Method and system for comprehensive recovery of copper-containing magnetite and hematite by multi-stage grading enrichment

Abstract

The application belongs to the technical field of metal production or refining, and discloses a comprehensive recovery method and system for multistage grading enrichment of copper-containing magnetite and hematite, which comprises the following steps: crushing the raw ore and adopting wet screening to obtain three particle sizes of coarse, medium and fine; crushing the coarse particle size into two particle sizes of medium and fine, combining the medium particle size and adopting a heavy medium cyclone to discard waste, to obtain a heavy medium concentrate; crushing the heavy medium concentrate into a fine particle size, combining the fine particle size and adopting strong magnetic separation to discard waste, to obtain a magnetic separation concentrate. The application adopts a multi-crushing and less-milling process, and the raw ore is crushed and subjected to multistage grading, and the heavy medium cyclone and the strong magnetic separation are used for pre-discarding waste, so that the waste ore milling is reduced, the ore milling cost is reduced, the energy consumption is reduced, the pre-enrichment of the iron ore is realized, the magnetic separation concentrate after the discarding is used in the separation process, and through multistage grading and flotation enrichment, the efficient enrichment of the magnetite, hematite and copper-containing minerals can be realized.

Description

Technical Field

[0001] This invention relates to the field of metal production or refining technology, and in particular to a multi-stage graded enrichment and comprehensive recovery method and system for copper-containing magnetite and hematite. Background Technology

[0002] Steel and copper are essential raw materials for economic development. The demand for steel and copper is increasing rapidly with economic growth. Developing and utilizing copper and iron ore resources at low cost and low energy consumption is a key focus of developing a low-carbon economy. Currently, a large number of mineral processing researchers have conducted in-depth research on copper-bearing iron ore resources. Conventional mineral processing methods mainly include crushing, grinding followed by gravity separation, magnetic separation, and flotation, or a combination of these processes.

[0003] In the mineral processing process, the grinding stage accounts for the highest cost, representing 30% to 40% of the unit mineral processing cost.

[0004] Current processes typically involve directly grinding the raw ore to a certain fineness (e.g., grinding to -0.074mm accounting for 70%), followed by enrichment using appropriate beneficiation processes such as gravity separation, magnetic separation, or flotation. For example, Chinese application CN 118847349 A discloses a beneficiation method for hematite, which directly grinds the raw ore to -0.076mm accounting for 80%, and then uses magnetic separation and flotation processes to enrich the hematite. Another example is Chinese patent CN117225595B, which discloses a reverse flotation process for hematite, which directly grinds the raw ore to -0.076mm ≥ 70%, and then uses reverse flotation to enrich the hematite. All of these processes involve direct grinding of the raw ore, resulting in large grinding volumes and increased energy consumption.

[0005] Chinese patent application CN 114669395 A discloses a beneficiation method for hematite, which adopts a method of coarse crushing ---- dry magnetic separator for one-time waste removal ---- medium crushing ---- dry magnetic separator for two-time waste removal. The waste rock is removed in advance, and after waste removal, it is crushed into fine ore of less than 2mm and then ground.

[0006] Although this process reduces the amount of ore fed into the mill and lowers grinding costs by pre-discarding waste, the inventors recognize that this process, which directly discards waste through magnetic separation after crushing the raw ore, has the following disadvantages: 1) Due to the large differences in ore particle size after crushing, coarser particles are not easily recovered into magnetic concentrate during magnetic separation because of their weaker magnetic properties, resulting in iron loss and reduced iron recovery rate; 2) Because the ore that meets the waste disposal particle size distribution is not separated in time after crushing, there is a problem of over-crushing during the crushing process, which leads to uneven particle size distribution of the crushed product, reducing waste disposal efficiency and separation efficiency of the beneficiation process.

[0007] In view of this, the present invention is proposed. Summary of the Invention

[0008] According to one embodiment of the present invention, the purpose is to provide a multi-stage classification enrichment and comprehensive recovery method and system for copper-bearing magnetite and hematite. The method adopts a multi-crushing and minimal grinding process, in which the raw ore is crushed and then classified in multiple stages. Heavy medium cyclones and strong magnetic separation are used for pre-disposal of waste rock, which reduces grinding costs and energy consumption. At the same time, it achieves pre-enrichment of iron ore, which is more conducive to the efficient enrichment of iron ore in the subsequent process.

[0009] The above objective can be achieved through the following technical solutions: According to one aspect of the present invention, a multi-stage enrichment and comprehensive recovery method for copper-bearing magnetite and hematite is provided, comprising: Step S1: Crush the raw ore and wet screen it into three particle sizes: coarse, medium, and fine. Step S2: The coarse particles are crushed into medium and fine particles, the medium particles are combined and discarded using a heavy medium cyclone separator to obtain heavy medium concentrate; Step S3: The heavy medium concentrate is crushed into fine particles, the fine particles are combined and discarded by strong magnetic separation to obtain magnetic concentrate.

[0010] Preferably, in step S1, the wet sieving separates the particles into three continuous particle sizes: coarse, medium, and fine. More preferably, the two dividing values ​​for the three continuous particle sizes range from 20-30 mm to 2-5 mm.

[0011] Preferably, the three particle sizes of coarse, medium, and fine are +25mm, -25mm to +3mm, and -3mm, respectively.

[0012] Preferably, in step S2, the coarse-grained closed-circuit crusher is broken into medium and fine-grained particles.

[0013] Preferably, in step S2, when the heavy medium hydrocyclone is discarded, the heavy medium used is an organic solvent or a heavy suspension. The organic solvent is one of carbon tetrachloride, tribromomethane, and tetrabromoethane. The heavy suspension is an aqueous solution prepared by mixing ferrosilicon or magnetite powder ferrosilicon solid particles with water.

[0014] Preferably, the specific gravity of the heavy suspension is 3.0–6.5 g / cm³. 3 The preferred concentration is 3.5–4.5 g / cm³. 3 .

[0015] Preferably, in step S3, a high-pressure roller is used to crush the heavy medium concentrate into fine particles in a closed circuit.

[0016] Preferably, in step S3, the background magnetic field strength of the strong magnetic separation waste disposal is 0.3T to 1.75T, more preferably 0.5T to 1.0T.

[0017] Preferably, the method further includes: Step S4: After grinding the magnetic concentrate, perform weak magnetic separation to obtain magnetite and weak magnetic separation tailings; Step S5: After grinding the weak magnetic separation tailings, copper flotation is performed to obtain copper concentrate and copper flotation tailings. Step S6: The copper flotation tailings are subjected to strong magnetic separation, wet screening, and flotation in sequence to obtain hematite.

[0018] Preferably, in step S4, a magnetic drum is used for weak magnetic separation, and the magnetic field strength of the magnetic drum is 800-1400 mT, preferably 900-1200 mT.

[0019] Preferably, in step S5, the copper flotation collector is selected from one or more of xanthate collectors, black powder collectors, and lipid collectors; the foaming agent is at least one of No. 2 oil and MIBC.

[0020] Preferably, step S6 includes: High-intensity magnetic separation is performed on copper flotation tailings to obtain high-intensity magnetic concentrate; The strong magnetic concentrate was separated into three particle sizes—large, medium, and small—using wet screening. Hematite was flotated using a positive flotation process on the intermediate particle size to obtain flotation concentrate; The flotation concentrate is combined with the smaller particles obtained after wet screening to obtain hematite.

[0021] Preferably, in step S6, the strong magnetic concentrate is wet-screened into three continuous particle sizes: large, medium, and small. More preferably, the ranges of the two dividing values ​​in the three continuous particle sizes are 0.070-0.080 mm and 0.050-0.060 mm, respectively.

[0022] Preferably, in step S6, the strong magnetic concentrate is wet screened into three particle sizes: +0.074mm, -0.074mm to +0.053mm, and -0.053mm, respectively.

[0023] Preferably, when performing hematite flotation, the hematite flotation collector is one or more of sodium petroleum sulfonate, oxidized paraffin soap, oleic acid, and sodium oleate.

[0024] Preferably, when performing hematite flotation, the modifier is one or more of water glass, sodium fluorosilicate, sodium hexametaphosphate, and CMC.

[0025] According to one aspect of the present invention, a multi-stage graded enrichment and comprehensive recovery system for copper-bearing magnetite and hematite is provided, comprising a waste disposal device, said waste disposal device comprising: The crushing and screening unit is used to crush raw ore and use wet screening to separate it into three particle sizes: coarse, medium, and fine; it is used to crush coarse particles into two particle sizes: medium and fine; and it is used to crush heavy media concentrate into fine particles. Heavy medium hydrocyclones are used to remove waste from the combined medium-sized particles to obtain heavy medium concentrate. Magnetic separators are used to perform strong magnetic separation to remove waste from the combined fine particles and obtain magnetic concentrate.

[0026] Preferably, the system further includes: Grinding equipment is used to grind magnetic concentrate and weak magnetic tailings after waste disposal. Magnetic drum is used for weak magnetic separation after grinding magnetic concentrate to obtain magnetite and weak magnetic separation tailings; Copper flotation equipment is used to perform copper flotation after grinding weak magnetic separation tailings to obtain copper concentrate and copper flotation tailings. Hematite flotation equipment is used to perform strong magnetic separation on copper flotation tailings. The strong magnetic separation concentrate is wet screened into three particle sizes, and the middle particle size is floated. The flotation concentrate and the small particle size are combined to obtain hematite.

[0027] Beneficial effects: According to one embodiment of the present invention, the multi-stage classification and enrichment method provides a multi-crushing and minimal grinding process. After crushing the raw ore, it is classified into multiple stages. Heavy medium cyclones and strong magnetic separation are used for pre-discarding waste rock, which reduces grinding waste, lowers grinding costs and energy consumption, and achieves pre-enrichment of iron ore. Based on the pre-enriched magnetic concentrate after waste disposal, it is further separated and enriched by flotation through multi-stage classification, which can achieve efficient enrichment of hematite.

[0028] Compared with the prior art, the present invention has the following advantages: 1) The pre-disposal process involves crushing without grinding. After crushing, the raw ore undergoes multi-stage classification, making full use of the differences in ore particle size, specific gravity, and magnetic properties. Heavy medium hydrocyclones and magnetic separation are used for pre-disposal, removing waste rock that meets the disposal particle size as early as possible and separating it from the operating system in a timely manner. This reduces waste rock (ineffective) grinding, lowers grinding costs, and reduces energy consumption. At the same time, it also achieves pre-enrichment of iron ore, reduces the unit concentrate processing cost, achieves cost reduction and efficiency improvement, and is more conducive to the subsequent efficient enrichment of iron ore.

[0029] 2) During the beneficiation process, the differences in particle size, specific gravity, magnetic properties, and floatability between magnetite, hematite, and gangue minerals are fully utilized to separate magnetite, hematite, and copper minerals from gangue minerals such as pyrite, chlorite, kaolinite, mica, talc, and amphibole. Magnetite is enriched by weak magnetic separation after regrinding, and copper minerals are floated after regrinding. Qualified products that meet the requirements are separated in a timely manner, reducing the processing volume of subsequent hematite flotation operations, reducing reagent consumption, and reducing the unit ore processing cost.

[0030] 3) The hematite enrichment process fully utilizes the characteristics of iron particle size distribution and achieves efficient enrichment of hematite through multi-stage classification and flotation.

[0031] 4) Screening processes are used to separate ores of different particle sizes, and corresponding operating systems are employed for further processing of each size, thereby reducing the load on the target operating system and lowering the power consumption or reagent consumption of crushing / grinding. For example, heavy media processes are used to process only waste materials in the -25mm to +3mm size range; magnetic separation processes are used to process waste materials in the -3mm size range; and positive flotation processes are used to process intermediate particle sizes after screening of strong magnetic concentrate. Attached Figure Description

[0032] Figure 1 This is a process flow diagram of a multi-stage enrichment and comprehensive recovery method for copper-containing magnetite and hematite in one embodiment of the present invention; Figure 2 This is a process flow diagram of a multi-stage enrichment and comprehensive recovery method for copper-containing magnetite and hematite in another embodiment of the present invention; Figure 3 This is a process flow diagram of Comparative Example 1 of the present invention. Detailed Implementation

[0033] The technical solution of the present invention will be clearly and completely described below with reference to embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. The following description of at least one exemplary embodiment is merely illustrative and is in no way intended to limit the present invention or its application or use. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention without creative effort are within the scope of protection of the present invention.

[0034] To reduce grinding costs and energy consumption, and to achieve low-cost and efficient enrichment of iron ore, this invention provides a multi-stage classification and enrichment method for copper-bearing magnetite and hematite. The method employs a multi-crushing and minimal-grinding process, with the raw ore being crushed and then classified in multiple stages. Heavy media hydrocyclones and strong magnetic separation are used for pre-disposal of waste rock, reducing waste stone grinding and lowering grinding costs.

[0035] In some embodiments of the present invention, a multi-stage classification and enrichment method for the comprehensive recovery of copper-bearing magnetite and hematite is provided. The system employed in this method includes waste disposal equipment, which comprises a crushing and screening unit, a heavy media hydrocyclone, and a magnetic separator. After crushing, the raw ore undergoes multi-stage classification, with primary waste disposal using a heavy media hydrocyclone and secondary waste disposal using a high-intensity magnetic separator. Figure 1 As shown, it includes: Step S1: Crush the raw ore and wet screen it into three particle sizes: coarse, medium, and fine. Step S2: The coarse particles are crushed into medium and fine particles, the medium particles are combined and discarded using a heavy medium hydrocyclone to obtain heavy medium concentrate and tailings 1; Step S3: The heavy medium concentrate is crushed into fine particles, the fine particles are combined and discarded by strong magnetic separation to obtain magnetic concentrate and tailings 2.

[0036] Based on the equipment and the types and properties of copper, iron, and other gangue in copper-bearing magnetite and hematite, the raw ore is crushed and wet-screened into three continuous particle sizes, with the two dividing values ​​for each of the three continuous particle sizes ranging from 20-30 mm to 2-5 mm. More preferably, the raw ore is crushed and wet-screened into three particle sizes: +25 mm, -25 mm to +3 mm, and -3 mm.

[0037] The principle of this invention is to crush more and grind less to reduce energy consumption. The feed size of the high-pressure roller is 20-80mm. The coarser the feed, the smaller the processing capacity of the high-pressure roller. The finer the feed, the lower the processing capacity of the front-end crushing. Taking all factors into consideration, a size of about 25mm is selected. Similarly, the selection of the particle size at the discharge port of the high-pressure roller is also related to the processing capacity and the hardness of the ore. Taking into consideration the type and properties of the ore and the processing capacity of the equipment, a size of about 3mm is selected.

[0038] For the different particle sizes after the above multi-stage classification, heavy medium cyclones and strong magnetic separation are used for pre-disposal of waste rock to improve waste disposal efficiency, reduce the load on the target operation system, and separate the waste rock from the operation system as early and timely as possible. This reduces waste rock grinding, grinding volume, grinding energy consumption, and grinding costs, while also reducing iron loss and achieving iron ore pre-enrichment. Based on the magnetic separation concentrate after waste disposal, the concentrate processing cost can be reduced, which is more conducive to the efficient enrichment of magnetite and hematite in the subsequent process.

[0039] In some embodiments of the present invention, the multi-stage enrichment and comprehensive recovery method for copper-bearing magnetite and hematite is provided. The system used in implementing the above method further includes: grinding equipment, magnetic drum, copper flotation equipment, and hematite flotation equipment. After pre-discarding waste according to steps S1-S3, the method further includes: performing concentrate beneficiation treatment on the magnetic concentrate after magnetic separation waste disposal to enrich magnetite, hematite, and copper concentrate. (Reference) Figure 2 As shown, it includes: Step S4: After grinding the magnetic concentrate, perform weak magnetic separation to enrich magnetite. Step S5: After grinding the tailings from the weak magnetic separation, copper flotation is performed to obtain copper concentrate; Step S6: The copper flotation tailings are subjected to strong magnetic separation, wet screening and flotation in sequence to obtain hematite.

[0040] After pre-discarding waste, the ore properties are fully utilized during the beneficiation process. Based on the iron distribution rate of different particle sizes, a multi-stage classification and enrichment process is adopted to separate products with iron grades that meet the requirements in a timely manner. This reduces the processing volume of subsequent flotation operations, reduces reagent consumption, and thus reduces the unit ore processing cost.

[0041] In some preferred embodiments, to further improve the recovery rate of hematite, step S6 includes: first, enriching the copper flotation tailings with strong magnetic separation to obtain strong magnetic concentrate; then, separating the strong magnetic concentrate into three continuous particle sizes of large, medium, and small using wet screening; next, performing flotation on the intermediate particle size using a positive flotation process to obtain flotation concentrate; and finally, merging the flotation concentrate with the small particle size after wet screening to obtain hematite.

[0042] By fully utilizing the differences in particle size, specific gravity, magnetic properties, and floatability between hematite and gangue minerals, the minerals are enriched through strong magnetic separation. Furthermore, based on the distribution characteristics of valuable metallic iron in different particle sizes in the ore, wet screening is performed to divide the minerals into three continuous particle sizes. In addition, the two dividing values ​​in the three continuous particle sizes can be selected from the ranges of 0.070-0.080 mm and 0.050-0.060 mm, respectively.

[0043] Preferably, the wet screening is divided into three consecutive particle sizes: +0.074mm (discarded waste), -0.074mm to +0.053mm, and -0.053mm. The coarse particle size is discarded, and the fine particle size is used directly as concentrate. Then, the intermediate particle size is floated, and the flotation concentrate and the fine particle size are mixed to form hematite. Since only the intermediate particle size is floated, the flotation feed rate is reduced, thereby achieving low-cost and high-efficiency enrichment of hematite.

[0044] Through particle size distribution analysis of hematite ore processing sections, the inventors discovered that the fine-grained feed (-0.053mm) has a very high iron grade (over 50% iron content, over 31% iron distribution), and can therefore be directly processed into concentrate; the coarse-grained feed (+0.074mm) has a very low grade (below 15% iron content), and can be discarded; further flotation of the intermediate-grained portion (around 30% iron content) can reduce the flotation feed rate, thereby reducing the unit ore flotation cost, including reagent consumption. Of course, the specific screening particle size can be adjusted appropriately for ores with different properties.

[0045] In some embodiments of the present invention, such as Figure 2 As shown, the provided method for multi-stage enrichment and comprehensive recovery of copper-bearing magnetite and hematite is as follows: Figure 2 As shown, the specific steps include: (1) The raw ore is pre-crushed so that large pieces of ore with a particle size greater than 100mm are crushed to a particle size less than 50mm. Then, it is wet-screened into three particle sizes: coarse, medium and fine, namely +25mm, -25mm to +3mm, -3mm. (2) The +25mm particle size is further crushed and screened in a closed circuit to form two medium and fine particle sizes, namely -25mm to +3mm and -3mm; (3) Combine the -3mm particle size product after (1) crushing with the -3mm particle size product after (2) crushing and enter the next processing step; (4) Combine the -25mm to +3mm particle size product after (1) crushing with the -25mm to +3mm particle size product after (2) crushing and perform heavy medium beneficiation (i.e., heavy medium hydrocyclone waste disposal) to obtain heavy medium concentrate and waste tailings 1.

[0046] To further improve the efficiency of heavy media beneficiation, the heavy media can be an organic solution, such as carbon tetrachloride, tribromomethane, or tetrabromoethane, or a heavy suspension. The heavy suspension is an aqueous solution prepared from ferrosilicon or magnetite powder ferrosilicon solid particles and water. Further, the specific gravity of the heavy suspension is 3.0–6.5 g / cm³. 3 The preferred specific gravity is 3.5–4.5 g / cm³. 3 .

[0047] (5) The heavy medium concentrate is crushed to -3mm by a high-pressure roller-screen closed-circuit crusher; (6) After merging product (5) and product (3), proceed to the next processing step; (7) The product of (6) is subjected to strong magnetic separation and discarded to obtain magnetic concentrate and discarded tailings 2.

[0048] To further improve the efficiency of strong magnetic separation, the background magnetic field strength is 0.3T to 1.75T, preferably 0.5T to 1.0T.

[0049] (8) After grinding the (7) strong magnetic separation concentrate, magnetite is enriched by magnetic drum; after grinding the magnetic separation tailings, copper flotation is carried out to obtain copper concentrate and copper flotation tailings.

[0050] To further improve the efficiency of weak magnetic separation for enriching magnetite, the magnetic field strength of the magnetic drum is 800–1400 mT, preferably 900–1200 mT.

[0051] In copper flotation, the collectors can be xanthate collectors, such as one or more of ethyl xanthate, butyl xanthate, pentylene xanthate, and isoamyl xanthate; or dimethicone collectors, such as No. 25 dimethicone, sodium isobutyl dimethicone, and sodium diisoamyl dithiophosphate; or lipid collectors such as Z-200 and ester 105. Different types of collectors can also be mixed. The specific method depends on the ore properties and the needs of the concentrator. For example, concentrators with high environmental protection requirements may not use xanthate collectors and can choose two other reagents. The frother can be No. 2 oil or MIBC (methyl isobutyl methanol) or one or more.

[0052] (9) First, the copper flotation tailings from (8) are enriched by strong magnetic separation, and the products are strong magnetic concentrate and tailings 3; then the strong magnetic concentrate is wet screened into 3 particle sizes: +0.074mm, -0.074mm to +0.053mm, and -0.053mm, of which +0.074mm is tailings 4; then the -0.074mm to +53mm particle size is floated with positive flotation process to flotate hematite, and the products are flotation concentrate and tailings 5; finally, the flotation concentrate and the -0.053mm particle size product are combined to obtain the hematite product.

[0053] To further improve the enrichment efficiency of strong magnetic separation and increase the recovery rate of hematite, the background magnetic field strength of strong magnetic separation is 0.4T to 1.6T, preferably 0.65T to 0.8T.

[0054] When flotating hematite, the hematite flotation collector can be one or more of sodium petroleum sulfonate, oxidized paraffin soap, oleic acid, and sodium oleate. The modifier can be one or more of water glass or acidified water glass, sodium fluorosilicate, sodium hexametaphosphate, and CMC (carboxymethyl cellulose).

[0055] The process involves wet grading of the raw ore (dividing it into coarse, medium, and fine grades), followed by fine crushing of the coarse and medium grades and subsequent consolidation with heavy medium cyclones for waste disposal. The heavy medium concentrate is then further crushed and combined with the fine particles for strong magnetic separation and waste disposal. The strong magnetic concentrate is then regrinded and followed by weak magnetic separation (enriching magnetite). The weak magnetic tailings are then regrinded and followed by copper flotation (enriching copper minerals). The flotation tailings are then subjected to strong magnetic separation / screening / flotation (enriching hematite) in sequence. This process effectively separates magnetite, hematite, and copper minerals from gangue minerals such as pyrite, chlorite, kaolinite, mica, talc, and amphibole.

[0056] Based on the types and properties of copper and iron in copper-bearing magnetite and hematite, and other gangues, the raw ore is crushed and then classified into multiple stages. Different waste disposal / benefiting methods are applied according to the particle size of the raw ore and the differences in specific gravity, magnetic properties, and floatability of different minerals, improving processing efficiency and reducing beneficiation costs. Specifically, the application of corresponding waste disposal methods after multi-stage classification based on the types and properties of copper and iron in copper-bearing magnetite and hematite, reduces the load on the target operating system, improves waste disposal efficiency, and effectively separates waste rock in a timely manner, reducing ineffective grinding of waste rock, lowering grinding energy consumption, and reducing grinding costs. Simultaneously, iron ore pre-enrichment is achieved, requiring only subsequent grinding and beneficiation of the high-intensity magnetic separation concentrate after two waste disposal stages, reducing grinding volume, lowering grinding energy consumption, and saving unit concentrate beneficiation costs, thus achieving cost reduction and efficiency improvement. Furthermore, by fully utilizing the differences in particle size, specific gravity, magnetic properties, and floatability of magnetite, copper minerals, hematite, and gangue minerals, and then re-grinding and enriching them sequentially, magnetite, copper minerals, and hematite are obtained, achieving low-cost and high-efficiency enrichment and recovery of magnetite / hematite.

[0057] The technical effects of the present invention will be explained below with reference to specific embodiments and comparative examples: Example 1 A copper-bearing magnetite / hematite deposit in Shandong Province contains magnetite, hematite, and copper minerals, primarily metallic copper. Gangue minerals include pyrite, chlorite, kaolinite, mica, talc, and amphibole. The iron grade is 33.09%, and the copper grade is 0.097%.

[0058] The comprehensive recovery of this ore through multi-stage grading and enrichment includes the following steps: (1) The raw ore is pre-crushed so that large pieces of ore with a particle size greater than 100mm are crushed to a particle size less than 50mm, and then wet-screened into three particle sizes: +25mm, -25mm to +3mm, and -3mm.

[0059] (2) The +25mm particle size is further crushed and screened in a closed loop into two particle sizes: -25mm to +3mm and -3mm.

[0060] (3) Combine the -3mm particle size after (1) crushing with the -3mm particle size after (2) crushing and proceed to the next processing step.

[0061] (4) The -25mm to +3mm particle size fractions from (1) and (2) are combined and subjected to heavy media beneficiation to obtain two products: heavy media concentrate and tailings 1, achieving coarse particle waste disposal. Tailings 1 can be disposed of with a waste yield of 16.3%. The heavy media is a heavy suspension, specifically an aqueous solution of ferrosilicon powder solid particles and water. The specific gravity of the heavy suspension is 4.5 g / cm³. 3 .

[0062] (5) The heavy medium concentrate is crushed to -3mm by high pressure roller-screen closed-circuit crushing.

[0063] (6) After merging (5) and (3), proceed to the next processing step.

[0064] (7) The waste from (6) is disposed of by strong magnetic separation. The background magnetic field strength of the strong magnetic separation is 0.9T, and magnetic concentrate and waste tailings 2 are obtained, realizing secondary waste disposal. The waste disposal yield of tailings 2 is 13.2%.

[0065] (8) After regrinding the strong magnetic separation concentrate from (7), magnetite is enriched by magnetic drum. The magnetic field strength of the magnetic drum is 1100mT. After regrinding the magnetic separation tailings, copper flotation is performed to obtain copper concentrate and copper flotation tailings.

[0066] The copper flotation collector is a mixture of a black powder collector and a lipid collector, specifically No. 25 black powder and Z-200, in a ratio of 2:1, with a dosage of 100g / t. The frother is No. 2 oil, with a dosage of 30g / t.

[0067] (9) First, the copper flotation tailings from (8) are enriched by strong magnetic separation. The background field strength of the strong magnetic separation is 0.8T. The products are strong magnetic concentrate and tailings 3. Then, the strong magnetic concentrate is wet-screened into three particle sizes: +0.074mm, -0.074mm to +0.053mm, and -0.053mm. Among them, +0.074mm is tailings 4. Next, the -0.074mm to +0.053mm particle size is floated with hematite using the positive flotation process. The products are flotation concentrate and tailings 5. Finally, the flotation concentrate and the -0.053mm particle size are combined to obtain the hematite product.

[0068] The hematite flotation collector is composed of oxidized paraffin soap and sodium oleate in a ratio of 4:1, with a dosage of 1300 g / t. The modifier is acidified water glass, with a dosage of 300 g / t.

[0069] Through multi-stage classification, the recovery rate of hematite in the -0.053mm particle size range reached 83.6%.

[0070] The experimental results of Example 1 are shown in Table 1.

[0071] Comparative Example 1

[0072] Process flow as follows Figure 3 As shown.

[0073] The iron content is 33.14%, and the copper content is 0.098%.

[0074] The difference between Comparative Example 1 and Example 1 is that the comparative example did not undergo pre-multi-stage classification and waste disposal, but started grinding directly from the raw ore. After grinding the raw ore directly, it was successively enriched with magnetite by magnetic drum, enriched with copper minerals by flotation, and enriched with hematite by strong magnetic process.

[0075] The experimental results of Comparative Example 1 are shown in Table 1.

[0076]

[0077] As shown in Table 1, Example 1 of the present invention, through multi-stage classification and pre-processing with heavy media cyclones and strong magnetic separation to remove waste rock, achieved experimental results close to those of Comparative Example 1, which involved direct grinding of the raw ore. Furthermore, due to the multi-stage classification and pre-processing with heavy media and strong magnetic separation, the waste rock removal process eliminated grinding, reducing ineffective grinding of waste rock and lowering grinding costs, thereby reducing beneficiation costs. Statistical analysis showed that, compared to Example 1, Comparative Example 1 increased ineffective grinding of waste rock by 29.5%, leading to increased beneficiation costs.

[0078] In summary, this invention targets raw ore, employing multi-stage grading after crushing. For different particle sizes, it utilizes heavy medium cyclones and high-intensity magnetic separation for pre-discarding, reducing the load on the target operating system, improving discarding efficiency, and reducing grinding volume, thereby lowering grinding energy consumption and saving unit concentrate beneficiation costs, achieving cost reduction and efficiency improvement. Based on the magnetically separated concentrate after two discarding processes, it fully utilizes the differences in particle size, specific gravity, magnetic properties, and floatability between magnetite / hematite and gangue minerals, sequentially enriching magnetite, flotation copper minerals, and hematite, achieving low-cost and high-efficiency enrichment of magnetite / hematite. This invention conforms to the principle of "discarding as early as possible, crushing more and grinding less," solving the problems in related processes where coarse ore meeting the sorting / discarding particle size cannot be separated from the operating system quickly enough, leading to further ineffective crushing and increased energy consumption; and where qualified products cannot be separated from the operating system in advance, requiring further processing within the system, resulting in increased reagent / energy consumption.

[0079] The description of this invention is given for illustrative and descriptive purposes only and is not intended to be exhaustive or to limit the invention to the forms disclosed. Many modifications and variations will be apparent to those skilled in the art. The embodiments were chosen and described in order to better illustrate the principles and practical application of the invention and to enable those skilled in the art to understand the invention and to design various embodiments with various modifications suitable for a particular purpose.

Claims

1. A multi-stage enrichment and comprehensive recovery method for copper-bearing magnetite and hematite, characterized in that, include: Step S1: Crush the raw ore and wet screen it into three particle sizes: coarse, medium, and fine. Step S2: The coarse particles are crushed into medium and fine particles, the medium particles are combined and discarded using a heavy medium cyclone separator to obtain heavy medium concentrate; Step S3: The heavy medium concentrate is crushed into fine particles, the fine particles are combined and discarded by strong magnetic separation to obtain magnetic concentrate.

2. The multi-stage enrichment and comprehensive recovery method for copper-bearing magnetite and hematite according to claim 1, characterized in that, Also includes: Step S4: After grinding the magnetic concentrate, perform weak magnetic separation to obtain magnetite and weak magnetic separation tailings; Step S5: After grinding the weak magnetic separation tailings, copper flotation is performed to obtain copper concentrate and copper flotation tailings. Step S6: The copper flotation tailings are subjected to strong magnetic separation, wet screening, and flotation in sequence to obtain hematite.

3. The multi-stage enrichment and comprehensive recovery method for copper-bearing magnetite and hematite according to claim 1, characterized in that, In step S1, the wet sieving separates the particles into three continuous sizes: coarse, medium, and fine. The ranges of the two dividing values ​​are 20-30 mm and 2-5 mm, respectively. Preferably, the three particle sizes of coarse, medium, and fine are +25mm, -25mm to +3mm, and -3mm, respectively.

4. The multi-stage enrichment and comprehensive recovery method for copper-bearing magnetite and hematite according to claim 1, characterized in that, In step S2, the coarse-grained closed-circuit crusher is broken into medium and fine-grained particles; In step S2, when the heavy medium hydrocyclone is discarded, the heavy medium used is an organic solvent or a heavy suspension. The organic solvent is one of carbon tetrachloride, tribromomethane, and tetrabromoethane. The heavy suspension is an aqueous solution prepared by mixing ferrosilicon or magnetite powder ferrosilicon solid particles with water. The specific gravity of the heavy suspension is 3.0–6.5 g / cm³. 3 The preferred concentration is 3.5–4.5 g / cm³. 3 .

5. The multi-stage enrichment and comprehensive recovery method for copper-bearing magnetite and hematite according to claim 1, characterized in that, In step S3, a high-pressure roller is used to crush the heavy medium concentrate into fine particles in a closed circuit. In step S3, the background magnetic field strength for strong magnetic separation waste disposal is 0.3T to 1.75T, preferably 0.5T to 1.0T.

6. The multi-stage enrichment and comprehensive recovery method for copper-bearing magnetite and hematite according to claim 2, characterized in that, In step S4, a magnetic drum is used for weak magnetic separation. The magnetic field strength of the magnetic drum is 800-1400 mT, preferably 900-1200 mT.

7. The multi-stage enrichment and comprehensive recovery method for copper-bearing magnetite and hematite according to claim 2, characterized in that, In step S5, the copper flotation collector is selected from one or more of xanthate collectors, black powder collectors, and lipid collectors; the foaming agent is at least one of No. 2 oil and MIBC.

8. The multi-stage enrichment and comprehensive recovery method for copper-bearing magnetite and hematite according to claim 2, characterized in that, Step S6 includes: High-intensity magnetic separation is performed on copper flotation tailings to obtain high-intensity magnetic concentrate; The strong magnetic concentrate was separated into three particle sizes—large, medium, and small—using wet screening. Hematite was flotated using a positive flotation process on the intermediate particle size to obtain flotation concentrate; The flotation concentrate is combined with the smaller particles obtained after wet screening to obtain hematite.

9. The multi-stage enrichment and comprehensive recovery method for copper-bearing magnetite and hematite according to claim 8, characterized in that, In step S6, the strong magnetic concentrate is wet-screened into three continuous particle sizes: large, medium, and small; the ranges of the two dividing values ​​are 0.070-0.080 mm and 0.050-0.060 mm, respectively. Preferably, the three particle sizes are: +0.074mm, -0.074mm to +0.053mm, and -0.053mm, respectively.

10. The multi-stage enrichment and comprehensive recovery method for copper-bearing magnetite and hematite according to claim 8, characterized in that, When performing hematite flotation, The hematite flotation collector is one or more of sodium petroleum sulfonate, oxidized paraffin soap, oleic acid, and sodium oleate; The modifier is one or more of water glass, sodium fluorosilicate, sodium hexametaphosphate, and CMC.

11. A multi-stage graded enrichment and comprehensive recovery system for copper-bearing magnetite and hematite, characterized in that, Including waste disposal devices, The waste disposal device includes: The crushing and screening unit is used to crush raw ore and wet screen it into three particle sizes: coarse, medium, and fine; to crush coarse particles into two particle sizes: medium and fine; and to crush heavy media concentrate into fine particles. Heavy medium hydrocyclones are used to remove waste from the combined medium-sized particles to obtain heavy medium concentrate. Magnetic separators are used to perform strong magnetic separation to remove waste from the combined fine particles and obtain magnetic concentrate.

12. The multi-stage enrichment and comprehensive recovery system for copper-bearing magnetite and hematite according to claim 11, characterized in that, Also includes: Grinding equipment is used to grind magnetic concentrate and weak magnetic tailings after waste disposal. Magnetic drum is used for weak magnetic separation after grinding magnetic concentrate to obtain magnetite and weak magnetic separation tailings; Copper flotation equipment is used to perform copper flotation after grinding weak magnetic separation tailings to obtain copper concentrate and copper flotation tailings. Hematite flotation equipment is used to perform strong magnetic separation on copper flotation tailings. The strong magnetic separation concentrate is wet screened into three particle sizes. The middle particle size is floated. The flotation concentrate and the small particle size are combined to obtain hematite.

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