Methods for separating carbonate rare earth minerals and monazite

Abstract

This invention discloses a method for separating carbonate rare earth minerals and monazite, comprising the following steps: 1) grinding a mixed ore containing rare earth elements to obtain a grinding product; 2) sequentially adding a mixture of octanoyl hydroxamic acid and alkali metal oleate, a mixture of dextrin and alum, a mixture of water glass and ethylenediaminetetraacetic acid, and pine oil to the slurry of the grinding product, followed by aeration flotation to obtain a rougher concentrate and a rougher tailings; 3) subjecting the rougher concentrate to three cleaning processes to obtain a carbonate rare earth concentrate and a three-stage cleaning tailings; 4) subjecting the rougher tailings to two scavenging processes to obtain a secondary scavenging concentrate and a secondary scavenging tailings; 5) subjecting the secondary scavenging tailings to magnetic separation using a magnetic separator to obtain a monazite concentrate and a final tailings. This invention can separate carbonate rare earth concentrate and monazite concentrate.

Description

Technical Field

[0001] This invention relates to a method for separating carbonate rare earth minerals and monazite. Background Technology

[0002] The Bayan Obo mining area is a polymetallic deposit containing iron, rare earth elements, niobium, and other minerals. The mixed ore produced by the concentrator includes carbonate rare earth minerals, phosphate rare earth minerals, and gangue minerals. The main gangue minerals are dolomite, apatite, and fluorite. The main carbonate rare earth minerals are bastnaesite, Yellow River bastnaesite, and bastnaesite-calcium bastnaesite, while the main phosphate rare earth mineral is monazite. Currently, the main beneficiation method is flotation to obtain mixed rare earth concentrate (mainly including bastnaesite and monazite), which is then roasted using concentrated sulfuric acid. This roasting process has been used to this day due to its simplicity and low requirements for rare earth concentrate quality. However, because the bastnaesite and monazite minerals are not separated, a large amount of radioactive smelting waste is generated during roasting, resulting in environmental problems such as the waste of fluorine and phosphorus resources. Separating the carbonate rare earth minerals from the monazite in the mixed ore containing rare earth minerals may be a better way to solve these problems.

[0003] CN102886312A discloses a beneficiation method for separating bastnaesite and monazite from a high-grade mixed rare earth concentrate. The method includes: roasting the high-grade mixed rare earth concentrate; performing flotation separation of bastnaesite and monazite from the roasted ore using a fractionation beneficiation method consisting of a primary roughing, secondary cleaning, and tertiary scavenging process. The flotation modifier used is aluminum sulfate or alum, the collector is phthalic acid or N-hydroxyphthalimide, and the frother is No. 2 oil, yielding bastnaesite and monazite respectively. In this patent document, the high-grade mixed rare earth concentrate is roasted before flotation.

[0004] CN102886309A discloses a method for separating fluorocarbon cerium concentrate and monazite concentrate from a high-grade mixed rare earth concentrate, comprising: using fractionation beneficiation to separate fluorocarbon cerium concentrate and monazite concentrate from the high-grade mixed rare earth concentrate by flotation; and obtaining fluorocarbon cerium concentrate and monazite concentrate by one roughing, three cleaning, and four scavenging stages.

[0005] CN101474597A discloses a flotation separation method for monazite and bastnaesite in a mixed rare earth concentrate, comprising: using aluminum sulfate inhibitor, collector, and frother as flotation reagents to treat a bastnaesite mixed rare earth concentrate with high monazite content; and performing a primary separation roughing to obtain a primary roughing bastnaesite concentrate and a primary roughing monazite concentrate; re-adjusting the primary roughing bastnaesite concentrate and performing a secondary cleaning to obtain a secondary cleaned bastnaesite concentrate; and re-adjusting the primary roughing monazite concentrate and performing a secondary cleaning to obtain a secondary cleaned monazite concentrate. Summary of the Invention

[0006] In view of this, the purpose of the present invention is to provide a method for separating carbonate rare earth minerals and monazite. This method can separate carbonate rare earth minerals and monazite minerals from mixed ores containing rare earth elements, and can obtain carbonate rare earth concentrate and monazite concentrate, both of which have high purity and recovery rate.

[0007] The present invention achieves the above objectives using the following technical solutions.

[0008] This invention provides a method for separating carbonate rare earth minerals and monazite, comprising the following steps:

[0009] 1) Grinding a mixed ore containing rare earth elements to obtain grinding products; wherein the REO grade of the mixed ore containing rare earth elements is 50-62.4 wt%, and it includes carbonate rare earth minerals, phosphate rare earth minerals and gangue minerals; the phosphate rare earth minerals are mainly monazite.

[0010] 2) The grinding products are used to form a grinding product slurry, and the pH of the grinding product slurry is adjusted to 8.0-9.0. Then, the following materials are added sequentially to the grinding product slurry: a mixture of octanoyl hydroxamic acid and alkali metal oleate at a dosage of 0.9-1.5 kg / t; a mixture of dextrin and alum at a dosage of 0.45-1.0 kg / t; a mixture of water glass and ethylenediaminetetraacetic acid at a dosage of 0.55-0.8 kg / t; and pine oil at a dosage of 50-80 g / t. Aeration flotation is then performed to obtain rougher concentrate and rougher tailings. The dosage of each material is calculated based on 1 t of grinding product.

[0011] 3) To the rougher concentrate slurry, sequentially add 0.3–0.5 kg / t of a mixture of octanoyl hydroxamic acid and alkali metal oleate, 0.25–0.5 kg / t of a mixture of dextrin and alum, 0.3–0.6 kg / t of a mixture of water glass and ethylenediaminetetraacetic acid, and 30–40 g / t of pine oil, followed by aeration flotation to obtain primary concentrate and primary tailings; to the primary concentrate slurry, sequentially add 0.15–0.25 kg / t of a mixture of octanoyl hydroxamic acid and alkali metal oleate, 0.12–0.25 kg / t of a mixture of dextrin and alum, and 0.15–0.6 kg / t of pine oil, followed by aeration flotation to obtain primary concentrate and primary tailings. A mixture of water glass and ethylenediaminetetraacetic acid (EDTA) and pine oil (15–20 g / t) are added to the pulp of the secondary concentrate by aeration flotation to obtain a secondary concentrate and secondary tailings. Then, a mixture of octanoyl hydroxamic acid and alkali metal oleate (0.08–0.12 kg / t), a mixture of dextrin and alum (0.05–0.10 kg / t), a mixture of water glass and EDTA (0.07–0.10 kg / t), and pine oil (15–20 g / t) are added sequentially to the pulp of the secondary concentrate by aeration flotation to obtain a carbonate rare earth concentrate and tertiary tailings. The dosage of each material is calculated based on 1 t of grinding product.

[0012] 4) Add a mixture of octanoyl hydroxamic acid and alkali metal oleate at a dosage of 0.35–0.6 kg / t and pine oil at a dosage of 33–50 g / t to the slurry of the roughing tailings, and perform aeration flotation to obtain primary scavenging concentrate and primary scavenging tailings; add a mixture of octanoyl hydroxamic acid and alkali metal oleate at a dosage of 0.2–0.4 kg / t and pine oil at a dosage of 12–30 g / t to the slurry of the primary scavenging concentrate, and perform aeration flotation to obtain secondary scavenging concentrate and secondary scavenging tailings; wherein the dosage of each material is calculated based on 1 t of grinding product;

[0013] 5) The secondary scavenging tailings are subjected to magnetic separation using a magnetic separator to obtain monazite concentrate and final tailings.

[0014] According to the method of the present invention, preferably, the REO grade of the mixed ore containing rare earth elements is 55-59 wt%; the carbonate rare earth minerals include bastnaesite, Yellow River bastnaesite, and bastnaesite; the gangue minerals include dolomite, apatite, and fluorite.

[0015] According to the method of the present invention, preferably, a ceramic-lined ball mill is used for grinding; the grinding time is 1 to 3 minutes.

[0016] According to the method of the present invention, preferably, the slurry concentration of the grinding product is 30-45 wt%; after adding a mixture of octanoyl hydroxamic acid and alkali metal oleate to the slurry of the grinding product, the mixture is stirred for 2-7 min; after adding a mixture of dextrin and alum, the mixture is stirred for 2-7 min; after adding a mixture of water glass and ethylenediaminetetraacetic acid, the mixture is stirred for 2-7 min; and after adding pine oil, the mixture is stirred for 2-7 min; the operating temperature of the aerated flotation is 50-65°C.

[0017] According to the method of the present invention, preferably, the mixture of octanoyl hydroxamic acid and alkali metal oleate is added to the slurry of the roughing concentrate and then stirred for 2 to 7 minutes; the mixture of dextrin and alum is added and then stirred for 2 to 7 minutes; the mixture of water glass and ethylenediaminetetraacetic acid is added and then stirred for 2 to 7 minutes; the pine oil is added and then stirred for 2 to 7 minutes; the operating temperature of the aerated flotation is 50 to 60°C.

[0018] According to the method of the present invention, preferably, the mixture of octanoyl hydroxamic acid and alkali metal oleate is added to the pulp of the primary concentrate and then stirred for 2-7 min; the mixture of dextrin and alum is added and then stirred for 2-7 min; the mixture of water glass and ethylenediaminetetraacetic acid is added and then stirred for 2-7 min; the pine oil is added and then stirred for 2-7 min; the operating temperature of the aerated flotation is 50-60°C.

[0019] According to the method of the present invention, preferably, the mixture of octanoyl hydroxamic acid and alkali metal oleate is added to the pulp of the secondary concentrate and stirred for 2-7 min; the mixture of dextrin and alum is added and stirred for 2-7 min; the mixture of water glass and ethylenediaminetetraacetic acid is added and stirred for 2-7 min; the pine oil is added and stirred for 2-7 min; the operating temperature of the aerated flotation is 50-60°C.

[0020] According to the method of the present invention, preferably, after adding a mixture of octanoyl hydroxamic acid and alkali metal oleate to the slurry of roughing tailings, the mixture is stirred for 2-5 minutes, and after adding pine oil, the mixture is stirred for 2-5 minutes; the operating temperature of the aerated flotation is 50-65°C.

[0021] According to the method of the present invention, preferably, after adding a mixture of octanoyl hydroxamic acid and alkali metal oleate to the slurry of the primary scavenging concentrate, the mixture is stirred for 2-5 minutes, and after adding pine oil, the mixture is stirred for 2-5 minutes; the operating temperature of the aerated flotation is 50-65°C.

[0022] According to the method of the present invention, preferably, the magnetic field strength of the magnetic separation is 8000-10000 Gs, the slurry concentration is 5-15 wt%, and the pulse is 10-15 Hz.

[0023] The method of this invention can separate carbonate rare earth minerals and monazite minerals from mixed rare earth ore (i.e., mixed rare earth ore) containing rare earth elements, obtaining rare earth carbonate concentrate and monazite concentrate. The obtained rare earth carbonate concentrate has a purity greater than 98.0% and a recovery rate greater than 95%; the monazite concentrate has a purity greater than 92% and a recovery rate greater than 90%. Detailed Implementation

[0024] The present invention will be further described below with reference to specific embodiments, but the scope of protection of the present invention is not limited thereto.

[0025] In this invention, unless otherwise specified, percentage content refers to weight percentage content.

[0026] The method for separating carbonate rare earth minerals and monazite according to the present invention includes: (1) a grinding step; (2) a roughing step; (3) a cleaning step; (4) a scavenging step; and (5) a magnetic separation step. These steps are described below.

[0027] <Grinding Steps>

[0028] The mixed ore containing rare earth elements is ground to obtain the grinding product.

[0029] The REO grade of the mixed ore containing rare earth elements is 50–62.4 wt%, preferably 55–59.5 wt%, more preferably 57–59.5 wt%, for example, 58 wt%, 58.5 wt%, or 59.36 wt%.

[0030] The mixed minerals containing rare earth elements include carbonate rare earth minerals, phosphate rare earth minerals, and gangue minerals. In this invention, the phosphate rare earth minerals are mainly monazite. The purity of monazite is 26–35 wt%, preferably 27–34 wt%, and more preferably 28–33 wt%. The carbonate rare earth minerals include bastnaesite, Yellow River bastnaesite, and bastnaesite. The purity of the carbonate rare earth minerals is 52–59 wt%, preferably 53–59 wt%, and more preferably 54–58.5 wt%. The gangue minerals include dolomite, apatite, and fluorite.

[0031] In this invention, a ceramic-lined ball mill is used to grind mixed ores containing rare earth elements. This helps to avoid the generation of Fe by the ball mill. 3+Effects on flotation. The purpose of grinding is to scrub the mineral surface, creating more fresh surface area, and to further liberate rare earth minerals from gangue minerals for better separation. The grinding concentration is 30–50 wt%, preferably 38–48 wt%, and more preferably 40–45 wt%. The grinding concentration refers to the mass concentration of the minerals during grinding. The grinding time is 1–3 min, preferably 1.5–2.5 min, and more preferably 2–2.5 min.

[0032] According to one embodiment of the present invention, a ceramic-lined ball mill is used to grind a mixed ore containing rare earth elements. The ground product is filtered and washed twice with water to obtain the ground product.

[0033] <Preliminary Selection Steps>

[0034] The grinding products are used to form a grinding slurry. The pH of the grinding slurry is adjusted to 8.0–9.0. A mixture of octanoyl hydroxamic acid and alkali metal oleate, a mixture of dextrin and alum, a mixture of water glass and ethylenediaminetetraacetic acid, and pine oil are added sequentially to the slurry. Aeration flotation is then performed to obtain a rougher concentrate and rougher tailings. This method is beneficial for obtaining high-quality carbonate rare earth minerals and high-quality monazite minerals.

[0035] In this invention, the grinding product is added to a roughing flotation cell. The grinding product is used to form a slurry with a concentration of 30-45 wt%, preferably 35-40 wt%, and more preferably 35-38 wt%. This is beneficial for improving roughing efficiency.

[0036] Preferably, the pH of the slurry containing the ground products is adjusted to 8.2 to 8.8; more preferably, the pH of the slurry containing the ground products is adjusted to 8.3 to 8.6. For example, the pH of the slurry containing the ground products can be adjusted to 8.4 or 8.5.

[0037] The operating temperature for aeration flotation can be 50–65°C, preferably 50–60°C, and more preferably 55–60°C.

[0038] In the mixture formed by octanoyl hydroxamic acid and alkali metal oleate, the mass ratio of octanoyl hydroxamic acid to alkali metal oleate can be 1:0.05 to 0.25, preferably 1:0.08 to 0.2, and more preferably 1:0.1 to 0.15. The alkali metal oleate can be sodium oleate, potassium oleate, or lithium oleate, preferably sodium oleate. Based on 1 t of grinding product, the amount of the mixture formed by octanoyl hydroxamic acid and alkali metal oleate is 0.9 to 1.5 kg / t, preferably 1.0 to 1.4 kg / t, and more preferably 1.1 to 1.3 kg / t. In this invention, after adding the mixture formed by octanoyl hydroxamic acid and alkali metal oleate, the mixture is stirred for 2 to 7 minutes, preferably 3 to 6 minutes, and more preferably 3 to 5 minutes.

[0039] In the mixture formed by dextrin and alum, the mass ratio of dextrin to alum can be 1:0.5 to 1, preferably 1:0.55 to 0.8, and more preferably 1:0.6 to 0.7. Based on 1 t of milled product, the amount of the mixture formed by dextrin and alum used is 0.45 to 1.0 kg / t, preferably 0.5 to 0.8 kg / t, and more preferably 0.6 to 0.75 kg / t. In this invention, after adding the mixture formed by dextrin and alum, the mixture is stirred for 2 to 7 minutes, preferably 2 to 5 minutes, and more preferably 3 to 4 minutes.

[0040] In the mixture formed by water glass and ethylenediaminetetraacetic acid (EDTA), the mass ratio of water glass to EDTA can be 1:0.1–0.2, preferably 1:0.12–0.18, and more preferably 1:0.15–0.17. Based on 1 t of grinding product, the amount of the mixture formed by water glass and EDTA is 0.55–0.8 kg / t, preferably 0.60–0.7 kg / t, and more preferably 0.65–0.68 kg / t. In this invention, after adding the mixture formed by water glass and EDTA, the mixture is stirred for 2–7 min, preferably 2–5 min, and more preferably 3–4 min.

[0041] Based on 1 ton of grinding product, the amount of pine oil used is 50-80 g / t, preferably 55-75 g / t, and more preferably 60-70 g / t. For example, the amount of pine oil used can be 65 g / t. In this invention, after adding the pine oil, the mixture is stirred for 2-7 minutes, preferably 2-5 minutes, and more preferably 2-3 minutes.

[0042] In this invention, through the above-mentioned operating steps, carbonate rare earth minerals are mainly found in the roughing concentrate, while monazite is mainly found in the roughing tailings, thus allowing for the initial separation of the two.

[0043] <Selected Steps>

[0044] The roughing concentrate is further subjected to flotation. This helps to improve the purity of the resulting rare earth carbonate concentrate.

[0045] In this invention, the selection process includes a first selection, a second selection, and a third selection, as detailed below:

[0046] First Selection

[0047] A mixture of octanoyl hydroxamic acid and alkali metal oleate, a mixture of dextrin and alum, a mixture of water glass and ethylenediaminetetraacetic acid, and pine oil are sequentially added to the pulp of the roughing concentrate. Aeration flotation is then performed to obtain a primary concentrate and a primary tailings. The preferred operating temperature for aeration flotation is 55–60°C, more preferably 55–58°C.

[0048] In the mixture formed by octanoyl hydroxamic acid and alkali metal oleate, the mass ratio of octanoyl hydroxamic acid to alkali metal oleate can be 1:0.05-0.25, preferably 1:0.08-0.2, and more preferably 1:0.1-0.15. The alkali metal oleate can be sodium oleate, potassium oleate, or lithium oleate, preferably sodium oleate. Based on 1 t of grinding product, the amount of the mixture formed by octanoyl hydroxamic acid and alkali metal oleate is 0.3-0.5 kg / t, preferably 0.35-0.45 kg / t, and more preferably 0.35-0.4 kg / t. After adding the mixture formed by octanoyl hydroxamic acid and alkali metal oleate, stir for 2-7 min, preferably 3-5 min, and more preferably 3-4 min.

[0049] In the mixture formed by dextrin and alum, the mass ratio of dextrin to alum can be 1:0.5 to 1, preferably 1:0.55 to 0.8, and more preferably 1:0.6 to 0.7. Based on 1 t of milled product, the amount of the mixture formed by dextrin and alum can be 0.25 to 0.5 kg / t, preferably 0.3 to 0.45 kg / t, and more preferably 0.35 to 0.4 kg / t.

[0050] In the mixture formed by water glass and ethylenediaminetetraacetic acid (EDTA), the mass ratio of water glass to EDTA can be 1:0.1 to 0.2, preferably 1:0.12 to 0.18, and more preferably 1:0.15 to 0.17. Based on 1 t of grinding product, the amount of the mixture formed by water glass and EDTA can be 0.3 to 0.6 kg / t, preferably 0.3 to 0.55 kg / t, and more preferably 0.4 to 0.5 kg / t.

[0051] After adding the mixture of dextrin and alum, stir for 2–7 minutes, preferably 3–5 minutes, more preferably 3–4 minutes. After adding the mixture of water glass and ethylenediaminetetraacetic acid, stir for 2–7 minutes, preferably 3–5 minutes, more preferably 3–4 minutes.

[0052] Based on 1 ton of grinding product, the amount of pine oil used can be 30-40 g / t, preferably 32-38 g / t, and more preferably 33-35 g / t. After adding the pine oil, stir for 2-7 minutes, preferably 3-5 minutes, and more preferably 3-4 minutes. This helps to improve the purity of the obtained carbonate rare earth concentrate.

[0053] Second selection

[0054] A mixture of octanoyl hydroxamic acid and alkali metal oleate, a mixture of dextrin and alum, a mixture of water glass and ethylenediaminetetraacetic acid, and pine oil are sequentially added to the pulp of the primary concentrate. Aeration flotation is then performed to obtain a secondary concentrate and secondary tailings. The operating temperature for aeration flotation can be 50–60°C, preferably 55–60°C, and more preferably 55–58°C.

[0055] In the mixture formed by octanoyl hydroxamic acid and alkali metal oleate, the mass ratio of octanoyl hydroxamic acid to alkali metal oleate can be 1:0.05-0.25, preferably 1:0.08-0.2, and more preferably 1:0.1-0.15. The alkali metal oleate can be sodium oleate, potassium oleate, or lithium oleate, preferably sodium oleate. Based on 1 t of grinding product, the amount of the mixture formed by octanoyl hydroxamic acid and alkali metal oleate can be 0.15-0.25 kg / t, preferably 0.17-0.22 kg / t, and more preferably 0.18-0.2 kg / t. After adding the mixture formed by octanoyl hydroxamic acid and alkali metal oleate, stir for 2-7 min, preferably 3-5 min, and more preferably 3-4 min.

[0056] In the mixture formed by dextrin and alum, the mass ratio of dextrin to alum can be 1:0.5 to 1, preferably 1:0.55 to 0.8, and more preferably 1:0.6 to 0.7. Based on 1 t of milled product, the amount of the mixture formed by dextrin and alum can be 0.12 to 0.25 kg / t, preferably 0.14 to 0.2 kg / t, and more preferably 0.15 to 0.18 kg / t.

[0057] In the mixture formed by water glass and ethylenediaminetetraacetic acid (EDTA), the mass ratio of water glass to EDTA can be 1:0.1 to 0.2, preferably 1:0.12 to 0.18, and more preferably 1:0.15 to 0.17. Based on 1 t of grinding product, the amount of the mixture formed by water glass and EDTA can be 0.15 to 0.2 kg / t, preferably 0.16 to 0.19 kg / t, and more preferably 0.17 to 0.18 kg / t.

[0058] The mixture of dextrin and alum is added and stirred for 2–7 minutes, preferably 2.5–5 minutes, more preferably 3–4 minutes. The mixture of water glass and ethylenediaminetetraacetic acid is added and stirred for 2–7 minutes, preferably 2.5–5 minutes, more preferably 3–4 minutes.

[0059] In this step, based on 1 ton of grinding product, the amount of pine oil used can be 15-20 g / t, preferably 16-18 g / t, and more preferably 17-18 g / t. After adding the pine oil, stir for 2-7 minutes, preferably 2.5-4 minutes, and more preferably 2.5-3.5 minutes.

[0060] Third Selection

[0061] A mixture of octanoyl hydroxamic acid and alkali metal oleate, a mixture of dextrin and alum, a mixture of water glass and ethylenediaminetetraacetic acid, and pine oil are sequentially added to the pulp of the secondary concentrate. Aeration flotation is then performed to obtain carbonate rare earth concentrate and tertiary concentrate tailings. The operating temperature of the aeration flotation can be 50–60°C, preferably 55–60°C, and more preferably 55–58°C.

[0062] In the mixture formed by octanoyl hydroxamic acid and alkali metal oleate, the mass ratio of octanoyl hydroxamic acid to alkali metal oleate can be 1:0.05 to 0.25, preferably 1:0.08 to 0.2, and more preferably 1:0.1 to 0.15. The alkali metal oleate can be sodium oleate, potassium oleate, or lithium oleate, preferably sodium oleate. Based on 1 t of grinding product, the amount of the mixture formed by octanoyl hydroxamic acid and alkali metal oleate can be 0.08 to 0.12 kg / t, preferably 0.1 to 0.12 kg / t, and more preferably 0.1 to 0.11 kg / t. After adding the mixture formed by octanoyl hydroxamic acid and alkali metal oleate, stir for 2 to 7 min, preferably 3 to 5 min, and more preferably 3 to 4 min.

[0063] In the mixture formed by dextrin and alum, the mass ratio of dextrin to alum can be 1:0.5 to 1, preferably 1:0.55 to 0.8, and more preferably 1:0.6 to 0.7. Based on 1 t of milled product, the amount of the mixture formed by dextrin and alum can be 0.05 to 0.10 kg / t, preferably 0.06 to 0.09 kg / t, and more preferably 0.07 to 0.08 kg / t.

[0064] In the mixture formed by water glass and ethylenediaminetetraacetic acid (EDTA), the mass ratio of water glass to EDTA can be 1:0.1 to 0.2, preferably 1:0.12 to 0.18, and more preferably 1:0.15 to 0.17. Based on 1 t of grinding product, the amount of the mixture formed by water glass and EDTA can be 0.07 to 0.10 kg / t, preferably 0.08 to 0.10 kg / t, and more preferably 0.08 to 0.09 kg / t.

[0065] After adding the mixture formed by dextrin and alum, stir for 2 to 7 minutes, preferably 2 to 5 minutes, more preferably 2.5 to 4 minutes. After adding the mixture formed by water glass and ethylenediaminetetraacetic acid, stir for 2 to 7 minutes, preferably 2 to 5 minutes, more preferably 2.5 to 4 minutes.

[0066] Based on 1 ton of grinding product, the amount of pine oil used can be 15-20 g / t, preferably 16-19 g / t, and more preferably 17-18 g / t. After adding the pine oil, stir for 2-7 minutes, preferably 2-4 minutes, and more preferably 2-3 minutes.

[0067] In this invention, the tailings are returned in stages. That is, mineral processing is a continuous process, and returning means returning the product to the previous process. The tailings from the first stage of beneficiation are returned to the roughing feed, the tailings from the second stage of beneficiation are returned to the first stage of beneficiation feed, and the tailings from the third stage of beneficiation are returned to the second stage of beneficiation feed.

[0068] In this invention, the obtained carbonate rare earth concentrate includes bastnaesite, bastnaesite, and Yellow River ore. The purity of the carbonate rare earth is greater than 98.0%, preferably greater than or equal to 98.1%, for example, it can reach 98.19%. The recovery rate of the carbonate rare earth is greater than 95%, preferably greater than or equal to 96%, for example, it can reach 96.36%.

[0069] The formula for calculating the recovery rate of carbonate rare earth minerals is as follows:

[0070] The recovery rate of carbonate rare earth minerals = (mass of carbonate rare earth concentrate × purity of carbonate rare earth minerals in carbonate rare earth concentrate) / (mass of mixed ore containing rare earth elements × purity of carbonate rare earth minerals in mixed ore containing rare earth elements) × 100%. The purity of carbonate rare earth minerals is calculated based on bastnaesite, bastnaesite, and Yellow River ore.

[0071] This invention utilizes a combination of specific mixtures of octanoyl hydroxamic acid and alkali metal oleate, a mixture of dextrin and alum, and a mixture of water glass and ethylenediaminetetraacetic acid to obtain high-purity carbonate rare earth concentrates and monazite concentrates, with both exhibiting high recovery rates.

[0072] <Scanning Steps>

[0073] The scanning steps of the present invention include a first scanning and a second scanning.

[0074] First scan

[0075] A mixture of octanoyl hydroxamic acid and alkali metal oleate and pine oil are added sequentially to the slurry of the roughing tailings, followed by aeration flotation to obtain primary scavenging concentrate and primary scavenging tailings.

[0076] In this step, based on 1 ton of grinding product, the amount of the mixture formed by octanoyl hydroxamic acid and alkali metal oleate can be 0.35–0.6 kg / t, preferably 0.4–0.55 kg / t, and more preferably 0.4–0.5 kg / t. Based on 1 ton of grinding product, the amount of pine oil can be 33–50 g / t, preferably 35–47 g / t, and more preferably 38–45 g / t. After adding the mixture formed by octanoyl hydroxamic acid and alkali metal oleate and the pine oil, the mixture is stirred for 2–5 min, preferably 2.5–4.5 min, and more preferably 2.5–3.5 min. The operating temperature of the aerated flotation can be 50–65 °C, preferably 60–65 °C.

[0077] The type and proportion of the mixture formed by octanoyl hydroxamic acid and alkali metal oleate used in the above-mentioned scavenging step are the same as those used in the roughing step. This will not be repeated here.

[0078] Second sweep

[0079] A mixture of octanoyl hydroxamic acid and alkali metal oleate and pine oil are added sequentially to the slurry of the primary scavenging concentrate, followed by aeration flotation to obtain secondary scavenging concentrate and secondary scavenging tailings.

[0080] In this step, based on 1 ton of grinding product, the amount of the mixture formed by octanoyl hydroxamic acid and alkali metal oleate can be 0.2–0.4 kg / t, preferably 0.25–0.35 kg / t, and more preferably 0.25–0.3 kg / t. Based on 1 ton of grinding product, the amount of pine oil can be 12–30 g / t, preferably 18–26 g / t, and more preferably 20–25 g / t. After adding the mixture formed by octanoyl hydroxamic acid and alkali metal oleate and the pine oil, the mixture is stirred for 2–5 min, preferably 2.5–4.5 min, and more preferably 2.5–3.5 min. The operating temperature of the aerated flotation can be 55–65 °C, preferably 60–65 °C. This is beneficial for improving the purity of the obtained monazite concentrate.

[0081] The type and proportion of the mixture formed by octanoyl hydroxamic acid and alkali metal oleate used in the above-mentioned scavenging step are the same as those used in the roughing step. This will not be repeated here.

[0082] In this invention, the scavenging concentrate is returned in stages. That is, the primary scavenging concentrate is returned to the roughing feed, and the secondary scavenging concentrate is returned to the primary scavenging feed.

[0083] <Magnetic Separation Steps>

[0084] The tailings from the secondary scavenging process are then subjected to magnetic separation to obtain monazite concentrate and final tailings. This process helps to improve the purity of the obtained monazite concentrate.

[0085] In this invention, the magnetic field strength during magnetic separation can be 8000–10000 Gs, preferably 8500–9500 Gs, and more preferably 9000–9500 Gs. The slurry concentration can be 5–15 wt%, preferably 8–15 wt%, and more preferably 10–12 wt%. The pulse can be 10–15 Hz, preferably 12–14.5 Hz, and more preferably 13–14 Hz, for example, 13.5 Hz.

[0086] In this invention, the purity of the obtained monazite concentrate is greater than 92%, preferably greater than or equal to 93%, for example, it can reach 93.24%. The recovery rate of monazite is greater than 90%, preferably greater than 91%, more preferably greater than or equal to 92%, for example, it can reach 92.53%.

[0087] The formula for calculating the recovery rate of monazite is:

[0088] The recovery rate of monazite is calculated as follows: (mass of monazite concentrate × purity of monazite in monazite concentrate) / (mass of mixed ore containing rare earth elements × purity of monazite in mixed ore containing rare earth elements) × 100%. In this invention, purity and content have the same meaning.

[0089] <Determination Method>

[0090] REO grade determination: The grade was determined using an automated quantitative analysis system for mineral characterization (AMICS).

[0091] Purity of carbonate rare earth minerals: determined using an automated quantitative analysis system for mineral characterization (AMICS).

[0092] Purity of monazite: determined using an automated quantitative analysis system for mineral characterization (AMICS).

[0093] The raw materials used in the following examples and comparative examples are described below:

[0094] Mixed ore containing rare earth elements: produced by the Baiyun Obo Baoshan Mining Mountain Beneficiation Plant.

[0095] Dextrin: Purchased from Sinopharm Chemical Reagent Co., Ltd., analytical grade.

[0096] Water glass: purchased from Shandong Gucheng Chemical Technology Co., Ltd., modulus 2.5.

[0097] Example 1

[0098] The rare earth REO grade of the mixed ore containing rare earth elements in this embodiment is 59.36 wt%. The main rare earth minerals are bastnaesite, bastnaesite, Yellow River bastnaesite, and monazite, while the main gangue minerals are dolomite, apatite, and fluorite. The purity of the carbonate rare earth minerals is 58.34 wt%, and the purity of monazite is 29.15 wt%.

[0099] A ceramic-lined ball mill was used to grind a mixed ore containing rare earth elements. The grinding concentration was 45 wt%, and the grinding time was 2 min. The ground product was filtered and washed twice with water to obtain the grinding product.

[0100] The grinding product is added to the roughing flotation cell to form a grinding product slurry. The slurry concentration is adjusted to 38 wt%, and sodium carbonate is added to adjust the pH of the grinding product slurry to 8.3. 1.3 kg / t of a mixture of octanoyl hydroxamic acid and sodium oleate (mass ratio of octanoyl hydroxamic acid to sodium oleate is 1:0.1) is added to the grinding product slurry and stirred for 3 min; 0.6 kg / t of a mixture of dextrin and alum (mass ratio of dextrin to alum is 1:0.5) is added and stirred for 2 min; 0.65 kg / t of a mixture of water glass and ethylenediaminetetraacetic acid (mass ratio of water glass to ethylenediaminetetraacetic acid is 1:0.1) is added and stirred for 2.5 min; 75 g / t of pine oil is added and stirred for 2 min; aeration flotation is performed at 55℃ to obtain roughing concentrate and roughing tailings. The amounts of each material are calculated based on 1 t of grinding product.

[0101] Add 0.35 kg / t of a mixture of octanoyl hydroxamic acid and sodium oleate (mass ratio of octanoyl hydroxamic acid to sodium oleate is 1:0.1) to the slurry of the roughing concentrate and stir for 3 min; add 0.03 kg / t of a mixture of dextrin and alum (mass ratio of dextrin to alum is 1:0.5) and stir for 2.5 min; add 0.3 kg / t of a mixture of water glass and ethylenediaminetetraacetic acid (mass ratio of water glass to ethylenediaminetetraacetic acid is 1:0.1) and stir for 3 min; add 30 g / t of pine oil and stir for 2.5 min; perform aeration flotation at 58℃ to obtain a primary concentrate and a primary tailings. Add 0.18 kg / t of a mixture of octanoyl hydroxamic acid and sodium oleate (mass ratio of octanoyl hydroxamic acid to sodium oleate is 1:0.1) to the slurry of the primary concentrate and stir for 3 min; add 0.15 kg / t of a mixture of dextrin and alum (mass ratio of dextrin to alum is 1:0.5) and stir for 2.5 min; add 0.15 kg / t of a mixture of water glass and ethylenediaminetetraacetic acid (mass ratio of water glass to ethylenediaminetetraacetic acid is 1:0.1) and stir for 2 min; add 18 g / t of pine oil and stir for 2 min; perform aeration flotation at 58℃ to obtain secondary concentrate and secondary tailings. Add 0.10 kg / t of a mixture of octanoyl hydroxamic acid and sodium oleate (mass ratio of octanoyl hydroxamic acid to sodium oleate is 1:0.1) to the slurry of the secondary concentrate, and stir for 3 min; add 0.075 kg / t of a mixture of dextrin and alum (mass ratio of dextrin to alum is 1:0.5), and stir for 2 min; add 0.08 kg / t of a mixture of water glass and ethylenediaminetetraacetic acid (mass ratio of water glass to ethylenediaminetetraacetic acid is 1:0.1), and stir for 2 min; add 17 g / t of pine oil, and stir for 2 min; perform aeration flotation at 58℃ to obtain carbonate rare earth concentrate and tertiary concentrate tailings. The dosage of each material is calculated based on 1 t of grinding product; the concentrate tailings are returned step-by-step. The purity and recovery rate of the carbonate rare earth concentrate are shown in Table 1 below.

[0102] Add 0.5 kg / t of a mixture of octanoyl hydroxamic acid and sodium oleate (mass ratio of octanoyl hydroxamic acid to sodium oleate is 1:0.1) to the roughing tailings slurry and stir for 3 min; add 45 g / t of pine oil and stir for 2 min; then perform aeration flotation at 57℃ to obtain primary scavenging concentrate and primary scavenging tailings. Add 0.3 kg / t of a mixture of octanoyl hydroxamic acid and sodium oleate (mass ratio of octanoyl hydroxamic acid to sodium oleate is 1:0.1) to the primary scavenging concentrate slurry and stir for 3 min; then add 25 g / t of pine oil and stir for 2 min; then perform aeration flotation at 57℃ to obtain secondary scavenging concentrate and secondary scavenging tailings. The dosage of each material is calculated based on 1 t of grinding product; the scavenging concentrate is returned step-by-step.

[0103] The tailings from the secondary scavenging were subjected to magnetic separation using a high-gradient magnetic separator at a magnetic field strength of 8500 Gs, a pulp concentration of 12 wt%, and a pulse frequency of 13.5 Hz to remove impurities, yielding monazite concentrate and final tailings. The purity and recovery rate of the obtained monazite concentrate are shown in Table 1 below.

[0104] Example 2

[0105] The rare earth REO grade of the mixed ore containing rare earth elements in this embodiment is 62.21 wt%. The main rare earth minerals are bastnaesite, bastnaesite, Yellow River bastnaesite, and monazite, while the main gangue minerals are dolomite, apatite, and fluorite. The purity of the carbonate rare earth minerals is 54.01 wt%, and the purity of monazite is 32.29 wt%.

[0106] A ceramic-lined ball mill was used to grind the mixed ore containing rare earth elements. The grinding concentration was 40 wt%, and the grinding time was 2.5 min. The ground product was filtered and washed twice with water to obtain the grinding product.

[0107] The grinding product is added to the roughing flotation cell to form a grinding product slurry. The slurry concentration is adjusted to 35 wt%, and sodium carbonate is added to adjust the pH of the grinding product slurry to 8.5. 1.0 kg / t of a mixture of octanoyl hydroxamic acid and alkali metal oleate (mass ratio of octanoyl hydroxamic acid to sodium oleate is 1:0.15) is added to the grinding product slurry and stirred for 4 min; 0.5 kg / t of a mixture of dextrin and alum (mass ratio of dextrin to alum is 1:0.7) is added and stirred for 2.5 min; 0.60 kg / t of a mixture of water glass and ethylenediaminetetraacetic acid (mass ratio of water glass to ethylenediaminetetraacetic acid is 1:0.15) is added and stirred for 2 min; 65 g / t of pine oil is added and stirred for 2 min; aeration flotation is performed at 60℃ to obtain roughing concentrate and roughing tailings. The amounts of each material are calculated based on 1 t of grinding product.

[0108] Add 0.4 kg / t of a mixture of octanoyl hydroxamic acid and alkali metal oleate (mass ratio of octanoyl hydroxamic acid to sodium oleate is 1:0.15) to the slurry of the roughing concentrate, and stir for 4 min; add 0.35 kg / t of a mixture of dextrin and alum (mass ratio of dextrin to alum is 1:0.7), and stir for 3 min; add 0.5 kg / t of a mixture of water glass and ethylenediaminetetraacetic acid (mass ratio of water glass to ethylenediaminetetraacetic acid is 1:0.15), and stir for 3 min; add 35 g / t of pine oil, and stir for 3 min; perform aeration flotation at 60℃ to obtain primary concentrate and primary tailings. Add 0.2 kg / t of a mixture of octanoyl hydroxamic acid and alkali metal oleate (mass ratio of octanoyl hydroxamic acid to sodium oleate is 1:0.15) to the slurry of the primary concentrate and stir for 3 min; add 0.15 kg / t of a mixture of dextrin and alum (mass ratio of dextrin to alum is 1:0.7) and stir for 3 min; add 0.18 kg / t of a mixture of water glass and ethylenediaminetetraacetic acid (mass ratio of water glass to ethylenediaminetetraacetic acid is 1:0.15) and stir for 3 min; add 17 g / t of pine oil and stir for 2.5 min; perform aeration flotation at 60℃ to obtain secondary concentrate and secondary tailings. Add 0.12 kg / t of a mixture of octanoyl hydroxamic acid and alkali metal oleate (mass ratio of octanoyl hydroxamic acid to sodium oleate is 1:0.15) to the slurry of the secondary concentrate, and stir for 3 min; add 0.08 kg / t of a mixture of dextrin and alum (mass ratio of dextrin to alum is 1:0.7), and stir for 2 min; add 0.09 kg / t of a mixture of water glass and ethylenediaminetetraacetic acid (mass ratio of water glass to ethylenediaminetetraacetic acid is 1:0.15), and stir for 2 min; add 18 g / t of pine oil, and stir for 2 min; perform aeration flotation at 60℃ to obtain carbonate rare earth concentrate and tertiary concentrate tailings. The dosage of each material is calculated based on 1 t of grinding product; the concentrate tailings are returned step-by-step. The purity and recovery rate of the carbonate rare earth concentrate are shown in Table 1.

[0109] Add 0.4 kg / t of a mixture of octanoyl hydroxamic acid and alkali metal oleate (mass ratio of octanoyl hydroxamic acid to sodium oleate is 1:0.15) to the roughing tailings slurry, and stir for 2.5 min; add 38 g / t of pine oil, and stir for 2 min; then perform aeration flotation at 60℃ to obtain primary scavenging concentrate and primary scavenging tailings. Add 0.25 kg / t of a mixture of octanoyl hydroxamic acid and alkali metal oleate (mass ratio of octanoyl hydroxamic acid to sodium oleate is 1:0.15) to the primary scavenging concentrate slurry, and stir for 2.5 min; then add 20 g / t of pine oil, and stir for 3 min; then perform aeration flotation at 60℃ to obtain secondary scavenging concentrate and secondary scavenging tailings. The dosage of each material is calculated based on 1 t of grinding product; the scavenging concentrate is returned step-by-step.

[0110] The tailings from the secondary scavenging were subjected to magnetic separation using a high-gradient magnetic separator at a magnetic field strength of 9000 Gs, a pulp concentration of 10 wt%, and a pulse frequency of 12 Hz to remove impurities, yielding monazite concentrate and final tailings. The purity and recovery rate of the obtained monazite concentrate are shown in Table 1 below.

[0111] Comparative Example 1

[0112] The only difference from Example 1 is that the mixture formed by water glass and ethylenediaminetetraacetic acid is omitted, and the total amount of inhibitor remains the same.

[0113] Comparative Example 2

[0114] The only difference from Example 1 is that the mixture formed by dextrin and alum is omitted, and the total amount of inhibitor remains the same.

[0115] Comparative Example 3

[0116] The raw material minerals used were the same as those in Example 1 (i.e., the rare earth-containing mixed ore used was produced by the Bayan Obo Baoshan Mining Plant. The rare earth REO grade of this mixed ore was 59.36%. The main rare earth minerals were bastnaesite, bastnaesite, Yellow River ore, and monazite, and the main gangue minerals were dolomite, apatite, and fluorite, etc. Among them, the purity of carbonate rare earth minerals was 58.34 wt%, and the purity of monazite was 29.15 wt%). The flotation methods used in the two examples were different.

[0117] This comparative example uses the method of Example 3 in CN102886309A (Method for separating fluorocarbonate cerium concentrate and monazite concentrate from high-grade mixed rare earth concentrate) to perform flotation on the raw material minerals. The purity and recovery rate of the obtained carbonate rare earth concentrate and monazite concentrate are shown in Table 1 below.

[0118] Table 1

[0119] Purity % of carbonate rare earth concentrate 98.04 98.57 83.65 62.13 96.57 Recovery rate of rare earth carbonates (%) 95.52 96.04 95.24 93.14 88.24 Purity % of monazite concentrate 92.06 93.81 91.37 48.73 90.18 Monazite recovery rate % 90.44 90.95 88.53 62.15 91.35

[0120] This invention is not limited to the above-described embodiments. Any modifications, improvements, or substitutions that can be conceived by those skilled in the art without departing from the essential content of this invention fall within the scope of this invention.

Claims

1. A method for separating carbonate rare earth minerals and monazite, characterized in that, Includes the following steps: 1) Grinding a mixed ore containing rare earth elements to obtain grinding products; wherein the REO grade of the mixed ore containing rare earth elements is 50-62.4 wt%, and it includes carbonate rare earth minerals, phosphate rare earth minerals and gangue minerals; the phosphate rare earth minerals are mainly monazite; 2) The grinding products are used to form a grinding product slurry, and the pH of the grinding product slurry is adjusted to 8.0-9.

0. Then, the following materials are added sequentially to the grinding product slurry: a mixture of octanoyl hydroxamic acid and alkali metal oleate at a dosage of 0.9-1.5 kg / t; a mixture of dextrin and alum at a dosage of 0.45-1.0 kg / t; a mixture of water glass and ethylenediaminetetraacetic acid at a dosage of 0.55-0.8 kg / t; and pine oil at a dosage of 50-80 g / t. Aeration flotation is then performed to obtain rougher concentrate and rougher tailings. The dosage of each material is calculated based on 1 t of grinding product. 3) To the rougher concentrate slurry, sequentially add 0.3–0.5 kg / t of a mixture of octanoyl hydroxamic acid and alkali metal oleate, 0.25–0.5 kg / t of a mixture of dextrin and alum, 0.3–0.6 kg / t of a mixture of water glass and ethylenediaminetetraacetic acid, and 30–40 g / t of pine oil, followed by aeration flotation to obtain primary concentrate and primary tailings; to the primary concentrate slurry, sequentially add 0.15–0.25 kg / t of a mixture of octanoyl hydroxamic acid and alkali metal oleate, 0.12–0.25 kg / t of a mixture of dextrin and alum, and 0.15–0.6 kg / t of pine oil, followed by aeration flotation to obtain primary concentrate and primary tailings. A mixture of water glass and ethylenediaminetetraacetic acid (EDTA) and pine oil (15–20 g / t) are added to the pulp of the secondary concentrate by aeration flotation to obtain a secondary concentrate and secondary tailings. Then, a mixture of octanoyl hydroxamic acid and alkali metal oleate (0.08–0.12 kg / t), a mixture of dextrin and alum (0.05–0.10 kg / t), a mixture of water glass and EDTA (0.07–0.10 kg / t), and pine oil (15–20 g / t) are added sequentially to the pulp of the secondary concentrate by aeration flotation to obtain a carbonate rare earth concentrate and tertiary tailings. The dosage of each material is calculated based on 1 t of grinding product. 4) Add a mixture of octanoyl hydroxamic acid and alkali metal oleate at a dosage of 0.35–0.6 kg / t and pine oil at a dosage of 33–50 g / t to the slurry of the roughing tailings, and perform aeration flotation to obtain primary scavenging concentrate and primary scavenging tailings; add a mixture of octanoyl hydroxamic acid and alkali metal oleate at a dosage of 0.2–0.4 kg / t and pine oil at a dosage of 12–30 g / t to the slurry of the primary scavenging concentrate, and perform aeration flotation to obtain secondary scavenging concentrate and secondary scavenging tailings; wherein the dosage of each material is calculated based on 1 t of grinding product; 5) The secondary scavenging tailings are subjected to magnetic separation using a magnetic separator to obtain monazite concentrate and final tailings; In the mixture formed by octanoyl hydroxamic acid and alkali metal oleate, the mass ratio of octanoyl hydroxamic acid to alkali metal oleate is 1:0.05 to 0.25; in the mixture formed by dextrin and alum, the mass ratio of dextrin to alum is 1:0.5 to 1; in the mixture formed by water glass and ethylenediaminetetraacetic acid, the mass ratio of water glass to ethylenediaminetetraacetic acid is 1:0.1 to 0.

2. The obtained carbonate rare earth minerals include bastnaesite, Yellow River bastnaesite, and bastnaesite; the purity of the obtained carbonate rare earth concentrate is greater than 98.0%, and the recovery rate is greater than 95%. The purity of the obtained monazite concentrate is greater than 92%, and the recovery rate is greater than 90%.

2. The method according to claim 1, characterized in that, The REO grade of the mixed ore containing rare earth elements is 55-59 wt%; the gangue minerals include dolomite, apatite and fluorite.

3. The method according to claim 1, characterized in that, A ceramic-lined ball mill is used for grinding; the grinding time is 1 to 3 minutes.

4. The method according to claim 1, characterized in that, The pulp concentration of the grinding product is 30–45 wt%. After adding a mixture of octanoyl hydroxamic acid and alkali metal oleate to the pulp of the grinding product, the mixture is stirred for 2–7 min. After adding a mixture of dextrin and alum, the mixture is stirred for 2–7 min. After adding a mixture of water glass and ethylenediaminetetraacetic acid, the mixture is stirred for 2–7 min. After adding pine oil, the mixture is stirred for 2–7 min. The operating temperature of the aerated flotation is 50–65 °C.

5. The method according to claim 1, characterized in that, After adding a mixture of octanoyl hydroxamic acid and alkali metal oleate to the slurry of the roughing concentrate, the mixture is stirred for 2–7 min; after adding a mixture of dextrin and alum, the mixture is stirred for 2–7 min; after adding a mixture of water glass and ethylenediaminetetraacetic acid, the mixture is stirred for 2–7 min; after adding pine oil, the mixture is stirred for 2–7 min; the operating temperature of the aerated flotation is 50–60 °C.

6. The method according to claim 1, characterized in that, After adding a mixture of octanoyl hydroxamic acid and alkali metal oleate to the pulp of the primary concentrate, the mixture is stirred for 2–7 min; after adding a mixture of dextrin and alum, the mixture is stirred for 2–7 min; after adding a mixture of water glass and ethylenediaminetetraacetic acid, the mixture is stirred for 2–7 min; after adding pine oil, the mixture is stirred for 2–7 min; the operating temperature of the aerated flotation is 50–60 °C.

7. The method according to claim 1, characterized in that, After adding a mixture of octanoyl hydroxamic acid and alkali metal oleate to the pulp of the secondary concentrate, stir for 2–7 min; after adding a mixture of dextrin and alum, stir for 2–7 min; after adding a mixture of water glass and ethylenediaminetetraacetic acid, stir for 2–7 min; after adding pine oil, stir for 2–7 min; the operating temperature of the aerated flotation is 50–60 °C.

8. The method according to claim 1, characterized in that, After adding a mixture of octanoyl hydroxamic acid and alkali metal oleate to the slurry of the roughing tailings, stir for 2-5 minutes, then add pine oil and stir for 2-5 minutes; the operating temperature of the aerated flotation is 50-65℃.

9. The method according to claim 1, characterized in that, After adding a mixture of octanoyl hydroxamic acid and alkali metal oleate to the slurry of the primary scavenging concentrate, stir for 2–5 minutes, then add pine oil and stir for 2–5 minutes; the operating temperature of the aerated flotation is 50–65°C.

10. The method according to any one of claims 1 to 9, characterized in that, The magnetic field strength of the magnetic separation is 8000-10000 Gs, the slurry concentration is 5-15 wt%, and the pulse is 10-15 Hz.