A mineral processing method for high-intensity magnetic separation concentrate of hematite ore

Abstract

This invention belongs to the field of mineral processing technology and discloses a beneficiation method for hematite ore concentrate by strong magnetic separation. Ultra-high-speed stirring at 3000 r / min to 4000 r / min is used for desorption of inhibitors, providing clean adsorption active sites for the anionic collector. Oleic acid-modified imidazoline methyl sulfate ammonium is used instead of the traditional collector, dodecylamine. Oleic acid-modified imidazoline quaternary ammonium salt compound, with a C18 unsaturated oleic acid group molecular structure, generates strong steric hindrance compared to the acyclic, large-volume groups of dodecylamine. This prevents the reagent molecules from agglomerating at high density on the bubble surface, thus avoiding the formation of thick, viscous bubbles like with traditional dodecylamine, resulting in stronger fluidity and better foam characteristics. This provides a key guarantee for achieving a stable iron concentrate grade of 66%-70% and a recovery rate of 60%-85%.

Description

Technical Field

[0001] This invention relates to the field of mineral processing technology, and specifically to a mineral processing method for high-intensity magnetic separation concentrate of hematite ore. Background Technology

[0002] Hematite is one of my country's important iron ore resources, with the Anshan-type sedimentary metamorphic hematite being the most representative. Its typical characteristics include low ore grade, extremely fine grain size, and close intergrowth of hematite with quartz / chlorite. While high-intensity magnetic separation in hematite beneficiation plants can efficiently recover magnetic hematite particles, insufficient magnetic inclusions and liberation result in a TFe grade in the high-intensity magnetic concentrate generally only 30%–40%, with a SiO2 content as high as 20%–40%, failing to meet the quality standards for qualified iron concentrate. Therefore, high-intensity magnetic separation has long been positioned as a "pre-selection and enrichment" stage. Its concentrate is usually combined with weak magnetic separation concentrate to form a mixed magnetic separation concentrate with a TFe grade of 45–48%, which is then subjected to anionic collector reverse flotation. Since weak magnetic separation concentrate can be efficiently recovered using low-cost magnetic separation operations to obtain high-grade iron concentrate with a slightly higher grade than iron concentrate, it is a feasible approach with good technical and economic costs and benefits to process strong magnetic separation operations separately to obtain iron concentrate with a slightly lower grade than qualified iron concentrate and then combine it with weak magnetic separation concentrate for further separation.

[0003] A Study on Direct Reverse Flotation of High-Intensity Magnetic Separation Concentrate. The grinding and beneficiation process at the Gushan hematite concentrator employs a "stage grinding—single high-gradient high-intensity magnetic separation" process, consistently maintaining a TFe grade of approximately 57% and a SiO2 content of approximately 12% in the iron concentrate. To further improve product quality, a high-intensity magnetic separation—anion reverse flotation experiment was conducted on the Gushan hematite concentrate to improve iron and reduce silica (Journal of Mineral Resources Protection and Utilization, Vol. 39, No. 1, 2019, Liu Jun). The experiment demonstrated that the TFe grade of the flotation iron concentrate reached 63.25%, with a recovery rate of 70.15%. This does not meet the generally required grade of over 65% for qualified iron concentrate.

[0004] Experimental Study on Direct Flotation of High-Intensity Magnetic Separation Concentrate. Experimental Study on Direct Flotation of High-Intensity Magnetic Separation Concentrate at Anshan-Qianjiang Mineral Processing Plant (Modern Mining, Vol. 40, No. 3, 2024, Preface by Lü Hong). A closed-circuit test of 1 roughing, 1 cleaning, and 2 scavenging operations on a raw ore with an iron grade of 21.42% yielded an iron concentrate with a yield of 41.38%, an iron grade of 43.54%, and an iron recovery rate of 84.11%. The qualified iron concentrate, which does not meet general requirements, has a grade of over 65%.

[0005] A combined process for high-intensity magnetic separation of concentrates. A study on the re-concentration of iron tailings from reverse flotation (Modern Mining, 2011, No. 415, Liu Wengang) conducted a re-concentration experiment on the reverse flotation tailings from the Qidashan concentrator using a combined process. Direct flotation was performed without pH adjustment. Reverse flotation was then performed when the grinding fineness of the direct flotation concentrate reached 95.50% (-0.045 mm). After one roughing, two cleaning, and one scavenging stage, the concentrate achieved an iron grade of 66.17% and an iron recovery rate of 27.64%. A study on the direct-reverse flotation of hematite (Metal Mines, 2004, No. 1, Liu Yahui) discussed the relatively ideal beneficiation indicators of the combined direct-reverse flotation process for hematite, but no flotation experiments were conducted on actual ore. Ji Zhenming conducted a mineral processing experiment on a hematite ore deposit in Yunnan Province, employing a process of first direct flotation followed by reverse flotation (Modern Mining, No. 11, 2018, Ji Zhenming). The combined process used was a combination of one rougher and one scavenger direct flotation and one rougher, one cleaner, and three scavengers reverse flotation, with middlings sequentially returned. The direct flotation-reverse flotation of hematite yielded an iron grade of 35.50% in the raw ore, resulting in a concentrate iron grade of 60.50% and an iron recovery rate of 80.95%. Sun Bingquan et al. proposed an alkaline-acidic dual-media direct flotation process for the lean hematite ore in Dong'anshan (Metal Mines, No. 12, 2000, Sun Bingquan). This alkaline-acidic dual-media flotation process, with a feed grade of 31.59%, achieved a concentrate grade of 62.89% and an operating recovery rate of 68.22%. Hu Yiming conducted comparative experiments on strong magnetic separation concentrate from the Bayan Obo oxide ore using single reverse flotation, reverse flotation-direct flotation, and direct flotation-reverse flotation schemes ("Metal Mines", 2009, No. 6, Hu Yiming). The closed-circuit test using the reverse flotation-direct flotation scheme achieved a concentrate iron grade of 59.32% and an iron recovery rate of 64.52%. However, none of these studies met the generally required acceptable iron concentrate grade of over 65%.

[0006] The reasons why it is difficult to obtain qualified iron concentrate and high recovery rate by strong magnetic separation are: (1) the inhibitors such as causticized starch have weak inhibitory ability on hematite, and excessive use can easily lead to the inhibition of minerals such as quartz; (2) the problem of reagent residue interference is serious; (3) it is difficult to sequentially apply inhibitors, cationic collectors and anionic collectors in the same slurry system. Therefore, based on the existing technical problems, it is necessary to design a beneficiation method for strong magnetic separation concentrate of hematite ore. Summary of the Invention

[0007] To address the problems existing in the prior art, this invention provides a beneficiation method for hematite ore concentrate obtained by strong magnetic separation. The method involves subjecting the strong magnetic separation concentrate to cationic collector reverse flotation, enhanced stirring de-reagenting, and anionic collector direct flotation to obtain qualified iron concentrate.

[0008] This invention breaks through the sequential enhanced flotation strategy of "cationic collector reverse flotation - enhanced stirring decanting - anion collector positive flotation", and proposes a process of "cationic collector starvation administration + hydrochloric acid gradient pH control + high-intensity stirring desorption of hematite inhibitor".

[0009] A method for beneficiating hematite concentrate by strong magnetic separation includes the following steps: Step 1: Place the raw ore slurry into the flotation equipment, adjust the slurry mass concentration to 30%-40%, and add inhibitors and stir for 3-4 minutes at a stirring speed of 1800-2000 r / min. Then add cationic collectors and stir for 3-4 minutes to perform reverse flotation roughing for 3-4 minutes to obtain reverse flotation roughing concentrate and reverse flotation roughing tailings. Step 2: Perform reverse flotation cleaning on the rougher concentrate. First, add cationic collector each time, stir for 3 min to 4 min at a stirring speed of 1800 r / min-2000 r / min, and then perform reverse flotation for 2 min to 3 min to obtain reverse flotation clean concentrate and reverse flotation clean tailings. Step 3: Perform a first reverse flotation scavenging on the rougher tailings for 2-3 minutes to obtain a first reverse flotation scavenged concentrate and a first reverse flotation scavenged tailings. Return the first reverse flotation scavenged concentrate to the reverse flotation rougher operation. Perform a second reverse flotation scavenging on the first reverse flotation scavenged tailings for 2-3 minutes to obtain a second reverse flotation scavenged concentrate and a second reverse flotation scavenged tailings. Return the second reverse flotation scavenged concentrate to the first reverse flotation scavenging operation. Perform a third reverse flotation scavenging on the obtained second reverse flotation scavenged tailings for 1-2 minutes to obtain a third reverse flotation scavenged concentrate and a third reverse flotation scavenged tailings. Return the third reverse flotation scavenged concentrate to the second reverse flotation scavenging operation. Step 4: When reverse flotation cleansing yields reverse flotation cleaned tailings and the first reverse flotation scavenging yields first reverse flotation scavenging concentrate, the reverse flotation cleaned tailings and the first reverse flotation scavenging concentrate are mixed with the raw ore pulp containing inhibitors and cationic collectors and subjected to reverse flotation roughing together. Step 5: The obtained reverse flotation concentrate is subjected to direct flotation roughing. Hydrochloric acid is added to adjust the pH of the pulp to 5.5-6.5, and desorption of inhibitors is carried out by ultra-high speed stirring. Anionic collector is added for direct flotation, and stirring is carried out for 3-4 minutes at a stirring speed of 1800-2000 r / min for 1.5-2.5 minutes to obtain direct flotation concentrate and direct flotation tailings. Step 6: Perform direct flotation cleaning on the obtained direct flotation concentrate without adding any reagents. Stir for 2-3 minutes at a stirring speed of 1800-2000 rpm. Perform direct flotation for 2-3 minutes to obtain direct flotation cleaned concentrate and direct flotation cleaned tailings. Perform direct flotation scavenging on the direct flotation tailings. Add an anionic collector and perform direct flotation scavenging at a stirring speed of 1800-2000 rpm. Stir for 2-3 minutes, then perform direct flotation for 2-3 minutes to obtain direct flotation scavenged concentrate and direct flotation scavenged tailings. Return the direct flotation cleaned tailings and direct flotation scavenged concentrate to the direct flotation roughing operation. Combine the direct flotation scavenged tailings with the tertiary reverse flotation scavenged tailings to form the final tailings.

[0010] In step 1, the cationic collector is ammonium methyl oleate imidazoline sulfate. Ammonium methyl oleate imidazoline sulfate is a large-volume cyclic imidazoline compound with the following molecular formula: .

[0011] The ultra-high-speed stirring speed in step 5 is 3000 r / min to 4000 r / min.

[0012] In step 1, the amount of inhibitor added is 400g / t to 600g / t, and after adding the inhibitor, the pH of the slurry becomes 9-10.

[0013] The amount of cationic collector added in step 1 is 500g / t to 600g / t.

[0014] In step 2, the amount of cationic collector added is 100g / t-150g / t.

[0015] The amount of anionic collector added in step 5 is 500g / t-800g / t.

[0016] The amount of anionic collector added in step 6 is 100g / t-200g / t.

[0017] Using the above method, the TFe grade of the iron concentrate obtained is 66-70% by weight.

[0018] The TFe recovery rate of the iron concentrate obtained by the above method is 60-85% by weight.

[0019] This invention employs a starvation method to reduce the interference of cationic collectors on the forward flotation operation of anionic collectors. It lowers the pH of the reverse flotation concentrate from 9-10 to 5.5-6.5, adjusting the interfacial characteristics of hematite and quartz and allowing the cationic collector to detach from the hematite surface. Simultaneously, it utilizes ultra-high-speed stirring at 3000-4000 r / min (exceeding 4000 r / min will cause mud formation) (far exceeding the conventional 1800-2000 r / min; after increasing the stirring speed to the ultra-high speed range, high-intensity turbulence and strong shear flow field are formed inside the slurry, continuously exerting a strong scouring and tearing effect on the adsorption layer at the mineral surface boundary, directly destroying the adsorption film formed by the inhibitor on the mineral surface), providing clean adsorption active sites for the anionic collector. This invention enhances the interfacial physicochemical regulation of minerals in strong magnetic separation concentrates and realizes a sequential enhanced flotation strategy for major minerals, providing a replicable paradigm for the green and efficient utilization of hematite.

[0020] This invention further improves the cationic collector by replacing the traditional collector, dodecylamine, with methyl oleate-based imidazoline sulfate. The methyl oleate-based imidazoline sulfate is an oleate-modified imidazoline quaternary ammonium salt compound with a C18 unsaturated oleate group. Compared to the acyclic, large-volume group of dodecylamine, it generates strong steric hindrance, preventing the reagent molecules from agglomerating at high density on the bubble surface. This avoids the formation of thick, viscous bubbles like with traditional dodecylamine, resulting in stronger fluidity and better foam characteristics. This foam system is less prone to foam entrainment and slurry runoff in closed-loop circulation, leading to more stable process operation and providing a crucial guarantee for achieving a stable iron concentrate grade of 66%-70% and a recovery rate of 60%-85%.

[0021] Compared with the prior art, the beneficial effects of the present invention are: The beneficiation method for hematite ore strong magnetic separation concentrate of the present invention firstly uses cationic collector oleic acid-modified imidazoline methyl sulfate ammonium sulfate (oleic acid-modified imidazoline quaternary ammonium salt compound, which, compared with traditional dodecylamine, has the characteristics of good foam brittleness, good foam fluidity, and high selectivity, and can effectively avoid the problem of gangue entrainment caused by large and viscous bubbles, thereby improving the quality improvement and impurity reduction effect of the reverse flotation stage) to remove siliceous gangue by reverse flotation. The depressant is removed by ultra-high speed stirring, which improves the flotation environment. The second step is positive flotation with an anionic collector to further enrich iron minerals and remove residual impurities. The process runs smoothly and can finally obtain iron concentrate with a TFe grade of 66%~70% and a recovery rate of 60%~85%, filling the technical gap of separate separation and purification of hematite ore strong magnetic separation concentrate. Attached Figure Description

[0022] Figure 1 A schematic diagram of the beneficiation process for hematite concentrate by strong magnetic separation; Figure 2This is a graph showing the relationship between grade and recovery rate at different stirring speeds. Detailed Implementation

[0023] In the following embodiments of the present invention, the cationic collector used is ammonium methyl oleate imidazoline sulfate, and in Comparative Example 1, the cationic collector used is dodecylamine.

[0024] In this embodiment of the invention, hydrochloric acid is used as the modifier.

[0025] In this embodiment of the invention, the inhibitors used are causticized starch and CMC.

[0026] The anionic collectors used in the embodiments of the present invention are TD-7, sodium oleate, and talc oil.

[0027] The reverse flotation equipment used in this embodiment of the invention is an RK / FD type single-cell flotation machine.

[0028] In this embodiment of the invention, the main gangue minerals of the strong magnetic separation concentrate are quartz and a small amount of silicate minerals; the hematite is finely embedded and unevenly distributed, and has a close intergrowth relationship with quartz, while the overall quartz embedded particles are coarser than the hematite; its main components contain 33.1%~34.8% Fe2O3 and 21.4%~22.4% SiO2 by weight, with the remainder being impurities.

[0029] Example 1 The process steps for high-intensity magnetic separation concentrate of hematite ore as the feed are as follows: The selected high-intensity magnetic separation concentrate has the following composition by weight percentage: Fe2O3 34.70%, SiO2 22.38%, with the remainder being impurities.

[0030] The raw ore slurry was placed in the flotation equipment, and the slurry mass concentration was adjusted to 30%. Under the condition of stirring speed of 1800 r / min, the inhibitor causticized starch was added and stirred for 3 min. The amount of causticized starch added was 400 g / t (after adding it, the pH of the slurry will become 9.04). Then, the cationic collector methyl oleate sulfate was added. The amount of methyl oleate sulfate added was 600 g / t. After stirring for 3 min, reverse flotation roughing was carried out for 3 min to obtain reverse flotation roughing concentrate and reverse flotation roughing tailings.

[0031] The rougher concentrate from the reverse flotation is further subjected to reverse flotation cleaning to obtain reverse flotation cleaned concentrate and reverse flotation cleaned tailings. Each time reverse flotation cleaning is performed, cationic collector methyl oleate sulfate ammonium is added first at a rate of 100 g / t. The mixture is stirred for 3 min at a stirring speed of 1800 r / min, and then reverse flotation cleaning is performed for 2 min to obtain reverse flotation cleaned concentrate and reverse flotation cleaned tailings.

[0032] The tailings from the reverse flotation roughing process are subjected to a first reverse flotation scavenging process for 2.5 minutes to obtain a first reverse flotation scavenging concentrate and a first reverse flotation scavenging tailings. The first reverse flotation scavenging concentrate is returned to the reverse flotation roughing process. The tailings from the first reverse flotation scavenging process are subjected to a second reverse flotation scavenging process for 2 minutes to obtain a second reverse flotation scavenging concentrate and a second reverse flotation scavenging tailings. The second reverse flotation scavenging concentrate is returned to the first reverse flotation scavenging process. The tailings from the second reverse flotation scavenging process are subjected to a third reverse flotation scavenging process for 1.5 minutes to obtain a third reverse flotation scavenging concentrate and a third reverse flotation scavenging tailings. The third reverse flotation scavenging concentrate is returned to the second reverse flotation scavenging process.

[0033] When reverse flotation cleaning yields reverse flotation cleaned tailings and primary reverse flotation scavenging yields primary reverse flotation scavenging concentrate, the reverse flotation cleaned tailings and primary reverse flotation scavenging concentrate are mixed with the raw ore pulp containing inhibitors and collectors, and then subjected to reverse flotation roughing.

[0034] The obtained reverse flotation concentrate was subjected to direct flotation roughing. Hydrochloric acid was added to adjust the pH of the pulp to 6. High-intensity stirring at a stirring speed of 3000 r / min was used to desorb the starch inhibitor. Anionic collector TD-7 was added at a rate of 600 g / t for direct flotation and stirred for 3 min. The stirring speed was then adjusted to 1800 r / min and direct flotation was carried out for 2.5 min to obtain direct flotation concentrate and direct flotation tailings.

[0035] The obtained direct flotation concentrate is subjected to direct flotation cleaning without the addition of any reagents. The mixture is stirred for 3 minutes at a stirring speed of 1800 r / min, followed by direct flotation cleaning for 2 minutes. The total cleaning time is 2 minutes, resulting in direct flotation cleaned concentrate and direct flotation cleaned tailings. The direct flotation tailings are then subjected to direct flotation scavenging. An anionic collector TD-7 is added at a stirring speed of 1800 r / min at a dosage of 150 g / t. The mixture is stirred for 2 minutes, followed by direct flotation scavenging for 2 minutes. The total scavenging time is 2 minutes, resulting in direct flotation scavenged concentrate and direct flotation scavenged tailings. The direct flotation cleaned tailings and direct flotation scavenged concentrate are returned to the direct flotation roughing operation.

[0036] Using the above method, the TFe grade of the iron concentrate obtained is 67.53% by weight.

[0037] The yield of iron concentrate obtained by the above method is 35.91% by weight.

[0038] The TFe recovery rate of the iron concentrate obtained by the above method is 69.88% by weight.

[0039] The above method yields iron tailings with a TFe grade of 14.74% by weight.

[0040] The yield of iron tailings obtained by the above method is 64.09% by weight.

[0041] The TFe recovery rate of the iron tailings obtained by the above method is 30.12% by weight.

[0042] Example 2 The process steps for high-intensity magnetic separation concentrate of hematite ore as the feed are as follows: The selected high-intensity magnetic separation concentrate has the following composition by weight percentage: Fe2O3 34.44%, SiO2 21.90%, with the remainder being impurities.

[0043] The raw ore slurry was placed into the flotation equipment, and the slurry mass concentration was adjusted to 30%. Under the condition of stirring speed of 1800 r / min, the inhibitor CMC was first added and stirred for 3 min. The amount of CMC added was 600 g / t. Then, the cationic collector methyl oleate sulfate was added. The amount of methyl oleate sulfate added was 500 g / t. After stirring for 3 min, reverse flotation roughing was carried out for 3 min to obtain reverse flotation roughing concentrate and reverse flotation roughing tailings.

[0044] The rougher concentrate from the reverse flotation process is further subjected to reverse flotation cleaning to obtain a cleaned reverse flotation concentrate and a cleaned reverse flotation tailings. Each time the reverse flotation cleaning is performed, a cationic collector, methyl oleate sulfate, is added at a rate of 150 g / t. The mixture is stirred for 3 min at a stirring speed of 1800 r / min, followed by reverse flotation cleaning for 2 min to obtain a cleaned reverse flotation concentrate and a cleaned reverse flotation tailings.

[0045] The tailings from the reverse flotation roughing process are subjected to a first reverse flotation scavenging process for 2.5 minutes to obtain a first reverse flotation scavenging concentrate and a first reverse flotation scavenging tailings. The first reverse flotation scavenging concentrate is returned to the reverse flotation roughing process. The tailings from the first reverse flotation scavenging process are subjected to a second reverse flotation scavenging process for 2 minutes to obtain a second reverse flotation scavenging concentrate and a second reverse flotation scavenging tailings. The second reverse flotation scavenging concentrate is returned to the first reverse flotation scavenging process. The tailings from the second reverse flotation scavenging process are subjected to a third reverse flotation scavenging process for 1.5 minutes to obtain a third reverse flotation scavenging concentrate and a third reverse flotation scavenging tailings. The third reverse flotation scavenging concentrate is returned to the second reverse flotation scavenging process.

[0046] When reverse flotation cleaning yields reverse flotation cleaned tailings and primary reverse flotation scavenging yields primary reverse flotation scavenging concentrate, the reverse flotation cleaned tailings and primary reverse flotation scavenging concentrate are mixed with the raw ore pulp containing inhibitors and collectors, and then subjected to reverse flotation roughing.

[0047] The obtained reverse flotation concentrate was subjected to direct flotation roughing. Under the condition of high-intensity stirring at a stirring speed of 3800 r / min to achieve desorption of the inhibitor CMC, hydrochloric acid was added to adjust the pH of the pulp to 5.82, and anionic collector TD-7 was added at a rate of 700 g / t for direct flotation. The mixture was stirred for 3 min, and then the stirring speed was adjusted to 1800 r / min for 2.5 min of direct flotation to obtain direct flotation concentrate and direct flotation tailings.

[0048] The obtained direct flotation concentrate is subjected to direct flotation cleaning without the addition of any reagents. The mixture is stirred for 3 minutes at a stirring speed of 1800 r / min, followed by direct flotation cleaning for 2 minutes. The total cleaning time is 2 minutes, resulting in direct flotation cleaned concentrate and direct flotation cleaned tailings. The direct flotation tailings are then subjected to direct flotation scavenging. An anionic collector TD-7 is added at a stirring speed of 1800 r / min at a dosage of 100 g / t. The mixture is stirred for 2 minutes, followed by direct flotation scavenging for 2 minutes. The total scavenging time is 2 minutes, resulting in direct flotation scavenged concentrate and direct flotation scavenged tailings. The direct flotation cleaned tailings and direct flotation scavenged concentrate are returned to the direct flotation roughing operation.

[0049] Using the above method, the TFe grade of the iron concentrate obtained is 66.80% by weight.

[0050] The yield of iron concentrate obtained by the above method is 36.90% by weight.

[0051] The TFe recovery rate of the iron concentrate obtained by the above method is 71.57% by weight.

[0052] The iron tailings obtained by the above method have a TFe grade of 15.52% by weight.

[0053] The yield of iron tailings obtained by the above method is 63.10% by weight.

[0054] The TFe recovery rate of the iron tailings obtained by the above method is 28.43% by weight.

[0055] Example 3 The process steps for high-intensity magnetic separation concentrate of hematite ore as the feed are as follows: The selected high-intensity magnetic separation concentrate has the following composition by weight percentage: Fe2O3 33.16%, SiO2 21.80%, with the remainder being impurities.

[0056] The raw ore slurry was placed in the flotation equipment, and the slurry mass concentration was adjusted to 30%. Under the condition of stirring speed of 1800 r / min, the inhibitor was first added and stirred for 3 min. The amount of causticized starch added as the inhibitor was 600 g / t (after adding it, the pH of the slurry will become 9.15). Then, the cationic collector methyl oleate sulfate ammonium was added. The amount of cationic collector methyl oleate sulfate ammonium was 500 g / t. After stirring for 3 min, reverse flotation roughing was carried out for 3 min to obtain reverse flotation roughing concentrate and reverse flotation roughing tailings.

[0057] The rougher concentrate from the reverse flotation process is further subjected to reverse flotation cleaning to obtain a cleaned reverse flotation concentrate and a cleaned reverse flotation tailings. Each time the reverse flotation cleaning is performed, a cationic collector, methyl oleate sulfate, is added at a rate of 150 g / t. The mixture is stirred for 3 min at a stirring speed of 1800 r / min, followed by reverse flotation cleaning for 2 min to obtain a cleaned reverse flotation concentrate and a cleaned reverse flotation tailings.

[0058] The tailings from the reverse flotation roughing process are subjected to a first reverse flotation scavenging process for 2.5 minutes to obtain a first reverse flotation scavenging concentrate and a first reverse flotation scavenging tailings. The first reverse flotation scavenging concentrate is returned to the reverse flotation roughing process. The tailings from the first reverse flotation scavenging process are subjected to a second reverse flotation scavenging process for 2 minutes to obtain a second reverse flotation scavenging concentrate and a second reverse flotation scavenging tailings. The second reverse flotation scavenging concentrate is returned to the first reverse flotation scavenging process. The tailings from the second reverse flotation scavenging process are subjected to a third reverse flotation scavenging process for 1.5 minutes to obtain a third reverse flotation scavenging concentrate and a third reverse flotation scavenging tailings. The third reverse flotation scavenging concentrate is returned to the second reverse flotation scavenging process.

[0059] When reverse flotation cleaning yields reverse flotation cleaned tailings and primary reverse flotation scavenging yields primary reverse flotation scavenging concentrate, the reverse flotation cleaned tailings and primary reverse flotation scavenging concentrate are mixed with the raw ore pulp containing inhibitors and collectors, and then subjected to reverse flotation roughing.

[0060] The obtained reverse flotation concentrate was subjected to direct flotation roughing. Hydrochloric acid was added to adjust the pH of the pulp to 5.93. Under the condition of high-intensity stirring at a stirring speed of 3000 r / min to achieve desorption of starch inhibitor, sodium oleate, anionic collector, was added for direct flotation at a rate of 500 g / t. The mixture was stirred for 3 min, and then the stirring speed was adjusted to 1800 r / min for 2.5 min of direct flotation to obtain direct flotation concentrate and direct flotation tailings.

[0061] The obtained direct flotation concentrate is subjected to direct flotation cleaning without the addition of any reagents. The mixture is stirred for 3 minutes at a stirring speed of 1800 r / min, followed by direct flotation cleaning for 2 minutes. The total cleaning time is 2 minutes, resulting in direct flotation cleaned concentrate and direct flotation cleaned tailings. The direct flotation tailings are then subjected to direct flotation scavenging. The anionic collector sodium oleate is added at a stirring speed of 1800 r / min at a dosage of 100 g / t. The mixture is stirred for 2 minutes, followed by direct flotation scavenging for 2 minutes. The total scavenging time is 2 minutes, resulting in direct flotation scavenged concentrate and direct flotation scavenged tailings. The direct flotation cleaned tailings and direct flotation scavenged concentrate are returned to the direct flotation roughing operation.

[0062] Using the above method, the TFe grade of the iron concentrate obtained is 66.97% by weight.

[0063] The yield of iron concentrate obtained by the above method is 36.20% by weight.

[0064] The TFe recovery rate of the iron concentrate obtained by the above method is 73.10% by weight.

[0065] The iron tailings obtained by the above method have a TFe grade of 13.98% by weight.

[0066] The yield of iron tailings obtained by the above method is 63.80% by weight.

[0067] The TFe recovery rate of the iron tailings obtained by the above method is 26.90% by weight.

[0068] Example 4 The process steps for high-intensity magnetic separation concentrate of hematite ore as the feed are as follows: The selected high-intensity magnetic separation concentrate has the following composition by weight percentage: Fe2O3 33.7%, SiO2 22.05%, with the remainder being impurities.

[0069] The raw ore slurry was placed in the flotation equipment, and the slurry mass concentration was adjusted to 30%. Under the condition of stirring speed of 1800 r / min, the inhibitor was first added and stirred for 3 min. The amount of causticized starch added as the inhibitor was 550 g / t (after adding it, the pH of the slurry will become 9.03). Then, the cationic collector methyl oleate sulfate ammonium was added. The amount of cationic collector methyl oleate sulfate ammonium was 550 g / t. After stirring for 3 min, reverse flotation roughing was carried out for 3 min to obtain reverse flotation roughing concentrate and reverse flotation roughing tailings.

[0070] The rougher concentrate from the reverse flotation process is further subjected to reverse flotation cleaning to obtain a cleaned reverse flotation concentrate and a cleaned reverse flotation tailings. Each time the reverse flotation cleaning is performed, a cationic collector, methyl oleate sulfate, is added at a rate of 150 g / t. The mixture is stirred for 3 min at a stirring speed of 1800 r / min, followed by reverse flotation cleaning for 2 min to obtain a cleaned reverse flotation concentrate and a cleaned reverse flotation tailings.

[0071] The tailings from the reverse flotation roughing process are subjected to a first reverse flotation scavenging process for 2.5 minutes to obtain a first reverse flotation scavenging concentrate and a first reverse flotation scavenging tailings. The first reverse flotation scavenging concentrate is returned to the reverse flotation roughing process. The tailings from the first reverse flotation scavenging process are subjected to a second reverse flotation scavenging process for 2 minutes to obtain a second reverse flotation scavenging concentrate and a second reverse flotation scavenging tailings. The second reverse flotation scavenging concentrate is returned to the first reverse flotation scavenging process. The tailings from the second reverse flotation scavenging process are subjected to a third reverse flotation scavenging process for 1.5 minutes to obtain a third reverse flotation scavenging concentrate and a third reverse flotation scavenging tailings. The third reverse flotation scavenging concentrate is returned to the second reverse flotation scavenging process.

[0072] When reverse flotation cleaning yields reverse flotation cleaned tailings and primary reverse flotation scavenging yields primary reverse flotation scavenging concentrate, the reverse flotation cleaned tailings and primary reverse flotation scavenging concentrate are mixed with the raw ore pulp containing inhibitors and collectors, and then subjected to reverse flotation roughing.

[0073] The obtained reverse flotation concentrate was subjected to direct flotation roughing. Hydrochloric acid was added to adjust the pH of the pulp to 6.23. Under the condition of high-intensity stirring at a stirring speed of 3000 r / min to achieve desorption of starch inhibitor, sodium oleate, anionic collector, was added for direct flotation at a rate of 650 g / t. The mixture was stirred for 3 min, and then the stirring speed was adjusted to 1800 r / min for 2.5 min of direct flotation to obtain direct flotation concentrate and direct flotation tailings.

[0074] The obtained direct flotation concentrate is subjected to direct flotation cleaning without the addition of any reagents. The mixture is stirred for 3 minutes at a stirring speed of 1800 r / min, followed by direct flotation cleaning for 2 minutes. The total cleaning time is 2 minutes, resulting in direct flotation clean concentrate and direct flotation clean tailings. The direct flotation tailings are then subjected to direct flotation scavenging. The anionic collector sodium oleate is added at a stirring speed of 1800 r / min at a dosage of 150 g / t. The mixture is stirred for 2 minutes, followed by direct flotation scavenging for 2 minutes. The total scavenging time is 2 minutes, resulting in direct flotation scavenged concentrate and direct flotation scavenged tailings. The direct flotation clean tailings and direct flotation scavenged concentrate are returned to the direct flotation roughing operation.

[0075] Using the above method, the TFe grade of the iron concentrate obtained is 66.73% by weight.

[0076] The yield of iron concentrate obtained by the above method is 35.80% by weight.

[0077] The TFe recovery rate of the iron concentrate obtained by the above method is 70.89% by weight.

[0078] The TFe grade of the iron tailings obtained by the above method is 15.28% by weight.

[0079] The yield of iron tailings obtained by the above method is 64.20% by weight.

[0080] The TFe recovery rate of the iron tailings obtained by the above method is 29.11% by weight.

[0081] Comparative Example 1 The process steps for high-intensity magnetic separation concentrate of hematite ore as the feed are as follows: The selected high-intensity magnetic separation concentrate has the following composition by weight percentage: Fe2O3 33.12%, SiO2 22.09%, with the remainder being impurities.

[0082] The raw ore slurry was placed in the flotation equipment, and the slurry mass concentration was adjusted to 30%. Under the condition of stirring speed of 1800 r / min, the inhibitor was first added and stirred for 3 min. The amount of causticized starch added as the inhibitor was 550 g / t (after adding it, the pH of the slurry will become 9.04). Then, the cationic collector methyl oleate sulfate was added. The amount of methyl oleate sulfate added as the cationic collector was 550 g / t. After stirring for 3 min, reverse flotation roughing was carried out for 3 min to obtain reverse flotation roughing concentrate and reverse flotation roughing tailings.

[0083] The rougher concentrate from the reverse flotation process is further subjected to reverse flotation cleaning to obtain a cleaned reverse flotation concentrate and a cleaned reverse flotation tailings. Each time the reverse flotation cleaning is performed, a cationic collector, methyl oleate sulfate, is added at a rate of 150 g / t. The mixture is stirred for 3 min at a stirring speed of 1800 r / min, followed by reverse flotation cleaning for 2 min to obtain a cleaned reverse flotation concentrate and a cleaned reverse flotation tailings.

[0084] The tailings from the reverse flotation roughing process are subjected to a first reverse flotation scavenging process for 2.5 minutes to obtain a first reverse flotation scavenging concentrate and a first reverse flotation scavenging tailings. The first reverse flotation scavenging concentrate is returned to the reverse flotation roughing process. The tailings from the first reverse flotation scavenging process are subjected to a second reverse flotation scavenging process for 2 minutes to obtain a second reverse flotation scavenging concentrate and a second reverse flotation scavenging tailings. The second reverse flotation scavenging concentrate is returned to the first reverse flotation scavenging process. The tailings from the second reverse flotation scavenging process are subjected to a third reverse flotation scavenging process for 1.5 minutes to obtain a third reverse flotation scavenging concentrate and a third reverse flotation scavenging tailings. The third reverse flotation scavenging concentrate is returned to the second reverse flotation scavenging process.

[0085] When reverse flotation cleaning yields reverse flotation cleaned tailings and primary reverse flotation scavenging yields primary reverse flotation scavenging concentrate, the reverse flotation cleaned tailings and primary reverse flotation scavenging concentrate are mixed with the raw ore pulp containing inhibitors and collectors, and then subjected to reverse flotation roughing.

[0086] The obtained reverse flotation concentrate was subjected to direct flotation roughing. Hydrochloric acid was added to adjust the pulp pH to 6.23. Under high-intensity stirring at a stirring speed of 4500 r / min to remove the starch inhibitor (slitting phenomenon was observed, so it is recommended to reduce the stirring speed to 3000 r / min-4000 r / min to remove the inhibitor), sodium oleate anionic collector was added for direct flotation at a rate of 650 g / t, and stirred for 3 min. The stirring speed was then adjusted to 1800 r / min and direct flotation was carried out for 2.5 min to obtain direct flotation concentrate and direct flotation tailings.

[0087] The obtained direct flotation concentrate is subjected to direct flotation cleaning without the addition of any reagents. The mixture is stirred for 3 minutes at a stirring speed of 1800 r / min, followed by direct flotation cleaning for 2 minutes. The total cleaning time is 2 minutes, resulting in direct flotation clean concentrate and direct flotation clean tailings. The direct flotation tailings are then subjected to direct flotation scavenging. The anionic collector sodium oleate is added at a stirring speed of 1800 r / min at a dosage of 150 g / t. The mixture is stirred for 2 minutes, followed by direct flotation scavenging for 2 minutes. The total scavenging time is 2 minutes, resulting in direct flotation scavenged concentrate and direct flotation scavenged tailings. The direct flotation clean tailings and direct flotation scavenged concentrate are returned to the direct flotation roughing operation.

[0088] Using the above method, the TFe grade of the obtained iron concentrate is 64.33% by weight. (Because the stirring speed exceeds the specified range, the mineral particles are repeatedly impacted and ground, resulting in particle breakage and mud formation. Fine mud will be mechanically carried into the foam concentrate indiscriminately, lowering the concentrate grade.) The yield of iron concentrate obtained by the above method is 32.80% by weight.

[0089] The TFe recovery rate of the iron concentrate obtained by the above method is 63.72% by weight.

[0090] The above method yields iron tailings with a TFe grade of 17.88% by weight.

[0091] The yield of iron tailings obtained by the above method is 67.20% by weight.

[0092] The TFe recovery rate of the iron tailings obtained by the above method is 36.28% by weight.

[0093] Comparative Example 2 The process steps for high-intensity magnetic separation concentrate of hematite ore as the feed are as follows: The selected high-intensity magnetic separation concentrate has the following composition by weight percentage: Fe2O3 33.1%, SiO2 21.42%, with the remainder being impurities.

[0094] The raw ore slurry was placed in the flotation equipment, and the slurry mass concentration was adjusted to 30%. Under the condition of stirring speed of 1800 r / min, the inhibitor causticized starch was added and stirred for 3 min. The amount of causticized starch added was 600 g / t (after adding it, the pH of the slurry will become 9.12). Then, the cationic collector dodecylamine was added. The amount of cationic collector dodecylamine added was 500 g / t. After stirring for 3 min, reverse flotation roughing was carried out for 3 min to obtain reverse flotation roughing concentrate and reverse flotation roughing tailings.

[0095] The rougher concentrate from the reverse flotation process is further subjected to reverse flotation cleaning to obtain a cleaned reverse flotation concentrate and a cleaned reverse flotation tailings. Each time the reverse flotation cleaning is performed, a cationic collector, dodecylamine, is added at a rate of 150 g / t. The mixture is stirred for 3 min at a stirring speed of 1800 r / min, followed by reverse flotation cleaning for 2 min to obtain a cleaned reverse flotation concentrate and a cleaned reverse flotation tailings.

[0096] The tailings from the reverse flotation roughing process are subjected to a first reverse flotation scavenging process for 2.5 minutes to obtain a first reverse flotation scavenging concentrate and a first reverse flotation scavenging tailings. The first reverse flotation scavenging concentrate is returned to the reverse flotation roughing process. The tailings from the first reverse flotation scavenging process are subjected to a second reverse flotation scavenging process for 2 minutes to obtain a second reverse flotation scavenging concentrate and a second reverse flotation scavenging tailings. The second reverse flotation scavenging concentrate is returned to the first reverse flotation scavenging process. The tailings from the second reverse flotation scavenging process are subjected to a third reverse flotation scavenging process for 1.5 minutes to obtain a third reverse flotation scavenging concentrate and a third reverse flotation scavenging tailings. The third reverse flotation scavenging concentrate is returned to the second reverse flotation scavenging process.

[0097] When reverse flotation cleaning yields reverse flotation cleaned tailings and primary reverse flotation scavenging yields primary reverse flotation scavenging concentrate, the reverse flotation cleaned tailings and primary reverse flotation scavenging concentrate are mixed with the raw ore pulp containing inhibitors and collectors, and then subjected to reverse flotation roughing.

[0098] The obtained reverse flotation concentrate was subjected to direct flotation roughing. Hydrochloric acid was added to adjust the pH of the pulp to 6.12. Under high-intensity stirring at a stirring speed of 3000 r / min to achieve starch desorption, anionic collector Tar oil was added for direct flotation at a rate of 550 g / t. The mixture was stirred for 3 min, and then the stirring speed was adjusted to 1800 r / min for 2.5 min of direct flotation to obtain direct flotation concentrate and direct flotation tailings.

[0099] The obtained direct flotation concentrate is subjected to direct flotation cleaning without the addition of any reagents. The mixture is stirred for 3 minutes at a stirring speed of 1800 r / min, followed by direct flotation cleaning for 2 minutes. The total cleaning time is 2 minutes, resulting in direct flotation clean concentrate and direct flotation clean tailings. The direct flotation tailings are then subjected to direct flotation scavenging. The anionic collector Tar oil is added at a stirring speed of 1800 r / min at a dosage of 100 g / t. The mixture is stirred for 2 minutes, followed by direct flotation scavenging for 2 minutes. The total scavenging time is 2 minutes, resulting in direct flotation scavenged concentrate and direct flotation scavenged tailings. The direct flotation clean tailings and direct flotation scavenged concentrate are returned to the direct flotation roughing operation.

[0100] Using the above method, the TFe grade of the obtained iron concentrate is 64.37% by weight. (When using the cationic collector dodecylamine, large-sized, highly viscous bubbles are generated, which mechanically entrain fine gangue minerals in the slurry that are not effectively attached to the bubbles into the foam layer, ultimately entering the concentrate and affecting the concentrate grade.) The yield of iron concentrate obtained by the above method is 36.36% by weight.

[0101] The TFe recovery rate of the iron concentrate obtained by the above method is 70.71% by weight.

[0102] The above method yields iron tailings with a TFe grade of 15.57% by weight.

[0103] The yield of iron tailings obtained by the above method is 63.64% by weight.

[0104] The TFe recovery rate of the iron tailings obtained by the above method is 29.29% by weight.

Claims

1. A beneficiation method of a hematite ore high intensity magnetic separation concentrate, characterized by, The steps include the following: Step 1: Place the raw ore slurry into the flotation equipment, adjust the slurry mass concentration to 30%-40%, and add inhibitors and stir for 3-4 minutes at a stirring speed of 1800-2000 r / min. Then add cationic collectors and stir for 3-4 minutes to perform reverse flotation roughing for 3-4 minutes to obtain reverse flotation roughing concentrate and reverse flotation roughing tailings. Step 2: Perform reverse flotation cleaning on the rougher concentrate. First, add cationic collector each time, stir for 3 min to 4 min at a stirring speed of 1800 r / min-2000 r / min, and then perform reverse flotation for 2 min to 3 min to obtain reverse flotation clean concentrate and reverse flotation clean tailings. Step 3: Perform a first reverse flotation scavenging on the tailings from the reverse flotation roughing process for 2-3 minutes to obtain a first reverse flotation scavenging concentrate and a first reverse flotation scavenging tailings; return the first reverse flotation scavenging concentrate to the reverse flotation roughing process. The tailings from the first reverse flotation scavenging are subjected to a second reverse flotation scavenging for 2-3 minutes to obtain the second reverse flotation scavenging concentrate and the second reverse flotation scavenging tailings. The secondary reverse flotation scavenging concentrate is returned to the primary reverse flotation scavenging operation; the obtained secondary reverse flotation scavenging tailings are subjected to a third reverse flotation scavenging operation for 1-2 minutes to obtain a tertiary reverse flotation scavenging concentrate and a tertiary reverse flotation scavenging tailings. The tertiary reverse flotation scavenging concentrate is then returned to the secondary reverse flotation scavenging operation. Step 4: When reverse flotation cleansing yields reverse flotation cleaned tailings and the first reverse flotation scavenging yields first reverse flotation scavenging concentrate, the reverse flotation cleaned tailings and the first reverse flotation scavenging concentrate are mixed with the raw ore pulp containing inhibitors and cationic collectors and subjected to reverse flotation roughing together. Step 5: The obtained reverse flotation concentrate is subjected to direct flotation roughing. Hydrochloric acid is added to adjust the pH of the pulp to 5.5-6.5, and desorption of inhibitors is carried out by ultra-high speed stirring. Anionic collector is added for direct flotation, and stirring is carried out for 3-4 minutes at a stirring speed of 1800-2000 r / min for 1.5-2.5 minutes to obtain direct flotation concentrate and direct flotation tailings. Step 6: Perform direct flotation cleaning on the obtained direct flotation concentrate without adding any reagents. Stir for 2-3 minutes at a stirring speed of 1800-2000 rpm. Perform direct flotation for 2-3 minutes to obtain direct flotation cleaned concentrate and direct flotation cleaned tailings. Perform direct flotation scavenging on the direct flotation tailings. Add an anionic collector and perform direct flotation scavenging at a stirring speed of 1800-2000 rpm. Stir for 2-3 minutes, then perform direct flotation for 2-3 minutes to obtain direct flotation scavenged concentrate and direct flotation scavenged tailings. Return the direct flotation cleaned tailings and direct flotation scavenged concentrate to the direct flotation roughing operation. Combine the direct flotation scavenged tailings with the tertiary reverse flotation scavenged tailings to form the final tailings.

2. The beneficiation method of hematite ore high intensity magnetic concentrate according to claim 1, characterized in that, The cationic collector is ammonium methyl oleate imidazoline sulfate.

3. The beneficiation method of hematite ore high intensity magnetic concentrate according to claim 1, characterized in that, The ultra-high-speed stirring speed in step 5 is 3000 r / min to 4000 r / min.

4. The beneficiation method of hematite ore high intensity magnetic concentrate according to claim 1, characterized by, In step 1, the amount of inhibitor added is 400g / t to 600g / t, and after adding the inhibitor, the pH of the slurry becomes 9-10.

5. The beneficiation method of hematite ore high intensity magnetic separation concentrate according to claim 1, characterized by, The amount of cationic collector added in step 1 is 500g / t to 600g / t.

6. The beneficiation method of hematite ore high intensity magnetic separation concentrate according to claim 1, characterized in that, In step 2, the amount of cationic collector added is 100g / t-150g / t.

7. The beneficiation method of hematite ore high intensity magnetic separation concentrate according to claim 1, characterized by, The amount of anionic collector added in step 5 is 500g / t-800g / t.

8. The beneficiation method of hematite ore high intensity magnetic separation concentrate according to claim 1, characterized by, The amount of anionic collector added in step 6 is 100g / t-200g / t.

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