. In the second roughing stage, no modifier or depressant is used, and the dosage of collector is 500 g / t of raw ore. In the three scavenging stages, no modifier, depressant, or collector is used. In the seven cleaning stages, no... Modifiers and collectors were used. In the first to fourth cleaning processes, the dosage of water glass in the inhibitors was 400 g / t·raw ore, 200 g / t·raw ore, 100 g / t·raw ore, and 100 g / t·raw ore, respectively, and the dosage of tannin in the inhibitors was 200 g / t·raw ore, 100 g / t·raw ore, 50 g / t·raw ore, and 50 g / t·raw ore, respectively. In the fifth to seventh cleaning processes, no inhibitors were used, and all were blank cleaning processes.

[0111] Example 4

[0112] A beneficiation method for fluorite ore, such as Figure 1 As shown, it includes S1 to S8.

[0113] S1. The raw ore (CaF2 grade of 42.02%) is crushed using a jaw crusher to obtain crushed ore with a particle size of -80mm.

[0114] S2. The crushed ore is dry-classified by vibrating screen to obtain the first oversize material with a particle size of +15 to -80 mm and the first undersize material with a particle size of -15 mm.

[0115] S3. A color sorter is used to color sort the material on the first screen to obtain metallurgical-grade fluorite ore (CaF2 grade of 78.95%) and sorted tailings. The operating conditions of the color sorter include: sensitivity of 35 values, cleaning time of 10 seconds, and cleaning cycle of 5 minutes.

[0116] S4. Combine the first screened material and the sorted tailings, and use a high-pressure roller mill to grind them at a working pressure of 10MPa to obtain a mixture with a particle size of -3mm.

[0117] S5. Perform wet classification on the mixture to obtain the second sieve oversize with a particle size of +0.5 to -3 mm and the second sieve undersize with a particle size of -0.5 mm.

[0118] S6. The material over the second screen is subjected to gravity separation using a heavy media hydrocyclone, followed by a first filtration separation to obtain gravity concentrate and gravity tailings (CaF2 grade 4.36%). The operating conditions of the heavy media hydrocyclone include: feed pressure of 0.1 MPa and media density of 2.0 g / cm³. 3 .

[0119] In S6, the mineral processing water produced by the first filtration separation is returned to the steps corresponding to wet classification and gravity separation for recycling.

[0120] S7. Combine the second screening undersize and gravity concentrate, and ball mill them to obtain the feed material (CaF2 grade is 49.73%); wherein, in the feed material, the weight percentage of minerals with a particle size of -0.074mm is 65%.

[0121] S8. The feed material is floated using a collector (sodium oleate and sodium dodecyl sulfate) with a mass concentration of 2%, a modifier (sodium hydroxide) with a mass concentration of 5%, an activator (aluminum sulfate) with a mass concentration of 5%, and an inhibitor (water glass and starch) with a mass concentration of 5%. Then, a second filtration separation is performed to obtain flotation fluorite concentrate (CaF2 grade of 97.73%) and flotation tailings (CaF2 grade of 8.78%).

[0122] In S8, the mineral processing water produced by the second filtration separation is returned to the corresponding steps of ball milling and flotation for recycling.

[0123] In S8, flotation includes two roughing stages, two scavenging stages, and seven cleaning stages. In the first roughing stage, the dosage of modifier is 200 g / t of raw ore, activator is 300 g / t of raw ore, water glass is 800 g / t of raw ore, starch is 600 g / t of raw ore, sodium oleate is 600 g / t of raw ore, and sodium dodecyl sulfate is 60 g / t of raw ore. In the second roughing stage, no activator, modifier, or depressant is used; sodium oleate is 200 g / t of raw ore, and sodium dodecyl sulfate is 20 g / t of raw ore. In the two scavenging stages, no activator, modifier, or depressant is used; oleic acid is... The dosage of sodium was 100 g / t·raw ore and 50 g / t·raw ore, respectively, and the dosage of sodium dodecyl sulfate in the collector was 10 g / t·raw ore and 5 g / t·raw ore, respectively. In the seven cleaning processes, no activator, modifier, or collector was used. In the first to fourth cleaning processes, the dosage of water glass in the inhibitor was 400 g / t·raw ore, 200 g / t·raw ore, 100 g / t·raw ore, and 100 g / t·raw ore, respectively, and the dosage of starch in the inhibitor was 200 g / t·raw ore, 100 g / t·raw ore, 50 g / t·raw ore, and 50 g / t·raw ore, respectively. In the fifth to seventh cleaning processes, no inhibitor was used, and all were blank cleaning processes.

[0124] Compare with Example 1

[0125] A comparison is made between Embodiment 1 of this disclosure and Comparative Example 1, wherein the difference between Comparative Example 1 and Embodiment 1 is as follows:

[0126] ① Delete S4~S6 and replace S7 with: Combine the first screen undersize and the sorting tailings, and ball mill them to obtain the flotation material (CaF2 grade is 26.07%); among which, the weight percentage of minerals with a particle size of -0.074mm in the flotation material is 80%.

[0127] Other conditions, such as the selection and dosage of reagents, as well as the process steps and parameters, are the same as those in Example 1 of this disclosure (compared to Example 1, this comparative example did not undergo high-pressure roller milling, wet classification, and gravity separation, which is used to demonstrate that the mineral processing method of this disclosure is more effective).

[0128] Compare with Example 2

[0129] A comparison is made between Embodiment 2 of this disclosure and Comparative Example 2, wherein the difference between Comparative Example 2 and Embodiment 2 is as follows:

[0130] ① Delete S4~S6 and replace S7 with: Combine the first screen undersize and the sorting tailings, and ball mill them to obtain the flotation material (CaF2 grade is 26.02%); among which, the weight percentage of minerals with a particle size of -0.074mm in the flotation material is 72%.

[0131] Other conditions, such as the selection and dosage of reagents, as well as the process steps and parameters, are the same as those in Example 2 of this disclosure (compared to Example 2, this comparative example did not undergo high-pressure roller milling, wet classification, and gravity separation, which is used to demonstrate that the mineral processing method of this disclosure is more effective).

[0132] Compare with Example 3

[0133] A comparison is made between Example 1 of this disclosure and Comparative Example 3, wherein the difference between Comparative Example 3 and Example 1 is as follows:

[0134] ① Delete S5~S6 and replace S7 with: The mixture is ball-milled to obtain the feed material (CaF2 grade is 28.57%); among which, the weight percentage of minerals with a particle size of -0.074mm in the feed material is 80%.

[0135] Other conditions, such as the selection and dosage of reagents, as well as the process steps and parameters, are the same as those in Example 1 of this disclosure (this comparative example, compared to Example 1, did not perform wet classification and gravity separation, and is used to demonstrate that the mineral processing method of this disclosure is more effective).

[0136] Compare with Example 4

[0137] A comparison is made between Example 2 of this disclosure and Comparative Example 4, wherein the difference between Comparative Example 4 and Example 2 is as follows:

[0138] ① Delete S5~S6 and replace S7 with: The mixture is ball-milled to obtain the feed material (CaF2 grade is 28.57%); among which, the weight percentage of minerals with a particle size of -0.074mm in the feed material is 72%.

[0139] Other conditions, such as the selection and dosage of reagents, as well as the process steps and parameters, are the same as those in Example 2 of this disclosure (this comparative example, compared to Example 2, does not perform wet classification and gravity separation, and is used to demonstrate that the mineral processing method of this disclosure is more effective).

[0140] Test results

[0141] To verify the effectiveness of the mineral processing method disclosed herein, the yields of each mineral obtained in Examples 1-4 and Comparative Examples 1-4, as well as the grade and recovery rate of CaF2, were tested.

[0142] The results are shown in the table below:

[0143]

[0144]

[0145] According to Examples 1-4, Comparative Examples 1-4, and the table above:

[0146] 1) Compared to Example 1:

[0147] In Comparative Example 1, the yield of metallurgical-grade fluorite lumps and the recovery rate of CaF2 therein both decreased, while the grade of CaF2 in the metallurgical-grade fluorite lumps increased. The grade of CaF2 in the feed material decreased significantly, resulting in a decrease in both the yield and recovery rate of the flotation fluorite concentrate, while the grade of CaF2 in the flotation fluorite concentrate showed no significant difference. In Comparative Example 3, the yield of metallurgical-grade fluorite lumps and the recovery rate of CaF2 therein both decreased, while the grade of CaF2 in the metallurgical-grade fluorite lumps increased. The grade of CaF2 in the feed material decreased significantly. The grade of CaF2 in the flotation fluorite concentrate decreased significantly, resulting in a lower yield and reduced recovery rate of CaF2. However, the grade of CaF2 in the flotation fluorite concentrate remained relatively unchanged. In contrast to Comparative Example 1, Comparative Example 3 showed an increased yield and recovery rate of CaF2 in metallurgical-grade fluorite lump ore, with no significant difference in CaF2 grade. The grade of CaF2 in the feed material increased, leading to higher yields and recovery rates of both flotation fluorite concentrates. Therefore, the high-pressure roller milling and gravity separation methods used in the mineral processing method provided in this disclosure can both improve the grade of CaF2 in the feed material. Furthermore, both methods can maximize the yield, recovery rate, and grade of high-quality acid-grade fluorite concentrate while ensuring the production of high-quality acid-grade fluorite powder.

[0148] 2) Compared to Example 2:

[0149] In Comparative Example 2, the yield of metallurgical-grade fluorite lumps, as well as the grade and recovery of CaF2 within them, were all reduced. The grade of CaF2 in the feed material was significantly lower, resulting in a decrease in the yield of flotation fluorite concentrate, as well as a decrease in the grade and recovery of CaF2. In Comparative Example 4, the yield of metallurgical-grade fluorite lumps showed no significant difference, but the grade and recovery of CaF2 in the metallurgical-grade fluorite lumps were both reduced. The grade of CaF2 in the feed material was significantly lower, resulting in a decrease in the yield of flotation fluorite concentrate, as well as a decrease in the grade and recovery of CaF2. The yields of the two methods showed no significant difference, but the grade and recovery of CaF2 in the flotation fluorite concentrate decreased. Compared to Comparative Example 2, in Comparative Example 4, the yield of metallurgical-grade fluorite lump ore and the recovery of CaF2 therein were both increased, while the grade of CaF2 in the metallurgical-grade fluorite lump ore decreased. The grade of CaF2 in the feed material increased, and the yield and recovery of the flotation fluorite concentrate were both increased, with no significant difference in the grade of CaF2 in the flotation fluorite concentrate. Therefore, it can be seen that the high-pressure roller mill and gravity separation used in the beneficiation method provided in this disclosure can both increase the grade of CaF2 in the feed material, and can maximize the yield, recovery, and grade of high-quality acid-grade fluorite concentrate while ensuring the production of high-quality acid-grade fluorite concentrate.

[0150] In summary, the fluorite ore beneficiation method disclosed herein not only achieves the simultaneous production of metallurgical-grade fluorite lumps (CaF2 grade of 60%–80%) and high-quality acid-grade fluorite concentrate (CaF2 grade of not less than 97%) from medium- and low-grade fluorite ore with a CaF2 grade of not more than 45% (or even less than 30%), but also maximizes the yield of high-quality acid-grade fluorite concentrate as well as the recovery rate and grade of CaF2. This aims to address the shortage of rich fluorite resources in China and maximize resource recovery.

[0151] The above description is merely a preferred embodiment of this disclosure. It should be understood that this disclosure is not limited to the forms disclosed herein and should not be construed as excluding other embodiments. It can be used in various other combinations, modifications, and environments, and can be altered within the scope of the concept described herein through the above teachings or techniques or knowledge in related fields. Any modifications and variations made by those skilled in the art that do not depart from the spirit and scope of this disclosure should be within the protection scope of the appended claims.

Claims

1. A beneficiation method for fluorite ore, characterized in that, include: The raw ore is crushed to obtain crushed ore; wherein the CaF2 grade in the raw ore is not greater than 45%; The crushed ore is first graded to obtain a first oversize and a first undersize; wherein the maximum particle size of the crushed ore is 60-80 mm, and the maximum particle size of the first undersize is 10-30 mm. The material over the first sieve is sorted to obtain metallurgical-grade fluorite lumps and sorted tailings; wherein the sorting includes at least one of color sorting and photoelectric sorting; the CaF2 grade in the metallurgical-grade fluorite lumps is 60%~80%; The first undersize material and the sorted tailings are combined and subjected to a first grinding process to obtain a mixture; wherein the maximum particle size of the mixture is 3~6mm; The mixture is subjected to a second classification to obtain a second sieve oversize and a second sieve undersize; wherein the maximum particle size of the second sieve undersize is 0.5~1mm; The material over the second sieve is subjected to gravity separation to obtain gravity concentrate and gravity tailings; The second undersize and the gravity concentrate are combined and subjected to a second grinding process to obtain the flotation feed material; and The feed material is subjected to flotation to obtain flotation fluorite concentrate and flotation tailings; wherein the grade of CaF2 in the flotation fluorite concentrate is not less than 97%.

2. The fluorite ore beneficiation method according to claim 1, characterized in that, The sorting includes only the color sorting.

3. The beneficiation method for fluorite ore according to claim 1 or 2, characterized in that, The color sorting is performed using a color sorter; The operating conditions of the color sorter include: sensitivity of 5 to 100 values, cleaning time of 1 to 60 seconds, and cleaning cycle of 5 to 30 minutes.

4. The fluorite ore beneficiation method according to claim 1, characterized in that, The photoelectric separator used is an X-ray photoelectric separator. The operating conditions of the X-ray photoelectric separator include: a jet pressure of 0.01~0.05MPa and a conveyor belt speed of 1~5m / s.

5. The fluorite ore beneficiation method according to claim 1, characterized in that, The reselection is performed using a heavy medium cyclone separator; The operating conditions of the heavy medium cyclone include: a feed pressure of 0.1~0.5MPa and a medium density of 1.5~2.5g / cm³. 3 .

6. The fluorite ore beneficiation method according to claim 1, characterized in that, The first grading is a dry grading.

7. The fluorite ore beneficiation method according to claim 1, characterized in that, The second classification is wet classification.

8. The fluorite ore beneficiation method according to claim 1, characterized in that, The first grinding method is a high-pressure roller mill; wherein the pressure of the high-pressure roller mill is 5~20MPa.

9. The fluorite ore beneficiation method according to claim 1, characterized in that, The second grinding method is ball milling.

10. The fluorite ore beneficiation method according to claim 1, characterized in that, The weight percentage of minerals with a particle size of -0.074 mm in the feed material is 55% to 85%.

11. The fluorite ore beneficiation method according to claim 1, characterized in that, The reagents used in the flotation include collectors, as well as at least one of activators, modifiers, and inhibitors.

12. The fluorite ore beneficiation method according to claim 1, characterized in that, The flotation process includes at least two roughing processes, at least two sweeping processes, and at least seven cleaning processes.

13. The fluorite ore beneficiation method according to claim 1, characterized in that, The grade of CaF2 in the gravity separation tailings is no greater than 5%.

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