Beneficiation method for stepwise recovering zirconium from complex zirconium-containing polymetallic ore

Abstract

The invention discloses a beneficiation method for recovering zirconium from complex zirconium-containing polymetallic ore in a stepped mode. The method sequentially comprises the steps of high-pressure roller grinding, wet screening, first-stage pre-screening and grading, first-stage ball milling, first-stage strong magnetic separation, screening and grading, coarse particle shaking table gravity separation, fine particle shaking table gravity separation, second-stage ball milling, second-stage cyclone grading, second-stage strong magnetic separation and second-stage fine particle shaking table gravity separation. Third-section ball milling, third-section cyclone classification, third-section strong magnetic separation and third-section heartbeat jigging gravity separation are conducted, third-section gravity separation zirconium concentrate, first-section gravity separation zirconium concentrate and second-section gravity separation zirconium concentrate are combined to obtain comprehensive zirconium concentrate, and third-section gravity separation zirconium tailings, first-section gravity separation tailings and second-section gravity separation tailings are combined to form total tailings. The beneficiation method has the advantages of being easy to operate, high in resource recovery rate, economical, environmentally friendly, energy-saving, efficient, high in applicability and the like, is particularly suitable for recovering zirconium concentrate from complex zirconium-containing polymetallic ore with the ZrO2 grade of 2%-4% and symbiotic with rare earth elements, niobium, beryllium and uranium, and is suitable for industrial application and popularization.

Description

Technical Field

[0001] The present invention belongs to the technical field of zirconium ore beneficiation, and specifically relates to a beneficiation method for recovering zirconium from complex zirconium-containing polymetallic ores. The method is particularly suitable for recovering zirconium concentrate from complex zirconium-containing polymetallic ores with a ZrO2 grade of 2% to 4% and paragenesis with rare earth elements, niobium, beryllium and uranium. Background Art

[0002] Zirconium has the advantages of high melting point, corrosion resistance, and good biocompatibility. It has been widely used in the nuclear industry, aerospace, chemical industry, biomedicine and other fields. Zirconium alloy as a nuclear reactor cladding material is known as the "guardian of nuclear reactors". Zirconium carbide and zirconium nitride are representatives of ultra-high temperature ceramics and are used in extreme environments such as aerospace engines and the leading edge of hypersonic aircraft. They are known as "high-temperature guards" and also have reputations such as "biocompatibility star" and "industrial vitamin". They are playing an increasingly important role in the development of high-end science and technology and daily life applications.

[0003] my country's zirconium reserves are relatively concentrated, with Inner Mongolia and Hainan accounting for 90% of the national total. Rich ores are rare, while associated deposits are numerous, with over 70% of the exploited minerals being associated deposits. The low grade and poor endowment make separation difficult. The "801" mine in Tongliao, Inner Mongolia, is a renowned complex zirconium-containing polymetallic deposit in my country, accounting for over 70% of the national total. In addition to zircon, the mine also contains recoverable minerals such as rare earths, niobium, uranium, and beryllium. However, due to its low grade (only niobium reaches industrial grade) and the difficulty of beneficiation, it remains unexploited. In recent years, with the rapid development of China's military technology, demand for zirconium and its derivatives has continued to grow. Furthermore, with the increasing emphasis on the green development of mineral resources, there is an urgent need to develop new, green, and efficient technologies and processes to address the challenges of recycling complex zirconium-containing polymetallic ores in China.

[0004] In order to solve the problem of zirconium recovery in complex zirconium-containing polymetallic ores, Chinese patent application 202111618483.8 discloses a method for obtaining rare earth concentrate, niobium concentrate and zirconium concentrate from polymetallic ores, comprising the following steps: grinding the raw ore, weak magnetic separation, strong magnetic separation, and strong magnetic separation tailings gravity separation to obtain zirconium concentrate 1, re-grinding the strong magnetic separation concentrate, and then flotation, strong magnetic separation, and strong magnetic separation tailings gravity separation to obtain zirconium concentrate 2, and combining zirconium concentrate 1 and zirconium concentrate 2 to form a comprehensive zirconium concentrate. This method is difficult to obtain zirconium concentrate with a high recovery rate or a high-grade zirconium concentrate, mainly because there is a part of the intermediate ore product between the zirconium concentrate and the zirconium tailings during the gravity separation process. The product is mainly composed of zirconium-containing conjoined bodies. Incorporating this product into the concentrate is bound to result in a low concentrate grade, and incorporating this product into the tailings is bound to result in a low concentrate recovery rate. Chinese patent application 202311672876.6 discloses a method for beneficiating zirconium concentrate from rare earth-niobium-bearing polymetallic rock ores. The method comprises the following steps: grinding the raw ore, high-intensity magnetic separation, graded gravity separation of high-intensity magnetic separation tailings, regrinding the gravity separation concentrate, high-intensity magnetic separation, and flotation of the high-intensity magnetic separation tailings to obtain zirconium concentrate 1; regrinding the high-intensity magnetic separation concentrate, flotation, high-intensity magnetic separation, and gravity separation of the high-intensity magnetic separation tailings to obtain zirconium concentrate 2; and combining zirconium concentrate 1 and zirconium concentrate 2 to form a comprehensive zirconium concentrate. The zirconium concentrate recovery rate obtained using this method is relatively low, and the process flow is relatively complex, with multiple gravity separation operations and a large flotation processing capacity, resulting in high costs and difficulty in practical production. Summary of the Invention

[0005] The purpose of the present invention is to address the problems of high energy consumption, low concentrate grade, low recovery rate, and reagent pollution in existing zirconium-containing polymetallic ore recovery methods, and to provide a cascaded zirconium beneficiation method from complex zirconium-containing polymetallic ores. This zirconium beneficiation method not only obtains higher-grade zirconium concentrate but also simultaneously enriches valuable components such as rare earths and niobium, which is of great significance to the comprehensive recovery of complex zirconium-containing polymetallic ores in my country.

[0006] To achieve the above-mentioned object of the present invention, a beneficiation method for cascade recovery of zirconium from complex zirconium-containing polymetallic ores is provided, which is implemented by the following processes and steps:

[0007] S1 High Pressure Roller Mill - Wet Screening - One Stage Pre-Screening and Classification - One Stage Ball Milling - One Stage Strong Magnetic Separation

[0008] -30mm complex zirconium-containing polymetallic ore is fed into a wet screening operation after high-pressure roller grinding to obtain oversize products and undersize products respectively; the oversize products are returned to the high-pressure roller grinding operation, and the undersize products are fed into a pre-screening and grading operation to obtain fine-grained products and coarse-grained products respectively; the coarse-grained products are returned to a pre-screening and grading operation after a ball milling operation, and the fine-grained products are fed into a high-intensity magnetic separation operation to obtain a high-intensity magnetic separation concentrate, and a high-intensity magnetic separation tailings are discharged.

[0009] The one-stage high-intensity magnetic separation operation is composed of a one-stage high-intensity magnetic roughing separation and a one-stage high-intensity magnetic scavenging separation, with magnetic field strengths of 1200mT~1600mT and 1400mT~1800mT respectively; the one-stage high-intensity magnetic separation operation adopts a Slon vertical ring pulsating high-gradient high-intensity magnetic separator; the one-stage high-intensity magnetic separation concentrate is formed by combining a one-stage high-intensity magnetic roughing separation concentrate and a one-stage high-intensity magnetic scavenging separation concentrate; the wet screening operation equipment adopts an arc screen with a sieve hole size of 2mm~6mm; the one-stage pre-screening and grading equipment adopts a Deruik laminated high-frequency vibration fine screen with a sieve hole size of 0.2mm~0.6mm.

[0010] S2 screening and classification - coarse particle shaking table gravity separation - fine particle shaking table gravity separation

[0011] The first stage strong magnetic separation tailings discharged from step S1 are fed into screening and grading operations to obtain coarse-grained products and fine-grained products respectively; the coarse-grained products are fed into a coarse-grained shaking table gravity separation operation to obtain coarse-grained zirconium concentrate and coarse-grained zirconium middlings, and the coarse-grained tailings are discarded; the fine-grained products are fed into a fine-grained shaking table gravity separation operation to obtain fine-grained zirconium concentrate and fine-grained zirconium middlings, and the fine-grained tailings are discarded; the coarse-grained zirconium concentrate and the fine-grained zirconium concentrate are combined to obtain a first stage gravity separation zirconium concentrate, and the coarse-grained tailings and the fine-grained tailings are combined to obtain a first stage gravity separation tailings.

[0012] The screening and grading equipment adopts a Derek laminated high-frequency vibration fine screen with a sieve size of 0.038mm to 0.063mm; the coarse particle shaking table gravity separation equipment has a horizontal slope of 3° to 5°, a stroke of 200 to 300 times / min, and a stroke of 15mm to 20mm; the fine particle shaking table gravity separation equipment has a horizontal slope of 1° to 2°, a stroke of 350 to 450 times / min, and a stroke of 5mm to 10mm.

[0013] S3 two-stage ball mill - two-stage cyclone classification - two-stage strong magnetic separation - two-stage fine particle shaking table gravity separation

[0014] The first-stage strong magnetic separation concentrate obtained in step S1 and the coarse-grained zirconium middlings obtained in step S2 are combined and fed into the second-stage ball milling operation. The second-stage ball milling products are fed into the second-stage cyclone classification operation to obtain classification overflow and classification sand respectively, and the classification sand is returned to the second-stage ball milling operation; the classification overflow is fed into the second-stage strong magnetic separation operation to obtain the second-stage strong magnetic separation concentrate, and the second-stage strong magnetic separation tailings are discharged; the second-stage strong magnetic separation tailings are fed into the second-stage fine-grained shaking table gravity separation operation to obtain the second-stage gravity separation zirconium concentrate and the second-stage gravity separation zirconium middlings, and the second-stage gravity separation tailings are discarded.

[0015] The classification overflow particle size is -0.076mm, accounting for 65% to 85%; the two-stage strong magnetic separation operation includes two-stage strong magnetic roughing and two-stage strong magnetic scavenging, with magnetic field strengths of 1200mT to 1600mT and 1400mT to 1800mT respectively. The two-stage strong magnetic separation operation adopts a Slon vertical ring pulsating high-gradient strong magnetic separator; the two-stage strong magnetic separation concentrate consists of two-stage strong magnetic roughing concentrate and two-stage strong magnetic scavenging concentrate; the two-stage fine particle shaking table re-selection equipment has a horizontal slope of 1° to 2°, a stroke rate of 350 to 450 times / min, and a stroke of 5mm to 10mm.

[0016] S4 three-stage ball mill - three-stage cyclone classification - three-stage strong magnetic separation - three-stage centrifugal jigging gravity separation

[0017] The second-stage strong magnetic separation concentrate obtained in step S3, the fine-grained zirconium middlings obtained in step S2 and the second-stage gravity separation zirconium middlings obtained in step S3 are combined and fed into a three-stage stirred mill operation. The grinding products of the stirred mill are fed into a three-stage cyclone classification operation to obtain classification overflow and classification sand settling. The classification sand settling is returned to the three-stage stirred mill operation. The classification overflow is fed into a three-stage strong magnetic separation operation to obtain a three-stage strong magnetic separation concentrate - a mixed product containing rare earth niobium, and the three-stage strong magnetic separation tailings are discharged; the three-stage strong magnetic separation tailings are fed into a three-stage centrifugal jig gravity separation operation to obtain a three-stage gravity separation zirconium concentrate, and the three-stage gravity separation zirconium tailings are discarded; the three-stage gravity separation zirconium concentrate, the first-stage gravity separation zirconium concentrate obtained in step S2, and the second-stage gravity separation zirconium concentrate obtained in step S3 are combined to obtain a comprehensive zirconium concentrate, and the three-stage gravity separation zirconium tailings, the first-stage gravity separation tailings discarded in step S2, and the second-stage gravity separation tailings discarded in step S3 are combined to form a total tailings.

[0018] Preferably, the graded overflow particle size in step S4 is -0.043 mm, accounting for 85% to 95%; the three-stage strong magnetic separation operation includes three-stage strong magnetic roughing and three-stage strong magnetic scavenging, and the magnetic field strength is 1200mT to 1600mT and 1400mT to 1800mT respectively. The three-stage strong magnetic separation operation adopts Slon vertical ring pulsating high gradient strong magnetic separator; the three-stage strong magnetic separation concentrate is formed by combining the three-stage strong magnetic roughing concentrate and the three-stage strong magnetic scavenging concentrate; the three-stage centrifugal jig re-selection operation adopts Kelsey centrifugal jig concentrator, and its structural parameters are: bed stone particle size 0.4mm to 0.6mm, bed stone density 3.0g / cm 3 ~4.0g / cm 3 , screen aperture 0.2mm~0.3mm, bed thickness 25mm~30mm, pulsation amplitude 1.8mm~2.4mm, pulsation frequency 1000 times / min~2000 times / min, centrifugal force field 60G~90G, pulsating flushing water volume 20L / min~30L / min.

[0019] Furthermore, the complex zirconium-containing polymetallic ore has a ZrO2 grade of 2% to 4%, a Nb2O5 grade of 0.1% to 0.5%, and a REO grade of 0.5% to 2%.

[0020] The core technical idea of the present invention is: the process mineralogical characteristics of the ore are the internal factors that determine the technical and economic indicators of mineral processing, and the mineral processing equipment and process parameters are the external factors that determine the technical indicators of mineral processing. For complex polymetallic ores containing zirconium, our research found that the zirconium minerals in the ore are evenly distributed in coarse-grained, fine-grained and micro-fine particles, which are extremely unequally distributed; part of the zirconium minerals in the ore are associated with non-magnetic gangue minerals, and part are associated with weakly magnetic iron-containing minerals, and their selectivity is significantly different; other useful minerals in the ore (rare earth minerals, niobium minerals) are micro-fine-grained. Based on the above characteristics, a process of zirconium mineral stage dissociation, narrow particle size selection, stage refinement, stage tailings discarding, and medium ore regrinding and re-selection is proposed. According to the particle size characteristics of the gravity separation feed, specific high-efficiency gravity separation equipment and process parameters are selected to achieve optimal and maximized recovery of zirconium.

[0021] Compared with the prior art, the present invention provides a cascaded recovery of zirconium from complex zirconium-containing polymetallic ores, which has the following advantages:

[0022] (1) The present invention creatively proposes a new process and technology for the staged dissociation of zirconium ore in zirconium-containing complex polymetallic ores, staged high-intensity magnetic separation + gravity separation to obtain fine tailings, and re-grinding and re-selection of the middlings to simultaneously recover zirconium, rare earths and niobium, thereby providing a possibility for the future development and utilization of the complex polymetallic mine "801".

[0023] For -30mm ore, high pressure roller mill + ball mill + pre-inspection screening and classification technology is used, which has the advantages of low energy consumption, small over-crushing and high grinding and classification efficiency.

[0024] (3) The method of the present invention not only obtains a relatively good zirconium concentrate grade recovery rate index, but also has a ZrO2 grade of more than 45.5% and a recovery rate of more than 73% in the comprehensive zirconium concentrate. It can also simultaneously enrich rare earth, niobium and other elements with a high recovery rate, without affecting its subsequent flotation quality improvement.

[0025] (4) The present invention adopts a purely physical mineral processing method of magnetic separation and gravity separation, which has the advantages of good economy, green environmental protection, energy saving and high efficiency, strong applicability, etc., and is suitable for industrial application and promotion. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] Figure 1 The present invention is a principle process flow chart of a mineral processing method for cascade recovery of zirconium from complex zirconium-containing polymetallic ores. DETAILED DESCRIPTION

[0027] To further describe the present invention, a beneficiation method for cascade recovery of zirconium from complex zirconium-containing polymetallic ores is described in further detail below with reference to the accompanying drawings and examples.

[0028] It should be noted that any modifications, equivalent replacements, improvements, etc. made within the technical ideas and principles of the present invention should be included in the scope of protection of the present invention. In addition, the embodiments described below are exemplary and should not be understood as limiting the present invention.

[0029] In the embodiment, the ore was taken from the "801" mine in Tongliao City, Inner Mongolia. The mine is rich in zirconium, rare earth, niobium, beryllium, uranium and other resources. It is a famous complex mine in my country where multiple rare metals and rare earths coexist. The ZrO2 grade in the original ore is 3.15%, the REO grade is 0.92%, and the Nb2O5 grade is 0.37%.

[0030] Depend on Figure 1 As shown in the process flow chart of the present invention, the cascade recovery of zirconium from complex zirconium-containing polymetallic ores is carried out by the following process steps:

[0031] S1 High Pressure Roller Mill - Wet Screening - One Stage Pre-Screening and Classification - One Stage Ball Milling - One Stage Strong Magnetic Separation

[0032] After high-pressure roller milling, the -30mm complex zirconium-containing polymetallic ore is fed into a wet screening process to obtain an oversize product and an undersize product. The oversize product returns to the high-pressure roller mill, and the undersize product is fed into a pre-screening and grading process to obtain a fine-grained product and a coarse-grained product. The coarse-grained product is then ball milled and returned to a pre-screening and grading process. The fine-grained product is fed into a high-intensity magnetic separation process to obtain a high-intensity magnetic separation concentrate, and a high-intensity magnetic separation tailings are discharged. The high-intensity magnetic separation process is composed of a high-intensity magnetic roughing process and a high-intensity magnetic scavenging process, with magnetic field strengths of 1400mT and 1600mT respectively. The high-intensity magnetic separation process uses a Slon vertical ring pulsating high-gradient high-intensity magnetic separator. The high-intensity magnetic separation concentrate is formed by combining a high-intensity magnetic roughing concentrate and a high-intensity magnetic scavenging concentrate. The wet screening process uses a curved screen with a mesh size of 4mm. The pre-screening and grading equipment uses a Deruik laminated high-frequency vibrating fine screen with a mesh size of 0.4mm.

[0033] S2 screening and classification - coarse particle shaking table gravity separation - fine particle shaking table gravity separation

[0034] The tailings of a section of strong magnetic separation discharged from step S1 are fed into a screening and grading operation to obtain coarse-grained products and fine-grained products respectively; the coarse-grained products are fed into a coarse-grained shaking table gravity separation operation to obtain coarse-grained zirconium concentrate and coarse-grained zirconium middlings, and the coarse-grained tailings are discarded; the fine-grained products are fed into a fine-grained shaking table gravity separation operation to obtain fine-grained zirconium concentrate and fine-grained zirconium middlings, and the fine-grained tailings are discarded; the coarse-grained zirconium concentrate and the fine-grained zirconium concentrate are combined to obtain a section of gravity-separated zirconium concentrate, and the coarse-grained tailings and the fine-grained tailings are combined to obtain a section of gravity-separated tailings. The screening and grading equipment uses a Derek laminated high-frequency vibrating fine screen with a sieve size of 0.043mm; the coarse-grained shaking table gravity separation equipment has a horizontal slope of 4°, a stroke of 250 times / min, and a stroke of 16mm, and the fine-grained shaking table gravity separation equipment has a horizontal slope of 1.5°, a stroke of 400 times / min, and a stroke of 6mm.

[0035] S3 two-stage ball mill - two-stage cyclone classification - two-stage strong magnetic separation - two-stage fine particle shaking table gravity separation

[0036] The first-stage strong magnetic separation concentrate obtained in step S1 and the coarse-grained zirconium middlings obtained in step S2 are combined and fed into the second-stage ball milling operation. The second-stage ball milling products are fed into the second-stage cyclone classification operation to obtain classification overflow and classification sand respectively, and the classification sand is returned to the second-stage ball milling operation; the classification overflow is fed into the second-stage strong magnetic separation operation to obtain the second-stage strong magnetic separation concentrate, and the second-stage strong magnetic separation tailings are discharged; the second-stage strong magnetic separation tailings are fed into the second-stage fine-grained shaking table gravity separation operation to obtain the second-stage gravity separation zirconium concentrate and the second-stage gravity separation zirconium middlings, and the second-stage gravity separation tailings are discarded. The classification overflow particle size is -0.076mm, accounting for 75%; the two-stage strong magnetic separation operation includes two-stage strong magnetic roughing and two-stage strong magnetic scavenging, with magnetic field strengths of 1500mT and 1700mT respectively. The two-stage strong magnetic separation operation adopts Slon vertical ring pulsating high-gradient strong magnetic separator; the two-stage strong magnetic separation concentrate consists of two-stage strong magnetic roughing concentrate and two-stage strong magnetic scavenging concentrate; the two-stage fine particle shaking table re-selection equipment has a horizontal slope of 1.5°, a stroke rate of 400 times / min, and a stroke of 7mm.

[0037] S4 three-stage ball mill - three-stage cyclone classification - three-stage strong magnetic separation - three-stage centrifugal jigging gravity separation

[0038] The second-stage strong magnetic separation concentrate obtained in step S3, the fine-grained zirconium middlings obtained in step S2 and the second-stage gravity separation zirconium middlings obtained in step S3 are combined and fed into a three-stage stirred mill operation. The grinding products of the stirred mill are fed into a three-stage cyclone classification operation to obtain classification overflow and classification sand settling. The classification sand settling is returned to the three-stage stirred mill operation. The classification overflow is fed into a three-stage strong magnetic separation operation to obtain a three-stage strong magnetic separation concentrate - a mixed product containing rare earth niobium, and the three-stage strong magnetic separation tailings are discharged; the three-stage strong magnetic separation tailings are fed into a three-stage centrifugal jig gravity separation operation to obtain a three-stage gravity separation zirconium concentrate, and the three-stage gravity separation zirconium tailings are discarded; the three-stage gravity separation zirconium concentrate, the first-stage gravity separation zirconium concentrate obtained in step S2, and the second-stage gravity separation zirconium concentrate obtained in step S3 are combined to obtain a comprehensive zirconium concentrate, and the three-stage gravity separation zirconium tailings, the first-stage gravity separation tailings discarded in step S2, and the second-stage gravity separation tailings discarded in step S3 are combined to form a total tailings. The classification overflow particle size is -0.043mm, accounting for 90%; the three-stage high-intensity magnetic separation operation includes three-stage high-intensity magnetic roughing and three-stage high-intensity magnetic scavenging, with magnetic field intensities of 1600mT and 1800mT respectively. The three-stage high-intensity magnetic separation operation adopts a Slon vertical ring pulsating high-gradient high-intensity magnetic separator; the three-stage high-intensity magnetic separation concentrate is formed by combining the three-stage high-intensity magnetic roughing concentrate and the three-stage high-intensity magnetic scavenging concentrate; the three-stage centrifugal jig re-selection operation adopts a Kelsey centrifugal jig concentrator, whose structural parameters are: bed stone particle size 0.5mm, bed stone density 3.3g / cm 3 , screen aperture 0.3mm, bed thickness 25mm, pulsation amplitude 2.0mm, pulsation frequency 1600 times / min, centrifugal force field 80G, pulsating flushing water volume 27L / min.

[0039] Table 1 Main test results

[0040]

[0041] The mineral processing technical indicators achieved in the examples are shown in Table 1. As can be seen from Table 1, when the ZrO2 grade in the original ore is 3.15%, the REO grade is 0.92%, and the Nb2O5 grade is 0.37%, the separation method of the present invention finally achieves excellent mineral processing technical indicators of a comprehensive zirconium concentrate ZrO2 grade of up to 45.96% and a recovery rate of up to 73.54%. The REO grade of the produced rare earth niobium mixed product is significantly increased from 0.92% to 4.44%, and the Nb2O5 grade is significantly increased from 0.37% to 1.75%, and the recovery rates are as high as 78.41% and 76.80%, respectively, achieving unexpected technical results.

[0042] The above are embodiments of the present invention, but the above examples are only used to help understand the method and core concept of the present invention and are not equivalent to the specific embodiments described above. For those skilled in the art, making several improvements, modifications or changes to the present invention, as well as combining the above technical features in an appropriate manner, these improvements, modifications, changes or combinations, or directly applying the inventive concept and technical solution to other occasions without modification, should all be considered as the scope of protection of the present invention.

[0043] The above are embodiments of the present invention, but the above examples are only used to help understand the method and core concept of the present invention and are not equivalent to the specific embodiments described above. For those skilled in the art, making several improvements, modifications or changes to the present invention, as well as combining the above technical features in an appropriate manner, these improvements, modifications, changes or combinations, or directly applying the inventive concept and technical solution to other occasions without modification, should all be considered as the scope of protection of the present invention.

Claims

1. A method for recovering zirconium from complex zirconium-containing polymetallic ores in stages, characterized in that Use the following steps to implement: S1 High Pressure Roller Mill - Wet Screening - One Stage Pre-Screening and Classification - One Stage Ball Milling - One Stage Strong Magnetic Separation -30mm complex zirconium-containing polymetallic ore is fed into a wet screening process after high-pressure roller grinding to obtain oversize and undersize products respectively; the oversize products are returned to the high-pressure roller grinding process, and the undersize products are fed into a pre-screening and grading process to obtain fine-grained products and coarse-grained products respectively; the coarse-grained products are fed into a pre-screening and grading process after a ball milling process, and the fine-grained products are fed into a high-intensity magnetic separation process to obtain a high-intensity magnetic separation concentrate, and a high-intensity magnetic separation tailings are discharged; S2 screening and classification - coarse particle shaking table gravity separation - fine particle shaking table gravity separation The tailings from the first stage of intense magnetic separation discharged in step S1 are fed into a screening and grading operation to obtain a coarse-grained product and a fine-grained product respectively; the coarse-grained product is fed into a coarse-grained shaking table for gravity separation to obtain a coarse-grained zirconium concentrate and a coarse-grained zirconium middling, and the coarse-grained tailings are discarded; the fine-grained product is fed into a fine-grained shaking table for gravity separation to obtain a fine-grained zirconium concentrate and a fine-grained zirconium middling, and the fine-grained tailings are discarded; the coarse-grained zirconium concentrate and the fine-grained zirconium concentrate are combined to obtain a first stage gravity separation zirconium concentrate, and the coarse-grained tailings and the fine-grained tailings are combined to obtain a first stage gravity separation tailings; S3 two-stage ball mill - two-stage cyclone classification - two-stage strong magnetic separation - two-stage fine particle shaking table gravity separation The first stage strong magnetic separation concentrate obtained in step S1 and the coarse-grained zirconium middling obtained in step S2 are combined and fed into the second stage ball milling operation. The second stage ball milling product is fed into the second stage cyclone classification operation to obtain classification overflow and classification sand respectively, and the classification sand is returned to the second stage ball milling operation; the classification overflow is fed into the second stage strong magnetic separation operation to obtain the second stage strong magnetic separation concentrate, and the second stage strong magnetic separation tailings are discharged; the second stage strong magnetic separation tailings are fed into the second stage fine particle shaking table gravity separation operation to obtain the second stage gravity separation zirconium concentrate and the second stage gravity separation zirconium middling, and the second stage gravity separation tailings are discarded; S4 three-stage ball mill - three-stage cyclone classification - three-stage strong magnetic separation - three-stage centrifugal jigging gravity separation The second-stage strong magnetic separation concentrate obtained in step S3, the fine-grained zirconium middlings obtained in step S2 and the second-stage gravity separation zirconium middlings obtained in step S3 are combined and fed into a three-stage stirred mill operation. The grinding products of the stirred mill are fed into a three-stage cyclone classification operation to obtain classification overflow and classification sand settling. The classification sand settling is returned to the three-stage stirred mill operation. The classification overflow is fed into a three-stage strong magnetic separation operation to obtain a three-stage strong magnetic separation concentrate - a mixed product containing rare earth niobium, and the three-stage strong magnetic separation tailings are discharged; the three-stage strong magnetic separation tailings are fed into a three-stage centrifugal jig gravity separation operation to obtain a three-stage gravity separation zirconium concentrate, and the three-stage gravity separation zirconium tailings are discarded; the three-stage gravity separation zirconium concentrate, the first-stage gravity separation zirconium concentrate obtained in step S2, and the second-stage gravity separation zirconium concentrate obtained in step S3 are combined to obtain a comprehensive zirconium concentrate, and the three-stage gravity separation zirconium tailings, the first-stage gravity separation tailings discarded in step S2, and the second-stage gravity separation tailings discarded in step S3 are combined to form a total tailings.

2. The method for recovering zirconium from a complex zirconium-containing polymetallic ore in stages according to claim 1, wherein: In step S1, the one-stage high-intensity magnetic separation operation is composed of a one-stage high-intensity magnetic roughing separation and a one-stage high-intensity magnetic scavenging separation, and the magnetic field strength is 1200mT~1600mT and 1400mT~1800mT respectively; the one-stage high-intensity magnetic separation operation adopts Slon vertical ring pulsating high gradient high-intensity magnetic separator; the one-stage high-intensity magnetic separation concentrate is formed by combining a one-stage high-intensity magnetic roughing concentration concentrate and a one-stage high-intensity magnetic scavenging concentration concentrate.

3. The method for recovering zirconium from a complex zirconium-containing polymetallic ore in stages according to claim 1, wherein: In step S1, the wet screening operation equipment uses a curved screen with a mesh size of 2mm to 6mm; the pre-screening and grading equipment uses a Derek laminated high-frequency vibrating fine screen with a mesh size of 0.2mm to 0.6mm.

4. The method for recovering zirconium from a complex zirconium-containing polymetallic ore in stages according to claim 1, wherein: In step S2, the screening and grading equipment adopts a Derek laminated high-frequency vibrating fine screen with a sieve size of 0.038mm to 0.063mm; the coarse particle shaking table gravity separation equipment has a transverse slope of 3° to 5°, a stroke of 200 to 300 times / min, and a stroke of 15mm to 20mm; the fine particle shaking table gravity separation equipment has a transverse slope of 1° to 2°, a stroke of 350 to 450 times / min, and a stroke of 5mm to 10mm.

5. The method for recovering zirconium from a complex zirconium-containing polymetallic ore in stages according to claim 1, wherein: In step S3, the classification overflow particle size is -0.076 mm, accounting for 65% to 85%; the two-stage strong magnetic separation operation includes two-stage strong magnetic roughing and two-stage strong magnetic scavenging, and the magnetic field strengths are 1200mT to 1600mT and 1400mT to 1800mT respectively. The two-stage strong magnetic separation operation adopts Slon vertical ring pulsating high gradient strong magnetic separator; the two-stage strong magnetic separation concentrate is composed of two-stage strong magnetic roughing concentrate and two-stage strong magnetic scavenging concentrate.

6. The method for recovering zirconium from a complex zirconium-containing polymetallic ore in stages according to claim 1, wherein: In step S3, the second-stage fine particle shaking table gravity separation equipment has a transverse slope of 1° to 2°, a stroke rate of 350 to 450 times / min, and a stroke of 5 mm to 10 mm.

7. The method for recovering zirconium from a complex zirconium-containing polymetallic ore in stages according to claim 1, wherein: In step S4, the graded overflow particle size is -0.043 mm, accounting for 85% to 95%; the three-stage high-intensity magnetic separation operation includes three-stage high-intensity magnetic roughing and three-stage high-intensity magnetic scavenging, and the magnetic field strengths are 1200mT to 1600mT and 1400mT to 1800mT respectively. The three-stage high-intensity magnetic separation operation adopts Slon vertical ring pulsating high-gradient high-intensity magnetic separator; the three-stage high-intensity magnetic separation concentrate is formed by merging the three-stage high-intensity magnetic roughing concentrate and the three-stage high-intensity magnetic scavenging concentrate.

8. The method for recovering zirconium from a complex zirconium-containing polymetallic ore in stages according to claim 1, wherein: In step S4, the three-stage centrifugal jig re-selection operation adopts a Kelsey centrifugal jig concentrator, whose structural parameters are: bed stone particle size 0.4mm-0.6mm, bed stone density 3.0g / cm 3 ~4.0g / cm 3 , screen aperture 0.2mm~0.3mm, bed thickness 25mm~30mm, pulsation amplitude 1.8mm~2.4mm, pulsation frequency 1000 times / min~2000 times / min, centrifugal force field 60G~90G, pulsating flushing water volume 20L / min~30L / min.

9. The ore dressing method for cascade recovery of zirconium from complex zirconium-containing polymetallic ores according to any one of claims 1 to 8, characterized in that: The complex zirconium-containing polymetallic ore has a ZrO2 grade of 2% to 4%, a Nb2O5 grade of 0.1% to 0.5%, and a REO grade of 0.5% to 2%.

Images