Combined inhibitor and method for flotation of calcium-containing rare earth ore by using combined inhibitor

Abstract

The invention belongs to the technical field of comprehensive utilization of rare earth resources, and particularly relates to a combined inhibitor and a calcium-containing rare earth ore flotation method thereof. The combined inhibitor is a combination of an organic chelating agent aqueous solution and a water glass aqueous solution; the organic chelating agent is one of polyaspartic acid, hydrolytic polymaleic acid and carboxymethyl chitosan; the mass ratio of the organic chelating agent to the water glass is 2: (10-25); the mass percent of the organic chelating agent aqueous solution is 2-10%, and the mass percent of the water glass aqueous solution is 5-8%. The combined inhibitor has the advantages of being high in selective inhibition effect on calcium-containing gangue minerals, environmentally friendly, environmentally friendly, easy to degrade, low in reagent dosage and the like, the grade and the recovery rate of rare earth in obtained rare earth ore concentrate are high, and the process structure is simple.

Description

Technical Field

[0001] The present invention belongs to the technical field of comprehensive utilization of rare earth resources, and particularly relates to a combined inhibitor and a method for flotation of rare earth ores containing calcium. Background Art

[0002] Rare earths are important strategic mineral resources. The associated ore in Bayan Obo is a deposit where multiple minerals such as iron, rare earths, niobium, and thorium coexist, containing more than 170 kinds of minerals. However, the associated ore in Bayan Obo has significant difficult-to-separate characteristics such as "poor, fine, complex, and scattered", and it is difficult to improve quality and reduce impurities using conventional separation methods and reagent systems.

[0003] Currently, during the flotation of rare earths from the iron tailings in Bayan Obo, due to the presence of a large amount of calcium-containing gangue minerals such as fluorite and calcite, the REO grade of the flotation rare earth concentrate is only 50%, and the recovery rate is less than 40%. This results in excessive emissions of "three wastes" in the subsequent rare earth smelting and separation processes, which is not conducive to the green and low-carbon development of the rare earth industrial chain. At the same time, rare earth minerals and main associated gangue minerals such as fluorite, calcite, and dolomite have similar atomic compositions and physical and chemical properties, and they all belong to semi-soluble minerals, which will release a large amount of inevitable ions into the pulp. Surface mutual transformation or hetero-aggregation may occur between the minerals, making the surface properties of the minerals similar and resulting in difficult flotation separation.

[0004] The main inhibitor commonly used in rare earth flotation is water glass. However, although water glass has a strong inhibitory effect on calcium-containing gangue minerals such as fluorite and calcite, it also has a certain inhibitory effect on bastnasite, resulting in poor selectivity.

[0005] In recent years, the application of organic chelating inhibitors in rare earth flotation separation has received increasing research attention. Research shows that chelating agents such as xanthan gum, citric acid, ethylenediaminetetraacetic acid, and oxalic acid can achieve selective inhibition of calcium-containing gangue through specific complexation with Ca 2+ However, in the actual application process, although the use of these organic chelating inhibitors can improve the inhibitory effect on calcium-containing gangue minerals to a certain extent, the dosage of organic chelating inhibitors is high, resulting in high costs for rare earth flotation; and competitive adsorption is likely to occur between organic molecules and the surface of rare earth minerals, reducing the selectivity for calcium-containing gangue minerals. Summary of the Invention

[0006] In order to solve the technical problem that it is difficult to selectively and efficiently inhibit calcium-containing gangue minerals such as fluorite and calcite during the flotation of rare earths from the iron tailings in Bayan Obo in the above-mentioned prior art, the present invention provides a combined inhibitor and a method for flotation of rare earth ores containing calcium.

[0007] The first object of the present invention is to provide a combined inhibitor. The combined inhibitor of the present invention is a combination of an aqueous solution of an organic chelating agent and an aqueous solution of sodium silicate; the organic chelating agent is one of polyaspartic acid, hydrolyzed polymaleic acid, and carboxymethyl chitosan; the mass ratio of the organic chelating agent to sodium silicate is 2:10 - 25; the mass percentage of the aqueous solution of the organic chelating agent is 2% - 10%, and the mass percentage of the aqueous solution of sodium silicate is 5% - 8%.

[0008] The present invention utilizes the good compatibility between the macromolecular polymer in the organic chelating agent and the silicate ions in sodium silicate, so that they have a synergistic inhibitory effect on calcium-containing gangue minerals. Further strengthening the adsorption of the collector on the surface of rare earth minerals is beneficial to the efficient separation of rare earth minerals in the iron tailings of Bayan Obo.

[0009] When the carboxyl and other oxygen-containing functional groups in the organic chelating agent of the present invention come into contact with the calcium-containing gangue minerals in the pulp, the carboxylic acid groups can be directly adsorbed on the surface of the calcium-containing gangue minerals, or can complex with some free Ca in the pulp 2+ and form a precipitate covering the surface of the calcium-containing gangue minerals; while having little effect on the surface of rare earth minerals; thereby preventing the subsequent collector from adsorbing on the calcium-containing gangue minerals and enhancing the inhibitory effect on the calcium-containing gangue minerals. At the same time, the silicate ions in sodium silicate can be adsorbed on the surface of the calcium-containing gangue minerals, increasing its negative charge density, thereby enhancing the electrostatic repulsion force on the surface of the calcium-containing gangue minerals, inhibiting the combination of the calcium-containing gangue and the collector, reducing the flotation ability of the calcium-containing gangue, and improving the flotation separation of rare earth minerals and calcium-containing gangue minerals.

[0010] An appropriate organic chelating agent can effectively combine with Ca in the calcium-containing gangue minerals 2+ to form a complex, thereby effectively inhibiting the flotation of calcium-containing gangue. If the dosage of the organic chelating agent is too much, it may have an adverse effect on the flotation property of rare earth minerals, resulting in a decrease in the recovery rate of rare earth minerals. An appropriate concentration of sodium silicate can enhance the negative charge on the mineral surface and inhibit the separation reaction with rare earth minerals. If the concentration is too high, the excessive concentration of sodium silicate may cause the slurry to be too viscous, affecting the formation of bubbles and the activity of the collector in the flotation process, thereby reducing the flotation effect of rare earth minerals.

[0011] Polyaspartic acid has rich functional groups such as carboxyl and amino; hydrolyzed polymaleic acid has multiple carboxyl and double bond structures; carboxymethyl chitosan has carboxyl and amino, and can form complexes with metal ions. Preferably, the molecular weight of polyaspartic acid is 1000 - 5000; the molecular weight of hydrolyzed polymaleic acid is 400 - 800; the modulus of sodium silicate is 2.5.

[0012] The second object of the present invention is to provide a method for flotation of calcium-containing rare earth ores.

[0013] Preferably, the specific method for flotation of rare earth ores containing calcium is as follows: Grind the raw rare earth ore, add water to prepare pulp, and adjust the pH.

[0014] Add a combined inhibitor, a collector, and a frother to the pulp in sequence for flotation to obtain rare earth concentrate.

[0015] It should be noted that during flotation, the carboxyl groups on the molecular chain of the organic chelating agent chelate with Ca on the surface of calcium-containing gangue minerals 2+ to form stable five- or six-membered ring complexes. The negatively charged property of water glass further enhances the electrostatic repulsion on the surface of calcium-containing gangue minerals, reduces the active sites on the surface of calcium-containing gangue minerals, and makes the chelation reaction more effective. This complex preferentially covers the active sites on the surface of gangue minerals, preventing the adsorption of the collector. At the same time, the silicic acid colloid generated by the hydrolysis of water glass adsorbs on the surface of gangue that is not completely covered by the organic chelating agent through hydrogen bonds and van der Waals forces to form a physical barrier, further inhibiting the floating of gangue. Moreover, Na in water glass + can adjust the pH of the pulp, promote the hydroxylation of the surface of rare earth minerals, and enhance the adsorption of the collector.

[0016] Preferably, the pH of the pulp is 8.8 - 10. The pH value has an important influence on the electrical properties and chemical states of the mineral surface, which is beneficial to inhibiting the flotation of calcium-containing gangue minerals.

[0017] Preferably, the flotation process is one roughing, one scavenging, and two cleanings; and during the flotation process, the dosages of reagents gradually decrease during roughing, first cleaning, second cleaning, and scavenging. Preferably, during the flotation process, the dosage of the combined inhibitor is 800 g / t - 2000 g / t, the dosage of the collector is 1000 g / t - 2500 g / t, and the dosage of the frother is 10 g / t - 150 g / t.

[0018] It should be noted that during roughing, add the combined inhibitor to the pulp. The combined inhibitor preferentially chelates Ca on the surface of gangue 2+, the water glass colloid covers the residual active sites; successively add the collector and the frother, stir for 2 min to 3 min in batches, and carry out air flotation for 2 min to 3 min. The foam product obtained is the rougher concentrate, and the bottom product obtained is the rougher tailings. During the cleaning process, adjust the concentration of the rougher concentrate to 30% - 60%, then successively add the combined inhibitor, the collector and the frother, stir for 2 min to 3 min in batches, and carry out air flotation for 3 min to 4 min to further remove the entrained fine-grained gangue and improve the concentrate grade. The foam product obtained is the first cleaning concentrate, and the bottom product obtained is the first cleaning middlings, and the first cleaning middlings are returned as the rougher feed. During the second cleaning process, adjust the concentration of the first cleaning concentrate to 30% - 60%, carry out the second cleaning, also add the combined inhibitor, the collector and the frother, stir for 2 min to 3 min in batches, and carry out air flotation for 3 min to 4 min. The foam product obtained is the second cleaning concentrate, and the bottom product obtained is the second cleaning middlings, and the second cleaning middlings are returned as the first cleaning flotation feed. During the scavenging process, successively add the combined inhibitor, the collector and the frother to the rougher tailings, stir for 2 min to 3 min in batches, and carry out air flotation for 3 min to 4 min to recover the rare earth minerals that are not fully floated in the rougher tailings, improve the recovery rate. The foam product obtained is the scavenging concentrate, and the bottom product obtained is the scavenging tailings, and the scavenging concentrate is returned as the rougher feed.

[0019] Preferably, the collector is a hydroxamic acid reagent, and the hydroxamic acid collector is one of octyl hydroxamic acid, benzohydroxamic acid and naphthohydroxamic acid; the mass percentage of the collector is 1% - 20%.

[0020] Preferably, the frother is No. 2 oil or pine oil.

[0021] The collector enhances its flotability through the affinity with the surface of rare earth minerals. While inhibiting the calcium-containing gangue minerals, it ensures that the rare earth minerals can be effectively trapped by the foam, improving the recovery rate. The frother can stabilize the bubbles at the mineral interface, increase the buoyancy of the foam, ensure that the rare earth minerals can effectively adhere to the bubbles, and enhance their separation effect during the flotation process.

[0022] Preferably, the temperature of the flotation is 50°C - 60°C.

[0023] Preferably, the particle size fraction less than 0.074 mm in the rare earth raw ore accounts for 80% - 90%, the mass percentage of the pulp is 30% - 60%, and the pH of the pulp is 8.8 - 10.

[0024] Compared with the prior art, the present invention has the following beneficial effects: 1. The present invention uses a combined inhibitor composed of an aqueous solution of an organic chelating agent and an aqueous solution of sodium silicate. By virtue of the good compatibility between the macromolecular polymer in the organic chelating agent and the silicate ions in sodium silicate, it has a synergistic inhibitory effect on calcium-containing gangue minerals, solving the technical problem in the prior art that it is difficult to selectively and efficiently inhibit calcium-containing gangue minerals during the flotation of rare earths.

[0025] 2. Through the selective inhibition of gangue minerals by the combined inhibitor of the present invention and the synergistic inhibitory effect of the organic chelating agent and sodium silicate in the combined inhibitor, the adsorption of the collector on the surface of rare earth minerals is further enhanced, which is beneficial to the efficient separation of rare earth minerals in the iron ore tailings of Bayan Obo, improves the flotation separation effect between rare earths and calcium-containing gangue minerals, and realizes the efficient recovery of rare earth minerals in the iron ore tailings of Bayan Obo.

[0026] 3. The combined inhibitor of the present invention is applied to the production process of rare earth flotation separation in the iron ore tailings of Bayan Obo, which can improve the selectivity of the inhibitor for rare earth minerals during the flotation separation process, and has the advantages of environmental friendliness, easy degradation, reducing the dosage of the inhibitor, and non-toxic beneficiation wastewater, thereby reducing the production cost of flotation of calcium-containing rare earth minerals, solving the problems of poor flotation indexes of rare earths in the iron ore tailings of Bayan Obo, excessive pollution emissions of "three wastes" in subsequent rare earth smelting, and being unfavorable to the green and low-carbon development of the rare earth industrial chain. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] Figure 1 It is a schematic flow chart of the process for flotation separation and recovery of rare earths from iron ore tailings of the present invention. DETAILED DESCRIPTION OF THE INVENTION

[0028] In order to enable those skilled in the art to better understand and implement the technical solutions of the present invention, the present invention will be further described below in conjunction with specific embodiments and the drawings.

[0029] In the description of the present invention, unless otherwise specified, the reagents used are commercially available, and the methods used are conventional techniques in the art.

[0030] It should be noted that in the process of rare earth flotation separation, a single organic chelating inhibitor is usually not used as a reagent. This is because when using a single organic chelating agent alone, a relatively high dosage is often required to achieve an ideal flotation effect, resulting in a high overall flotation cost and limiting large-scale industrial applications.

[0031] Therefore, the present invention develops a combined inhibitor composed of an aqueous solution of an organic chelating agent and an aqueous solution of sodium silicate. By using the combined inhibitor synergistically, while improving the flotation efficiency, the flotation cost is reduced, and the combined inhibitor has the advantages of environmental friendliness and easy degradation.

[0032] The full English name of rare earth oxide is rare earth oxide, and the English abbreviation is REO. In the following examples, the modulus of sodium silicate is 2.5 for all.

[0033] Figure 1 It is a schematic diagram of the beneficiation separation process flow of iron ore tailings flotation. As Figure 1 shown, the flotation process of the present invention is one roughing, one scavenging and two cleaning; a combined inhibitor, a collector and a frother are sequentially added to the raw ore for roughing of the raw ore, and the foam product obtained is the rough concentrate; the product at the bottom of the cell is the roughing tailings. A combined inhibitor, a collector and a frother are sequentially added to the rough concentrate for the first cleaning, and the first cleaning is denoted as cleaning I, and the foam product obtained is the first cleaning concentrate; the product at the bottom of the cell is the middlings of the first cleaning, and the middlings of the first cleaning are returned as the roughing feed. A combined inhibitor, a collector and a frother are sequentially added to the first cleaning concentrate for the second cleaning, and the second cleaning is denoted as cleaning II, and the foam product obtained is the second cleaning concentrate, the product at the bottom of the cell is the middlings of the second cleaning, and the middlings of the second cleaning are returned as the flotation feed of the first cleaning. A combined inhibitor, a collector and a frother are sequentially added to the roughing tailings for scavenging, and the foam product obtained is the scavenging concentrate; the product at the bottom of the cell is the scavenging tailings, and the scavenging concentrate is returned as the roughing feed.

[0034] Example 1 This example provides a combined inhibitor.

[0035] In this example, the combined inhibitor is formed by mixing an aqueous solution of polyaspartic acid with a mass percentage of 2% and an aqueous solution of sodium silicate with a mass percentage of 5%, and the mass ratio of polyaspartic acid to sodium silicate is 2:25.

[0036] Example 2 This example provides a combined inhibitor.

[0037] The combined inhibitor is formed by mixing an aqueous solution of hydrolyzed polymaleic acid with a mass percentage of 10% and an aqueous solution of sodium silicate with a mass percentage of 2%, and the mass ratio of hydrolyzed polymaleic acid to sodium silicate is 1:5.

[0038] Example 3 This example provides a combined inhibitor.

[0039] The combined inhibitor is formed by mixing an aqueous solution of carboxymethyl chitosan with a mass percentage of 5% and an aqueous solution of sodium silicate with a mass percentage of 8%, and the mass ratio of carboxymethyl chitosan to sodium silicate is 2:15.

[0040] Comparative Example 1 This comparative example provides an inhibitor.

[0041] The combined inhibitor is an aqueous solution of sodium silicate, and the mass concentration of the aqueous solution of sodium silicate is 5%.

[0042] Application Example 1 This application example provides a method for flotation of rare earth ores containing calcium.

[0043] Taking the rare earth sample from a tailings pond in Inner Mongolia as the raw ore, the REO grade is 8.47%.

[0044] Use the combined inhibitor prepared in Example 1 for flotation. The specific flotation method is as follows: Step 1: Prepare a pulp with a concentration of 55% from the raw ore, heat it to 60 °C, adjust the pH to 9.5, and stir for 2 min.

[0045] Step 2: Flotation process: Rougher flotation: Add 1000 g / t of the combined inhibitor to the pulp, stir for 3 min; add 1400 g / t of benzohydroxamic acid, stir for 3 min; then add 30 g / t of No. 2 oil, stir for 3 min; then aerate and stir, and scrape foam for 5 min. The foam product on the cell surface is the rougher concentrate, and the product at the bottom of the cell is the rougher tailings.

[0046] First cleaning: Adjust the rougher concentrate into a pulp with a concentration of 45%, stir for 2 min; add 800 g / t of the combined inhibitor, stir for 3 min; then add 1200 g / t of octyl hydroxamic acid, stir for 3 min; continue to add 20 g / t of No. 2 oil, stir for 3 min; then aerate and stir, and scrape foam for 4 min. The foam product on the cell surface is the first cleaning concentrate; the product at the bottom of the cell is the first cleaning middlings.

[0047] Second cleaning: Adjust the first cleaning concentrate into a pulp with a concentration of 40%, stir for 2 min; add 600 g / t of the combined inhibitor, stir for 3 min; then add 1000 g / t of hydroxamic acid collector, stir for 3 min; continue to add 10 g / t of No. 2 oil, stir for 3 min; then aerate and stir, and scrape foam for 3 min. The foam product on the cell surface is the second cleaning concentrate, that is, the rare earth concentrate; the product at the bottom of the cell is the second cleaning middlings.

[0048] Scavenging: Add 800 g / t of the combined inhibitor to the rougher tailings, stir for 3 min; then add 1200 g / t of hydroxamic acid collector, stir for 3 min; continue to add 20 g / t of No. 2 oil, stir for 3 min; then aerate and stir, and scrape foam for 1 min. The product on the cell surface is the scavenging concentrate; the product at the bottom of the cell is the scavenging tailings, that is, the rare earth tailings.

[0049] Return the first cleaning middlings as the rougher feed, and return the second cleaning middlings as the first cleaning feed; return the scavenging concentrate as the rougher feed, and repeat the above rougher flotation, first cleaning and second cleaning.

[0050] Application Example 2 This application example provides a method for flotation of rare earth ores containing calcium.

[0051] The difference between this application example and Application Example 1 is as follows: This application example uses the combined inhibitor of Example 2 for flotation.

[0052] Application Example 3 This application example provides a method for flotation of rare earth ores containing calcium.

[0053] The difference between this application example and Application Example 1 is as follows: This application example uses the combined inhibitor of Example 3 for flotation.

[0054] Application Example 4 This application example provides a method for flotation of rare earth ores containing calcium.

[0055] The difference between this application example and Application Example 1 is as follows: The REO grade of the raw ore in this application example is 6.8%.

[0056] Application Example 5 This application example provides a method for flotation of rare earth ores containing calcium.

[0057] The difference between this application example and Application Example 1 is as follows: The REO grade of the raw ore in this application example is 6.8%, and the combined inhibitor of Example 2 is used for flotation.

[0058] Application Example 6 This application example provides a method for flotation of rare earth ores containing calcium.

[0059] The difference between this application example and Application Example 1 is as follows: The REO grade of the raw ore in this application example is 6.8%, and the combined inhibitor of Example 3 is used for flotation.

[0060] Application Example 7 This application example provides a method for flotation of rare earth ores containing calcium.

[0061] The difference between this application example and Application Example 1 is as follows: The REO grade of the raw ore in this application example is 9.58%.

[0062] Application Example 8 This application example provides a method for flotation of rare earth ores containing calcium.

[0063] The difference between this application example and Application Example 1 is as follows: In the example of this application, the REO grade of the raw ore is 9.58%, and the combined inhibitor of Example 2 is used for flotation.

[0064] Example of Application 9 The example of this application provides a method for flotation of rare earth ores containing calcium.

[0065] The difference between the example of this application and Example 1 of the application is: In the example of this application, the REO grade of the raw ore is 9.58%, and the combined inhibitor of Example 3 is used for flotation.

[0066] Comparative Example 1 of Application This comparative example of the application provides a method for flotation of rare earth ores containing calcium.

[0067] The difference between this comparative example of the application and Example 1 of the application is: In Comparative Example 1 of this application, the inhibitor of Comparative Example 1 is used for flotation.

[0068] Comparative Example 2 of Application This comparative example of the application provides a method for flotation of rare earth ores containing calcium.

[0069] The difference between this comparative example of the application and Example 1 of the application is: In this comparative example of the application, the REO grade of the raw ore is 6.8%, and the inhibitor of Comparative Example 1 is used for flotation.

[0070] Comparative Example 3 of Application This comparative example of the application provides a method for flotation of rare earth ores containing calcium.

[0071] The difference between this comparative example of the application and Example 1 of the application is: In this comparative example of the application, the REO grade of the raw ore is 9.58%, and the inhibitor of Comparative Example 1 is used for flotation.

[0072] Table 1 Flotation Results of Application Examples 1 - 3 and Comparative Example 1 of Application As can be seen from Table 1, when the combined inhibitors of Examples 1 - 3 are used for flotation of rare earth ores in a tailings pond in Inner Mongolia, the flotation effect is good. From Comparative Example 1 of the application, when the inhibitor is only water glass, the grade of the flotation concentrate is 48.15%; under the action of the combined inhibitor, the grades of the flotation concentrates of Application Examples 1 - 3 are increased to 59.35%, 58.14% and 62.67% respectively. In summary, the combined inhibitor has a remarkable flotation effect on rare earth ores in a tailings pond in Inner Mongolia.

[0073] Table 2 Flotation Results of Application Examples 4 - 6 and Comparative Example 2 of Application As can be seen from Table 2, when the inhibitor is only water glass, the grade of the flotation concentrate in Comparative Example 2 is 45.75%; while when using a combined inhibitor, the grades of the flotation concentrates in Examples 4 to 6 are increased to 60.89%, 58.68% and 62.01%. Compared with using a single water glass as the inhibitor in Comparative Example 2, under the action of the combined inhibitor, the grade of the flotation concentrate is increased by 13% - 16%. In summary, the combined inhibitor has a good effect on the iron tailings of Bayan Obo and can be applied to industrial production.

[0074] Table 3 Flotation results of Examples 7 to 9 and Comparative Example 3 As can be seen from Table 3, when the inhibitor is only water glass, the grade of the flotation concentrate in Comparative Example 3 is 53.49%; while under the action of the combined inhibitor, the grades of the flotation concentrates in Examples 7 to 9 are increased to 62.49%, 60.64% and 66.13% respectively, and the grade of the flotation concentrate is increased by about 10%. In summary, using the combined inhibitor of the present invention achieves better rare earth flotation indexes than the conventional water glass inhibitor, and the reagent is green and environmentally friendly, which is beneficial to the green and low-carbon development of the rare earth industry.

[0075] Obviously, those skilled in the art can make various changes and modifications to the present invention without departing from the spirit and scope of the present invention. If these modifications and variations of the present invention fall within the scope of the equivalent technology of the present invention, the present invention also intends to include these changes and modifications.

Claims

1. A combined inhibitor, characterized in that, The combined inhibitor is a combination of an aqueous solution of an organic chelating agent and an aqueous solution of water glass; The organic chelating agent is one of polyaspartic acid, hydrolyzed polymaleic acid, and carboxymethyl chitosan; The mass ratio of the organic chelating agent to water glass is 2:10 - 25; The mass percentage of the aqueous solution of the organic chelating agent is 2% - 10%, and the mass percentage of the aqueous solution of water glass is 5% - 8%.

2. The combined inhibitor according to claim 1, wherein The molecular weight of polyaspartic acid is 1000 - 5000; the molecular weight of hydrolyzed polymaleic acid is 400 - 800; the modulus of water glass is 2.

5.

3. A method for flotation of rare earth ores containing calcium, characterized in that, Flotation is carried out using the combined inhibitor according to any one of claims 1 - 3, including the following steps: Grind the rare earth raw ore, add water to prepare a pulp, and adjust the pH; Add the combined inhibitor, collector, and frother to the pulp in sequence for flotation to obtain rare earth concentrate.

4. The method for flotation of rare earth ores containing calcium according to claim 3, characterized in that, The collector is a hydroxamic acid reagent, and the mass percentage of the collector is 1% - 20%.

5. The method for flotation of rare earth ores containing calcium according to claim 3, characterized in that, The frother is No. 2 oil or pine oil.

6. The method for flotation of rare earth ores containing calcium according to claim 3, characterized in that, The temperature of flotation is 50°C - 60°C.

7. The method for flotation of rare earth ores containing calcium according to claim 3, characterized in that, The particle size fraction less than 0.074mm in the rare earth raw ore accounts for 80% - 90%, the mass percentage of the pulp is 30% - 60%, and the pH of the pulp is 8.8 - 10.

8. The method for flotation of rare earth ores containing calcium according to claim 3, characterized in that, During the flotation process, the dosage of the combined inhibitor is 800g / t - 2000g / t, the dosage of the collector is 1000g / t - 2500g / t, and the dosage of the frother is 10g / t - 150g / t.

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