Process for recovering ultra-fine particle ilmenite

Abstract

The invention relates to the technical field of ilmenite grading, in particular to a process for recycling ultra-fine particle grade ilmenite. According to the technology for recycling the ultra-fine-particle-grade ilmenite, the ultra-fine-particle-grade ilmenite recycling technology is deployed and improved from a titanium separation source, according to the characteristics of the ultra-fine-particle-grade ilmenite, the ultra-fine-particle-grade ilmenite is separated out in advance in a fine-particle strong magnetic scavenging operation section through a high-intensity magnetic separator with the ultrahigh magnetic field intensity, and the ultra-fine-particle-grade ilmenite is separated out in advance; a series of problems of long recovery process, large interference of residual chemicals, high recovery cost and the like when the ultra-micro-fine-particle ilmenite is recovered from the titanium separation tail end are solved, and efficient recovery of the ultra-micro-fine-particle ilmenite is realized.

Description

Technical Field

[0001] This invention relates to the field of ilmenite beneficiation technology, and in particular to a process for recovering ultrafine-grained ilmenite. Background Technology

[0002] Currently, the main method for recovering ultrafine-grained ilmenite in China is to reprocess it from titanium beneficiation tailings. The recovery process mainly involves: firstly, separating the recovery of fine-grained ilmenite and ultrafine-grained ilmenite, see [link to relevant documentation]. Figure 1 Second, a process for the mixed recovery of fine-grained and ultrafine-grained ilmenite, see [link to relevant documentation]. Figure 2 .

[0003] Currently, the two main processes mentioned above have the following problems:

[0004] (1) Titanium beneficiation tailings include strong magnetic separation tailings, gravity separation tailings, and flotation tailings. Flotation tailings contain reagents, and flocculants need to be added during the treatment of titanium beneficiation tailings in order to improve the utilization efficiency of recycled water. These residual titanium beneficiation reagents and flocculants greatly increase the cost of subsequent flotation recovery of ultrafine ilmenite, and the recovery cost of ultrafine ilmenite is 1-2 times higher than that of fine ilmenite recovery at the front end.

[0005] (2) Neither of the two processes mentioned above can recover the ultrafine ilmenite with fine intercalation, because the TiO2 grade of this part of the mineral is only 6-12% and the liberation degree of the ilmenite is only about 70%. The loss of this type of titanium resource reaches 25%.

[0006] (3) above Figure 2 The process shown recovers approximately 75% of the ultrafine titanium concentrate with a particle size of -0.074mm, while... Figure 1 The recovered ultrafine titanium concentrate has a particle size content of up to 90% (0.038mm), indicating that... Figure 2 The process recovers less than [amount of] ultrafine ilmenite. Figure 1 Analysis revealed that the main losses occurred during inclined plate overflow classification, with a loss rate exceeding 25%. In the mixed flotation of fine and ultrafine ilmenite, the loss rate reached over 40%. Currently, the metal materials market is experiencing a sustained downturn. How to improve the recovery rate of ilmenite, especially the recovery rate of ultrafine ilmenite, at low cost is a pressing problem that needs to be solved in titanium beneficiation technology. Summary of the Invention

[0007] In view of this, the present invention provides a process for recovering ultrafine-grained ilmenite, which solves a series of problems such as long recovery process, large interference from residual reagents, and high recovery cost in recovering ultrafine-grained ilmenite from the end of titanium beneficiation, and achieves efficient recovery of ultrafine-grained ilmenite.

[0008] This invention provides a process for recovering ultrafine-grained ilmenite, comprising the following steps:

[0009] S1. The fine-grained iron ore tailings are fed into a weak magnetic separator for primary iron removal, resulting in primary iron-removed concentrate and primary iron-removed tailings.

[0010] S2. Perform a strong magnetic roughing separation on the iron removal tailings to obtain a strong magnetic roughing concentrate and a strong magnetic roughing tailings.

[0011] S3. Perform a first-stage strong magnetic roughing tailings separation on the first-stage strong magnetic scavenging to obtain a first-stage strong magnetic scavenging concentrate and a first-stage strong magnetic scavenging tailings; perform a second-stage iron removal on the first-stage strong magnetic roughing concentrate to obtain a second-stage iron removal concentrate and a second-stage iron removal tailings.

[0012] S4. Perform two-stage strong magnetic separation on the two-stage iron removal tailings to obtain two-stage strong magnetic separation concentrate and two-stage strong magnetic separation tailings respectively.

[0013] S5. Perform two-stage strong magnetic scavenging on the tailings obtained in step S4 to obtain two-stage strong magnetic scavenging concentrate and two-stage strong magnetic scavenging tailings, respectively; perform inclined plate classification on the two-stage strong magnetic concentrate obtained in step S4 to obtain inclined plate underflow and inclined plate overflow, respectively; wherein, the inclined plate underflow is used for fine-particle flotation to select titanium, to obtain fine-particle titanium concentrate and flotation tailings 1, respectively.

[0014] S6. The first-stage strong magnetic scavenging concentrate obtained in step S3, the second-stage strong magnetic scavenging concentrate obtained in step S5, and the inclined plate overflow obtained in step S5 are fed into the first-stage hydrocyclone for processing to obtain the first-stage hydrocyclone underflow and the first-stage hydrocyclone overflow, respectively.

[0015] S7. Feed the sand from the first-stage hydrocyclone into the sand mill for ultrafine grinding to obtain the ground product;

[0016] S8. Perform three-stage iron removal on the grinding product to obtain three-stage iron-removed concentrate and three-stage iron-removed tailings respectively.

[0017] S9. The overflow of the first-stage hydrocyclone obtained in step S6 and the three-stage iron removal tailings obtained in step S8 are fed into the second-stage hydrocyclone for processing to obtain the second-stage hydrocyclone underflow and the second-stage hydrocyclone overflow, respectively.

[0018] S10. Perform ultrafine flotation on the sediment from the secondary hydrocyclone to obtain ultrafine titanium concentrate and flotation tailings 2.

[0019] Preferably, in step S1, the magnetic field strength of the weak magnetic separator is 3500~5000 Oersted.

[0020] Preferably, in step S2, the magnetic field strength of the strong magnetic coarse selection section is 7000~9000 Oersted.

[0021] Preferably, in step S3:

[0022] The magnetic field strength of the strong magnetic sweep section is 12000~18000 Oersted;

[0023] The magnetic field strength of the two-stage iron removal is 3500~5000 Oersted.

[0024] Preferably, in step S4, the magnetic field strength of the two-stage strong magnetic field selection is 6000~8000 Oersted.

[0025] Preferably, in step S5, the magnetic field strength of the two-stage strong magnetic sweep is 10000~15000 Oersted.

[0026] Preferably, in step S5, the fine-particle flotation for titanium is carried out using a flotation machine, and the flotation process is sulfur flotation and titanium flotation; the reagents used in the flotation include sulfuric acid and titanium collector; wherein, the amount of sulfuric acid used is 4000~5000g / t of flotation raw ore, and the amount of titanium collector used is 1500~2000g / t of flotation raw ore.

[0027] Preferably, in step S8, the magnetic field strength of the three-stage iron removal is 3500~5000 Oersted.

[0028] Preferably, in step S10, the ultrafine particle flotation for titanium removal uses a flotation column, and the flotation process is sulfur flotation and titanium flotation; the reagents used in the flotation include sulfuric acid and a titanium removal collector; wherein, the amount of sulfuric acid used is 8000~15000g / t of the raw flotation ore, and the amount of the titanium removal collector used is 3000~5000g / t of the raw flotation ore.

[0029] Preferably, in step S7, the specifications of the ground product are: 100% content of -0.038mm, more than 85% content of -0.019mm, and more than 88% degree of liberation of ilmenite monomers.

[0030] The process provided by this invention includes the following steps: feeding fine-grained iron ore tailings (second-, third-, or even fourth-stage iron ore tailings) into a weak magnetic separator for first-stage iron removal to obtain first-stage iron-removed concentrate and tailings; feeding the first-stage iron-removed tailings into a first-stage strong magnetic roughing separator to obtain first-stage strong magnetic rough concentrate and tailings; feeding the first-stage strong magnetic rough tailings into a first-stage strong magnetic scavenging separator to obtain first-stage strong magnetic scavenging concentrate and tailings; feeding the first-stage strong magnetic rough concentrate into a weak magnetic separator for second-stage iron removal to obtain second-stage iron-removed concentrate and tailings; feeding the second-stage iron-removed tailings into a second-stage strong magnetic cleaning separator to obtain second-stage strong magnetic cleaning concentrate and tailings; feeding the second-stage strong magnetic cleaning tailings into a second-stage strong magnetic scavenging separator to obtain second-stage strong magnetic scavenging concentrate and tailings. The tailings from the first and second stages of strong magnetic scavenging are the final titanium tailings. The second-stage strong magnetic concentrate is fed into a swash plate for classification, and the underflow from the swash plate is fed into a fine-particle flotation system to obtain fine-particle titanium concentrate. The overflow from the swash plate, the first-stage strong magnetic scavenging concentrate, and the second-stage strong magnetic scavenging concentrate are mixed and fed into a first-stage hydrocyclone to obtain first-stage hydrocyclone underflow and overflow. The first-stage hydrocyclone underflow is fed into an argon mill, and the grinding product is fed into a weak magnetic separator for three-stage iron removal to obtain third-stage iron-removed concentrate and tailings. The third-stage iron-removed tailings and the first-stage hydrocyclone overflow are mixed and fed into a second-stage hydrocyclone. The second-stage hydrocyclone overflow is discarded as slime, and the second-stage hydrocyclone underflow is fed into an ultrafine flotation system to obtain ultrafine-particle titanium concentrate. This invention improves the recovery process of ultrafine-grained ilmenite from the titanium beneficiation source. Based on the characteristics of ultrafine-grained ilmenite, it uses an ultra-high magnetic field strength magnetic separator to pre-select it in the fine-grained strong magnetic scavenging stage. This solves a series of problems such as the long recovery process, significant interference from residual reagents, and high recovery costs of ultrafine-grained ilmenite from the end of titanium beneficiation, achieving efficient recovery of ultrafine-grained ilmenite. At the same time, the finely embedded ilmenite is dissociated by an ultrafine grinding mill, which can generate hundreds of millions of yuan in additional benefits annually. Attached Figure Description

[0031] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on the provided drawings without creative effort.

[0032] Figure 1 Flowchart of the process for separately recovering fine-grained ilmenite and ultrafine-grained ilmenite;

[0033] Figure 2 A flowchart for the process of mixed recovery of fine-grained ilmenite and ultrafine-grained ilmenite;

[0034] Figure 3 This is a flowchart of the process for recovering ultrafine-grained ilmenite according to the present invention. Detailed Implementation

[0035] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application belongs. The terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the application.

[0036] In this article, the technical features described in an open-ended manner include both closed technical solutions composed of the listed features and open technical solutions that include the listed features.

[0037] The term “and / or” as used herein includes any and all combinations of one or more of the related listed items.

[0038] In this document, numerical ranges are referred to as continuous unless otherwise specified, and include the minimum and maximum values ​​of the range, as well as every value between the minimum and maximum values. Furthermore, when a range refers to an integer, it includes every integer between the minimum and maximum values ​​of the range. Additionally, when multiple ranges are provided to describe a feature or characteristic, the ranges may be combined. In other words, unless otherwise specified, all ranges disclosed herein should be understood to include any and all subranges to which they are incorporated.

[0039] In this article, when referring to units of data ranges, if the unit is only followed by the right endpoint, it means that the units of the left and right endpoints are the same. For example, 3500~5000 Ørsted means that the units of the left endpoint "3500" and the right endpoint "5000" are both Ørsted.

[0040] A process for recovering ultrafine-grained ilmenite includes the following steps:

[0041] S1. The fine-grained iron ore tailings are fed into a weak magnetic separator for primary iron removal, resulting in primary iron-removed concentrate and primary iron-removed tailings.

[0042] S2. Perform a strong magnetic roughing separation on the iron removal tailings to obtain a strong magnetic roughing concentrate and a strong magnetic roughing tailings.

[0043] S3. Perform a first-stage strong magnetic roughing tailings separation on the first-stage strong magnetic scavenging to obtain a first-stage strong magnetic scavenging concentrate and a first-stage strong magnetic scavenging tailings; perform a second-stage iron removal on the first-stage strong magnetic roughing concentrate to obtain a second-stage iron removal concentrate and a second-stage iron removal tailings.

[0044] S4. Perform two-stage strong magnetic separation on the two-stage iron removal tailings to obtain two-stage strong magnetic separation concentrate and two-stage strong magnetic separation tailings respectively.

[0045] S5. Perform two-stage strong magnetic scavenging on the tailings obtained in step S4 to obtain two-stage strong magnetic scavenging concentrate and two-stage strong magnetic scavenging tailings, respectively; perform inclined plate classification on the two-stage strong magnetic concentrate obtained in step S4 to obtain inclined plate underflow and inclined plate overflow, respectively; wherein, the inclined plate underflow is used for fine-particle flotation to select titanium, to obtain fine-particle titanium concentrate and flotation tailings 1, respectively.

[0046] S6. The first-stage strong magnetic scavenging concentrate obtained in step S3, the second-stage strong magnetic scavenging concentrate obtained in step S5, and the inclined plate overflow obtained in step S5 are fed into the first-stage hydrocyclone for processing to obtain the first-stage hydrocyclone underflow and the first-stage hydrocyclone overflow, respectively.

[0047] S7. Feed the sand from the first-stage hydrocyclone into the sand mill for ultrafine grinding to obtain the ground product;

[0048] S8. Perform three-stage iron removal on the grinding product to obtain three-stage iron-removed concentrate and three-stage iron-removed tailings respectively.

[0049] S9. The overflow of the first-stage hydrocyclone obtained in step S6 and the three-stage iron removal tailings obtained in step S8 are fed into the second-stage hydrocyclone for processing to obtain the second-stage hydrocyclone underflow and the second-stage hydrocyclone overflow, respectively.

[0050] S10. Perform ultrafine flotation on the sediment from the secondary hydrocyclone to obtain ultrafine titanium concentrate and flotation tailings 2.

[0051] In this invention, there are no special restrictions on the order of steps that are not related in the above process.

[0052] See Figure 3 , Figure 3 This is a flowchart illustrating the process for recovering ultrafine-grained ilmenite according to the present invention. The present invention changes the current process of recovering ultrafine-grained ilmenite from the end of titanium beneficiation, pioneering a process that improves the recovery of ultrafine-grained ilmenite from the source of titanium beneficiation. This process can shorten the process, significantly reduce recovery costs, and increase the ilmenite recovery rate.

[0053] Regarding step S1 :

[0054] S1. The fine-grained iron ore tailings are fed into a weak magnetic separator for primary iron removal, resulting in primary iron-removed concentrate and primary iron-removed tailings.

[0055] In this invention, the fine-grained iron ore tailings are at least one of two-stage, three-stage, and four-stage iron ore tailings, more preferably two-stage, three-stage, and four-stage iron ore tailings. Specifically: Vanadium-titanium magnetite resources mainly recover titanomagnetite (iron concentrate) and ilmenite (titanium concentrate). Currently, the recovery process mainly involves first beneficiating iron, and then recovering ilmenite from the tailings after iron beneficiation. The iron beneficiation process mainly adopts a three-stage or even four-stage stepped grinding and beneficiation process. One stage mainly involves dissociating coarse-grained ilmenite first, and then recovering coarse-grained ilmenite from the tailings of the first stage. The second, third, and fourth stage iron ore tailings mainly recover fine-grained and ultrafine-grained ilmenite. The tailings of the second, third, and fourth stages are collectively referred to as fine-grained iron ore tailings.

[0056] In this invention, the magnetic field strength of the weak magnetic separator is preferably 3500~5000 Oersted, specifically 3500 Oersted, 3600 Oersted, 3700 Oersted, 3800 Oersted, 3900 Oersted, 4000 Oersted, 4100 Oersted, 4200 Oersted, 4300 Oersted, 4400 Oersted, 4500 Oersted, 4600 Oersted, 4700 Oersted, 4800 Oersted, 4900 Oersted, 5000 Oersted, etc. The purpose of using a weak magnetic separator for primary iron removal is to remove the strongly magnetic mineral, iguanomagnetite, reducing its impact on subsequent titanium beneficiation operations. After primary iron removal, primary iron concentrate and primary iron tailings are obtained.

[0057] Regarding step S2 :

[0058] S2. Perform a strong magnetic roughing separation on the iron removal tailings to obtain a strong magnetic roughing concentrate and a strong magnetic roughing tailings.

[0059] In this invention, the first-stage strong magnetic roughing can be carried out in a strong magnetic separator. The magnetic field strength of the first-stage strong magnetic roughing is preferably 7000~9000 Oersted, specifically 7000 Oersted, 7100 Oersted, 7200 Oersted, 7300 Oersted, 7400 Oersted, 7500 Oersted, 7600 Oersted, 7700 Oersted, 7800 Oersted, 7900 Oersted, 8000 Oersted, 8100 Oersted, 8200 Oersted, 8300 Oersted, 8400 Oersted, 8500 Oersted, 8600 Oersted, 8700 Oersted, 8800 Oersted, 8900 Oersted, and 9000 Oersted. After the above-mentioned first-stage strong magnetic roughing, a first-stage strong magnetic roughing concentrate and a first-stage strong magnetic roughing tailings are obtained.

[0060] Regarding step S3 :

[0061] S3. Perform a first-stage strong magnetic roughing tailings separation on the first-stage strong magnetic scavenging to obtain a first-stage strong magnetic scavenging concentrate and a first-stage strong magnetic scavenging tailings. Perform a second-stage iron removal on the first-stage strong magnetic roughing concentrate to obtain a second-stage iron removal concentrate and a second-stage iron removal tailings.

[0062] In this invention, after obtaining a first-stage strong magnetic roughing concentrate and a first-stage strong magnetic roughing tailings in step S2, the two are subjected to different processing:

[0063] The tailings from the first-stage strong magnetic roughing process are then subjected to a second-stage strong magnetic scavenging process. The magnetic field strength of this second-stage strong magnetic scavenging is preferably 12,000 to 18,000 Oersted, specifically 12,000, 13,000, 14,000, 15,000, 16,000, 17,000, or 18,000 Oersted. After this first-stage strong magnetic scavenging, a first-stage strong magnetic scavenging concentrate and a first-stage strong magnetic scavenging tailings are obtained.

[0064] The concentrate from the first-stage strong magnetic roughing process is fed into a weak magnetic separator for secondary iron removal. The magnetic field strength of the weak magnetic separator is preferably 3500-5000 Oersted, specifically 3500 Oersted, 3600 Oersted, 3700 Oersted, 3800 Oersted, 3900 Oersted, 4000 Oersted, 4100 Oersted, 4200 Oersted, 4300 Oersted, 4400 Oersted, 4500 Oersted, 4600 Oersted, 4700 Oersted, 4800 Oersted, 4900 Oersted, and 5000 Oersted. This secondary iron removal further removes the strongly magnetic mineral, iguanomagnetite, reducing its impact on subsequent titanium beneficiation operations. After the secondary iron removal, a secondary iron-removed concentrate and tailings are obtained.

[0065] Regarding step S4 :

[0066] S4. Perform two-stage strong magnetic separation on the iron removal tailings to obtain two-stage strong magnetic separation concentrate and two-stage strong magnetic separation tailings respectively.

[0067] In this invention, the magnetic field strength of the two-stage strong magnetic separation is preferably 6000~8000 Oersted, specifically 6000 Oersted, 6100 Oersted, 6200 Oersted, 6300 Oersted, 6400 Oersted, 6500 Oersted, 6600 Oersted, 6700 Oersted, 6800 Oersted, 6900 Oersted, 7000 Oersted, 7100 Oersted, 7200 Oersted, 7300 Oersted, 7400 Oersted, 7500 Oersted, 7600 Oersted, 7700 Oersted, 7800 Oersted, 7900 Oersted, 8000 Oersted, etc. After the two-stage strong magnetic separation, two-stage strong magnetic separation concentrate and two-stage strong magnetic separation tailings are obtained respectively.

[0068] Regarding step S5 :

[0069] S5. Perform two-stage strong magnetic scavenging on the tailings obtained in step S4 to obtain two-stage strong magnetic scavenging concentrate and two-stage strong magnetic scavenging tailings respectively; perform inclined plate classification on the two-stage strong magnetic scavenging concentrate obtained in step S4 to obtain inclined plate underflow and inclined plate overflow respectively; wherein, the inclined plate underflow is used for fine-particle flotation to select titanium, to obtain fine-particle titanium concentrate and flotation tailings 1 respectively.

[0070] In this invention, after obtaining the two-stage strong magnetic concentrate and the two-stage strong magnetic tailings in step S4, they are subjected to different processing:

[0071] The tailings are subjected to a two-stage strong magnetic scavenging process. The magnetic field strength of the two-stage strong magnetic scavenging is preferably 10,000~15,000 Oersted, specifically 10,000 Oersted, 11,000 Oersted, 12,000 Oersted, 13,000 Oersted, 14,000 Oersted, 15,000 Oersted, etc. After the two-stage strong magnetic scavenging, two-stage strong magnetic scavenging concentrate and two-stage strong magnetic scavenging tailings are obtained. The tailings obtained in this step and the tailings obtained in step S3 are the final titanium-fed tailings, which are discharged into the tailings pond. The final titanium-fed tailings contain low-grade (TiO2 content below 3%) and lowest-quality ilmenite lean aggregates and gangue minerals. These low-grade (TiO2 content below 3%) and lowest-quality ilmenite lean aggregates have no economic recovery value using the current titanium beneficiation process, therefore they are called final titanium-fed tailings and are directly discharged into the tailings pond.

[0072] The concentrate from the two-stage strong magnetic separation process undergoes inclined plate classification to remove -0.038mm particle size materials that interfere with fine-particle flotation, resulting in inclined plate underflow and inclined plate overflow. The inclined plate underflow is then used for fine-particle flotation of titanium, yielding fine-particle titanium concentrate and flotation tailings 1.

[0073] In this invention, the fine-particle flotation for titanium mainly employs a flotation machine, and the flotation process is sulfur flotation + titanium flotation; wherein each flotation step consists of one roughing and three scavenging or three cleaning steps (i.e., sulfur flotation consists of one roughing and three scavenging step, and titanium flotation consists of one roughing and three cleaning steps). The reagents used for titanium flotation include sulfuric acid, diesel oil, and titanium collectors; wherein, the mass fraction of the sulfuric acid used is preferably 15%~35%, specifically 15%, 20%, 25%, 30%, 35%, etc.; the amount of sulfuric acid used is preferably 4000~5000 g / t of flotation ore, specifically 4000 g / t of flotation ore, 4100 g / t of flotation ore, 4200 g / t of flotation ore, 4300 g / t of flotation ore, 4400 g / t of flotation ore, 4500 g / t of flotation ore, 4600 g / t of flotation ore, 4700 g / t of flotation ore, 4800 g / t of flotation ore, 4900 g / t of flotation ore, and 5000 g / t of flotation ore. The preferred dosage of diesel fuel is 400-800 g / t of flotation ore, specifically 400 g / t, 450 g / t, 500 g / t, 550 g / t, 600 g / t, 650 g / t, 700 g / t, 750 g / t, or 800 g / t. The preferred titanium collector is a combination of MOH titanium flotation collector and a high-quality titanium flotation collector; the preferred mass ratio of the two is 2:3. The preferred dosage of the titanium collector is 1500-2000 g / t of flotation ore, specifically 1500 g / t, 1600 g / t, 1700 g / t, 1800 g / t, 1900 g / t, or 2000 g / t. The flotation particle size range for fine-particle titanium flotation is -0.098 mm to +0.038 mm. After fine-particle titanium flotation, fine-particle titanium concentrate and flotation tailings 1 are obtained.

[0074] Regarding step S6 :

[0075] S6. The first-stage strong magnetic scavenging concentrate obtained in step S3, the second-stage strong magnetic scavenging concentrate obtained in step S5, and the inclined plate overflow obtained in step S5 are fed into the first-stage hydrocyclone for processing to obtain the first-stage hydrocyclone underflow and the first-stage hydrocyclone overflow, respectively.

[0076] In this invention, the first-stage strong magnetic scavenging concentrate obtained in step S3, the second-stage strong magnetic scavenging concentrate obtained in step S5, and the inclined plate overflow obtained in step S5 are all fed into a primary hydrocyclone for processing. Additionally, the inclined plate overflow of gravity concentrate, coarse-grained and fine-grained strong magnetic concentrate from conventional titanium beneficiation processes can also be introduced into the process of this invention and fed into the primary hydrocyclone for processing in this step. The purpose of the primary hydrocyclone classification is to separate the ultrafine-grained ilmenite, and through processing, primary hydrocyclone underflow and primary hydrocyclone overflow are obtained respectively.

[0077] The concentration range of the overflow from the inclined plate is 3% to 6%, and after enrichment by the hydrocyclone, it can reach 40% to 50%, meeting the requirement of the optimal flotation concentration of 45%.

[0078] Regarding step S7 :

[0079] S7. The sand from the first-stage hydrocyclone is fed into the sand mill for ultrafine grinding to obtain the grinding product.

[0080] The particle size range of the sand product obtained in step S6 is -0.18mm to +0.038mm, a large span, and the degree of liberation of ilmenite monomers in these particle sizes is low, only 73%. To improve its degree of liberation, it needs to be ground to 100% content in -0.038mm particles, or even above 90% content in -0.019mm particles. This invention uses an abrasive mill for ultrafine grinding, which can achieve the classification and grinding of such fine minerals. In this invention, the rotation speed of the abrasive mill is preferably 20~25 r / min, specifically 20 r / min, 21 r / min, 22 r / min, 23 r / min, 24 r / min, or 25 r / min. The grinding concentration of the abrasive mill is preferably 60%~75%, specifically 60%, 65%, 70%, or 75%. The grinding media used in the abrasive mill is preferably ceramic ball media; the media filling rate of the abrasive mill is preferably 30%~45%, specifically 30%, 35%, 40%, or 45%. After ultrafine grinding in the abrasive mill, the ground product is obtained.

[0081] In some embodiments of the present invention, the specifications of the ground product are: 100% -0.038mm content, more than 85% -0.019mm content, and more than 88% liberation degree of ilmenite monomers.

[0082] Regarding step S8 :

[0083] S8. Perform three-stage iron removal on the grinding product to obtain three-stage iron-removed concentrate and three-stage iron-removed tailings.

[0084] In this invention, after obtaining the grinding product in step S7, it is fed into a weak magnetic separator for three-stage iron removal. The magnetic field strength of the weak magnetic separator is preferably 3500-5000 Oersted, specifically 3500 Oersted, 3600 Oersted, 3700 Oersted, 3800 Oersted, 3900 Oersted, 4000 Oersted, 4100 Oersted, 4200 Oersted, 4300 Oersted, 4400 Oersted, 4500 Oersted, 4600 Oersted, 4700 Oersted, 4800 Oersted, 4900 Oersted, and 5000 Oersted. The three-stage iron removal using the weak magnetic separator removes the strongly magnetic mineral, i.e., titania magnetite, reducing its impact on subsequent titanium beneficiation operations. After the three-stage iron removal, three-stage iron-removed concentrate and three-stage iron-removed tailings are obtained.

[0085] Regarding step S9 :

[0086] S9. The overflow of the primary hydrocyclone obtained in step S6 and the three-stage iron removal tailings obtained in step S8 are fed into the secondary hydrocyclone for processing to obtain the secondary hydrocyclone underflow and the secondary hydrocyclone overflow, respectively.

[0087] In this invention, the overflow from the primary hydrocyclone obtained in step S6 and the three-stage iron removal tailings obtained in step S8 are mixed and fed into a secondary hydrocyclone for treatment. The purpose is to remove the -0.010mm slime and obtain a suitable feed concentration for ultrafine particle flotation. In this invention, the secondary hydrocyclone serves as a thickener and deslimer. The diameter of the secondary hydrocyclone is preferably 100-200mm, specifically 100mm, 110mm, 120mm, 130mm, 140mm, 150mm, 160mm, 170mm, 180mm, 190mm, or 200mm. The pressure of the secondary hydrocyclone is preferably 0.15-2MPa, specifically 0.15MPa, 0.3MPa, 0.5MPa, 1MPa, 1.5MPa, or 2MPa. The preferred diameter of the settling inlet of the secondary hydrocyclone is 10-30 mm, specifically 10 mm, 15 mm, 20 mm, 25 mm, or 30 mm. The preferred diameter of the overflow pipe of the secondary hydrocyclone is 15-55 mm, specifically 15 mm, 20 mm, 25 mm, 30 mm, 35 mm, 40 mm, 45 mm, or 55 mm. Through the above-mentioned secondary hydrocyclone treatment, secondary hydrocyclone settling and secondary hydrocyclone overflow are obtained. The secondary hydrocyclone overflow is discarded as slurry.

[0088] Regarding step S10 :

[0089] S10. Perform ultrafine flotation on the sediment from the secondary hydrocyclone to obtain ultrafine titanium concentrate and flotation tailings 2.

[0090] In this invention, the ultrafine-grained flotation of titanium obtained from the secondary hydrocyclone in step S9 is performed, primarily using a flotation column. The flotation process is sulfur flotation + titanium flotation; wherein sulfur flotation consists of one roughing and three scavenging stage, and titanium flotation consists of one roughing and two cleaning stages. The reagents used for titanium flotation include sulfuric acid, diesel oil, and a titanium collector; wherein the mass fraction of the sulfuric acid used is preferably 15%~35%, specifically 15%, 20%, 25%, 30%, or 35%; the amount of sulfuric acid used is preferably 8000~15000 g / t of the raw flotation ore, specifically 8000 g / t, 8500 g / t, 9000 g / t, or 9500 g / t of the raw flotation ore. Raw ore, 10000g / t flotation raw ore, 10500g / t flotation raw ore, 11000g / t flotation raw ore, 11500g / t flotation raw ore, 12000g / t flotation raw ore, 12500g / t flotation raw ore, 13000g / t flotation raw ore, 13500g / t flotation raw ore, 14000g / t flotation raw ore, 14500g / t flotation raw ore, 15000g / t flotation raw ore. The preferred dosage of diesel fuel is 300-600 g / t of flotation ore, specifically 300 g / t, 350 g / t, 400 g / t, 450 g / t, 500 g / t, 550 g / t, or 600 g / t. The preferred titanium collector is a high-quality titanium flotation collector. The preferred dosage of the titanium collector is 3000-5000 g / t of flotation ore, specifically 3000 g / t, 3500 g / t, 4000 g / t, 4500 g / t, or 5000 g / t. The flotation particle size range for ultrafine titanium flotation is -0.038 mm to +0.005 mm. Titanium was separated by ultrafine flotation to obtain ultrafine titanium concentrate and flotation tailings 2.

[0091] Compared with the prior art, the present invention has the following beneficial effects:

[0092] (1) Deploying efficient recovery of ultrafine-grained ilmenite from the source. Currently, the process recovery of ultrafine-grained ilmenite mainly starts from the end of titanium beneficiation, that is, recovering it again from titanium beneficiation tailings (see Appendix). Figure 1 and attached Figure 2Titanium tailings contain residual reagents that adhere to the surface of ultrafine ilmenite, interfering with flotation recovery. To expose the ultrafine ilmenite on a fresh surface, sulfuric acid is often used for washing. However, large amounts of sulfuric acid inhibit ilmenite flotation. To improve recovery, large amounts of titanium collectors need to be added, creating a vicious cycle that significantly increases flotation costs. Investigations revealed that ultrafine ilmenite mainly occurs in the second, third, and even fourth stages of iron ore beneficiation tailings and in various inclined plate overflows. Separating it beforehand in the titanium beneficiation process, preventing contact with flotation tailings, can reduce the amount of flotation reagents used for subsequent ultrafine ilmenite flotation. To prove this finding, ultrafine ilmenite that was not mixed into the flotation tailings was separated from ultrafine ilmenite that was mixed into the flotation tailings and then enriched before being floated. The amount of sulfuric acid used in the flotation reagents can be reduced by 35%, and the amount of collector can be reduced by 25%. Based on an annual processing capacity of 6 million tons of titanium tailings, this can reduce the cost of flotation reagents by tens of millions of yuan per year.

[0093] (2) Shortening the titanium beneficiation process for ultrafine-grained ilmenite. This invention changes the magnetic field strength of the conventional two-stage high-intensity magnetic separator for fine-grained scavenging, increasing it from less than 10,000 Oersted to 15,000-18,000 Oersted. This ultra-high magnetic field strength magnetic separator combined with the scavenging process can achieve the early enrichment of ultrafine-grained ilmenite in the fine-grained high-intensity magnetic separation process, eliminating the current two-stage high-intensity magnetic process for recovering ultrafine-grained ilmenite from titanium beneficiation tailings. The process is reduced from the current four-stage high-intensity magnetic separation (two stages for fine-grained scavenging and two stages for ultrafine-grained scavenging) to a single two-stage high-intensity magnetic separation for fine-grained scavenging. Based on an annual processing capacity of 6 million tons of titanium beneficiation tailings, this saves more than 40 million yuan in investment.

[0094] (3) Titanium selection employs ultrafine grinding using an abrasive mill. Experiments revealed that in the first and second stage strong magnetic scavenging concentrates, the ilmenite in the 0.038mm and larger particle sizes is mainly composed of minerals associated with titanomagnetite and gangue, and the ilmenite particles are finely intercalated. Conventional ball mills and tower mills cannot efficiently separate the ultrafine ilmenite. Currently, this portion of ultrafine titanium resources is directly discharged into tailings ponds. This invention will achieve efficient recovery of this type of resource. Taking a beneficiation plant in the Panxi region as an example, the fine-grained first and second stage strong magnetic scavenging concentrates, after being classified by hydrocyclones, are ultrafinely ground to a 0.038mm particle size content of 100%. After weak magnetic iron removal and hydrocyclone desliming, ultrafine flotation is performed, resulting in the recovery of nearly 50,000 tons of ultrafine titanium concentrate annually, yielding significant economic benefits.

[0095] To further understand the present invention, preferred embodiments of the present invention are described below in conjunction with examples. However, it should be understood that these descriptions are only for further illustrating the features and advantages of the present invention, and not for limiting the scope of the claims of the present invention.

[0096] Example 1

[0097] according to Figure 3 The process flow shown is as follows:

[0098] S1. The fine-grained iron ore tailings (second-stage, third-stage, and fourth-stage iron ore tailings) are fed into a weak magnetic separator (magnetic field strength 4000 Oersted) for first-stage iron removal, to obtain first-stage iron-removed concentrate and first-stage iron-removed tailings respectively.

[0099] S2. Perform a strong magnetic roughing separation (magnetic field strength 8000 Oersted) on the iron removal tailings to obtain a strong magnetic roughing concentrate and a strong magnetic roughing tailings.

[0100] S3. Perform a first-stage strong magnetic scavenging (magnetic field strength 15000 Oersted) on the tailings obtained in step S2 to obtain a first-stage strong magnetic scavenging concentrate and a first-stage strong magnetic scavenging tailings. Feed the first-stage strong magnetic roughing concentrate obtained in step S2 into a weak magnetic separator (magnetic field strength 4000 Oersted) for two-stage iron removal to obtain a two-stage iron removal concentrate and a two-stage iron removal tailings.

[0101] S4. Perform two-stage strong magnetic separation (magnetic field strength 7000 Oersted) on the two-stage iron removal tailings to obtain two-stage strong magnetic separation concentrate and two-stage strong magnetic separation tailings respectively.

[0102] S5. Perform two-stage strong magnetic scavenging (magnetic field strength 12000 Oersted) on the tailings obtained in step S4 to obtain two-stage strong magnetic scavenging concentrate and two-stage strong magnetic scavenging tailings respectively; perform inclined plate classification on the two-stage strong magnetic scavenging concentrate obtained in step S4 to remove -0.038mm particle size material to obtain inclined plate underflow and inclined plate overflow respectively.

[0103] The inclined plate bottom flow is used for fine-grained titanium flotation, employing a flotation machine. The flotation process is sulfur flotation + titanium flotation; each flotation stage consists of one roughing and three scavenging or three cleaning stages (i.e., sulfur flotation consists of one roughing and three scavenging stage, and titanium flotation consists of one roughing and three cleaning stage). The reagents used in the flotation include sulfuric acid, diesel oil, and titanium flotation collectors; the sulfuric acid mass fraction is 25%, and the titanium flotation collectors are MOH titanium flotation collector and high-quality titanium flotation collector; the sulfuric acid dosage is 4500 g / t of raw flotation ore, the diesel oil dosage is 700 g / t of raw flotation ore, and the titanium flotation collector dosage is 1800 g / t of raw flotation ore (the mass ratio of the two titanium flotation collectors is 2:3). After the above fine-grained titanium flotation, fine-grained titanium concentrate and flotation tailings 1 are obtained.

[0104] S6. The first-stage strong magnetic scavenging concentrate obtained in step S3, the second-stage strong magnetic scavenging concentrate obtained in step S5, and the inclined plate overflow obtained in step S5 are fed into the first-stage hydrocyclone for processing to obtain the first-stage hydrocyclone underflow and the first-stage hydrocyclone overflow, respectively.

[0105] S7. The sand from the first-stage hydrocyclone is fed into the sand mill for ultrafine grinding to obtain the grinding product.

[0106] The particle size range of the sand product obtained in step S6 is -0.18mm to +0.038mm, which is a large range. Moreover, the degree of liberation of ilmenite monomers in these particle sizes is low, only 73%. After ultrafine grinding by an abrasive mill (process conditions: abrasive mill speed 20r / min, grinding concentration 65%, grinding media using ceramic balls, media filling rate 35%), the content of -0.038mm is 100%, the content of -0.019mm is 88%, and the degree of liberation of ilmenite monomers is 90%.

[0107] S8. The grinding product is fed into a weak magnetic separator for three-stage iron removal (magnetic field strength 4000 Oersted) to obtain three-stage iron removal concentrate and three-stage iron removal tailings.

[0108] S9. The overflow from the primary hydrocyclone obtained in step S6 and the three-stage iron removal tailings obtained in step S8 are fed into the secondary hydrocyclone for processing (the parameters of the secondary hydrocyclone are as follows: hydrocyclone diameter 150mm, pressure 0.5MPa, sand discharge port diameter 20mm, overflow pipe diameter 30mm), to obtain the secondary hydrocyclone sand discharge and the secondary hydrocyclone overflow, thereby removing the -0.010mm slime.

[0109] S10. Perform ultrafine flotation on the sediment from the secondary hydrocyclone to obtain ultrafine titanium concentrate and flotation tailings 2, respectively.

[0110] The ultrafine-grained titanium flotation process employs a flotation column, with a flotation flow of sulfur flotation followed by titanium flotation. Sulfur flotation involves one roughing and three cleaning stages, while titanium flotation involves one roughing and two cleaning stages. The reagents used for titanium flotation include sulfuric acid, diesel fuel, and a titanium-flotation collector. The sulfuric acid has a mass fraction of 25%, and the titanium-flotation collector is a high-quality titanium flotation collector. The sulfuric acid dosage is 10,000 g / t of raw flotation ore, the diesel fuel dosage is 450 g / t of raw flotation ore, and the titanium-flotation collector dosage is 4,000 g / t of raw flotation ore. After ultrafine-grained titanium flotation, ultrafine-grained titanium concentrate and flotation tailings are obtained.

[0111] Effect test :

[0112] The flotation operation parameters for Example 1 are shown in Table 1, and the reagent dosage is shown in Table 2.

[0113] Table 1: Flotation Operation Indicators for Example 1

[0114]

[0115] Table 2: Reagent Dosage for Flotation Operation in Example 1

[0116]

[0117] Comparative Example 1

[0118] To demonstrate the difference in flotation between ultrafine ilmenite mixed in with titanium flotation tailings and ultrafine ilmenite not mixed in with titanium flotation tailings in this invention, the ultrafine ilmenite mixed in with titanium flotation tailings was enriched according to the following process: The titanium flotation tailings containing reagents were fed into a primary hydrocyclone for classification (primary hydrocyclone parameters: hydrocyclone diameter 250mm, pressure 0.12MPa, underflow diameter 30mm, overflow pipe diameter 60mm), obtaining primary hydrocyclone underflow and primary hydrocyclone overflow respectively; the primary hydrocyclone overflow was then fed into a secondary hydrocyclone for thickening and desliming (secondary hydrocyclone parameters: hydrocyclone diameter 150mm, pressure 0.2MPa, underflow diameter 26mm, overflow pipe diameter 50mm), respectively. The process involves obtaining secondary hydrocyclone underflow and secondary hydrocyclone overflow; the secondary hydrocyclone underflow is fed into a weak magnetic separator for iron removal (magnetic field strength 4000 Oersted), yielding iron-removed concentrate and iron-removed tailings; the iron-removed tailings are fed into a primary strong magnetic roughing separator (magnetic field strength 12000 Oersted), yielding primary strong magnetic rough concentrate and primary strong magnetic rough tailings; the primary strong magnetic rough tailings are fed into a secondary strong magnetic scavenging separator (magnetic field strength 16000 Oersted), yielding secondary strong magnetic scavenging concentrate and secondary strong magnetic scavenging tailings; the primary strong magnetic rough concentrate and secondary strong magnetic scavenging concentrate are mixed and fed into a tertiary strong magnetic cleaning separator (magnetic field strength 10000 Oersted), yielding tertiary strong magnetic concentrate and tertiary strong magnetic tailings; the tertiary strong magnetic concentrate is subjected to ultrafine flotation to remove titanium, yielding ultrafine titanium concentrate and flotation tailings. The ultrafine flotation of titanium employs a flotation column, with a flotation process of sulfur flotation followed by titanium flotation. Sulfur flotation involves one roughing and three scavenging stages, while titanium flotation involves one roughing and two cleaning stages. The reagents used for titanium flotation include sulfuric acid, diesel fuel, and a titanium flotation collector. The sulfuric acid has a mass fraction of 25%, and the titanium flotation collector is a high-quality titanium flotation collector. The sulfuric acid dosage is 13,500 g / t of raw ore, the diesel fuel dosage is 600 g / t of raw ore, and the titanium flotation collector dosage is 5,000 g / t of raw ore.

[0119] Effect test :

[0120] The flotation operation parameters for Comparative Example 1 are shown in Table 3, and the reagent dosage is shown in Table 4.

[0121] Table 3: Flotation Operation Indicators of Comparative Example 1

[0122]

[0123] Table 4: Reagent dosage for flotation operation in Comparative Example 1

[0124]

[0125] Comparing Example 1 and Comparative Example 1, the recovery rate of ultrafine titanium concentrate obtained by the present invention is 9.4 percentage points higher than that of Comparative Example 1. The amount of each component in the titanium flotation agent is reduced, with sulfuric acid reduced by 35%, diesel oil reduced by 33.33%, and titanium flotation collector reduced by 25%.

[0126] This document uses specific examples to illustrate the principles and implementation methods of the present invention. The descriptions of these embodiments are merely to aid in understanding the method and core ideas of the present invention, including the best mode, and to enable any person skilled in the art to practice the present invention, including manufacturing and using any device or system, and implementing any combined method. It should be noted that those skilled in the art can make various improvements and modifications to the present invention without departing from its principles, and these improvements and modifications also fall within the scope of protection of the claims. The scope of protection of this patent is defined by the claims and may include other embodiments that can be conceived by those skilled in the art. If these other embodiments have structural elements similar to those expressed in the claims, or if they include equivalent structural elements that are not substantially different from those expressed in the claims, then these other embodiments should also be included within the scope of the claims.

Claims

1. A process for recovering ultrafine-grained ilmenite, characterized in that, Includes the following steps: S1. The fine-grained iron ore tailings are fed into a weak magnetic separator for primary iron removal, resulting in primary iron-removed concentrate and primary iron-removed tailings. S2. Perform a strong magnetic roughing separation on the iron removal tailings to obtain a strong magnetic roughing concentrate and a strong magnetic roughing tailings. S3. Perform a first-stage strong magnetic roughing tailings separation on the first-stage strong magnetic scavenging to obtain a first-stage strong magnetic scavenging concentrate and a first-stage strong magnetic scavenging tailings; perform a second-stage iron removal on the first-stage strong magnetic roughing concentrate to obtain a second-stage iron removal concentrate and a second-stage iron removal tailings. S4. Perform two-stage strong magnetic separation on the two-stage iron removal tailings to obtain two-stage strong magnetic separation concentrate and two-stage strong magnetic separation tailings respectively. S5. Perform two-stage strong magnetic scavenging on the tailings obtained in step S4 to obtain two-stage strong magnetic scavenging concentrate and two-stage strong magnetic scavenging tailings, respectively; perform inclined plate classification on the two-stage strong magnetic concentrate obtained in step S4 to obtain inclined plate underflow and inclined plate overflow, respectively; wherein, the inclined plate underflow is used for fine-particle flotation to select titanium, to obtain fine-particle titanium concentrate and flotation tailings 1, respectively. S6. The first-stage strong magnetic scavenging concentrate obtained in step S3, the second-stage strong magnetic scavenging concentrate obtained in step S5, and the inclined plate overflow obtained in step S5 are fed into the first-stage hydrocyclone for processing to obtain the first-stage hydrocyclone underflow and the first-stage hydrocyclone overflow, respectively. S7. Feed the sand from the first-stage hydrocyclone into the sand mill for ultrafine grinding to obtain the ground product; S8. Perform three-stage iron removal on the grinding product to obtain three-stage iron-removed concentrate and three-stage iron-removed tailings respectively. S9. The overflow of the first-stage hydrocyclone obtained in step S6 and the three-stage iron removal tailings obtained in step S8 are fed into the second-stage hydrocyclone for processing to obtain the second-stage hydrocyclone underflow and the second-stage hydrocyclone overflow, respectively. S10. Perform ultrafine flotation on the sediment from the secondary hydrocyclone to obtain ultrafine titanium concentrate and flotation tailings 2.

2. The process according to claim 1, characterized in that, In step S1, the magnetic field strength of the weak magnetic separator is 3500~5000 Oersted.

3. The process according to claim 1, characterized in that, In step S2, the magnetic field strength of the strong magnetic coarse selection section is 7000~9000 Oersted.

4. The process according to claim 1, characterized in that, In step S3: The magnetic field strength of the strong magnetic sweep section is 12000~18000 Oersted; The magnetic field strength of the two-stage iron removal is 3500~5000 Oersted.

5. The process according to claim 1, characterized in that, In step S4, the magnetic field strength of the two-stage strong magnetic selection is 6000~8000 Oersted.

6. The process according to claim 1, characterized in that, In step S5, the magnetic field strength of the two-stage strong magnetic sweep is 10000~15000 Oersted.

7. The process according to claim 1, characterized in that, In step S5, the fine-particle flotation for titanium is carried out using a flotation machine, and the flotation process is sulfur flotation and titanium flotation. The reagents used in the flotation include sulfuric acid and titanium collector. The amount of sulfuric acid used is 4000~5000g / t of raw flotation ore, and the amount of titanium collector used is 1500~2000g / t of raw flotation ore.

8. The process according to claim 1, characterized in that, In step S8, the magnetic field strength of the three-stage iron removal is 3500~5000 Oersted.

9. The process according to claim 1, characterized in that, In step S10, the ultrafine flotation of titanium uses a flotation column, and the flotation process is sulfur flotation and titanium flotation; the reagents used in the flotation include sulfuric acid and titanium collector; wherein, the amount of sulfuric acid used is 8000~15000g / t of flotation raw ore, and the amount of titanium collector used is 3000~5000g / t of flotation raw ore.

10. The process according to claim 1, characterized in that, In step S7, the specifications of the grinding product are: 100% content of -0.038mm, more than 85% content of -0.019mm, and more than 88% degree of liberation of ilmenite monomers.

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