Fluorite flotation composite inhibitor and preparation method and application thereof

Abstract

The invention provides a fluorite flotation composite inhibitor and a preparation method and application thereof.The composite inhibitor can be used for flotation of phosphorus-containing high-calcium low-grade fluorite mine and comprises, by mass, 1-5 parts of sodium hexametaphosphate, 8-40 parts of sodium humate, 2.8-14 parts of tannin extract, 5-40 parts of water glass and 0.2-1 part of sodium acrylate. The preparation method comprises the following steps: S1, dissolving sodium hexametaphosphate, water glass and sodium acrylate in water to obtain a mixed solution; and S2, adding the tannin extract and the sodium humate into the mixed solution, and uniformly mixing the tannin extract and the sodium humate. The fluorite flotation composite inhibitor is high in selective inhibition performance, small in influence on floatability of fluorite while inhibiting calcite and apatite, better in selective inhibition effect compared with a single traditional inhibitor such as water glass and the like, capable of achieving efficient separation of calcite, apatite and other calcium-containing gangue minerals and fluorite and capable of achieving efficient flotation of fluorite. And high-quality and high-recovery-rate fluorite concentrate is obtained, and the comprehensive benefits of the flotation process are greatly improved.

Description

Technical Field

[0001] The present invention relates to the technical field of ore dressing, and particularly relates to a composite inhibitor for fluorite flotation with selective inhibition effect, a preparation method thereof and an application thereof. Background Art

[0002] Fluorite ( ) is an important non-metallic mineral, which is widely used in the fields of metallurgy, chemical industry, building materials, etc. However, the basic reserves of fluorite resources in China are about 100 million tons, among which the associated fluorite resource reserves account for more than 70%, and most of them are complex low-grade fluorite ores with low fluorite grade ( grade ≤ 30%), complex co-occurrence, and many gangue mineral components. It is difficult to develop and utilize. High-calcium and low-grade fluorite ores often co-occur with calcium-containing minerals such as apatite ( ) and calcite ( ). These minerals have similar surface properties and floatability to fluorite, resulting in difficult flotation separation. Traditional inhibitors (such as water glass, acidified water glass, salinized water glass, starch, etc.) have poor selective inhibition effect on calcium-containing minerals, and it is difficult to effectively separate fluorite from calcium-containing minerals. Summary of the Invention

[0003] The present invention provides a composite inhibitor for fluorite flotation, a preparation method thereof and an application thereof, so as to solve the technical problems mentioned in the background art that the existing traditional inhibitors have poor selective inhibition effect and cannot effectively separate fluorite and calcium-containing minerals.

[0004] To solve the above technical problems, the technical solution proposed by the present invention is as follows: A composite inhibitor for fluorite flotation, comprising the following components in parts by mass: 1-5 parts of sodium hexametaphosphate, 8-40 parts of humate, 2.8-14 parts of tannin extract, 5-40 parts of water glass and 0.2-1 part of acrylate.

[0005] Regarding the composite inhibitor for fluorite flotation for high-calcium and low-grade fluorite ores containing phosphorus provided by the present invention, its action principle in the flotation process is as follows: Water glass is a commonly used dispersant and a silicon-calcium gangue inhibitor, but it has poor selectivity in the use process. Under alkaline conditions, it has strong inhibitory ability for silicate minerals but weak inhibitory ability for calcite and apatite. The cyclic structure composed of in sodium hexametaphosphate enables it to form stable water-soluble complexes with metal ions such as , in the solution, thus showing strong inhibitory ability for calcium-containing minerals such as calcite and apatite, and the inhibition selectivity is poor. And sodium humate and tannin extract have various groups such as carboxyl group and phenolic hydroxyl group, and can achieve high-selectivity inhibition of calcium-containing gangues such as calcite and apatite through chelation and selective adsorption on the mineral surface The acrylate molecule chain is rich in many -COO- Strong hydrophilic groups can combine with multivalent ions such as calcium and magnesium to form soluble chain anions, showing inhibitory and dispersive properties. The fluorite flotation composite inhibitor invented in this article contains phosphate groups, carboxyl groups, phenolic hydroxyl groups, SiO4 2- and other groups. These groups achieve good synergistic effects through scientific ratios of components. For example, the high-selectivity adsorption on the surface of the main component humate compensates for the defects of the broad-spectrum inhibition of sodium hexametaphosphate and acrylate, improving the selective inhibition performance of the composite inhibitor; while the strong chelating groups of sodium hexametaphosphate enhance the inhibitory ability of the composite inhibitor against gangue such as calcite and apatite. Sodium silicate not only has a synergistic inhibitory effect, but also is beneficial to the dissociation of phenolic hydroxyl groups in humate and tannin under alkaline conditions, enhancing the chelation and adsorption ability with the surface of gangue minerals such as calcite and apatite ; while a small amount of low-molecular-weight acrylate can strengthen the dispersion of mineral particles, assisting the chelation of groups such as phosphate groups and phenolic hydroxyl groups with the surface of gangue minerals to strengthen the inhibitory effect.

[0006] As a further preference of the above technical solution, the acrylate is sodium acrylate, and the relative molecular mass of the acrylate is 1000 - 5000. The applicant's research found that if the molecular weight of sodium acrylate is too low or too high, the inhibitory ability is poor. Controlling within the above range helps to obtain good separation effects.

[0007] As a further preference of the above technical solution, the humate is sodium humate, and the soluble matter content of the humate is ≥85%.

[0008] As a further preference of the above technical solution, the tannin includes at least one of myrica tannin and larch tannin, and is further preferably larch tannin. The applicant's research found that both myrica tannin and larch tannin are extracts of plant tannins, and larch tannin has high stability, strong acid and alkali resistance, wide sources and low prices.

[0009] As a further preference of the above technical solution, it also includes water, and the mass of water is 1 - 40 times the total mass of sodium hexametaphosphate, humate, tannin, sodium silicate and acrylate.

[0010] As a further preference of the above technical solution, it includes the following components in parts by mass: 2.5 parts of sodium hexametaphosphate, 20 parts of humate, 7 parts of tannin, 20 parts of sodium silicate and 0.5 part of acrylate.

[0011] Based on the same technical concept, the present invention also provides a preparation method of the above fluorite flotation composite inhibitor, including the following steps: S1. Dissolve the sodium hexametaphosphate, water glass and acrylate in water according to the mass ratio to obtain a mixed solution; S2. Add the tannin extract and humate to the mixed solution according to the mass ratio, and obtain the composite depressant for fluorite flotation after mixing evenly.

[0012] Based on the same inventive concept, the present invention also provides an application of the above composite depressant for fluorite flotation, and the composite depressant for fluorite flotation can be used for the flotation of fluorite ore with high phosphorus and low calcium grade.

[0013] As a further preference of the above technical solution, when the composite depressant for fluorite flotation is used for the flotation of fluorite ore with high phosphorus and low calcium grade, the following operations are carried out for flotation: (1) Crush and grind the fluorite raw ore to obtain pulp; (2) Add a regulator, the composite depressant for fluorite flotation and a collector to the pulp respectively to obtain rough concentrate and rougher tailings; (3) Carry out cleaning on the rough concentrate to obtain fluorite concentrate.

[0014] As a further preference of the above technical solution, the regulator is soda ash and the collector is saponified oleic acid. In the roughing process of step (2), based on 1000 kg of raw ore, the dosage of soda ash is 1000 - 2000 g, and the dosage of saponified oleic acid is 200 - 800 g.

[0015] As a further preference of the above technical solution, the saponified oleic acid is an aqueous solution of sodium oleate with a mass fraction of 5% - 10%, and its preparation method is as follows: Stir oleic acid, sodium carbonate and water at 90°C - 100°C for 45 min - 60 min, wherein the mass ratio of oleic acid to sodium carbonate is 4:1, and cool to room temperature after full reaction to obtain saponified oleic acid.

[0016] As a further preference of the above technical solution, in step (3), the rough concentrate is subjected to 7 cleaning treatments to obtain fluorite concentrate; except for the first cleaning, the middlings generated in each cleaning process are sequentially returned to the previous cleaning operation process; carry out one rough scavenging on the middlings obtained from the first cleaning to obtain rough scavenging foam and cleaning tailings, and the rough scavenging foam is returned to the roughing operation process; the dosage of the composite depressant for fluorite flotation in the first cleaning treatment is 100 - 300 g / t, the dosages of the composite depressant for fluorite flotation in the remaining 6 cleaning treatments are sequentially reduced, and the dosage of the composite depressant for fluorite flotation in the last cleaning treatment is greater than or equal to 5 g / t.

[0017] When carrying out rough scavenging on the middlings obtained from the first cleaning, add 50 - 200 g / t of the composite depressant for fluorite flotation and 20 - 100 g / t of saponified oleic acid.

[0018] As a further preference of the above technical solution, the rough-selected tailings are subjected to one scavenging operation to obtain rough scavenged tailings, and saponified oleic acid is added during the scavenging process, with a dosage of 50-150 g / t.

[0019] The present invention has the following beneficial effects: The selective inhibition performance of the fluorite flotation composite inhibitor of the present invention is strong. Through the synergistic complementary effect between different components, while inhibiting calcite and apatite, the floatability of fluorite is less affected. Compared with a single traditional inhibitor such as water glass or an existing simple compound inhibitor, it has a better selective inhibition effect, can achieve the efficient separation of calcium-containing gangue minerals such as calcite and apatite and fluorite, obtain high-quality and high-recovery fluorite concentrate, and greatly improve the comprehensive benefit of the flotation process. Moreover, the fluorite flotation composite inhibitor of the invention is non-toxic and harmless, can be biodegradable in nature, belongs to an environmentally friendly beneficiation green reagent, has a low price, wide sources, and simple preparation, which is conducive to industrial application. Specific embodiments

[0020] The following is a detailed description of the embodiments of the present invention, but the present invention can be implemented in many different ways defined and covered by the claims.

[0021] The fluorite flotation composite inhibitor used in each embodiment is composed of the following components in parts by mass: 2.5 parts of sodium hexametaphosphate, 20 parts of sodium humate, 7 parts of tannin extract, 20 parts of water glass, 0.5 part of sodium acrylate, and 200 parts of water, wherein the soluble substance content of sodium humate ≥ 85%, the relative molecular mass of sodium acrylate is 2000, and the tannin extract selects larch tannin extract.

[0022] The fluorite flotation composite inhibitor used in each embodiment is prepared by the following steps: S1. Dissolve sodium hexametaphosphate, water glass and sodium acrylate in water according to the mass ratio to obtain a mixed solution; S2. Add tannin extract and sodium humate to the mixed solution according to the mass ratio, and obtain the fluorite flotation composite inhibitor after mixing evenly.

[0023] Example 1: In this embodiment, a certain low-grade fluorite ore with high phosphorus and high calcium in Inner Mongolia is used as the raw material. The mass percentage of CaF2 in the raw ore is 26.26%, the mass percentage of CaCO3 is 14.05%, and the mass percentage of P is 0.85%.

[0024] The application process of this embodiment specifically includes the following steps: (1) Crush the fluorite raw ore, and then grind it to a fineness of -0.074 mm accounting for 75.67%, and add water to a pulp with a concentration of 40%.

[0025] (2) Add a regulator, the fluorite flotation composite inhibitor of the present invention, and a collector to the pulp for one rough selection to obtain a rough concentrate and a rough tailing. Among them, the regulator is soda ash, and the collector is saponified oleic acid.

[0026] (3) Conduct seven cleaning operations (cleaning 1 to cleaning 7) on the rough concentrate to obtain a fluorite concentrate; conduct one scavenging operation on the rough tailing to obtain a rough scavenging tailing; conduct one fine scavenging operation on the middlings of cleaning 1 to obtain a cleaning tailing.

[0027] In step (2), during the rough selection process, based on 1 t of raw ore, the dosage of soda ash is 1500 g, the dosage of the fluorite flotation composite inhibitor is 400 g, and the dosage of saponified oleic acid is 500 g.

[0028] In step (3), during the cleaning 1 process, based on 1 t of raw ore, the dosage of the fluorite flotation composite inhibitor is 150 g. During the cleaning 2 process, based on 1 t of raw ore, the dosage of the fluorite flotation composite inhibitor is 100 g. During the cleaning 3 process, based on 1 t of raw ore, the dosage of the fluorite flotation composite inhibitor is 75 g. During the cleaning 4 process, based on 1 t of raw ore, the dosage of the fluorite flotation composite inhibitor is 50 g. During the cleaning 5 process, based on 1 t of raw ore, the dosage of the fluorite flotation composite inhibitor is 50 g. During the cleaning 6 process, based on 1 t of raw ore, the dosage of the fluorite flotation composite inhibitor is 25 g. During the cleaning 7 process, based on 1 t of raw ore, the dosage of the fluorite flotation composite inhibitor is 10 g. In step (3), during the scavenging process of the middlings obtained from cleaning 1, based on 1 t of raw ore, the dosage of the fluorite flotation composite inhibitor is 100 g, and the dosage of saponified oleic acid is 100 g. In step (3), during the scavenging process of the rough tailing, based on 1 t of raw ore, the dosage of saponified oleic acid is 100 g / t.

[0029] Comparative Example 1 The technological process of this comparative example is the same as that of the example. The difference between this comparative example and Example 1 for comparison is that: the inhibitor uses a single inhibitor sodium silicate, and the flotation results are shown in Table 1. The specific operation steps are as follows: During the rough selection of fluorite, the single inhibitor sodium silicate is selected as the inhibitor. Based on 1 t of raw ore, the dosage of sodium silicate is 400 g. During the cleaning of fluorite, based on 1 t of raw ore, the dosage of sodium silicate in cleaning 1 is 150 g. The dosage of sodium silicate in cleaning 2 is 100 g. The dosage of sodium silicate in cleaning 3 is 75 g. The dosage of sodium silicate in cleaning 4 is 50 g. The dosage of sodium silicate in cleaning 5 is 50 g. The dosage of sodium silicate in cleaning 6 is 25 g. The dosage of sodium silicate in cleaning 7 is 10 g. During the scavenging process of the middlings obtained from cleaning 1, based on 1 t of raw ore, the dosage of sodium silicate is 100 g. The types and dosages of other added reagents are the same as those in Example 1. Comparative Example 2 The process flow of this comparative example is the same as that of the example. The difference between this comparative example and Example 1 for comparison is that: a single inhibitor, sodium hexametaphosphate, is used as the inhibitor. The flotation results are shown in Table 1. The specific operation steps are as follows: During the rough flotation of fluorite, a single inhibitor, sodium hexametaphosphate, is selected as the inhibitor. Based on 1 ton of raw ore, the amount of sodium hexametaphosphate is 400 g. During the cleaning of fluorite, based on 1 ton of raw ore, the dosage of sodium hexametaphosphate for the first cleaning is 150 g, for the second cleaning is 100 g, for the third cleaning is 75 g, for the fourth cleaning is 50 g, for the fifth cleaning is 50 g, for the sixth cleaning is 25 g, and for the seventh cleaning is 10 g. During the scavenging process of the middlings obtained from the first cleaning, based on 1 ton of raw ore, the dosage of sodium hexametaphosphate is 100 g. The types and dosages of the remaining reagents added are the same as those in Example 1. Comparative Example 3 The process flow of this comparative example is the same as that of the example. The difference between this comparative example and Example 1 for comparison is that: a single inhibitor, sodium humate, is used as the inhibitor. The flotation results are shown in Table 1. The specific operation steps are as follows: During the rough flotation of fluorite, a single inhibitor, sodium humate, is selected as the inhibitor. Based on 1 ton of raw ore, the amount of sodium humate is 400 g. During the cleaning of fluorite, based on 1 ton of raw ore, the dosage of sodium humate for the first cleaning is 150 g, for the second cleaning is 100 g, for the third cleaning is 75 g, for the fourth cleaning is 50 g, for the fifth cleaning is 50 g, for the sixth cleaning is 25 g, and for the seventh cleaning is 10 g. During the scavenging process of the middlings obtained from the first cleaning, based on 1 ton of raw ore, the dosage of sodium humate is 100 g. The types and dosages of the remaining reagents added are the same as those in Example 1. Comparative Example 4 The process flow of this comparative example is the same as that of the example. The difference between this comparative example and Example 1 for comparison is that: a single inhibitor, sodium acrylate, is used as the inhibitor. The flotation results are shown in Table 1. The specific operation steps are as follows: During the rough flotation of fluorite, a single inhibitor, sodium acrylate, is selected as the inhibitor. Based on 1 ton of raw ore, the amount of sodium acrylate is 400 g. During the cleaning of fluorite, based on 1 ton of raw ore, the dosage of sodium acrylate for the first cleaning is 150 g, for the second cleaning is 100 g, for the third cleaning is 75 g, for the fourth cleaning is 50 g, for the fifth cleaning is 50 g, for the sixth cleaning is 25 g, and for the seventh cleaning is 10 g. During the scavenging process of the middlings obtained from the first cleaning, based on 1 ton of raw ore, the dosage of sodium acrylate is 100 g. The types and dosages of the remaining reagents added are the same as those in Example 1. Comparative Example 5 The process flow of this comparative example is the same as that of the example. The difference between this comparative example and Example 1 for comparison lies in that: the inhibitor uses a single inhibitor tannin extract. The flotation results are shown in Table 1. The specific operation steps are as follows: During the rough flotation of fluorite, the inhibitor selects a single inhibitor tannin extract. Based on 1 t of raw ore, the amount of tannin extract is 400 g. During the cleaning of fluorite, based on 1 t of raw ore, the dosage of tannin extract in the first cleaning is 150 g, in the second cleaning is 100 g, in the third cleaning is 75 g, in the fourth cleaning is 50 g, in the fifth cleaning is 50 g, in the sixth cleaning is 25 g, and in the seventh cleaning is 10 g. For the middlings obtained from the first cleaning during the scavenging process, based on 1 t of raw ore, the dosage of tannin extract is 100 g. The types and dosages of the remaining reagents added are the same as those in Example 1. Comparative Example 6 The process flow of this comparative example is the same as that of the example. The difference between this comparative example and Example 1 for comparison lies in that: the inhibitor uses Inhibitor 1# (mass ratio of sodium silicate / tannin extract / sodium humate is 20:7:20). The flotation results are shown in Table 1. The specific operation steps are as follows: During the rough flotation of fluorite, the inhibitor selects Inhibitor 1#. Based on 1 t of raw ore, the amount of Inhibitor 1# is 400 g. During the cleaning of fluorite, based on 1 t of raw ore, the dosage of Inhibitor 1# in the first cleaning is 150 g, in the second cleaning is 100 g, in the third cleaning is 75 g, in the fourth cleaning is 50 g, in the fifth cleaning is 50 g, in the sixth cleaning is 25 g, and in the seventh cleaning is 10 g. For the middlings obtained from the first cleaning during the scavenging process, based on 1 t of raw ore, the dosage of Inhibitor 1# is 100 g. The types and dosages of the remaining reagents added are the same as those in Example 1.

[0030] Comparative Example 7 The process flow of this comparative example is the same as that of the example. The difference between this comparative example and Example 1 for comparison lies in that: the inhibitor uses Inhibitor 2# (mass ratio of sodium silicate / tannin extract / sodium hexametaphosphate is 20:7:2.5). The flotation results are shown in Table 1. The specific operation steps are as follows: During the rough flotation of fluorite, the inhibitor selects Inhibitor 2#. Based on 1 t of raw ore, the amount of Inhibitor 2# is 400 g. During the cleaning of fluorite, based on 1 t of raw ore, the dosage of Inhibitor 2# in the first cleaning is 150 g, in the second cleaning is 100 g, in the third cleaning is 75 g, in the fourth cleaning is 50 g, in the fifth cleaning is 50 g, in the sixth cleaning is 25 g, and in the seventh cleaning is 10 g. For the middlings obtained from the first cleaning during the scavenging process, based on 1 t of raw ore, the dosage of Inhibitor 2# is 100 g. The types and dosages of the remaining reagents added are the same as those in Example 1.

[0031] Comparative Example 8 The technological process of this comparative example is the same as that of the example. The difference between this comparative example and Example 1 is that the inhibitor used is Inhibitor 3# (2.5 parts of sodium hexametaphosphate, 20 parts of sodium humate, 7 parts of tannin extract, 20 parts of water glass, 0.5 part of sodium acrylate and 200 parts of water, where the relative molecular mass of sodium acrylate is 6000). The flotation results are shown in Table 1, and the specific operation steps are as follows: During the rough flotation of fluorite, Inhibitor 3# is selected as the inhibitor, and based on 1 t of raw ore, the amount of Inhibitor 3# is 400 g. In the cleaning of fluorite, based on 1 t of raw ore, the dosage of Inhibitor 3# in the first cleaning is 150 g. The dosage of Inhibitor 3# in the second cleaning is 100 g. The dosage of Inhibitor 3# in the third cleaning is 75 g. The dosage of Inhibitor 3# in the fourth cleaning is 50 g. The dosage of Inhibitor 3# in the fifth cleaning is 50 g. The dosage of Inhibitor 3# in the sixth cleaning is 25 g. The dosage of Inhibitor 3# in the seventh cleaning is 10 g. During the scavenging process of the middlings obtained from the first cleaning, based on 1 t of raw ore, the dosage of Inhibitor 3# is 100 g. The types and dosages of the remaining added reagents are the same as those in Example 1.

[0032] Table 1 Full-process closed-circuit test results of Example 1 and Comparative Examples 1 - 8 (%)

[0033] As can be seen from Table 1, under the conditions of the same flotation technological process, flotation collector and regulator, compared with the single inhibitors of water glass, sodium hexametaphosphate, sodium humate, sodium acrylate and tannin extract, Inhibitor 1#, Inhibitor 2# and Inhibitor 3#, the fluorite flotation composite inhibitor provided by the present invention can effectively process the high-phosphorus, high-calcium and low-grade fluorite ore with a CaF₂ grade of 26.26%, a CaCO₃ content of 14.05% and a P content of 0.85%, and achieve the efficient separation of fluorite from calcium carbonate and apatite, obtaining fluorite concentrate with a yield of 23.87%, a CaF₂ grade of 94.67%, a CaCO₃ content of 1.54% and a P content of 0.045%.

[0034] Example 2: This example uses a certain high-phosphorus, high-calcium and low-grade fluorite ore in Henan as the raw material. The mass percentage of CaF₂ in the raw ore is 21.78%, the mass percentage of CaCO₃ is 31.85%, and the mass percentage of P is 1.35%.

[0035] The application process of this example specifically includes the following steps: (1) Crush the fluorite raw ore, and then grind it to a fineness of -0.074 mm accounting for 80.68%, and add water to make a pulp with a concentration of 45%.

[0036] (2) Add a regulator, the fluorite flotation composite inhibitor of the present invention, and a collector to the pulp for one rough selection to obtain a rough concentrate and a rough tailing. Among them, the regulator is soda ash, and the collector is saponified oleic acid.

[0037] (3) Conduct seven cleaning operations (Cleaning 1 to Cleaning 7) on the rough concentrate to obtain a fluorite concentrate; conduct one scavenging operation on the rough tailing to obtain a rough scavenging tailing; conduct one fine scavenging operation on the middling product of Cleaning 1 to obtain a cleaning tailing.

[0038] In step (2), during the rough selection process, based on 1 t of raw ore, the dosage of soda ash is 1500 g, the dosage of the fluorite flotation composite inhibitor is 500 g, and the dosage of saponified oleic acid is 400 g.

[0039] In step (3), during the Cleaning 1 process, based on 1 t of raw ore, the dosage of the fluorite flotation composite inhibitor is 250 g. During the Cleaning 2 process, based on 1 t of raw ore, the dosage of the fluorite flotation composite inhibitor is 80 g. During the Cleaning 3 process, based on 1 t of raw ore, the dosage of the fluorite flotation composite inhibitor is 60 g. During the Cleaning 4 process, based on 1 t of raw ore, the dosage of the fluorite flotation composite inhibitor is 40 g. During the Cleaning 5 process, based on 1 t of raw ore, the dosage of the fluorite flotation composite inhibitor is 20 g. During the Cleaning 6 process, based on 1 t of raw ore, the dosage of the fluorite flotation composite inhibitor is 10 g. During the Cleaning 7 process, based on 1 t of raw ore, the dosage of the fluorite flotation composite inhibitor is 5 g. In step (3), during the scavenging process of the middling product obtained from Cleaning 1, based on 1 t of raw ore, the dosage of the fluorite flotation composite inhibitor is 50 g, and the dosage of saponified oleic acid is 100 g. In step (3), during the scavenging process of the rough tailing, based on 1 t of raw ore, the dosage of saponified oleic acid is 100 g / t.

[0040] Comparative Example 9 The process flow of this comparative example is the same as that of the example. The difference between this comparative example and Example 2 for comparison is that: the inhibitor uses a single inhibitor sodium silicate, and the flotation results are shown in Table 2. The specific operation steps are as follows: During the fluorite rough selection process, the single inhibitor sodium silicate is selected as the inhibitor. Based on 1 t of raw ore, the dosage of sodium silicate is 500 g. During the fluorite cleaning process, based on 1 t of raw ore, the dosage of sodium silicate in Cleaning 1 is 250 g. The dosage of sodium silicate in Cleaning 2 is 80 g. The dosage of sodium silicate in Cleaning 3 is 60 g. The dosage of sodium silicate in Cleaning 4 is 40 g. The dosage of sodium silicate in Cleaning 5 is 20 g. The dosage of sodium silicate in Cleaning 6 is 10 g. The dosage of sodium silicate in Cleaning 7 is 5 g. During the scavenging process of the middling product obtained from Cleaning 1, based on 1 t of raw ore, the dosage of sodium silicate is 50 g. The types and dosages of other reagents added are the same as those in Example 2. Comparative Example 10 The technological process of this comparative example is the same as that of the example. The difference between this comparative example and Example 2 is as follows: The inhibitor used is a single inhibitor, sodium hexametaphosphate. The flotation results are shown in Table 2. The specific operation steps are as follows: During the rough flotation of fluorite, the single inhibitor sodium hexametaphosphate was selected as the inhibitor. Based on 1 t of raw ore, the amount of sodium hexametaphosphate was 500 g. During the cleaning of fluorite, based on 1 t of raw ore, the dosage of sodium hexametaphosphate in cleaning 1 was 250 g, in cleaning 2 was 80 g, in cleaning 3 was 60 g, in cleaning 4 was 40 g, in cleaning 5 was 20 g, in cleaning 6 was 10 g, and in cleaning 7 was 5 g. During the scavenging process of the middlings obtained from cleaning 1, based on 1 t of raw ore, the dosage of sodium hexametaphosphate was 50 g. The types and dosages of the remaining reagents added were the same as those in Example 2. Comparative Example 11 The technological process of this comparative example is the same as that of the example. The difference between this comparative example and Example 1 is as follows: The inhibitor used is a single inhibitor, sodium humate. The flotation results are shown in Table 2. The specific operation steps are as follows: During the rough flotation of fluorite, the single inhibitor sodium humate was selected as the inhibitor. Based on 1 t of raw ore, the amount of sodium humate was 500 g. During the cleaning of fluorite, based on 1 t of raw ore, the dosage of sodium humate in cleaning 1 was 250 g, in cleaning 2 was 80 g, in cleaning 3 was 60 g, in cleaning 4 was 40 g, in cleaning 5 was 20 g, in cleaning 6 was 10 g, and in cleaning 7 was 5 g. During the scavenging process of the middlings obtained from cleaning 1, based on 1 t of raw ore, the dosage of sodium humate was 50 g. The types and dosages of the remaining reagents added were the same as those in Example 2. Comparative Example 12 The technological process of this comparative example is the same as that of the example. The difference between this comparative example and Example 1 is as follows: The inhibitor used is a single inhibitor, sodium acrylate. The flotation results are shown in Table 2. The specific operation steps are as follows: During the rough flotation of fluorite, the single inhibitor sodium acrylate was selected as the inhibitor. Based on 1 t of raw ore, the amount of sodium acrylate was 500 g. During the cleaning of fluorite, based on 1 t of raw ore, the dosage of sodium acrylate in cleaning 1 was 250 g, in cleaning 2 was 80 g, in cleaning 3 was 60 g, in cleaning 4 was 40 g, in cleaning 5 was 20 g, in cleaning 6 was 10 g, and in cleaning 7 was 5 g. During the scavenging process of the middlings obtained from cleaning 1, based on 1 t of raw ore, the dosage of sodium acrylate was 50 g. The types and dosages of the remaining reagents added were the same as those in Example 2. Comparative Example 13 The process flow of this comparative example is the same as that of the example. The difference between this comparative example and Example 1 for comparison is that: the inhibitor uses a single inhibitor tannin extract. The flotation results are shown in Table 2. The specific operation steps are as follows: During the rough flotation of fluorite, a single inhibitor tannin extract is selected as the inhibitor. Based on 1 t of raw ore, the amount of tannin extract is 500 g. During the cleaning of fluorite, based on 1 t of raw ore, the dosage of tannin extract in the first cleaning is 250 g, in the second cleaning is 80 g, in the third cleaning is 60 g, in the fourth cleaning is 40 g, in the fifth cleaning is 20 g, in the sixth cleaning is 10 g, and in the seventh cleaning is 5 g. For the middlings obtained from the first cleaning during the scavenging process, based on 1 t of raw ore, the dosage of tannin extract is 50 g. The types and dosages of the remaining reagents added are the same as those in Example 2. Comparative Example 14 The process flow of this comparative example is the same as that of the example. The difference between this comparative example and Example 1 for comparison is that: the inhibitor uses Inhibitor 1# (mass ratio of sodium silicate / tannin extract / sodium humate is 20:7:20). The flotation results are shown in Table 2. The specific operation steps are as follows: During the rough flotation of fluorite, Inhibitor 1# is selected as the inhibitor. Based on 1 t of raw ore, the amount of Inhibitor 1# is 500 g. During the cleaning of fluorite, based on 1 t of raw ore, the dosage of Inhibitor 1# in the first cleaning is 250 g, in the second cleaning is 80 g, in the third cleaning is 60 g, in the fourth cleaning is 40 g, in the fifth cleaning is 20 g, in the sixth cleaning is 10 g, and in the seventh cleaning is 5 g. For the middlings obtained from the first cleaning during the scavenging process, based on 1 t of raw ore, the dosage of Inhibitor 1# is 50 g. The types and dosages of the remaining reagents added are the same as those in Example 2. Comparative Example 15 The process flow of this comparative example is the same as that of the example. The difference between this comparative example and Example 1 for comparison is that: the inhibitor uses Inhibitor 2# (mass ratio of sodium silicate / tannin extract / sodium hexametaphosphate is 20:7:2.5). The flotation results are shown in Table 2. The specific operation steps are as follows: During the rough flotation of fluorite, Inhibitor 2# is selected as the inhibitor. Based on 1 t of raw ore, the amount of Inhibitor 2# is 500 g. During the cleaning of fluorite, based on 1 t of raw ore, the dosage of Inhibitor 2# in the first cleaning is 250 g, in the second cleaning is 80 g, in the third cleaning is 60 g, in the fourth cleaning is 40 g, in the fifth cleaning is 20 g, in the sixth cleaning is 10 g, and in the seventh cleaning is 5 g. For the middlings obtained from the first cleaning during the scavenging process, based on 1 t of raw ore, the dosage of Inhibitor 2# is 50 g. The types and dosages of the remaining reagents added are the same as those in Example 2.

[0041] Comparative Example 16 The technological process of this comparative example is the same as that of the example. The difference between this comparative example and Example 1 is as follows: The inhibitor used is Inhibitor 3# (2.5 parts of sodium hexametaphosphate, 20 parts of sodium humate, 7 parts of tannin extract, 20 parts of water glass, 0.5 part of sodium acrylate and 200 parts of water, where the relative molecular mass of sodium acrylate is 6000). The flotation results are shown in Table 2. The specific operation steps are as follows: During the rough flotation of fluorite, Inhibitor 3# is selected as the inhibitor. Based on 1 t of raw ore, the dosage of Inhibitor 3# is 500 g. During the cleaning of fluorite, based on 1 t of raw ore, the dosage of Inhibitor 3# for the first cleaning is 250 g. The dosage of Inhibitor 3# for the second cleaning is 80 g. The dosage of Inhibitor 3# for the third cleaning is 60 g. The dosage of Inhibitor 3# for the fourth cleaning is 40 g. The dosage of Inhibitor 3# for the fifth cleaning is 20 g. The dosage of Inhibitor 3# for the sixth cleaning is 10 g. The dosage of Inhibitor 3# for the seventh cleaning is 5 g. During the scavenging process of the middlings obtained from the first cleaning, based on 1 t of raw ore, the dosage of Inhibitor 3# is 50 g. The types and dosages of the other added reagents are the same as those in Example 2.

[0042] Table 2 Full-process closed-circuit test results of Example 2 and Comparative Examples 9 - 16 (%)

[0043] As can be seen from Table 2, under the conditions of the same flotation technological process, flotation collector and regulator, compared with single inhibitors such as water glass, sodium hexametaphosphate, sodium humate, sodium acrylate, tannin extract, Inhibitor 1#, Inhibitor 2# and Inhibitor 3#, the fluorite flotation composite inhibitor provided by the present invention can effectively treat the high-phosphorus, high-calcium and low-grade fluorite ore with a CaF2 grade of 21.78%, a CaCO3 content of 31.85% and a P content of 1.35%, and achieve the efficient separation of fluorite from calcium carbonate and apatite, obtaining fluorite concentrate with a yield of 14.03%, a CaF2 grade of 95.89%, a CaCO3 content of 1.26% and a P content of 0.029%.

[0044] Example 3: In this example, a certain high-phosphorus, high-calcium and low-grade fluorite ore in Henan is used as the raw material. The mass percentage of CaF2 in the raw ore is 25.49%, the mass percentage of CaCO3 is 39.17%, and the mass percentage of P is 1.05%.

[0045] The application process of this example specifically includes the following steps: (1) Crush the fluorite raw ore, and then grind it to a fineness of 80.68% passing through -0.074 mm, and add water to make a pulp with a concentration of 45%.

[0046] (2) The regulator, the fluorite flotation composite inhibitor of the present invention, and the collector are respectively added to the pulp for one rough selection to obtain rough concentrate and rough tailings. Among them, the regulator is soda ash, and the collector is saponified oleic acid.

[0047] (3) The rough concentrate is subjected to seven times of cleaning (cleaning 1 to cleaning 7) to obtain fluorite concentrate; the rough tailings are subjected to one scavenging to obtain rough scavenging tailings; the middlings in cleaning 1 are subjected to one fine scavenging to obtain cleaning tailings.

[0048] In step (2), during the rough selection process, based on 1 t of raw ore, the dosage of soda ash is 1200 g, the dosage of the fluorite flotation composite inhibitor is 600 g, and the dosage of saponified oleic acid is 500 g.

[0049] In step (3), during the cleaning 1 process, based on 1 t of raw ore, the dosage of the fluorite flotation composite inhibitor is 150 g. During the cleaning 2 process, based on 1 t of raw ore, the dosage of the fluorite flotation composite inhibitor is 100 g. During the cleaning 3 process, based on 1 t of raw ore, the dosage of the fluorite flotation composite inhibitor is 50 g. During the cleaning 4 process, based on 1 t of raw ore, the dosage of the fluorite flotation composite inhibitor is 30 g. During the cleaning 5 process, based on 1 t of raw ore, the dosage of the fluorite flotation composite inhibitor is 20 g. During the cleaning 6 process, based on 1 t of raw ore, the dosage of the fluorite flotation composite inhibitor is 10 g. During the cleaning 7 process, based on 1 t of raw ore, the dosage of the fluorite flotation composite inhibitor is 5 g. In step (3), during the scavenging of the middlings obtained from cleaning 1, based on 1 t of raw ore, the dosage of the fluorite flotation composite inhibitor is 100 g, and the dosage of saponified oleic acid is 100 g. In step (3), during the scavenging of the rough tailings, based on 1 t of raw ore, the dosage of saponified oleic acid is 100 g / t.

[0050] Comparative Example 17 The process flow of this comparative example is the same as that of the example. The difference between this comparative example and Example 3 for comparison is that: the inhibitor uses a single inhibitor sodium silicate, and the flotation results are shown in Table 3. The specific operation steps are as follows: During the rough selection of fluorite, a single inhibitor sodium silicate is selected as the inhibitor. Based on 1 t of raw ore, the dosage of sodium silicate is 600 g. During the cleaning of fluorite, based on 1 t of raw ore, the dosage of sodium silicate in cleaning 1 is 150 g. The dosage of sodium silicate in cleaning 2 is 100 g. The dosage of sodium silicate in cleaning 3 is 50 g. The dosage of sodium silicate in cleaning 4 is 30 g. The dosage of sodium silicate in cleaning 5 is 20 g. The dosage of sodium silicate in cleaning 6 is 10 g. The dosage of sodium silicate in cleaning 7 is 5 g. During the scavenging of the middlings obtained from cleaning 1, based on 1 t of raw ore, the dosage of sodium silicate is 50 g. The types and dosages of other reagents added are the same as those in Example 3. Comparative Example 18 The technological process of this comparative example is the same as that of the example. The difference between this comparative example and Example 2 is as follows: The inhibitor uses a single inhibitor, sodium hexametaphosphate. The flotation results are shown in Table 3. The specific operation steps are as follows: During the rough flotation of fluorite, a single inhibitor, sodium hexametaphosphate, is selected. Based on 1 t of raw ore, the amount of sodium hexametaphosphate is 600 g. During the cleaning of fluorite, based on 1 t of raw ore, the dosage of sodium hexametaphosphate for the first cleaning is 150 g, for the second cleaning is 100 g, for the third cleaning is 50 g, for the fourth cleaning is 30 g, for the fifth cleaning is 20 g, for the sixth cleaning is 10 g, and for the seventh cleaning is 5 g. For the middlings obtained from the first cleaning during the scavenging process, based on 1 t of raw ore, the dosage of sodium hexametaphosphate is 50 g. The types and dosages of the remaining reagents added are the same as those in Example 3. Comparative Example 19 The technological process of this comparative example is the same as that of the example. The difference between this comparative example and Example 1 is as follows: The inhibitor uses a single inhibitor, sodium humate. The flotation results are shown in Table 3. The specific operation steps are as follows: During the rough flotation of fluorite, a single inhibitor, sodium humate, is selected. Based on 1 t of raw ore, the amount of sodium humate is 600 g. During the cleaning of fluorite, based on 1 t of raw ore, the dosage of sodium humate for the first cleaning is 150 g, for the second cleaning is 100 g, for the third cleaning is 50 g, for the fourth cleaning is 30 g, for the fifth cleaning is 20 g, for the sixth cleaning is 10 g, and for the seventh cleaning is 5 g. For the middlings obtained from the first cleaning during the scavenging process, based on 1 t of raw ore, the dosage of sodium humate is 50 g. The types and dosages of the remaining reagents added are the same as those in Example 3. Comparative Example 20 The technological process of this comparative example is the same as that of the example. The difference between this comparative example and Example 1 is as follows: The inhibitor uses a single inhibitor, sodium acrylate. The flotation results are shown in Table 3. The specific operation steps are as follows: During the rough flotation of fluorite, a single inhibitor, sodium acrylate, is selected. Based on 1 t of raw ore, the amount of sodium acrylate is 600 g. During the cleaning of fluorite, based on 1 t of raw ore, the dosage of sodium acrylate for the first cleaning is 150 g, for the second cleaning is 100 g, for the third cleaning is 50 g, for the fourth cleaning is 30 g, for the fifth cleaning is 20 g, for the sixth cleaning is 10 g, and for the seventh cleaning is 5 g. For the middlings obtained from the first cleaning during the scavenging process, based on 1 t of raw ore, the dosage of sodium acrylate is 50 g. The types and dosages of the remaining reagents added are the same as those in Example 3. Comparative Example 21 The process flow of this comparative example is the same as that of the example. The difference between this comparative example and Example 1 is as follows: The inhibitor used is a single inhibitor, tannin extract. The flotation results are shown in Table 3. The specific operation steps are as follows: During the rough flotation of fluorite, the single inhibitor tannin extract was selected as the inhibitor. Based on 1 ton of raw ore, the amount of tannin extract was 600 g. During the cleaning of fluorite, based on 1 ton of raw ore, the amount of tannin extract used in the first cleaning was 150 g, 100 g in the second cleaning, 50 g in the third cleaning, 30 g in the fourth cleaning, 20 g in the fifth cleaning, 10 g in the sixth cleaning, and 5 g in the seventh cleaning. During the scavenging of the middlings obtained from the first cleaning, based on 1 ton of raw ore, the amount of tannin extract used was 50 g. The types and amounts of other reagents added were the same as those in Example 3. Comparative Example 22 The process flow of this comparative example is the same as that of the example. The difference between this comparative example and Example 1 is as follows: The inhibitor used is Inhibitor 1# (mass ratio of sodium silicate / tannin extract / sodium humate is 20:7:20). The flotation results are shown in Table 3. The specific operation steps are as follows: During the rough flotation of fluorite, Inhibitor 1# was selected as the inhibitor. Based on 1 ton of raw ore, the amount of Inhibitor 1# was 600 g. During the cleaning of fluorite, based on 1 ton of raw ore, the amount of Inhibitor 1# used in the first cleaning was 150 g, 100 g in the second cleaning, 50 g in the third cleaning, 30 g in the fourth cleaning, 20 g in the fifth cleaning, 10 g in the sixth cleaning, and 5 g in the seventh cleaning. During the scavenging of the middlings obtained from the first cleaning, based on 1 ton of raw ore, the amount of Inhibitor 1# used was 50 g. The types and amounts of other reagents added were the same as those in Example 3. Comparative Example 23 The process flow of this comparative example is the same as that of the example. The difference between this comparative example and Example 1 is as follows: The inhibitor used is Inhibitor 2# (mass ratio of sodium silicate / tannin extract / sodium hexametaphosphate is 20:7:2.5). The flotation results are shown in Table 3. The specific operation steps are as follows: During the rough flotation of fluorite, Inhibitor 2# was selected as the inhibitor. Based on 1 ton of raw ore, the amount of Inhibitor 2# was 600 g. During the cleaning of fluorite, based on 1 ton of raw ore, the amount of Inhibitor 2# used in the first cleaning was 150 g, 100 g in the second cleaning, 50 g in the third cleaning, 30 g in the fourth cleaning, 20 g in the fifth cleaning, 10 g in the sixth cleaning, and 5 g in the seventh cleaning. During the scavenging of the middlings obtained from the first cleaning, based on 1 ton of raw ore, the amount of Inhibitor 2# used was 50 g. The types and amounts of other reagents added were the same as those in Example 3. Comparative Example 24 The process flow of this comparative example is the same as that of the example. The differences between this comparative example and Example 1 are as follows: The inhibitor used is Inhibitor 3# (2.5 parts of sodium hexametaphosphate, 20 parts of sodium humate, 7 parts of tannin extract, 20 parts of water glass, 0.5 part of sodium acrylate and 200 parts of water, where the relative molecular mass of sodium acrylate is 6000). The flotation results are shown in Table 3. The specific operation steps are as follows: During the rough flotation of fluorite, Inhibitor 3# was selected as the inhibitor. Based on 1 t of raw ore, the amount of Inhibitor 3# was 600 g. During the cleaning of fluorite, based on 1 t of raw ore, the dosage of Inhibitor 3# for the first cleaning was 150 g, 100 g for the second cleaning, 50 g for the third cleaning, 30 g for the fourth cleaning, 20 g for the fifth cleaning, 10 g for the sixth cleaning, and 5 g for the seventh cleaning. During the scavenging process of the middlings obtained from the first cleaning, based on 1 t of raw ore, the dosage of Inhibitor 3# was 50 g. The types and dosages of the other reagents added were the same as those in Example 3. Table 3 Full-process closed-circuit test results of Example 3 and Comparative Examples 17 - 24 (%)

[0051] As can be seen from Table 3, under the conditions of the same flotation process flow, flotation collector and regulator, compared with single inhibitors such as water glass, sodium hexametaphosphate, sodium humate, sodium acrylate, tannin extract, Inhibitor 1#, Inhibitor 2# and Inhibitor 3#, the fluorite flotation composite inhibitor provided by the present invention can effectively treat a high-phosphorus, high-calcium and low-grade fluorite ore with a CaF₂ grade of 25.49%, a CaCO₃ content of 39.89% and a P content of 1.05%, and achieve the efficient separation of fluorite from calcium carbonate and apatite, obtaining a fluorite concentrate with a yield of 17.58%, a CaF₂ grade of 90.23%, a CaCO₃ content of 2.95% and a P content of 0.034%.

[0052] The above is only the preferred embodiment of the present invention, and the protection scope of the present invention is not limited to the above embodiments. For those skilled in the art of this technology, the improvements and transformations obtained without departing from the technical concept of the present invention should also be regarded as the protection scope of the present invention.

[0053] Although the embodiments of the present invention have been shown and described above, it can be understood that the above embodiments are exemplary and should not be construed as limiting the present invention. Those of ordinary skill in the art can make changes, modifications, substitutions and variations to the above embodiments within the scope of the present invention.

Claims

1. A composite depressant for fluorite flotation, characterized in that, It comprises components in the following parts by mass: 1 to 5 parts of sodium hexametaphosphate, 8 to 40 parts of humate, 2.8 to 14 parts of tannin extract, 5 to 40 parts of water glass, and 0.2 to 1 part of acrylate.

2. The fluorite flotation composite inhibitor according to claim 1, wherein The acrylate is sodium acrylate, and the relative molecular mass of the acrylate is 1000 to 5000.

3. The fluorite flotation composite inhibitor according to claim 1, wherein The humate is sodium humate, and the soluble matter content of the humate is ≥85%.

4. The fluorite flotation composite inhibitor according to claim 1, wherein, It further comprises water, and the mass of water is 1 to 40 times the total mass of sodium hexametaphosphate, sodium humate, tannin extract, water glass, and acrylate.

5. The fluorite flotation composite inhibitor according to any one of claims 1-4, characterized in that, It comprises components in the following parts by mass: 2.5 parts of sodium hexametaphosphate, 20 parts of humate, 7 parts of tannin extract, 20 parts of water glass, and 0.5 part of acrylate.

6. A preparation method of the fluorite flotation composite inhibitor according to any one of claims 1-5, characterized in that, It comprises the following steps: S1. Dissolve the sodium hexametaphosphate, water glass, and acrylate in water according to the mass ratio to obtain a mixed solution. S2. Add the tannin extract and humate to the mixed solution according to the mass ratio, and after mixing evenly, the composite depressant for fluorite flotation is obtained.

7. Use of the fluorite flotation composite inhibitor according to any one of claims 1-5 or the fluorite flotation composite inhibitor prepared by the preparation method according to claim 6, characterized in that, The composite depressant for fluorite flotation is used for the flotation of high-phosphorus and low-calcium low-grade fluorite ore.

8. The application of the composite depressant for fluorite flotation according to claim 7, wherein When the composite depressant for fluorite flotation is used for the flotation of high-phosphorus and low-calcium low-grade fluorite ore, the flotation is carried out according to the following operations: (1) Crush and grind the original fluorite ore to obtain pulp. (2) Add a regulator, the composite depressant for fluorite flotation, and a collector to the pulp respectively, and then obtain rough concentrate and rougher tailings through flotation. (3) Carry out cleaning on the rough concentrate to obtain fluorite concentrate.

9. The application of the composite depressant for fluorite flotation according to claim 8, wherein In step (3), the rough concentrate is subjected to 7 times of cleaning treatment to obtain fluorite concentrate; except for the first cleaning, the middlings generated in each cleaning process are sequentially returned to the previous cleaning operation process; the middlings obtained from the first cleaning are subjected to one rough scavenging to obtain rough scavenging foam and cleaning tailings, and the rough scavenging foam is returned to the rougher operation process; the dosage of the composite depressant for fluorite flotation in the first cleaning treatment is 100 to 300 g / t, and the dosages of the composite depressant for fluorite flotation in the remaining 6 cleaning treatments are sequentially reduced.

10. The application of the composite depressant for fluorite flotation according to claim 8, characterized in that, Carry out one scavenging on the rougher tailings to obtain rough scavenging tailings.

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