Method for extracting fine iron powder from raw iron ore
By combining multi-stage magnetic separation and flotation, and using specific collectors, the iron recovery rate in iron ore is improved, solving the problem of insufficient iron recovery rate in existing technologies and achieving efficient iron concentrate extraction.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- HEBEI BOQUAN RENEWABLE RESOURCES UTILIZATION CO LTD
- Filing Date
- 2026-03-17
- Publication Date
- 2026-04-21
AI Technical Summary
The existing technology for extracting iron concentrate from iron ore has insufficient iron recovery rate, resulting in waste of iron resources and failing to meet the needs of large-scale and efficient production in the steel industry.
A combination of multi-stage magnetic separation and flotation is employed, using collectors with specific compositions, including sodium oleate, sodium stearate, benzoic acid, nonylcyclohexanol polyoxyethylene ether, and castor oil polyoxyethylene ether. By adjusting the pH value and adding inhibitor solutions, the separation efficiency of iron minerals is improved.
It significantly improves the iron recovery rate, obtains high-grade iron concentrate, and meets the production needs of the steel industry.
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Abstract
Description
Technical Field
[0001] This invention relates to the field of mineral processing technology, and more specifically, to a method for extracting iron concentrate from iron ore. Background Technology
[0002] Currently, the main industrial methods for extracting iron concentrate from iron ore are physical beneficiation and chemical leaching. Physical beneficiation, primarily using magnetic separation, flotation, and gravity separation, is characterized by its simplicity, low energy consumption, and controllable cost, making it the most widely used technology. Chemical leaching is mainly used for processing refractory iron ore, using acid and alkali reagents to dissolve gangue minerals and separate and purify iron. However, it suffers from high reagent consumption and environmental concerns, limiting its application. While physical beneficiation is the mainstream choice, it struggles to achieve complete separation of iron minerals from gangue minerals, resulting in some iron minerals being lost with the tailings. This leads to a low overall iron recovery rate, wasting iron resources and failing to meet the demands of large-scale, high-efficiency production in the steel industry. Therefore, there is an urgent need to develop an extraction method that can significantly improve iron recovery. Summary of the Invention
[0003] This invention proposes a method for extracting iron concentrate from iron ore, which solves the problem of insufficient iron recovery rate in related technologies for extracting iron concentrate from iron ore.
[0004] The technical solution of the present invention is as follows: This invention proposes a method for extracting iron concentrate from iron ore, comprising the following steps: The iron ore is crushed and screened to obtain crude iron ore. The crude iron ore is subjected to a first stage of grinding, a first stage of magnetic separation, a second stage of grinding, a second stage of magnetic separation, a third stage of magnetic separation, and flotation extraction to obtain iron concentrate. A collector is added during the flotation extraction. The collector comprises the following components in parts by weight: 42-45.5 parts sodium oleate, 18-19.5 parts sodium stearate, 8-11.5 parts benzoyl hydroxamic acid, 5-7.5 parts nonylcyclohexanol polyoxyethylene ether, 5-7 parts castor oil polyoxyethylene ether, 5-7.5 parts polypropylene glycol, and 2-4.5 parts sodium citrate.
[0005] As a further technical solution, the particle size of the crude iron ore is ≤10mm.
[0006] As a further technical solution, the first stage of grinding yields first-grade iron powder with a particle size of -0.060mm.
[0007] As a further technical solution, the magnetic field strength of the first stage of magnetic separation is 1.5~2.0T.
[0008] As a further technical solution, the second stage of grinding yields secondary iron powder with a particle size of -0.020mm.
[0009] As a further technical solution, the magnetic field strength of the second stage magnetic separation is 1.2~1.5T.
[0010] As a further technical solution, the magnetic field strength of the third stage magnetic separation is 0.8~1.0T.
[0011] As a further technical solution, the flotation extraction includes the following steps: Water is added to the iron powder obtained after the third stage magnetic separation to obtain a slurry. The pH of the slurry is adjusted to 8.5-10, and an inhibitor solution and a collector solution are added for extraction.
[0012] As a further technical solution, the mass concentration of the slurry is 20%~30%.
[0013] As a further technical solution, the inhibitor solution includes a starch solution.
[0014] As a further technical solution, the mass concentration of the starch solution is 10%~15%.
[0015] As a further technical solution, the amount of the inhibitor solution added is 0.1% to 0.3% of the iron powder mass.
[0016] As a further technical solution, the amount of the collector solution added is 0.15% to 0.25% of the iron powder mass.
[0017] As a further technical solution, the mass concentration of the capture agent solution is 8%~10%.
[0018] As a further technical solution, the method for preparing the collector solution includes the following steps: Add water to sodium oleate and stir. Then add sodium citrate, polypropylene glycol, sodium stearate, and benzoic acid in sequence. Finally, add nonylcyclohexanol polyoxyethylene ether and castor oil polyoxyethylene ether to obtain a collector solution.
[0019] As a further technical solution, the stirring temperature is 45~55℃ and the stirring speed is 200~300rpm.
[0020] As a further technical solution, the castor oil polyoxyethylene ether includes a first castor oil polyoxyethylene ether and a second castor oil polyoxyethylene ether.
[0021] As a further technical solution, the saponification value and HLB value of the first castor oil polyoxyethylene ether and the second castor oil polyoxyethylene ether are different.
[0022] As a further technical solution, the first castor oil polyoxyethylene ether has a saponification value of 70~80 mgKOH / g and an HLB value of 11.5~12.5.
[0023] As a further technical solution, the second castor oil polyoxyethylene ether has a saponification value of 57~67 mgKOH / g and an HLB value of 13~14.
[0024] As a further technical solution, the mass ratio of the first castor oil polyoxyethylene ether to the second castor oil polyoxyethylene ether is 2:2.5~3.5.
[0025] In the collector of this invention, castor oil polyoxyethylene ether is used in combination with a first castor oil polyoxyethylene ether and a second castor oil polyoxyethylene ether to further improve the iron recovery rate when extracting iron concentrate from iron ore. The two castor oil polyoxyethylene ethers have different saponification values and HLB values, and different adsorption sites and intensities on the iron ore surface, which can more comprehensively cover the iron ore surface, thereby more effectively changing the wettability of the iron ore surface and enhancing hydrophobicity. Moreover, the first castor oil polyoxyethylene ether focuses on enhancing the adhesion between iron ore and bubbles, while the second castor oil polyoxyethylene ether has a stronger ability to stabilize bubbles, together improving flotation efficiency and further enhancing the iron recovery rate.
[0026] Preferably, the mass ratio of the first castor oil polyoxyethylene ether to the second castor oil polyoxyethylene ether is 2:3.
[0027] In the collector of this invention, the synergistic effect is best when the mass ratio of the first castor oil polyoxyethylene ether to the second castor oil polyoxyethylene ether is 2:3. When the proportion of the first castor oil polyoxyethylene ether is relatively high, the stability of the foam layer decreases. When the proportion of the second castor oil polyoxyethylene ether is relatively high, the adhesion between iron minerals and bubbles decreases. Both of these situations result in a decrease in the iron recovery rate.
[0028] The working principle and beneficial effects of this invention are as follows: In this invention, nonylcyclohexanol polyoxyethylene ether and castor oil polyoxyethylene ether are added together to the collector during the flotation extraction process, which can improve the iron recovery rate when extracting iron concentrate from iron ore. Nonylcyclohexanol polyoxyethylene ether can uniformly disperse other components of the collector in the slurry, increasing the contact area between the collector and the iron mineral surface. At the same time, the polyoxyethylene segments adsorb onto the iron mineral surface, enhancing the adsorption stability of the collector. Both nonylcyclohexanol polyoxyethylene ether and castor oil polyoxyethylene ether have amphiphilic structures, which can adsorb onto the surface of iron minerals and change the wettability of iron minerals. The adsorption of both onto the iron mineral surface increases hydrophobicity, thereby more effectively separating iron minerals from iron ore, improving the iron recovery rate, and obtaining high-grade iron concentrate. Detailed Implementation
[0029] The technical solutions of the present invention will be clearly and completely described below with reference to the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of the present invention.
[0030] In the following examples and comparative examples, the iron ore was magnetite with a TFe content of 20%~30%; nonylcyclohexanol polyoxyethylene ether was manufactured by Taixing Lingfei Chemical Technology Co., Ltd.; the first castor oil polyoxyethylene ether was model EL-30 with a saponification value of 70~80 mgKOH / g and an HLB value of 11.5~12.5; the second castor oil polyoxyethylene ether was model EL-40 with a saponification value of 57~67 mgKOH / g and an HLB value of 13~14; polypropylene glycol was PPG-400; and the starch was corn starch.
[0031] Example 1 The iron ore is crushed and screened to obtain coarse iron ore with a particle size of 10 mm. The crude iron ore is first-stage ground to obtain 80% primary iron powder with a particle size of -0.060mm. Then, it is subjected to first-stage magnetic separation under a magnetic field strength of 1.5T. The second-stage grinding is then carried out to obtain 85% secondary iron powder with a particle size of -0.020mm. Then, it is subjected to second-stage magnetic separation under a magnetic field strength of 1.2T. Finally, it is subjected to third-stage magnetic separation under a magnetic field strength of 0.8T to obtain iron powder. Water was added to the iron powder to obtain a slurry with a mass concentration of 20%. The pH was adjusted to 8.5 with sodium carbonate. A starch solution with a mass concentration of 10% and a collector solution with a mass concentration of 8% were added (the amount of starch solution added was 0.1% of the total amount of iron powder, and the amount of collector solution added was 0.15% of the total amount of iron powder) to obtain iron concentrate. The collector comprises the following components in parts by weight: 42 parts sodium oleate, 18 parts sodium stearate, 8 parts benzoic acid, 5 parts nonylcyclohexanol polyoxyethylene ether, 5 parts castor oil polyoxyethylene ether, 5 parts polypropylene glycol, and 2 parts sodium citrate. Castor oil polyoxyethylene ether is the first castor oil polyoxyethylene ether; The method for preparing the collector solution includes the following steps: Add water to sodium oleate and stir for 10 minutes at 45°C and 300 rpm. Then add sodium citrate, polypropylene glycol, sodium stearate, and benzoic acid in sequence. Finally, add nonylcyclohexanol polyoxyethylene ether and first castor oil polyoxyethylene ether and mix well to obtain the collector solution.
[0032] Example 2 The iron ore is crushed and screened to obtain coarse iron ore with a particle size of 10 mm. The crude iron ore is first-stage ground to obtain 80% primary iron powder with a particle size of -0.060mm. Then, it is subjected to first-stage magnetic separation under a magnetic field strength of 1.8T. The second-stage grinding is then carried out to obtain 85% secondary iron powder with a particle size of -0.020mm. Then, it is subjected to second-stage magnetic separation under a magnetic field strength of 1.3T. Finally, it is subjected to third-stage magnetic separation under a magnetic field strength of 0.9T to obtain iron powder. Water was added to the iron powder to obtain a slurry with a mass concentration of 25%. The pH was adjusted to 9 with sodium carbonate. A starch solution with a mass concentration of 12% and a collector solution with a mass concentration of 9% were added (the amount of starch solution added was 0.2% of the total amount of iron powder, and the amount of collector solution added was 0.2% of the total amount of iron powder) to obtain iron concentrate. The collector comprises the following components in parts by weight: 43 parts sodium oleate, 19 parts sodium stearate, 10 parts benzoic acid, 6.5 parts nonylcyclohexanol polyoxyethylene ether, 6 parts castor oil polyoxyethylene ether, 6.5 parts polypropylene glycol, and 3.5 parts sodium citrate. Castor oil polyoxyethylene ether is the first castor oil polyoxyethylene ether; The method for preparing the collector solution includes the following steps: Add water to sodium oleate and stir for 10 minutes at 50°C and 250 rpm. Then add sodium citrate, polypropylene glycol, sodium stearate, and benzoic acid in sequence. Finally, add nonylcyclohexanol polyoxyethylene ether and first castor oil polyoxyethylene ether and mix well to obtain the collector solution.
[0033] Example 3 The iron ore is crushed and screened to obtain coarse iron ore with a particle size of 10 mm. The crude iron ore is first-stage ground to obtain 80% primary iron powder with a particle size of -0.060mm. Then, it is subjected to first-stage magnetic separation under a magnetic field strength of 2.0T. The second-stage grinding is then carried out to obtain 85% secondary iron powder with a particle size of -0.020mm. Then, it is subjected to second-stage magnetic separation under a magnetic field strength of 1.5T. Finally, it is subjected to third-stage magnetic separation under a magnetic field strength of 1.0T to obtain iron powder. Water was added to the iron powder to obtain a slurry with a mass concentration of 30%. The pH was adjusted to 10 with sodium carbonate. A starch solution with a mass concentration of 15% and a collector solution with a mass concentration of 10% were added (the amount of starch solution added was 0.3% of the total amount of iron powder, and the amount of collector solution added was 0.25% of the total amount of iron powder) to obtain iron concentrate. The collector comprises the following components in parts by weight: 45.5 parts sodium oleate, 19.5 parts sodium stearate, 11.5 parts benzoyl hydroxamic acid, 7.5 parts nonylcyclohexanol polyoxyethylene ether, 7 parts castor oil polyoxyethylene ether, 7.5 parts polypropylene glycol, and 4.5 parts sodium citrate. Castor oil polyoxyethylene ether is the first castor oil polyoxyethylene ether; The method for preparing the collector solution includes the following steps: Add water to sodium oleate and stir for 10 minutes at 55°C and 200 rpm. Then add sodium citrate, polypropylene glycol, sodium stearate, and benzoic acid in sequence. Finally, add nonylcyclohexanol polyoxyethylene ether and first castor oil polyoxyethylene ether and mix well to obtain the collector solution.
[0034] Example 4 The iron ore is crushed and screened to obtain coarse iron ore with a particle size of 10 mm. The crude iron ore is first-stage ground to obtain 80% primary iron powder with a particle size of -0.060mm. Then, it is subjected to first-stage magnetic separation under a magnetic field strength of 1.8T. The second-stage grinding is then carried out to obtain 85% secondary iron powder with a particle size of -0.020mm. Then, it is subjected to second-stage magnetic separation under a magnetic field strength of 1.3T. Finally, it is subjected to third-stage magnetic separation under a magnetic field strength of 0.9T to obtain iron powder. Water was added to the iron powder to obtain a slurry with a mass concentration of 25%. The pH was adjusted to 9 with sodium carbonate. A starch solution with a mass concentration of 12% and a collector solution with a mass concentration of 9% were added (the amount of starch solution added was 0.2% of the total amount of iron powder, and the amount of collector solution added was 0.2% of the total amount of iron powder) to obtain iron concentrate. The collector comprises the following components in parts by weight: 43 parts sodium oleate, 19 parts sodium stearate, 10 parts benzoic acid, 6.5 parts nonylcyclohexanol polyoxyethylene ether, 6 parts castor oil polyoxyethylene ether, 6.5 parts polypropylene glycol, and 3.5 parts sodium citrate. Castor oil polyoxyethylene ether is a second castor oil polyoxyethylene ether; The method for preparing the collector solution includes the following steps: Add water to sodium oleate and stir for 10 minutes at 50°C and 250 rpm. Then add sodium citrate, polypropylene glycol, sodium stearate, and benzoic acid in sequence. Finally, add nonylcyclohexanol polyoxyethylene ether and first castor oil polyoxyethylene ether and mix well to obtain the collector solution.
[0035] Example 5 The iron ore is crushed and screened to obtain coarse iron ore with a particle size of 10 mm. The crude iron ore is first-stage ground to obtain 80% primary iron powder with a particle size of -0.060mm. Then, it is subjected to first-stage magnetic separation under a magnetic field strength of 1.8T. The second-stage grinding is then carried out to obtain 85% secondary iron powder with a particle size of -0.020mm. Then, it is subjected to second-stage magnetic separation under a magnetic field strength of 1.3T. Finally, it is subjected to third-stage magnetic separation under a magnetic field strength of 0.9T to obtain iron powder. Water was added to the iron powder to obtain a slurry with a mass concentration of 25%. The pH was adjusted to 9 with sodium carbonate. A starch solution with a mass concentration of 12% and a collector solution with a mass concentration of 9% were added (the amount of starch solution added was 0.2% of the total amount of iron powder, and the amount of collector solution added was 0.2% of the total amount of iron powder) to obtain iron concentrate. The collector comprises the following components in parts by weight: 43 parts sodium oleate, 19 parts sodium stearate, 10 parts benzoic acid, 6.5 parts nonylcyclohexanol polyoxyethylene ether, 6 parts castor oil polyoxyethylene ether, 6.5 parts polypropylene glycol, and 3.5 parts sodium citrate. The castor oil polyoxyethylene ether is a first castor oil polyoxyethylene ether and a second castor oil polyoxyethylene ether with a mass ratio of 2:2.5. The method for preparing the collector solution includes the following steps: Add water to sodium oleate and stir for 10 minutes at 50°C and 250 rpm. Then add sodium citrate, polypropylene glycol, sodium stearate, and benzoic acid in sequence. Finally, add nonylcyclohexanol polyoxyethylene ether and first castor oil polyoxyethylene ether and mix well to obtain the collector solution.
[0036] Example 6 The iron ore is crushed and screened to obtain coarse iron ore with a particle size of 10 mm. The crude iron ore is first-stage ground to obtain 80% primary iron powder with a particle size of -0.060mm. Then, it is subjected to first-stage magnetic separation under a magnetic field strength of 1.8T. The second-stage grinding is then carried out to obtain 85% secondary iron powder with a particle size of -0.020mm. Then, it is subjected to second-stage magnetic separation under a magnetic field strength of 1.3T. Finally, it is subjected to third-stage magnetic separation under a magnetic field strength of 0.9T to obtain iron powder. Water was added to the iron powder to obtain a slurry with a mass concentration of 25%. The pH was adjusted to 9 with sodium carbonate. A starch solution with a mass concentration of 12% and a collector solution with a mass concentration of 9% were added (the amount of starch solution added was 0.2% of the total amount of iron powder, and the amount of collector solution added was 0.2% of the total amount of iron powder) to obtain iron concentrate. The collector comprises the following components in parts by weight: 43 parts sodium oleate, 19 parts sodium stearate, 10 parts benzoic acid, 6.5 parts nonylcyclohexanol polyoxyethylene ether, 6 parts castor oil polyoxyethylene ether, 6.5 parts polypropylene glycol, and 3.5 parts sodium citrate. The castor oil polyoxyethylene ether is a first castor oil polyoxyethylene ether and a second castor oil polyoxyethylene ether in a mass ratio of 2:3. The method for preparing the collector solution includes the following steps: Add water to sodium oleate and stir for 10 minutes at 50°C and 250 rpm. Then add sodium citrate, polypropylene glycol, sodium stearate, and benzoic acid in sequence. Finally, add nonylcyclohexanol polyoxyethylene ether and first castor oil polyoxyethylene ether and mix well to obtain the collector solution.
[0037] Example 7 The iron ore is crushed and screened to obtain coarse iron ore with a particle size of 10 mm. The crude iron ore is first-stage ground to obtain 80% primary iron powder with a particle size of -0.060mm. Then, it is subjected to first-stage magnetic separation under a magnetic field strength of 1.8T. The second-stage grinding is then carried out to obtain 85% secondary iron powder with a particle size of -0.020mm. Then, it is subjected to second-stage magnetic separation under a magnetic field strength of 1.3T. Finally, it is subjected to third-stage magnetic separation under a magnetic field strength of 0.9T to obtain iron powder. Water was added to the iron powder to obtain a slurry with a mass concentration of 25%. The pH was adjusted to 9 with sodium carbonate. A starch solution with a mass concentration of 12% and a collector solution with a mass concentration of 9% were added (the amount of starch solution added was 0.2% of the total amount of iron powder, and the amount of collector solution added was 0.2% of the total amount of iron powder) to obtain iron concentrate. The collector comprises the following components in parts by weight: 43 parts sodium oleate, 19 parts sodium stearate, 10 parts benzoic acid, 6.5 parts nonylcyclohexanol polyoxyethylene ether, 6 parts castor oil polyoxyethylene ether, 6.5 parts polypropylene glycol, and 3.5 parts sodium citrate. The castor oil polyoxyethylene ether is a first castor oil polyoxyethylene ether and a second castor oil polyoxyethylene ether with a mass ratio of 2:3.5. The method for preparing the collector solution includes the following steps: Add water to sodium oleate and stir for 10 minutes at 50°C and 250 rpm. Then add sodium citrate, polypropylene glycol, sodium stearate, and benzoic acid in sequence. Finally, add nonylcyclohexanol polyoxyethylene ether and first castor oil polyoxyethylene ether and mix well to obtain the collector solution.
[0038] Comparative Example 1 The iron ore is crushed and screened to obtain coarse iron ore with a particle size of 10 mm. The crude iron ore is first-stage ground to obtain 80% primary iron powder with a particle size of -0.060mm. Then, it is subjected to first-stage magnetic separation under a magnetic field strength of 1.8T. The second-stage grinding is then carried out to obtain 85% secondary iron powder with a particle size of -0.020mm. Then, it is subjected to second-stage magnetic separation under a magnetic field strength of 1.3T. Finally, it is subjected to third-stage magnetic separation under a magnetic field strength of 0.9T to obtain iron powder. Water was added to the iron powder to obtain a slurry with a mass concentration of 25%. The pH was adjusted to 9 with sodium carbonate. A starch solution with a mass concentration of 12% and a collector solution with a mass concentration of 9% were added (the amount of starch solution added was 0.2% of the total amount of iron powder, and the amount of collector solution added was 0.2% of the total amount of iron powder) to obtain iron concentrate. The collector comprises the following components in parts by weight: 43 parts sodium oleate, 19 parts sodium stearate, 10 parts benzoic acid, 6.5 parts nonylcyclohexanol polyoxyethylene ether, 6.5 parts polypropylene glycol, and 3.5 parts sodium citrate. The method for preparing the collector solution includes the following steps: Add water to sodium oleate and stir for 10 minutes at 50°C and 250 rpm. Then add sodium citrate, polypropylene glycol, sodium stearate, and benzoic acid in sequence. Finally, add nonylcyclohexanol polyoxyethylene ether and mix well to obtain the collector solution.
[0039] Comparative Example 2 The iron ore is crushed and screened to obtain coarse iron ore with a particle size of 10 mm. The crude iron ore is first-stage ground to obtain 80% primary iron powder with a particle size of -0.060mm. Then, it is subjected to first-stage magnetic separation under a magnetic field strength of 1.8T. The second-stage grinding is then carried out to obtain 85% secondary iron powder with a particle size of -0.020mm. Then, it is subjected to second-stage magnetic separation under a magnetic field strength of 1.3T. Finally, it is subjected to third-stage magnetic separation under a magnetic field strength of 0.9T to obtain iron powder. Water was added to the iron powder to obtain a slurry with a mass concentration of 25%. The pH was adjusted to 9 with sodium carbonate. A starch solution with a mass concentration of 12% and a collector solution with a mass concentration of 9% were added (the amount of starch solution added was 0.2% of the total amount of iron powder, and the amount of collector solution added was 0.2% of the total amount of iron powder) to obtain iron concentrate. The collector comprises the following components in parts by weight: 43 parts sodium oleate, 19 parts sodium stearate, 10 parts benzoic acid, 6 parts castor oil polyoxyethylene ether, 6.5 parts polypropylene glycol, and 3.5 parts sodium citrate. Castor oil polyoxyethylene ether is the first castor oil polyoxyethylene ether; The method for preparing the collector solution includes the following steps: Add water to sodium oleate and stir for 10 minutes at 50°C and 250 rpm. Then add sodium citrate, polypropylene glycol, sodium stearate, and benzoic acid in sequence. Finally, add castor oil polyoxyethylene ether and mix well to obtain the collector solution.
[0040] Experimental Example 1 The iron concentrates obtained in Examples 1-7 and Comparative Examples 1-2 were tested for iron grade and recovery rate. The test results are shown in Table 1. Table 1. Test results of iron grade and recovery rate of iron concentrate obtained in Examples 1-7 and Comparative Examples 1-2
[0041] 1. Compared with Comparative Examples 1-2, the recovery rate of Examples 1-7 is higher than that of Comparative Examples 1-2, indicating that the addition of nonylcyclohexanol polyoxyethylene ether and castor oil polyoxyethylene ether improves the iron recovery rate when preparing iron concentrate from iron ore and obtains high-grade iron concentrate.
[0042] 2. Compared with Examples 3 to 7, the recovery rates of Examples 5 to 7 are higher than those of Examples 3 and 4, indicating that the combined use of the first castor oil polyoxyethylene ether and the second castor oil polyoxyethylene ether can further improve the iron recovery rate; the recovery rate of Example 6 is higher than that of Examples 5 and 7, indicating that when the mass ratio of the first castor oil polyoxyethylene ether and the second castor oil polyoxyethylene ether is 2:3, the iron recovery rate is further improved when preparing iron concentrate from iron ore.
[0043] The above are merely preferred embodiments of the present invention and are not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.
Claims
1. A method for extracting iron concentrate from iron ore, characterized in that, Includes the following steps: The iron ore is crushed and screened to obtain crude iron ore. The crude iron ore is subjected to a first stage of grinding, a first stage of magnetic separation, a second stage of grinding, a second stage of magnetic separation, a third stage of magnetic separation, and flotation extraction to obtain iron concentrate. A collector is added during the flotation extraction. The collector comprises the following components in parts by weight: 42-45.5 parts sodium oleate, 18-19.5 parts sodium stearate, 8-11.5 parts benzoyl hydroxamic acid, 5-7.5 parts nonylcyclohexanol polyoxyethylene ether, 5-7 parts castor oil polyoxyethylene ether, 5-7.5 parts polypropylene glycol, and 2-4.5 parts sodium citrate.
2. The method for extracting iron concentrate from iron ore according to claim 1, characterized in that, The particle size of the crude iron ore is ≤10mm.
3. The method for extracting iron concentrate from iron ore according to claim 1, characterized in that, The first stage of grinding yields primary iron powder with a particle size of -0.060 mm; The magnetic field strength of the first stage of magnetic separation is 1.5~2.0T.
4. The method for extracting iron concentrate from iron ore according to claim 1, characterized in that, The second stage of grinding yields secondary iron powder with a particle size of -0.020 mm.
5. The method for extracting iron concentrate from iron ore according to claim 1, characterized in that, The magnetic field strength of the second stage of magnetic separation is 1.2~1.5T; The magnetic field strength of the third stage magnetic separation is 0.8~1.0T.
6. The method for extracting iron concentrate from iron ore according to claim 1, characterized in that, The flotation extraction includes the following steps: Water is added to the iron powder obtained after the third stage magnetic separation to obtain a slurry. The pH of the slurry is adjusted to 8.5-10, and an inhibitor solution and a collector solution are added for extraction.
7. A method for extracting iron concentrate from iron ore according to claim 6, characterized in that, The mass concentration of the slurry is 20%~30%; The inhibitor solution includes a starch solution; The amount of the inhibitor solution added is 0.1% to 0.3% of the iron powder mass; The amount of the collector solution added is 0.15% to 0.25% of the iron powder mass; The mass concentration of the capture agent solution is 8%~10%; The method for preparing the collector solution includes the following steps: Add water to sodium oleate and stir. Then add sodium citrate, polypropylene glycol, sodium stearate, and benzoic acid in sequence. Finally, add nonylcyclohexanol polyoxyethylene ether and castor oil polyoxyethylene ether to obtain a collector solution.
8. The method for extracting iron concentrate from iron ore according to claim 1, characterized in that, The castor oil polyoxyethylene ether includes a first castor oil polyoxyethylene ether and a second castor oil polyoxyethylene ether. The first castor oil polyoxyethylene ether and the second castor oil polyoxyethylene ether have different saponification values and HLB values.
9. A method for extracting iron concentrate from iron ore according to claim 1, characterized in that, The first castor oil polyoxyethylene ether has a saponification value of 70~80 mgKOH / g and an HLB value of 11.5~12.5; The second castor oil polyoxyethylene ether has a saponification value of 57~67 mgKOH / g and an HLB value of 13~14.
10. A method for extracting iron concentrate from iron ore according to claim 1, characterized in that, The mass ratio of the first castor oil polyoxyethylene ether to the second castor oil polyoxyethylene ether is 2:2.5~3.5.