CN116943871B - Efficient collector, preparation method thereof and application of efficient collector in fluorite flotation in high-calcium fluorite ore - Google Patents

Abstract

The present invention discloses a highly efficient collector, a preparation method thereof, and an application in the flotation of fluorite in high-calcium fluorite ore, belonging to the technical field of mineral separation. Aiming at the problems of low selectivity and low separation process index of high-calcium fluorite flotation collector in the prior art, the present invention proposes an effective solution: the BHA-Ce metal complex and BHA-Ce mixture synthesized by the present invention using benzohydroxamic acid and cerium trichloride as raw materials have excellent selectivity for fluorite, effectively avoiding the problems of poor selectivity and low flotation index caused by the traditional fluorite collector using calcium points as adsorption sites. The synthetic preparation routes of the BHA-Ce metal complex collector and the BHA-Ce mixture collector provided by the present invention are simple and feasible, with good performance and no special requirements for the use environment.

Description

A high-efficiency collector and its preparation method and its application in flotation of fluorite in high-calcium fluorite ore

Technical Field

The invention belongs to the technical field of mineral separation, and specifically relates to a collector, and more specifically, the invention relates to a high-efficiency collector and a preparation method thereof and application in flotation of fluorite in high-calcium fluorite ore.

Background technique

At present, the fluorite beneficiation technology in China is mainly flotation. According to the different fluorite gangue minerals, fluorite can be divided into silicate fluorite, barite fluorite, carbonate fluorite, etc. The gangue minerals in carbonate fluorite are mainly calcite and dolomite, and the main component is calcium carbonate CaCO ₃ . When the carbonate content in this type of fluorite ore is about 10-20% and the remaining gangue is mainly quartz, fluorite concentrate can be obtained by using a combination of inhibitors and a collector with good selectivity under alkaline conditions after multiple concentrations. Once the calcium carbonate content is as high as 20-50% and the quartz content drops to about 10%, the conventional reagent system can hardly achieve satisfactory flotation indicators. A large amount of acid must be used to adjust to acidic conditions [Yang Kailu. Fluorite/dolomite flotation separation and mechanism research [D]. Wuhan University of Science and Technology, 2018.] or a large amount of inhibitors must be added [for example, Chinese patent, a high calcium carbonate type fluorite beneficiation method, public patent number CN107377198B; Chinese patent, a high calcium carbonate type fluorite beneficiation method, public patent number CN103706485B] before it can be separated, which greatly increases the separation cost and the effect is not ideal.

Among the existing fluorite flotation research data, the most reported collectors for flotation of fluorite and its gangue minerals (quartz, calcite, dolomite, barite, etc.) are oleic acid and fatty acid anionic collectors. It is generally believed that oleic acid and fatty acid collector molecules can chemically adsorb with Ca ²⁺ particles on the surface of fluorite to generate calcium oleate or fatty acid salts, making the fluorite surface hydrophobic and floating. Since there are no Ca ²⁺ particles on the surface of quartz, the degree of interaction with oleic acid and fatty acid collector molecules is weak, so these collectors have a good effect in selecting quartz-type fluorite ore; while calcite and dolomite also have Ca ²⁺ particles on their surfaces, which have very similar chemical properties to the surface of fluorite and can adsorb with oleic acid or fatty acid collector molecules, making it difficult to separate from fluorite by flotation. Researchers have done a lot of research on the selectivity of fluorite collectors. The results show that some higher fatty acids or deeply oxidized fatty acids have higher selectivity for fluorite than oleic acid, but it is still not enough to achieve a good separation from carbonate gangue.

In addition to the above-mentioned anionic collectors, cationic collectors can play a certain role in collecting fluorite through electrostatic adsorption. It has been reported that fatty amine cationic collectors have a strong collection ability for fluorite, but cannot achieve separation from calcium-containing gangue. In previous studies, only [Study on the collection performance of lanthanide metal-benzohydroxamic acid organic complexes on fluorite and calcite] used a mixture of Ce ions and BHA in a molar ratio of 1:2 as a report on the micro-flotation separation of pure fluorite and calcite minerals, but this study did not have an example of flotation in actual ores. In addition, the molar ratio of Ce to BHA in the above-mentioned prior art of 1:2 is converted into a mass ratio of cerium trichloride and benzohydroxamic acid of about 1:1. The BHA-Ce mixture prepared under this ratio will seriously deteriorate the separation effect during the flotation process of actual ores. It can be seen from this that there is currently a lack of effective collectors with particularly strong selectivity for carbonate fluorite.

Based on the above reasons, this application is hereby filed.

Summary of the invention

Based on the above reasons, in view of the problems or defects existing in the prior art, the purpose of the present invention is to provide a high-efficiency collector and a preparation method thereof and its application in the flotation of fluorite in high-calcium fluorite ore, so as to solve or at least partially solve the above-mentioned technical defects existing in the prior art.

In order to achieve the above first object of the present invention, the technical solution adopted by the present invention is as follows:

A highly efficient collector, which is a benzohydroxamic acid (BHA)-Ce metal complex or a BHA-Ce mixture.

The second object of the present invention is to provide a method for preparing the above-mentioned collector.

On the one hand, the BHA-Ce metal complex is prepared by the following method, which specifically comprises the following steps:

Benzohydroxamic acid (BHA) and cerium trichloride (CeCl ₃ ) are dissolved in an organic solvent in sequence according to a ratio, the obtained mixed solution is stirred at 45-55° C., and then the obtained uniform mixed solution is stirred at 10-55° C. for reaction for 4-6 hours; after the reaction is completed, the obtained product is filtered, and after the solvent in the obtained filtrate is completely volatilized or evaporated, a white crystalline powder is obtained, and the BHA-Ce metal complex is obtained after purification.

Furthermore, in the above technical solution, the mass ratio of cerium trichloride to benzohydroxamic acid is (1-3):1. Under this dosage condition, Ce ions are completely excessive during the reaction. If the mass ratio of cerium trichloride to benzohydroxamic acid is lower than (1-3):1, the yield of the synthesized BHA-Ce metal complex will be reduced. Only within the above ratio range can a target product with a higher yield be obtained.

Furthermore, in the above technical solution, the above-mentioned organic solvent can be any one of anhydrous methanol, anhydrous ethanol, acetone, etc.

Specifically, in the above technical solution, the amount of the organic solvent used may not be specifically limited, as long as it does not affect the reaction. For example, the amount of benzohydroxamic acid and the organic solvent used may be 1 mmol: (20-50) mL.

Furthermore, in the above technical solution, the stirring time is not specifically limited, as long as the benzohydroxamic acid and cerium trichloride can be uniformly mixed in the organic solvent.

Furthermore, in the above technical solution, the stirring reaction is preferably carried out at room temperature, which refers to the natural room temperature conditions in all seasons without additional cooling or heating treatment. Generally, the room temperature is controlled at 10-30°C, preferably 15-25°C.

Furthermore, in the above technical solution, the volatilization of the solvent in the filtrate can be natural volatilization under normal temperature environment, and the volatilization time is preferably 26-35 days.

Specifically, in the above technical solution, the solvent in the obtained filtrate can be evaporated and crystallized using a rotary evaporator, and the evaporation temperature does not exceed 55°C.

Specifically, in the above technical solution, the BHA-Ce metal complex is a solid complex, which can be dissolved in water in various proportions according to the flotation reagent system or process requirements and used as a flotation collector.

On the other hand, the BHA-Ce mixture of the present invention is prepared by the following method, which specifically comprises the following steps:

Benzohydroxamic acid (BHA) and cerium trichloride (CeCl ₃ ) are sequentially added into deionized water according to a ratio, and mixed to obtain the BHA-Ce mixture.

Furthermore, in the above technical solution, the mass ratio of cerium trichloride to benzohydroxamic acid is 1:30 to 1:20. If the Ce ion concentration is too high, it will directly form a precipitate with BHA, which is equivalent to consuming BHA and has no collection effect.

Further, in the above technical solution, the stirring time may not be specifically limited, as long as the benzohydroxamic acid and cerium trichloride can be uniformly mixed and dissolved in water. For example, the stirring time may be 30 minutes.

Specifically, in the above technical solution, the BHA-Ce mixture can be used as a flotation collector by appropriately changing the concentration according to the flotation reagent system or process requirements.

The third object of the present invention is to provide the use of the above-mentioned BHA-Ce complex and/or BHA-Ce mixture in the flotation of fluorite in high-calcium fluorite ore.

The solid complex or liquid mixture of the collector provided by the present invention is consistent with the use method of conventional flotation collectors. The solid complex collector is soluble in water, mixed with water according to the dosage requirements, and added to the flotation operation after mechanical stirring to fully dissolve. The liquid mixture can be directly added to the flotation operation according to the flotation dosage requirements. The use of the BHA-Ce metal complex collector and the BHA-Ce mixture collector prepared by the present invention is not restricted by seasonal room temperature conditions, but it should be noted that the solid complex should not be dissolved at more than 55°C to avoid reducing the performance of the collector.

Compared with the prior art, the present invention has the following beneficial effects:

(1) The present invention provides a preparation process and a method for using a complex-type fluorite efficient collector BHA-Ce synthesized from organic matter and metal ions. The collector is mainly generated by the reaction of benzohydroxamic acid (BHA) and a soluble metal salt of metal cerium ion (Ce ³⁺ ). In addition, the present invention also provides a preparation process and a method for using a BHA-Ce mixture. Since the main component of fluorite is calcium fluoride (CaF ₂ ), more F atoms will be exposed on the dissociation surface of the broken fluorite crystal. Cerium ions have a high affinity for fluoride ions and can undergo strong chemical adsorption. However, cerium ions will not react with common gangue minerals such as calcite, dolomite, and quartz in fluorite ore, mainly because the surfaces of these gangue minerals do not have effective sites that can serve as cerium ion adsorption sites. When the BHA-Ce complex and/or the BHA-Ce mixture contacts the fluorite surface in the flotation solution environment, Ce selectively adsorbs fluoride ions on the fluorite surface but not on other gangue minerals. The BHA ions at the other end act as a hydrophobic force, making the fluorite surface hydrophobic and floating, thus achieving a highly selective capture effect.

(2) The present invention proposes an effective solution to the problems of low selectivity and low separation process index of high-calcium fluorite flotation collectors in the prior art. The present invention uses benzohydroxamic acid and cerium trichloride as raw materials to synthesize BHA-Ce metal complex and BHA-Ce mixture, both of which have excellent selectivity for fluorite, effectively avoiding the problems of poor selectivity and low flotation index caused by the traditional fluorite collector using calcium points as adsorption sites. The synthetic preparation routes of the BHA-Ce metal complex collector and the BHA-Ce mixture collector provided by the present invention are simple and feasible, have good performance, and have no special requirements for the use environment.

(3) The present invention aims to provide a highly selective collector that can effectively float fluorite from fluorite ore with a high calcium content, and does not require the addition of acid or a large amount of inhibitors during the separation process, which is environmentally friendly.

BRIEF DESCRIPTION OF THE DRAWINGS

In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

FIG1 is a comparison diagram of infrared spectra of the BHA-Ce complex prepared in Example 1 of the present invention and BHA;

FIG2 is a flow chart of the raw ore separation process in Application Example 1;

FIG3 is a flow chart of the raw ore separation process in Application Example 2.

Detailed ways

The present invention is further described in detail below through implementation cases. This implementation case is implemented based on the technology of the present invention, and a detailed implementation method and specific operation process are now given to illustrate that the present invention is creative, but the protection scope of the present invention is not limited to the following implementation cases.

According to the information contained in this application, various changes can be easily made to the precise description of the present invention for those skilled in the art.It should be understood that the scope of the present invention is not limited to defined processes, properties or components, because these embodiments and other descriptions are only for illustrating specific aspects of the present invention.

In order to better understand the present invention but not to limit the scope of the present invention, all the numbers used in this application to express the amount, percentage, and other numerical values should be understood as modified by the word "about" in all cases. Therefore, unless otherwise specified, the numerical parameters listed in the specification are approximate values, which may be changed according to the different ideal properties attempted to be obtained. Each numerical parameter should at least be regarded as obtained based on the reported significant figures and by conventional rounding methods.

The equipment and raw materials used in the present invention can be purchased from the market or are commonly used in the art. The methods in the following embodiments are all conventional methods in the art unless otherwise specified.

Example 1

A BHA-Ce metal complex of this embodiment is prepared by the following method, which specifically comprises the following steps:

First, 50 mmol (6.857 g) of benzohydroxamic acid (BHA) and 18.6235 g of cerium trichloride (CeCl ₃ ) were weighed and dissolved in 1000 mL of methanol. The resulting mixture was stirred in a water bath at 55°C for 30 min, and then stirred at room temperature (24°C) for 5.0 h before filtering. The resulting filtrate was evaporated and crystallized on a rotary evaporator for 24 hours, with the evaporation temperature not exceeding 55°C. A white crystalline powder was obtained.

The white crystalline powder was placed in 500 mL of ultrapure water and heated at 55° C. in a water bath with stirring for 1 hour until the precipitate no longer dissolved further, the hot solution was filtered to remove solid particles, and the filtrate was allowed to stand and cool to room temperature to obtain precipitated white crystals, which were naturally air-dried to obtain pure benzohydroxamic acid (BHA)-Ce metal complex. Finally, 14.4877 g of the product was obtained with a yield of about 56.86%.

The infrared spectrum comparison of the BHA-Ce complex synthesized in this example and BHA is shown in Figure 1. As shown in Figure 1, compared with the infrared spectrum of BHA, BHA-Ce has a new characteristic peak of Ce-Cl bond near 600nm wavelength, indicating the existence of the BHA-Ce complex.

Example 2

A BHA-Ce mixture of this embodiment is prepared by the following method, which specifically includes the following steps:

Cerium trichloride (CeCl ₃ ) and benzohydroxamic acid (BHA) were directly mixed and stirred in deionized water in a mass ratio of 1:30 for 30 minutes to obtain a BHA-Ce mixture.

Comparative Example 1

A BHA-Ce (BHA to Ce molar ratio 2:1) mixture of this comparative example was prepared by the following method, which specifically includes the following steps:

Cerium trichloride (CeCl ₃ ) and benzohydroxamic acid (BHA) were directly mixed and stirred in deionized water in a molar ratio of 1:2 for 30 minutes to obtain a BHA-Ce (BHA to Ce molar ratio 2:1) mixture.

Application Example 1

The BHA-Ce metal complex prepared in Example 1, the BHA-Ce mixture prepared in Comparative Example 1, and oleic acid were respectively used as collectors to flotation fluorite in high-calcium fluorite ore. The specific application method is as follows:

The high calcium fluorite ore sample is a calcite type high calcium fluorite ore sample from Sichuan, in which the proportion of calcite (calcium carbonate CaCO ₃ ) is as high as 32.8%, and the fluorite grade is only about 8%. The main component analysis of the ore sample is shown in Table 1. The separation process of the ore is shown in Figure 2.

After the raw ore is ground to a particle size of -0.074 mm accounting for 88%, it is added to the flotation tank, and an appropriate amount of water is added and stirred in the flotation machine. First, add the pH adjuster sodium bicarbonate and stir for 3 minutes to adjust the pH of the slurry to about 7.5, then add the gangue inhibitor acidified water glass and sodium humate in turn, stir for 5 minutes, and then add the collector and stir for 3 minutes. This application example uses oleic acid, the BHA-Ce mixture prepared in Comparative Example 1, and the BHA-Ce metal complex prepared in Example 1 as fluorite roughing collectors. When oleic acid is used as a collector, add the collector and stir for 3 minutes before aerating and starting flotation, and the flotation time is 10 minutes. When the BHA-Ce mixture prepared in Comparative Example 1 or the BHA-Ce metal complex prepared in Example 1 is used as a fluorite roughing collector, after adding the collector and stirring for 3 minutes, it is necessary to continue to add the foaming agent pine oil, and finally aerate and start flotation, and the flotation time is 10 minutes. After flotation, the foam product, i.e., the fluorite coarse concentrate product, and the slurry sediment, i.e., the tailings product, are obtained.

In this application example, the acidified water glass is prepared by mixing 1500g of sulfuric acid and 2200g of water glass (sodium silicate) and stirring them evenly. In addition, the amount of acidified water glass used in the flotation using three different collectors in this application example is 3700g/ton (i.e., the amount of acidified water glass required to process 1 ton of high-calcium fluorite ore is 3700g); the amount of sodium humate used in the flotation using three different collectors in this application example is 450g/ton (i.e., the amount of sodium humate required to process 1 ton of high-calcium fluorite ore is 450g). In addition, the amount of oleic acid in this application example is 50 g/ton (i.e., the amount of oleic acid required to treat 1 ton of high-calcium fluorite ore is 50 g); the amount of BHA-Ce mixture prepared in Comparative Example 1 is 320 g/ton (i.e., the amount of BHA-Ce mixture prepared in Comparative Example 1 required to treat 1 ton of high-calcium fluorite ore is 320 g); the amount of BHA-Ce metal complex prepared in Example 1 is 320 g/ton (i.e., the amount of BHA-Ce metal complex prepared in Example 1 required to treat 1 ton of high-calcium fluorite ore is 320 g); when the BHA-Ce mixture prepared in Comparative Example 1 or the BHA-Ce metal complex prepared in Example 1 is used as a fluorite roughing collector, the amount of pine oil used as a foaming agent is 50 g/ton (i.e., the amount of pine oil required to treat 1 ton of high-calcium fluorite ore is 50 g). Other flotation conditions (such as pH adjuster, inhibitor dosage, etc.) are exactly the same, and flotation tests are carried out respectively, and the results are compared in Table 2.

The data in Table 1 are obtained based on XRF fluorescence semi-quantitative analysis or chemical analysis, and the analysis results are all from testing institutions with testing and analysis qualifications.

The grade results of the raw ore and fluorite concentrate in Table 2 are derived from the chemical analysis results of a testing agency with testing and analysis qualifications. The recovery rates of tailings and all products are calculated according to the recovery rate calculation formula:

Rough concentrate _CaF2 recovery rate = (rough concentrate _CaF2 grade × rough concentrate yield) / (raw ore _CaF2 grade × raw ore yield) × 100%;

Tailings _CaF2 recovery rate = (1-rough concentrate _CaF2 recovery rate) × 100%.

Table 1 Analysis of main components of raw ore samples

Element SiO ₂ Al ₂ O ₃ CaCO ₃ MgO _{K2O Na2O CaF2} content,% 17.61 20.54 32.8 11.27 0.79 3.48 8.00 Element BaO S Fe As content,% 1.10 0.004 0.42 0.01

Table 2 Flotation test results

The test results in Table 2 show that compared with oleic acid, the use of BHA-Ce (including the BHA-Ce mixture prepared in Comparative Example 1 and the BHA-Ce metal complex prepared in Example 1) as a collector significantly improves the grade of CaF ₂ in the coarse concentrate, while ensuring the recovery rate, and the selectivity for fluorite is significantly higher than that of oleic acid. However, the BHA-Ce mixture collector prepared in Comparative Example 1 has a very poor ability to collect fluorite. Under the same dosage conditions as the BHA-Ce metal complex prepared in Example 1, the recovery rate is about 27 percentage points lower, even far lower than the separation effect of oleic acid.

Application Example 2

The BHA-Ce mixture prepared in Example 2, the BHA-Ce mixture prepared in Comparative Example 1, and sodium oleate were respectively used as collectors to flotation fluorite in high-calcium fluorite ore. The specific application method is as follows:

The high calcium fluorite ore sample is a dolomite type high calcium fluorite ore sample from Inner Mongolia, in which the proportion of dolomite and calcite (calcium carbonate CaCO ₃ ) is as high as 50%, and the fluorite grade is about 32%. The main component analysis of the ore sample is shown in Table 3. The separation process of the ore is shown in Figure 3.

After the raw ore is ground to a particle size of -0.074 mm accounting for 92%, it is added to the flotation tank, and an appropriate amount of water is added and stirred in the flotation machine. First, add the pH adjuster sodium hydroxide and stir for 3 minutes to adjust the pH of the pulp to about 7.5, then add the gangue inhibitor acidified water glass, sodium humate and tannic acid in sequence, stir for 5 minutes, and then add the collector and stir for 3 minutes. This application example uses sodium oleate, the BHA-Ce mixture prepared in Comparative Example 1, and the BHA-Ce mixture prepared in Example 2 as fluorite roughing collectors. When sodium oleate is used as a collector, add the collector and stir for 3 minutes before aerating and starting flotation, and the flotation time is 10 minutes. When the BHA-Ce mixture prepared in Comparative Example 1 or the BHA-Ce mixture prepared in Example 2 is used as a fluorite roughing collector, after adding the collector and stirring for 3 minutes, it is necessary to continue to add the foaming agent pine oil, and finally aerate and start flotation, and the flotation time is 10 minutes. After flotation, the foam product, i.e., the fluorite coarse concentrate product, and the slurry sedimentation product, i.e., the tailings product, are obtained.

The acidified water glass is prepared by mixing 250 g of sulfuric acid with 250 g of water glass (sodium silicate) and stirring evenly.

In this application example, when three different collectors are used for flotation, the acidified water glass used is 500 g/ton, the sodium humate used is 100 g/ton (i.e., the amount of sodium humate required to treat 1 ton of high-calcium fluorite ore is 100 g), and the amount of tannic acid used is 200 g/ton (i.e., the amount of tannic acid required to treat 1 ton of high-calcium fluorite ore is 200 g). In this application example, the amount of sodium oleate used is 65 g/ton (i.e., the amount of sodium oleate required to treat 1 ton of high-calcium fluorite ore is 65 g); the amount of BHA-Ce mixture prepared in Comparative Example 1 is 400 g/ton (i.e., the amount of BHA-Ce mixture prepared in Comparative Example 1 required to treat 1 ton of high-calcium fluorite ore is 400 g); the amount of BHA-Ce mixture prepared in Example 2 is 400 g/ton (i.e., the amount of BHA-Ce mixture prepared in Example 2 required to treat 1 ton of high-calcium fluorite ore is 400 g); when the BHA-Ce mixture prepared in Comparative Example 1 or the BHA-Ce mixture prepared in Example 2 is used as a fluorite roughing collector, the amount of pine oil used as a foaming agent is 50 g/ton (i.e., the amount of pine oil required to treat 1 ton of high-calcium fluorite ore is 50 g). Other flotation conditions (such as pH adjuster, inhibitor dosage, etc.) are exactly the same, and flotation tests are carried out respectively, and the results are compared in Table 4.

The data in Table 3 are obtained based on XRF fluorescence semi-quantitative analysis or chemical analysis, and the analysis results are all from testing institutions with testing and analysis qualifications.

The results of the fluorite rough concentrate and tailings grades in Table 4 are derived from the chemical analysis results of a testing agency with testing and analysis qualifications. The ore grade and the recovery rate of all products are calculated according to the following recovery calculation formula:

Raw ore _CaF2 grade = (concentrate _CaF2 grade × rough concentrate yield + tailings _CaF2 grade × tailings yield) / raw ore yield × 100%;

Rough concentrate _CaF2 recovery rate = (concentrate _CaF2 grade × rough concentrate yield) / (raw ore _CaF2 grade × raw ore yield) × 100%;

Tailings _CaF2 recovery rate = (1-rough concentrate _CaF2 recovery rate) × 100%.

Table 3 Main component analysis of raw ore samples

Element SiO ₂ Al ₂ O ₃ CaCO ₃ MgO _{K2O Na2O CaF2} content,% 2.66 7.10 50 3.27 1.07 2.77 32.34 Element BaO _{Li2O Fe2O3 ​ P2O5 ​} content,% 0.013 0.02 0.07 0.02

Table 4 Flotation test results

The results in Table 4 show that compared with sodium oleate, the use of the BHA-Ce mixture prepared in Example 2 as a collector significantly improves the grade of CaF ₂ in the coarse concentrate, while ensuring the recovery rate, and the selectivity for fluorite is significantly higher than that of sodium oleate. However, the BHA-Ce mixture collector prepared in Comparative Example 1 has a very poor ability to collect fluorite. Under the same dosage conditions as the BHA-Ce mixture prepared in Example 2, the recovery rate is about 45 percentage points lower, even far lower than the separation effect of sodium oleate.

The standard for selectivity is usually grade rather than recovery rate. Recovery rate is generally used as a basis for judging the collection capacity of the collector. The grade of the crude concentrate of sodium oleate is only 43.68%, while the grade of the crude concentrate of the BHA-Ce mixture prepared in Example 2 reaches 52.91%, an increase of nearly 10%.

Claims (3)

1. Application of a benzohydroxamic acid-Ce metal complex or a benzohydroxamic acid-Ce mixture in the flotation of fluorite in a high-calcium fluorite ore, characterized in that: the benzohydroxamic acid-Ce metal complex is prepared by the following method, which specifically comprises the following steps: dissolving benzohydroxamic acid and cerium trichloride in an organic solvent in turn according to a ratio, stirring and mixing the obtained mixed solution at 45-55° C., and then stirring the obtained uniform mixed solution at 10-55° C. for 4-6 hours; after the reaction is completed, filtering the obtained product, and obtaining a white crystalline powder after the solvent in the obtained filtrate is completely volatilized or evaporated, and obtaining the benzohydroxamic acid-Ce metal complex after purification; the mass ratio of the cerium trichloride to the benzohydroxamic acid is (1-3):1; The benzohydroxamic acid-Ce mixture is prepared by the following method, which specifically comprises the following steps: Benzohydroxamic acid and cerium trichloride are sequentially added into deionized water according to a ratio, and mixed to obtain the benzohydroxamic acid-Ce mixture, wherein the mass ratio of the cerium trichloride to the benzohydroxamic acid is 1:30 to 1:20. 2. The use according to claim 1, characterized in that: in the preparation method of the benzohydroxamic acid-Ce metal complex, the amount of the benzohydroxamic acid and the organic solvent is 1 mmol: (20-50) mL. 3. The use according to claim 1, characterized in that: in the preparation method of the benzohydroxamic acid-Ce metal complex, the evaporation temperature used for evaporating the solvent in the obtained filtrate does not exceed 55°C.