Rare earth ore direct flotation combined collector, method of preparation and flotation method using the same

Abstract

The present application provides a kind of rare earth ore positive flotation combined collector, preparation method and the flotation method using it, the rare earth ore positive flotation combined collector includes the following components: alpha chlorinated fatty acid, alkyl hydroxamic acid, second oil and sodium hydroxide solution.The mass ratio of alpha chlorinated fatty acid and alkyl hydroxamic acid is 2-3:1;Second oil is 2-5% of the mass sum of alpha chlorinated fatty acid and alkyl hydroxamic acid;The mass concentration of sodium hydroxide solution is 10-20%, and its mass is 1-2 times of the mass sum of alpha chlorinated fatty acid, alkyl hydroxamic acid and second oil.The present application provides the preparation method of the rare earth ore positive flotation combined collector and the rare earth flotation method using it, the rare earth ore positive flotation combined collector has the advantages of high efficiency, low temperature resistance, green environmental protection, is used for mineral type rare earth ore separation with high mud content and fine dissemination size, can significantly improve the grade and recovery rate of flotation concentrate.

Description

Technical Field

[0001] This invention relates to the field of mineral processing technology. More specifically, this invention relates to a combined collector for the positive flotation of rare earth ores, its preparation method, and its application in flotation. Background Technology

[0002] The main method for separating rare earth minerals from rare earth ores is flotation. The key to achieving good results in flotation separation is finding rare earth mineral collectors with strong collecting power and good selectivity. Since the 1960s, mineral processing researchers both domestically and internationally have conducted extensive basic research on rare earth ore flotation collectors, developing various types of collectors. Carboxylic acid rare earth collectors, represented by oleic acid, benzoic acid, and phthalic acid, have good selectivity but poor collecting capacity. They require strict pH control during flotation, necessitate pulp heating, and have low recovery rates and concentrate grades. Therefore, they generally need to be used in combination with other collectors.

[0003] For example, Chinese invention patent CN105057112A discloses a rare earth mineral collector and its preparation method. It mixes fatty acids with an iodine value of 90-130 with Span-80 and various hydroxamic acids to prepare a collector suitable for positive flotation of rare earth minerals with coarse crystal size. However, it cannot achieve good separation results for low-grade rare earth minerals with high slime content, complex mineral composition, and fine particle size. Currently, most rare earth mine flotation operations use hydroxamic acid collectors with strong collecting properties, such as alkyl hydroxamic acids, cycloalkyl hydroxamic acids, phenyl hydroxamic acids, and naphthyl hydroxamic acids (e.g., H2O5). Chinese invention patent CN106008266A introduces a short-process, pollutant-free preparation method for synthesizing alkyl hydroxamic acids from fatty acids. Chinese invention patents CN114276276A and CN113522533A disclose a chelating rare earth collector of 2,5-dihydroxy-4-tert-butylbenzohydroxyxamic acid and 2,5-diamino-4-alkoxybenzohydroxyxamic acid. Examples of these collectors have verified that both collectors have good collecting ability and low-temperature resistance, and can improve the concentrate grade and recovery rate of rare earth minerals. However, the reagents are expensive, require large amounts, are highly toxic, difficult to degrade, and have weak foaming properties. Summary of the Invention

[0004] The purpose of this invention is to provide a combined collector for positive flotation of rare earth minerals, a preparation method thereof, and a flotation method using the same. This combined collector for positive flotation of rare earth minerals has the advantages of high efficiency, low temperature resistance, and environmental friendliness. It can be used for the separation of mineral-type rare earth minerals with high mud content and fine particle size, and can significantly improve the grade and recovery rate of flotation concentrate.

[0005] To achieve these objectives and other advantages according to the present invention, a rare earth ore positive flotation collector is provided, comprising the following components:

[0006] α-chloro fatty acids, alkyl hydroxamic acids, No. 2 oil, and sodium hydroxide solution.

[0007] The mass ratio of α-chloro fatty acids to alkyl hydroxamic acids is 2-3:1; the mass of No. 2 oil is 2-5% of the sum of the masses of α-chloro fatty acids and alkyl hydroxamic acids; the mass concentration of sodium hydroxide solution is 10-20%, and its mass is 1-2 times the total mass of α-chloro fatty acids, alkyl hydroxamic acids and No. 2 oil.

[0008] This invention also provides a method for preparing the above-mentioned rare earth ore positive flotation combined collector, comprising the following steps:

[0009] S1, synthesizing α-chloro fatty acids;

[0010] S2, Synthesis of alkyl hydroxyoxime acids;

[0011] S3. Mix the α-chloro fatty acid obtained in S1 and the alkyl hydroxamic acid obtained in S2 at a mass ratio of 2-3:1, add 2-5% of No. 2 oil (based on the total mass of the two), mix evenly to obtain a mixture, add 1-2 times the mass of the mixture to a 10-20% sodium hydroxide solution, saponify for 5-10 minutes, and obtain a pre-product.

[0012] S4. Dilute the pre-product with water by 10-50 times to obtain the rare earth ore positive flotation combined collector.

[0013] Preferably, in the preparation method of the rare earth ore positive flotation combined collector, the synthesis method of α-chloro fatty acid in S1 is as follows:

[0014] Melt 80-100 parts by weight of fatty acid, add 3-5 parts by weight of catalyst PCl3, stir continuously for 1-2 hours, raise the reaction temperature to 90-100℃ and introduce chlorine gas, continue the reaction for 2-3 hours, stop introducing chlorine gas and continue the reaction under reflux. After the reaction is completed, extract the unreacted chlorine gas and residual HCl to obtain α-chloro fatty acid.

[0015] Preferably, in the preparation method of the rare earth ore positive flotation combined collector, the fatty acid in S1 is melted at a temperature of 50-70℃.

[0016] Preferably, in the preparation method of the rare earth ore positive flotation combined collector, the flow rate of chlorine gas introduced into S1 is 150-200 mL / min, and the reaction reflux time after stopping the introduction of chlorine gas is 5-7 hours.

[0017] Preferably, in the preparation method of the rare earth ore positive flotation combined collector, the synthesis method of the alkyl hydroxamic acid in S2 is as follows:

[0018] Mix 80-100 parts by weight of fatty acid with 30-40 parts by weight of catalyst PCl3 at 50℃-70℃, stir and reflux for 3-5 hours, then add 30-40 parts by weight of hydroxylamine hydrochloride, and continue stirring for 8-10 hours. During the stirring reaction, add 20-30% sodium hydroxide aqueous solution dropwise to maintain the pH of the reaction system at 11-12. After the reaction is completed, adjust the pH to 3-5 with 10-20% dilute hydrochloric acid. After filtration and drying, alkyl hydroxyxamic acid is obtained.

[0019] Preferably, in the method for preparing a combined collector for positive flotation of rare earth minerals, the fatty acids used in S1 and S2 are C8-C. 18 Saturated fatty acids.

[0020] The present invention also provides a rare earth flotation method using the above-mentioned rare earth ores positive flotation combined collector, comprising the following steps:

[0021] A. Crush rare earth ore to a particle size of less than 0.074 mm, where the proportion of ore particles is 60-90%.

[0022] B. Perform a rough flotation on the rare earth ore powder crushed in step A to obtain rough concentrate and rough tailings;

[0023] During the rough flotation, the amount of water glass used is 400-800 g / t, the amount of the combined collector used in the positive flotation of rare earth minerals is 600-1000 g / t, the pH value of the pulp is 8-9.5, and the mass concentration of the pulp is 30-40%.

[0024] C. Perform a scavenging process on the roughing tailings obtained in step B to obtain flotation tailings;

[0025] During scavenging, the dosage of the collector in the positive flotation combination of rare earth ore is 200-300 g / t;

[0026] D. Perform three fine flotations on the rough concentrate obtained in step B to obtain flotation concentrate, and use the flotation concentrate as rare earth concentrate.

[0027] During fine flotation, the amount of water glass used is 100-200 g / t, and the amount of collector used in the positive flotation of rare earth minerals is 200-300 g / t.

[0028] Preferably, in the rare earth flotation method, the concentrate obtained from the scavenging in step C and the tailings obtained from the first fine flotation in step D are returned to the feed for the next roughing flotation; the tailings obtained from the second fine flotation in step D are returned to the feed for the first fine flotation in the next step D; and the tailings obtained from the third fine flotation in step D are returned to the feed for the second fine flotation in the next step D.

[0029] Preferably, in the rare earth flotation method, the rough flotation time in step B is 4-6 minutes and the temperature is 15-40℃; the scavenging time in step C is 1-2 minutes; and the fine flotation time in step D is 1-2 minutes and the temperature is 15-40℃.

[0030] The beneficial effects of this invention are:

[0031] 1. The rare earth ore positive flotation combined collector of the present invention is made from inexpensive and readily available fatty acids as raw materials, and the reagent cost can be reduced by 10-30% compared with industrial collectors such as H2O5 and salicylic acid hydroxamic acid.

[0032] 2. The rare earth ore positive flotation combined collector of the present invention has the characteristics of good water solubility, low temperature resistance, easy dispersion, stable performance, non-corrosiveness, low toxicity and easy degradation. It can be adapted to rare earth flotation under normal temperature conditions, and the amount of reagent used can be reduced by 20-40% compared with conventional collectors.

[0033] 3. The rare earth flotation method of the present invention, which combines a rare earth ores positive flotation collector with a 1-roughing, 3-cleaning, and 1-scavenging rare earth flotation process, can not only obtain rare earth products of better quality, but also greatly reduce the loss of rare earth minerals in tailings, ensure the recovery rate of rare earth minerals, and maximize economic benefits.

[0034] Other advantages, objectives and features of the present invention will become apparent in part from the following description, and in part from those skilled in the art through study and practice of the invention. Attached Figure Description

[0035] Figure 1 This is a flowchart of the preparation method of the rare earth ore positive flotation combined collector according to the present invention;

[0036] Figure 2 This is a flowchart of the rare earth flotation method using a combination of collectors for positive flotation of rare earth ores, as described in this invention. Detailed Implementation

[0037] The present invention will now be described in further detail with reference to the accompanying drawings, so that those skilled in the art can implement it based on the description.

[0038] It should be noted that, unless otherwise specified, the experimental methods described in the following embodiments are all conventional methods, and the reagents and materials described are all commercially available unless otherwise specified. In the description of this invention, the terms "lateral", "longitudinal", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", and "outer" indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this invention.

[0039] Embodiments of the present invention provide a rare earth ore positive flotation combined collector, comprising the following components:

[0040] α-chloro fatty acids, alkyl hydroxamic acids, No. 2 oil, and sodium hydroxide solution.

[0041] The mass ratio of α-chloro fatty acids to alkyl hydroxamic acids is 2-3:1; the mass of No. 2 oil is 2-5% of the sum of the masses of α-chloro fatty acids and alkyl hydroxamic acids; the mass concentration of sodium hydroxide solution is 10-20%, and its mass is 1-2 times the total mass of α-chloro fatty acids, alkyl hydroxamic acids and No. 2 oil.

[0042] Among them, No. two oil is a chemical substance with the molecular formula ROH (R-alkane group).

[0043] like Figure 1 As shown, embodiments of the present invention also provide a method for preparing the above-mentioned rare earth ore positive flotation combined collector, comprising the following steps:

[0044] S1, synthesizing α-chloro fatty acids;

[0045] Specifically, 80-100 parts by weight of fatty acids are melted at 50-70℃, and 3-5 parts by weight of catalyst PCl3 are added. After stirring continuously for 1-2 hours, the reaction temperature is raised to 90-100℃ and chlorine gas is introduced. After reacting for 2-3 hours, the chlorine gas is stopped and the reaction is continued under reflux. The chlorine gas flow rate is 150-200 mL / min. After stopping the chlorine gas, the reaction continues under reflux for 5-7 hours. After the reaction is completed, the unreacted chlorine gas and residual HCl are extracted to obtain α-chloro fatty acids. The chlorine gas flow rate in S1 is 150-200 mL / min, and the reaction continues under reflux for 5-7 hours after stopping the chlorine gas.

[0046] S2, Synthesis of alkyl hydroxyoxime acids;

[0047] Specifically, 80-100 parts by weight of fatty acids and 30-40 parts by weight of catalyst PCl3 are mixed at 50℃-70℃ and stirred under reflux for 3-5 hours. Then, 30-40 parts by weight of hydroxylamine hydrochloride are added and the reaction is continued to be stirred for 8-10 hours. During the stirring reaction, a 20-30% sodium hydroxide aqueous solution is added dropwise to maintain the pH of the reaction system at 11-12. After the reaction is completed, the pH is adjusted to 3-5 with a 10-20% dilute hydrochloric acid solution. After filtration and drying, alkyl hydroxyxamic acid is obtained.

[0048] S3. Mix the α-chloro fatty acid obtained in S1 and the alkyl hydroxamic acid obtained in S2 at a mass ratio of 2-3:1, add 2-5% of No. 2 oil (based on the total mass of the two), mix evenly to obtain a mixture, add 1-2 times the mass of the mixture to a 10-20% sodium hydroxide solution, saponify for 5-10 minutes, and obtain a pre-product.

[0049] S4. Dilute the pre-product with water by 10-50 times to obtain the rare earth ore positive flotation combined collector.

[0050] In this embodiment, the fatty acids used in S1 and S2 are C8-C18 saturated fatty acids, and the chemical reaction equations involved in S1-S3 are as follows:

[0051] Fatty acid α-chloro

[0052] Fatty acid acyl chloride:

[0053] Fatty acyl chloride oxime:

[0054] like Figure 2 As shown, embodiments of the present invention also provide a rare earth flotation method using the rare earth ore positive flotation combination collector, comprising the following steps:

[0055] A. Crush rare earth ore to a particle size of less than 0.074 mm, where the proportion of ore particles is 60-90%.

[0056] B. Perform a rough flotation on the rare earth ore powder crushed in step A to obtain rough concentrate and rough tailings;

[0057] During the rough flotation, the amount of water glass used is 400-800 g / t, the amount of the combined collector used in the positive flotation of rare earth minerals is 600-1000 g / t, the pH value of the pulp is 8-9.5, and the mass concentration of the pulp is 30-40%.

[0058] C. Perform a scavenging process on the roughing tailings obtained in step B to obtain flotation tailings;

[0059] During scavenging, the dosage of the collector in the positive flotation combination of rare earth ore is 200-300 g / t;

[0060] D. Perform three fine flotations on the rough concentrate obtained in step B to obtain flotation concentrate, and use the flotation concentrate as rare earth concentrate.

[0061] During fine flotation, the amount of water glass used is 100-200 g / t, and the amount of collector used in the positive flotation of rare earth minerals is 200-300 g / t.

[0062] Specifically, the concentrate obtained from the scavenging in step C and the tailings obtained from the first fine flotation in step D are returned to the feed for the next rough flotation; the tailings obtained from the second fine flotation in step D are returned to the feed for the first fine flotation in the next step D; and the tailings obtained from the third fine flotation in step D are returned to the feed for the second fine flotation in the next step D.

[0063] In step B, the rough flotation time is 4-6 minutes and the temperature is 15-40℃; in step C, the scavenging time is 1-2 minutes; and in step D, the fine flotation time is 1-2 minutes and the temperature is 15-40℃.

[0064] To demonstrate the beneficial effects of the rare earth ore positive flotation combined collector, its preparation method, and the rare earth flotation method using it, the following examples are provided for verification:

[0065] In the following examples, the synthetic raw materials fatty acids, PCl3, hydroxylamine hydrochloride, and sodium hydroxide were all commercially available analytical grade; the synthetic raw material No. 2 oil was a commercially available industrial product; the rare earth ore positive flotation combined collector synthesis device used a commercially available hydrothermal reactor; the flotation used a commercially available mechanically stirred flotation machine; the flotation pH adjuster used commercially available analytical grade NaOH and HCl; and the rare earth ore was fluorocarbon cerium ore with a REO grade of 0.5-6%.

[0066] <Example 1>

[0067] A rare earth ore positive flotation collector comprises the following components in parts by weight:

[0068] α-chloro fatty acids, alkyl hydroxamic acids, No. 2 oil, and sodium hydroxide solution.

[0069] The mass ratio of α-chloro fatty acids to alkyl hydroxamic acids is 2:1; the mass of No. 2 oil is 3% of the sum of the masses of α-chloro fatty acids and alkyl hydroxamic acids; the mass concentration of sodium hydroxide solution is 15%, and its mass is 1 times the total mass of α-chloro fatty acids, alkyl hydroxamic acids and No. 2 oil.

[0070] The preparation method of the above-mentioned rare earth ore positive flotation combined collector includes the following steps:

[0071] S1, synthesizing α-chloro fatty acids;

[0072] 100 parts by weight of capric acid (C 10 Fatty acids were melted at 70°C, and 3.5 parts by weight of catalyst PCl3 were added. After stirring continuously for 2 hours, the reaction temperature was raised to 90°C and chlorine gas was introduced at a flow rate of 180 mL / min. After the reaction was continued for 2 hours, the chlorine gas was stopped and the reaction was continued under reflux for 6 hours. After the reaction was completed, the unreacted chlorine gas and residual HCl were extracted. The reaction product was washed with water until the pH reached about 8, and the resulting light yellow liquid was the α-chloro fatty acid.

[0073] S2, Synthesis of alkyl hydroxyoxime acids;

[0074] 100 parts by weight of capric acid (C 10 Fatty acids were mixed with 40 parts by weight of catalyst PCl3 at 70°C and stirred under reflux for 3 hours. Then, 40 parts by weight of hydroxylamine hydrochloride were added, and the reaction was continued with stirring for 8 hours. During the reaction, a 20% sodium hydroxide aqueous solution was added dropwise to maintain the pH of the reaction system at approximately 11.5. After the reaction was completed, the pH was adjusted to below 5 with 10% dilute hydrochloric acid. The mixture was then filtered and dried to obtain alkyl hydroxyxamic acid.

[0075] S3. The α-chloro fatty acid obtained in S1 and the alkyl hydroxamic acid obtained in S2 are mixed at a mass ratio of 2:1. 3% of the total mass of the two oils is added. After mixing evenly, a 15% sodium hydroxide solution with a mass concentration of 1 times the mass of the mixture is added. After saponification for 5-10 minutes, a pre-product is obtained.

[0076] S4. Dilute the pre-product with water 50 times to obtain the rare earth ore positive flotation combined collector.

[0077] The rare earth flotation method using the above-mentioned rare earth ore positive flotation combined collector includes the following steps:

[0078] A. The rare earth ore is crushed until the proportion of ore particles with a diameter of less than 0.074 mm is 70%;

[0079] B. Perform a rough flotation on the rare earth ore powder crushed in step A to obtain rough concentrate and rough tailings;

[0080] During the rough flotation, the amount of water glass used is 400 g / t, the amount of rare earth ore positive flotation combined collector used is 700 g / t, the pulp pH value is 9, and the pulp mass concentration is 40%.

[0081] C. Perform a scavenging process on the roughing tailings obtained in step B to obtain flotation tailings;

[0082] During the scavenging process, the amount of collector used in the positive flotation combination of rare earth ore is 300g / t;

[0083] D. Perform three fine flotations on the rough concentrate obtained in step B to obtain flotation concentrate, and use the flotation concentrate as rare earth concentrate.

[0084] During fine flotation, the amount of water glass used is 100 g / t, and the amount of rare earth ore positive flotation combined collector used is 300 g / t.

[0085] Specifically, the concentrate obtained from the scavenging in step C and the tailings obtained from the first fine flotation in step D are returned to the feed for the next rough flotation; the tailings obtained from the second fine flotation in step D are returned to the feed for the first fine flotation in the next step D; and the tailings obtained from the third fine flotation in step D are returned to the feed for the second fine flotation in the next step D.

[0086] In step B, the rough flotation time is 6 minutes and the temperature is 30℃; in step C, the scavenging time is 2 minutes; and in step D, the fine flotation time is 2 minutes and the temperature is 30℃.

[0087] The rare earth ore used in this embodiment comes from Zhushan area, Hubei Province; its composition is shown in Table 1 (weight percentage);

[0088] Table 1 Chemical Multi-Element Analysis of Example 1

[0089] Element REO <![CDATA[Nb2O5]]> TFe <![CDATA[TiO2]]> <![CDATA[SiO2]]> <![CDATA[Al2O3]]> CaO <![CDATA[K2O]]> <![CDATA[Na2O]]> MgO content / % 2.34 0.11 6.31 1.66 39.80 10.00 8.71 4.98 0.38 1.60

[0090] The separation parameters of the rare earth flotation method using the above-mentioned rare earth ore positive flotation combined collector are as follows:

[0091] Table 2 Sorting Indicators for Example 1

[0092]

[0093] <Example 2>

[0094] A rare earth ore positive flotation collector comprises the following components in parts by weight:

[0095] α-chloro fatty acids, alkyl hydroxamic acids, No. 2 oil, and sodium hydroxide solution.

[0096] The mass ratio of α-chloro fatty acids to alkyl hydroxamic acids is 2:1; the mass of No. 2 oil is 3% of the sum of the masses of α-chloro fatty acids and alkyl hydroxamic acids; the mass concentration of sodium hydroxide solution is 15%, and its mass is 1 times the total mass of α-chloro fatty acids, alkyl hydroxamic acids and No. 2 oil.

[0097] The preparation method of the above-mentioned rare earth ore positive flotation combined collector includes the following steps:

[0098] S1, synthesizing α-chloro fatty acids;

[0099] 100 parts by weight of palmitic acid (C 16 Fatty acids were melted at 70°C, and 3.5 parts by weight of catalyst PCl3 were added. After stirring continuously for 2 hours, the reaction temperature was raised to 90°C and chlorine gas was introduced at a flow rate of 180 mL / min. After the reaction was continued for 2 hours, the chlorine gas was stopped and the reaction was continued under reflux for 6 hours. After the reaction was completed, the unreacted chlorine gas and residual HCl were extracted. The reaction product was washed with water until the pH reached about 8, and the resulting light yellow liquid was the α-chloro fatty acid.

[0100] S2, Synthesis of alkyl hydroxyoxime acids;

[0101] 100 parts by weight of palmitic acid (C 16 Fatty acids were mixed with 40 parts by weight of catalyst PCl3 at 70°C and stirred under reflux for 3 hours. Then, 40 parts by weight of hydroxylamine hydrochloride were added, and the reaction was continued with stirring for 8 hours. During the reaction, a 20% sodium hydroxide aqueous solution was added dropwise to maintain the pH of the reaction system at approximately 11.5. After the reaction was completed, the pH was adjusted to below 5 with 10% dilute hydrochloric acid. The mixture was then filtered and dried to obtain alkyl hydroxyxamic acid.

[0102] S3. The α-chloro fatty acid obtained in S1 and the alkyl hydroxamic acid obtained in S2 are mixed at a mass ratio of 2:1. 3% of the total mass of the two oils is added. After mixing evenly, a 15% sodium hydroxide solution with a mass concentration of 1 times the mass of the mixture is added. After saponification for 5-10 minutes, a pre-product is obtained.

[0103] S4. Dilute the pre-product with water 50 times to obtain the rare earth ore positive flotation combined collector.

[0104] The rare earth flotation method using the above-mentioned rare earth ore positive flotation combined collector includes the following steps:

[0105] A. The rare earth ore is crushed until the proportion of ore particles with a diameter of less than 0.074 mm is 70%;

[0106] B. Perform a rough flotation on the rare earth ore powder crushed in step A to obtain rough concentrate and rough tailings;

[0107] During the rough flotation, the amount of water glass used is 400 g / t, the amount of rare earth ore positive flotation combined collector used is 600 g / t, the pulp pH value is 9, and the pulp mass concentration is 40%.

[0108] C. Perform a scavenging process on the roughing tailings obtained in step B to obtain flotation tailings;

[0109] During the scavenging process, the amount of collector used in the positive flotation combination of rare earth ore is 300g / t;

[0110] D. Perform three fine flotations on the rough concentrate obtained in step B to obtain flotation concentrate, and use the flotation concentrate as rare earth concentrate.

[0111] During fine flotation, the amount of water glass used is 100g / t, and the amount of rare earth ore positive flotation combined collector used is 200g / t.

[0112] Specifically, the concentrate obtained from the scavenging in step C and the tailings obtained from the first fine flotation in step D are returned to the feed for the next rough flotation; the tailings obtained from the second fine flotation in step D are returned to the feed for the first fine flotation in the next step D; and the tailings obtained from the third fine flotation in step D are returned to the feed for the second fine flotation in the next step D.

[0113] In step B, the rough flotation time is 10 minutes and the temperature is 35°C; in step C, the scavenging time is 3 minutes; and in step D, the fine flotation time is 3 minutes and the temperature is 35°C.

[0114] The rare earth ore used in this embodiment comes from Zhushan area, Hubei Province; its composition is shown in Table 3 (weight percentage);

[0115] Table 3 Chemical Multi-Element Analysis of Example 2

[0116] Element REO <![CDATA[Nb2O5]]> TFe <![CDATA[TiO2]]> <![CDATA[SiO2]]> <![CDATA[Al2O3]]> CaO <![CDATA[K2O]]> <![CDATA[Na2O]]> MgO content / % 2.34 0.11 6.31 1.66 39.80 10.00 8.71 4.98 0.38 1.60

[0117] The separation parameters of the rare earth flotation method using the above-mentioned rare earth ore positive flotation combined collector are as follows:

[0118] Table 4 Sorting Indicators for Example 2

[0119]

[0120] <Example 3>

[0121] A rare earth ore positive flotation collector comprises the following components in parts by weight:

[0122] α-chloro fatty acids, alkyl hydroxamic acids, No. 2 oil, and sodium hydroxide solution.

[0123] The mass ratio of α-chloro fatty acids to alkyl hydroxamic acids is 2:1; the mass of No. 2 oil is 3% of the sum of the masses of α-chloro fatty acids and alkyl hydroxamic acids; the mass concentration of sodium hydroxide solution is 15%, and its mass is 1 times the total mass of α-chloro fatty acids, alkyl hydroxamic acids and No. 2 oil.

[0124] The preparation method of the above-mentioned rare earth ore positive flotation combined collector includes the following steps:

[0125] S1, synthesizing α-chloro fatty acids;

[0126] 100 parts by weight of capric acid (C 10 Fatty acids were melted at 70°C, and 3.5 parts by weight of catalyst PCl3 were added. After stirring continuously for 2 hours, the reaction temperature was raised to 90°C and chlorine gas was introduced at a flow rate of 180 mL / min. After the reaction was continued for 2 hours, the chlorine gas was stopped and the reaction was continued under reflux for 6 hours. After the reaction was completed, the unreacted chlorine gas and residual HCl were extracted. The reaction product was washed with water until the pH reached about 8, and the resulting light yellow liquid was the α-chloro fatty acid.

[0127] S2, Synthesis of alkyl hydroxyoxime acids;

[0128] 100 parts by weight of capric acid (C 10 Fatty acids were mixed with 40 parts by weight of catalyst PCl3 at 70°C and stirred under reflux for 3 hours. Then, 40 parts by weight of hydroxylamine hydrochloride were added, and the reaction was continued with stirring for 8 hours. During the reaction, a 20% sodium hydroxide aqueous solution was added dropwise to maintain the pH of the reaction system at approximately 11.5. After the reaction was completed, the pH was adjusted to below 5 with 10% dilute hydrochloric acid. The mixture was then filtered and dried to obtain alkyl hydroxyxamic acid.

[0129] S3. The α-chloro fatty acid obtained in S1 and the alkyl hydroxamic acid obtained in S2 are mixed at a mass ratio of 2:1. 3% of the total mass of the two oils is added. After mixing evenly, a 15% sodium hydroxide solution with a mass concentration of 1 times the mass of the mixture is added. After saponification for 5-10 minutes, a pre-product is obtained.

[0130] S4. Dilute the pre-product with water 50 times to obtain the rare earth ore positive flotation combined collector.

[0131] The rare earth flotation method using the above-mentioned rare earth ore positive flotation combined collector includes the following steps:

[0132] A. The rare earth ore is crushed until the proportion of ore particles with a diameter of less than 0.050 mm is 70%;

[0133] B. Perform a rough flotation on the rare earth ore powder crushed in step A to obtain rough concentrate and rough tailings;

[0134] During the rough flotation, the amount of water glass used is 400 g / t, the amount of rare earth ore positive flotation combined collector used is 600 g / t, the pulp pH value is 9, and the pulp mass concentration is 40%.

[0135] C. Perform a scavenging process on the roughing tailings obtained in step B to obtain flotation tailings;

[0136] During the scavenging process, the amount of collector used in the positive flotation combination of rare earth ore is 300g / t;

[0137] D. Perform three fine flotations on the rough concentrate obtained in step B to obtain flotation concentrate, and use the flotation concentrate as rare earth concentrate.

[0138] During fine flotation, the amount of water glass used is 100g / t, and the amount of rare earth ore positive flotation combined collector used is 200g / t.

[0139] Specifically, the concentrate obtained from the scavenging in step C and the tailings obtained from the first fine flotation in step D are returned to the feed for the next rough flotation; the tailings obtained from the second fine flotation in step D are returned to the feed for the first fine flotation in the next step D; and the tailings obtained from the third fine flotation in step D are returned to the feed for the second fine flotation in the next step D.

[0140] In step B, the rough flotation time is 6 minutes and the temperature is 30℃; in step C, the scavenging time is 2 minutes; and in step D, the fine flotation time is 2 minutes and the temperature is 30℃.

[0141] The rare earth ore used in this embodiment comes from the Bayan Obo region; its composition is shown in Table 5 (weight percentage).

[0142] Table 5 Chemical Multi-Element Analysis of Example 3

[0143] Element REO <![CDATA[Nb2O5]]> TFe <![CDATA[TiO2]]> <![CDATA[SiO2]]> BaO CaO <![CDATA[K2O]]> <![CDATA[Na2O]]> MgO content / % 2.25 0.12 33.08 0.36 0.50 0.39 19.34 0.026 0.030 8.97

[0144] The separation parameters of the rare earth flotation method using the above-mentioned rare earth ore positive flotation combined collector are as follows:

[0145] Table 6 Sorting Indicators for Example 3

[0146]

[0147] <Example 4>

[0148] A rare earth ore positive flotation collector comprises the following components in parts by weight:

[0149] α-chloro fatty acids, alkyl hydroxamic acids, No. 2 oil, and sodium hydroxide solution.

[0150] The mass ratio of α-chloro fatty acids to alkyl hydroxamic acids is 2:1; the mass of No. 2 oil is 3% of the sum of the masses of α-chloro fatty acids and alkyl hydroxamic acids; the mass concentration of sodium hydroxide solution is 15%, and its mass is 1 times the total mass of α-chloro fatty acids, alkyl hydroxamic acids and No. 2 oil.

[0151] The preparation method of the above-mentioned rare earth ore positive flotation combined collector includes the following steps:

[0152] S1, synthesizing α-chloro fatty acids;

[0153] 100 parts by weight of capric acid (C 10 Fatty acids were melted at 70°C, and 3.5 parts by weight of catalyst PCl3 were added. After stirring continuously for 2 hours, the reaction temperature was raised to 90°C and chlorine gas was introduced at a flow rate of 180 mL / min. After the reaction was continued for 2 hours, the chlorine gas was stopped and the reaction was continued under reflux for 6 hours. After the reaction was completed, the unreacted chlorine gas and residual HCl were extracted. The reaction product was washed with water until the pH reached about 8, and the resulting light yellow liquid was the α-chloro fatty acid.

[0154] S2, Synthesis of alkyl hydroxyoxime acids;

[0155] 100 parts by weight of capric acid (C 10 Fatty acids were mixed with 40 parts by weight of catalyst PCl3 at 70°C and stirred under reflux for 3 hours. Then, 40 parts by weight of hydroxylamine hydrochloride were added, and the reaction was continued with stirring for 8 hours. During the reaction, a 20% sodium hydroxide aqueous solution was added dropwise to maintain the pH of the reaction system at approximately 11.5. After the reaction was completed, the pH was adjusted to below 5 with 10% dilute hydrochloric acid. The mixture was then filtered and dried to obtain alkyl hydroxyxamic acid.

[0156] S3. The α-chloro fatty acid obtained in S1 and the alkyl hydroxamic acid obtained in S2 are mixed at a mass ratio of 2:1. 3% of the total mass of the two oils is added. After mixing evenly, a 15% sodium hydroxide solution with a mass concentration of 1 times the mass of the mixture is added. After saponification for 5-10 minutes, a pre-product is obtained.

[0157] S4. Dilute the pre-product with water 50 times to obtain the rare earth ore positive flotation combined collector.

[0158] The rare earth flotation method using the above-mentioned rare earth ore positive flotation combined collector includes the following steps:

[0159] A. The rare earth ore is crushed until the proportion of ore particles with a diameter of less than 0.050 mm is 70%;

[0160] B. Perform a rough flotation on the rare earth ore powder crushed in step A to obtain rough concentrate and rough tailings;

[0161] During the rough flotation, the amount of water glass used is 400 g / t, the amount of rare earth ore positive flotation combined collector used is 600 g / t, the pulp pH value is 9, and the pulp mass concentration is 40%.

[0162] C. Perform a scavenging process on the roughing tailings obtained in step B to obtain flotation tailings;

[0163] During the scavenging process, the dosage of the collector in the rare earth ore positive flotation combination is 200 g / t.

[0164] D. Perform three fine flotations on the rough concentrate obtained in step B to obtain flotation concentrate, and use the flotation concentrate as rare earth concentrate.

[0165] During fine flotation, the amount of water glass used is 100g / t, and the amount of rare earth ore positive flotation combined collector used is 200g / t.

[0166] Specifically, the concentrate obtained from the scavenging in step C and the tailings obtained from the first fine flotation in step D are returned to the feed for the next rough flotation; the tailings obtained from the second fine flotation in step D are returned to the feed for the first fine flotation in the next step D; and the tailings obtained from the third fine flotation in step D are returned to the feed for the second fine flotation in the next step D.

[0167] In step B, the rough flotation time is 6 minutes and the temperature is 30℃; in step C, the scavenging time is 2 minutes; and in step D, the fine flotation time is 2 minutes and the temperature is 30℃.

[0168] The rare earth ore used in this embodiment comes from Weishan area, Shandong Province; its composition is shown in Table 7 (weight percentage);

[0169] Table 7 Chemical Multi-Element Analysis of Example 4

[0170] Element REO <![CDATA[CaF2]]> <![CDATA[CaCO3]]> CaO <![CDATA[SiO2]]> <![CDATA[Al2O3]]> MgO <![CDATA[SrSO4]]> content / % 3.78 1.31 31.50 18.65 24.50 4.40 0.81 7.79

[0171] The separation parameters of the rare earth flotation method using the above-mentioned rare earth ore positive flotation combined collector are as follows:

[0172] Table 8 Sorting Indicators for Example 4

[0173]

[0174] As can be seen from Examples 1-4 above, the rare earth ore positive flotation combined collector of the present invention has a significant enrichment effect on rare earth ore. As can be seen from Examples 1 and 2, the selection of fatty acids has a certain impact on the recovery quality of the ore sample, and the enrichment effect is better when long carbon chain fatty acids are used. As can be seen from Examples 1, 3 and 4, the rare earth ore positive flotation combined collector of the present invention has a certain effect on minerals in different regions and has universality.

[0175] Although embodiments of the present invention have been disclosed above, they are not limited to the applications listed in the specification and embodiments. They can be applied to various fields suitable for the present invention. For those skilled in the art, other modifications can be easily made. Therefore, without departing from the general concept defined by the claims and their equivalents, the present invention is not limited to the specific details and embodiments shown and described herein.

Claims

1. A combined collector for the direct flotation of rare earth minerals, characterized in that it comprises a mixture of Comprise the following components: Alpha chloro fatty acid, alkyl hydroxamic acid, secondary oil and sodium hydroxide solution; Wherein the mass ratio of alpha chloro fatty acid and alkyl hydroxamic acid is 2-3:1; the mass of the secondary oil is 2-5% of the mass sum of alpha chloro fatty acid and alkyl hydroxamic acid; the mass concentration of sodium hydroxide solution is 10-20%, and its mass is 1-2 times the mass sum of alpha chloro fatty acid, alkyl hydroxamic acid and secondary oil.

2. A method for preparing a combined collector for positive flotation of rare earth minerals as described in claim 1, characterized in that, Comprise the following steps: S1, synthesis of alpha chloro fatty acid; S2, synthesis of alkyl hydroxamic acid; S3, the alpha chloro fatty acid obtained in S1 and the alkyl hydroxamic acid obtained in S2 are mixed in a mass ratio of 2-3:1, 2-5% of the mass sum of the two is added to the secondary oil, and the mixture is obtained after mixing uniformly, and the mass concentration of the sodium hydroxide solution is 10-20%, and its mass is 1-2 times the mass of the mixture, and after saponification for 5-10 minutes, the prepared product is prepared; S4, dilute the prepared product by 10-50 times with water, that is, the rare earth ore direct flotation combined collector is prepared.

3. A process for the preparation of a combined collector for the direct flotation of rare earth minerals as claimed in claim 2, wherein, The synthesis method of alpha chloro fatty acid in S1 is: Melt 80-100 parts by weight of fatty acid, add 3-5 parts by weight of catalyst PCl3, continuously stir for 1-2 hours, then increase the reaction temperature to 90-100℃ and pass chlorine, continue to react for 2-3 hours, then stop passing chlorine and continue to reflux, after the reaction is completed, the unreacted chlorine and residual HCl are extracted, and the alpha chloro fatty acid is obtained.

4. A process for the preparation of a combined collector for the direct flotation of rare earth minerals as claimed in claim 3, wherein, The fatty acid in S1 is melted at a temperature of 50-70℃.

5. The preparation method of a combined collector for positive flotation of rare earth minerals as described in claim 3, characterized in that, The flow rate of chlorine gas introduced in S1 is 150-200mL / min, and the time for continuing to reflux after stopping the introduction of chlorine gas is 5-7 hours.

6. The preparation method of a rare earth ore positive flotation combined collector as described in claim 3, characterized in that, The synthesis method of alkyl hydroxamic acid in S2 is: Mix 80-100 parts by weight of fatty acid with 30-40 parts by weight of catalyst PCl3 at 50-70℃, stir and reflux for 3-5 hours, then add 30-40 parts by weight of hydroxylamine hydrochloride, continue to stir for 8-10 hours, drop 20-30% sodium hydroxide solution in the stirring process, keep the pH of the reaction system at 11-12, after the reaction is completed, adjust the pH to 3-5 with 10-20% dilute hydrochloric acid, filter and dry, and the alkyl hydroxamic acid is obtained.

7. The preparation method of a combined collector for positive flotation of rare earth minerals as described in claim 6, characterized in that, The fatty acids used in S1 and S2 are C8-C 18 saturated fatty acids.

8. A rare earth flotation process using the rare earth ore positive flotation combined collector of claim 1, characterized in that, Comprise the following steps: A, the rare earth ore is crushed to a particle size of 60-90% of the total particle size of 0.074mm; B, the crushed rare earth ore in step A is subjected to one rough flotation to obtain rough concentrate and rough tailings; Wherein, during rough flotation, the dosage of water glass is 400-800g / t, the dosage of rare earth ore direct flotation combined collector is 600-1000g / t, the pH value of the ore pulp is 8-9.5, and the mass concentration of the ore pulp is 30-40%; C, the rough tailings obtained in step B are subjected to one scavenging to obtain flotation tailings; Wherein, during scavenging, the dosage of rare earth ore direct flotation combined collector is 200-300g / t; D, the rough concentrate obtained in step B is subjected to three times of fine flotation to obtain flotation concentrate, and the flotation concentrate is taken as rare earth concentrate; The water glass is used in an amount of 100-200 g / t, and the combined collector for positive flotation of rare earth ore is used in an amount of 200-300 g / t.

9. A rare earth flotation process as claimed in claim 8, wherein, The tailings obtained in the first step D are returned to the feed of the next step D; the tailings obtained in the second step D are returned to the feed of the next step D; and the tailings obtained in the third step D are returned to the feed of the next step D.

10. A rare earth flotation process as claimed in claim 8, characterised in that, The rough flotation in step B is performed for 4-6 min at a temperature of 15-40℃; the scavenging in step C is performed for 1-2 min; and the cleaning flotation in step D is performed for 1-2 min at a temperature of 15-40℃.

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