A method for resource utilization of extremely low-grade zinc oxide ore

Abstract

The present invention discloses a method for resource utilization of extremely low-grade zinc oxide ore. The method adopts a combined process of coarse grinding, coarse-grained strong magnetic separation pre-enrichment, and fine grinding and flotation quality improvement to comprehensively recover low-grade, high-mud zinc oxide. Compared with a process of recovering zinc oxide by flotation alone, the method significantly reduces grinding costs, reduces the adverse effects of ore slime on zinc oxide flotation, and improves the recovery index of the mineral processing process. In addition, the coarse-grained strong magnetic separation pre-enrichment can reduce the cut-off grade of industrial ore in mining enterprises, increase reserves, improve the mineable amount of ore, and improve resource development and utilization rate.

Description

Technical Field

[0001] The present invention relates to the technical field of ore resource utilization, and in particular to a method for resource utilization of extremely low-grade zinc oxide ore. Background Art

[0002] The formation of zinc oxide ore is mainly due to the long-term interaction of exposed zinc sulfide deposits with O2, H2O, CO2 and biological organic matter, which forms an oxidation zone of a certain thickness on the surface of the zinc sulfide deposit. The geological environment is usually more complex, so there are many types of zinc oxide ores. Calcite, quartz, dolomite, clay, iron oxides and hydroxides are the most common gangue minerals in zinc oxide ores.

[0003] Currently, flotation is the primary method used in industrial processing of zinc oxide ore. Domestic and international scholars have conducted extensive research on zinc oxide flotation and developed a series of flotation methods, including direct flotation with fatty acid collectors, flotation with chelating collectors, flotation with mercaptan collectors, sulfide-amine flotation, and sulfide-xanthate flotation. However, each flotation method has its own shortcomings, and no single flotation method can effectively solve the problem of difficult zinc oxide ore processing.

[0004] When the sulfide xanthate method or mercaptan collector flotation method is used to treat zinc oxide ore, due to the poor natural floatability of smithsonite, the Zn exposed by the surface fracture 2+Active sites have very weak interactions with sulfhydryl collectors such as xanthates and mercaptans, making them difficult to adsorb on the surface of smithsonite or easily detaching after adsorption. Direct flotation of smithsonite with fatty acid collectors increases collector consumption and poor selectivity, as smithsonite shares a carbonate structure with gangue minerals such as calcite and dolomite, and the carboxyl groups in fatty acid collectors have strong calcium chelation. Zinc oxide ore is brittle and prone to overgrinding, resulting in sliming. While pre-desliming can improve flotation performance, it also results in significant zinc metal loss. Zinc oxide ore has a high soluble salt content, and various ions react with carbonate ions to form precipitates that coat the mineral surface, hindering flotation and making it difficult to separate and utilize. Due to these issues, in recent years, an increasing number of mineral processing professionals have begun exploring processes other than flotation for zinc oxide ore recovery, particularly the integration of hydrometallurgical smelting, gravity separation, and magnetic separation. When processing zinc oxide ores with relatively coarse particle size and high zinc oxide grade, gravity separation technology is used for tailings disposal. When processing zinc oxide ores with high iron content, a magnetic flotation combined process is used to separate iron by magnetic separation and recover zinc by flotation. When processing zinc oxide ores with relatively low grade, a flotation + wet leaching combined process is used to pre-enrich the zinc oxide ores by flotation, improve the grade of wet raw materials, reduce calcium and magnesium carbonate minerals, and reduce acid consumption. These combined processes have improved the recovery effect of zinc oxide ores to a certain extent and improved the beneficiation indicators of zinc oxide ores. However, they still cannot solve the key problems in the recovery of low-grade zinc oxide ores (ore containing zinc <2.5%), which are mainly manifested in high energy consumption, the inability to balance the enrichment ratio and recovery rate, and the high cost of processing tonnes of ore.

[0005] Therefore, developing a mineral processing technology with good separation effect, strong adaptability and low production cost will help to efficiently recover low-grade zinc oxide ore and realize the resource utilization of low-grade ore. Summary of the Invention

[0006] In view of the shortcomings of the existing technology, the present invention aims to provide a method for resource utilization of extremely low-grade zinc oxide ore.

[0007] In order to achieve the above object, the present invention adopts the following technical solutions:

[0008] A method for resource utilization of extremely low-grade zinc oxide ore comprises the following steps:

[0009] S1. Coarse grinding: Mix the crushed ore with water and grind it;

[0010] S2, zinc oxide strong magnetic separation roughing: the ground material obtained in step S1 is subjected to a multi-stage zinc oxide strong magnetic separation roughing operation, and the strong magnetic separation roughing tailings obtained in each stage of zinc oxide strong magnetic separation roughing operation are fed into the next stage of zinc oxide strong magnetic separation roughing operation, and the tailings obtained in the last stage of zinc oxide strong magnetic separation roughing operation are magnetic separation tailings;

[0011] S3, combining the high-intensity magnetic separation roughing concentrates obtained from the high-intensity magnetic separation roughing operations of zinc oxide at each level in step S2 and then finely grinding them;

[0012] S4, zinc oxide flotation roughing operation: Sodium carbonate as a conditioning agent, water glass, sodium sulfide as an activator, and dodecylamine as a collector are sequentially added to the finely ground product obtained in step S3, and then zinc oxide flotation roughing operation is performed. The resulting zinc oxide coarse concentrate enters the zinc oxide flotation cleaning operation I in step S7, and the resulting roughing tailings enter the zinc oxide flotation scavenging operation I in step S5;

[0013] S5, zinc oxide flotation scavenging operation 1: sodium carbonate as a regulator, water glass, sodium sulfide as an activator, and dodecylamine as a collector are sequentially added to the roughing tailings obtained in step S4, and then zinc oxide flotation scavenging operation 1 is performed. The resulting zinc oxide scavenging concentrate is returned to the zinc oxide flotation roughing operation, and the resulting scavenging tailings are fed into zinc oxide flotation scavenging operation 2 in step S6;

[0014] S6, zinc oxide flotation scavenging operation 2: sodium carbonate as a regulator, water glass, sodium sulfide as an activator, and dodecylamine as a collector are sequentially added to the scavenging tailings obtained in step S5, and then the zinc oxide flotation scavenging operation 2 is performed. The obtained zinc oxide scavenging concentrate is returned to the zinc oxide flotation scavenging operation 1, and the obtained scavenging tailings are the flotation tailings;

[0015] S7, zinc oxide flotation and concentration operation 1: adding sodium sulfide as an activator to the zinc oxide rougher concentrate obtained in step S4, and then performing zinc oxide flotation and concentration operation 1. The obtained zinc oxide flotation and concentration concentrate 1 enters zinc oxide flotation and concentration operation 2, and the obtained concentration tailings 1 are returned to the zinc oxide flotation and concentration operation 2.

[0016] S8, zinc oxide flotation and concentration second operation: add activating agent sodium sulfide to the zinc oxide flotation and concentration first concentrate obtained in step S7, and then carry out zinc oxide flotation and concentration second operation. The obtained zinc oxide concentration second concentrate is zinc oxide concentrate, and the obtained concentration second tailings are returned to the zinc oxide flotation and concentration first operation.

[0017] Furthermore, in step S1, the raw ore is crushed to less than 2 mm, and then mixed with water in a ratio of 2:1 and fed into a mill for grinding, and the ore is ground until the product fineness is -0.3 mm, accounting for 60%.

[0018] Furthermore, in step S2, the magnetic field strength of each level of zinc oxide strong magnetic roughing operation is 1.35-1.75T, and the pulsation frequency is adjusted to 0-10 times / minute.

[0019] Furthermore, in step S3, the high intensity magnetic separation roughing concentrates obtained from each level of zinc oxide high intensity magnetic separation roughing operation are combined and the pulp mass concentration is adjusted to 60%-65%, and the fineness of the finely ground product is -0.074mm and the content is 55%-60%.

[0020] Furthermore, in step S4, based on the dry weight of each ton of raw ore, the amount of sodium carbonate used is 1200g / t-1500g / t, the amount of water glass used is 1200g / t-1500g / t, the amount of sodium sulfide used is 2000-3000g / t, and the amount of dodecylamine used is 40g / t-60g / t.

[0021] Furthermore, in step S5, based on the dry weight of each ton of raw ore, the amount of sodium carbonate used is 500g / t-800g / t, the amount of water glass used is 500g / t-800g / t, the amount of sodium sulfide used is 500g / t-1000g / t, and the amount of dodecylamine used is 20g / t-30g / t.

[0022] Furthermore, in step S6, based on the dry weight of each ton of raw ore, the amount of sodium carbonate used is 100g / t-300g / t, the amount of water glass used is 100g / t-300g / t, the amount of sodium sulfide used is 200g / t-400g / t, and the amount of dodecylamine used is 10g / t-20g / t.

[0023] Furthermore, in steps S4, S5 and S6, the stirring time after adding sodium carbonate, water glass, sodium sulfide and dodecylamine is 2 minutes, 2 minutes, 1 minute and 2 minutes respectively.

[0024] Furthermore, in step S7, the amount of sodium sulfide used is 300 g / t-500 g / t per ton of dry weight of the ore, and the mixture is stirred for 1 minute after adding the sodium sulfide.

[0025] Furthermore, in step S8, the amount of sodium sulfide used is 100 g / t-200 g / t per ton of dry weight of the ore, and the mixture is stirred for 1 minute after adding the sodium sulfide.

[0026] The beneficial effects of the present invention are:

[0027] 1. The method of the present invention realizes the pre-discarding of coarse-grained tailings of low-grade zinc oxide minerals through coarse grinding-coarse-grained strong magnetic separation pre-enrichment. The tailings can be pre-discarded through the strong magnetic separation process, with high tailing yield, low zinc loss rate, good pre-enrichment effect, and greatly reduced amount of ore required for subsequent fine grinding and flotation quality improvement, thus significantly reducing grinding costs.

[0028] 2. The method of the present invention realizes the removal of primary ore slime and influencing ions during the magnetic separation pre-enrichment process through coarse grinding and coarse particle strong magnetic separation pre-enrichment, fully solving the influence of primary ore slime and influencing ions on the flotation process in a single flotation process, thereby improving the quality and recovery rate of zinc oxide concentrate.

[0029] 3. The method of the present invention uses coarse grinding and coarse-grained strong magnetic separation for pre-enrichment, with a tailing rate of 60%-70% and an enrichment ratio of 2%-3%. It can minimize the grade of zinc oxide ore entering the mine, realize the resource utilization of low-grade zinc oxide ore, improve the comprehensive utilization rate of resources, and extend the service life of the mine.

[0030] 4. The method of the present invention fully utilizes the respective characteristics and advantages of magnetic separation and flotation processes through a combined magnetic flotation process, exerts the synergistic effect of magnetic separation and flotation, and achieves the ultimate goal of magnetic separation pre-discarding tailings-flotation quality improvement; it exhibits the process advantages of low grinding cost, simple and stable process flow, and good product recovery effect.

[0031] In summary, the method of the present invention adopts a combined process of coarse grinding-coarse-grained strong magnetic separation pre-enrichment-fine grinding flotation quality improvement, and comprehensively recovers low-grade, high-mud zinc oxide. Compared with the process of recovering zinc oxide by flotation alone, the method significantly reduces the grinding cost, reduces the adverse effect of ore slime on zinc oxide flotation, and improves the recovery index of the mineral processing process. In addition, the coarse-grained strong magnetic separation pre-enrichment can reduce the industrial ore cutoff grade of mining enterprises, increase reserves, increase the mineable amount of ore, and improve the resource development and utilization rate. BRIEF DESCRIPTION OF THE DRAWINGS

[0032] Figure 1 This is a flow chart of the method of Examples 1-2 of the present invention.

[0033] In the picture:

[0034] K: zinc oxide concentrate; X1: magnetic separation tailings; X2: flotation tailings; a: raw ore; b: strong magnetic separation rougher concentrate 1; c: strong magnetic separation rougher concentrate 2; d: strong magnetic separation rougher concentrate 3; e: strong magnetic separation rougher concentrate 4; g: sodium carbonate; h: water glass; i: sodium sulfide; j: dodecylamine. DETAILED DESCRIPTION

[0035] The present invention will be further described below in conjunction with the accompanying drawings. It should be noted that this embodiment is based on the technical solution and provides a detailed implementation method and specific operation process, but the protection scope of the present invention is not limited to this embodiment.

[0036] Low-grade zinc oxide ore in a certain mining area is primarily composed of smithsonite, with a zinc oxidation rate exceeding 95%. Experimental comparisons were conducted using different ore samples from two ore bodies in this mining area. The original ore used in Example 1 contained 1.18% Zn, 0.12% Pb, and a zinc oxidation rate of 97.68%. The original ore used in Example 2 contained 2.07% Zn, 0.16% Pb, and a zinc oxidation rate of 96.36%.

[0037] Example 1

[0038] This embodiment provides a method for resource utilization of extremely low-grade zinc oxide ore, such as Figure 1 As shown, specifically:

[0039] The raw ore (a) crushed to less than 2 mm is mixed with water in a mass ratio of 2:1 and fed into a grinding mill for grinding until the product fineness is -0.3 mm, accounting for 60%.

[0040] The ground material was passed through a SLON-100 high-gradient high-intensity magnetic separator for zinc oxide high-intensity magnetic separation roughing operation 1. The magnetic field strength was 1.7 T, and the pulsation rate was adjusted to 10 times / minute. The material enriched in the magnetic medium box was high-intensity magnetic separation roughing concentrate 1 (b), and high-intensity magnetic separation roughing tailing 1 was fed into the zinc oxide high-intensity magnetic separation roughing operation 2. The magnetic field strength in the zinc oxide high-intensity magnetic separation roughing operation 2 was 1.7 T, and the pulsation rate was adjusted to 10 times / minute. The material enriched in the magnetic medium box was high-intensity magnetic separation roughing concentrate 2 (c), and high-intensity magnetic separation roughing tailing 2 was fed into the zinc oxide high-intensity magnetic separation roughing operation 3. The magnetic field strength in the zinc oxide high-intensity magnetic separation roughing operation 3 was 1.7 T, and the pulsation rate was adjusted to 10 times / minute. The material enriched in the magnetic medium box was high-intensity magnetic separation roughing concentrate 3 (d), and high-intensity magnetic separation roughing tailing 3 was fed into the zinc oxide high-intensity magnetic separation roughing operation 4. The magnetic field intensity of the zinc oxide strong magnetic roughing operation 4 is 1.7T, and the pulsation frequency is adjusted to 10 times / minute. The material enriched in the magnetic medium box is the strong magnetic roughing concentrate 4 (e), and the strong magnetic roughing tailings 4 are the magnetic tailings (X1).

[0041] The strong magnetic separation rougher concentrate 1, the strong magnetic separation rougher concentrate 2, the strong magnetic separation rougher concentrate 3 and the strong magnetic separation rougher concentrate 4 are combined, concentrated to a mass concentration of 60%, and added into a ball mill for fine grinding. The fineness of the grinding product is -0.074mm and the content is 55%.

[0042] The finely ground product is added to the hanging trough flotation machine. Sodium carbonate (g) is added in an amount of 1200g / t per ton of dry weight of the original ore. After stirring for 2 minutes, water glass (h) is added in an amount of 1200g / t. After stirring for 2 minutes, sodium sulfide (i) is added in an amount of 2000g / t. After stirring for 1 minute, collector dodecylamine (j) is added in an amount of 40g / t. After stirring for 2 minutes, zinc oxide flotation roughing operation is carried out. The zinc oxide coarse concentrate (foam product) enters the zinc oxide flotation cleaning operation 1, and the zinc oxide roughing tailings (in-tank product) enter the zinc oxide flotation scavenging operation 1.

[0043] Based on the dry weight of each ton of raw ore, sodium carbonate (g) is added to the zinc oxide roughing tailings tank in an amount of 500g / t. After stirring for 2 minutes, water glass (h) is added in an amount of 500g / t. After stirring for 2 minutes, sodium sulfide (i) is added in an amount of 500g / t. After stirring for 1 minute, collector dodecylamine (j) is added in an amount of 20g / t. After stirring for 2 minutes, the zinc oxide flotation scavenging operation is carried out. The zinc oxide scavenging concentrate (foam product) of the first scavenging process is returned to the zinc oxide flotation roughing process, and the scavenging tailings (product in the tank) enter the zinc oxide flotation scavenging operation II.

[0044] Based on the dry weight of each ton of raw ore, sodium carbonate (g) is added to the zinc oxide scavenging tailings tank in an amount of 100g / t, and after stirring for 2 minutes, water glass (h) is added in an amount of 100g / t, and after stirring for 2 minutes, sodium sulfide (i) is added in an amount of 200g / t, and after stirring for 1 minute, collector dodecylamine (j) is added in an amount of 10g / t, and after stirring for 2 minutes, the zinc oxide flotation scavenging operation is carried out. The zinc oxide scavenging concentrate (foam product) of the second scavenging is returned to the zinc oxide flotation scavenging operation of the first scavenging. The scavenging tailings of the second scavenging (product in the tank) are the flotation tailings (X2).

[0045] The zinc oxide rougher concentrate is added to the flotation cell, and sodium sulfide (i) is added at a rate of 300 g / t per ton of dry weight of the raw ore. After stirring for 1 minute, the zinc oxide flotation cleaning process (I) is carried out. The zinc oxide flotation cleaning process (I concentrate) (foam product) enters the zinc oxide flotation cleaning process (II concentrate), and the tailings (in-tank product) of the first concentrate are returned to the zinc oxide flotation rougher process. The zinc oxide flotation cleaning process (I concentrate) is added to the flotation cell, and sodium sulfide (i) is added at a rate of 100 g / t. After stirring for 1 minute, the zinc oxide flotation cleaning process (II concentrate) is carried out. The zinc oxide concentrate (foam product) is zinc oxide concentrate (K), and the tailings (in-tank product) of the second concentrate are returned to the zinc oxide flotation cleaning process (I concentrate).

[0046] Example 2

[0047] This embodiment provides a method for resource utilization of extremely low-grade zinc oxide ore, such as Figure 1 As shown, specifically:

[0048] The raw ore (a) crushed to less than 2 mm is mixed with water in a mass ratio of 2:1 and fed into the mill for grinding until the product fineness is -0.3 mm, accounting for 60%.

[0049] The ground material was passed through a SLON-100 high-gradient high-intensity magnetic separator for zinc oxide high-intensity magnetic separation roughing operation 1. The magnetic field strength was 1.7 T, and the pulsation rate was adjusted to 10 times / minute. The material enriched in the magnetic medium box was high-intensity magnetic separation roughing concentrate 1 (b), and high-intensity magnetic separation roughing tailing 1 was fed into the zinc oxide high-intensity magnetic separation roughing operation 2. The magnetic field strength in the zinc oxide high-intensity magnetic separation roughing operation 2 was 1.7 T, and the pulsation rate was adjusted to 10 times / minute. The material enriched in the magnetic medium box was high-intensity magnetic separation roughing concentrate 2 (c), and high-intensity magnetic separation roughing tailing 2 was fed into the zinc oxide high-intensity magnetic separation roughing operation 3. The magnetic field strength in the zinc oxide high-intensity magnetic separation roughing operation 3 was 1.7 T, and the pulsation rate was adjusted to 10 times / minute. The material enriched in the magnetic medium box was high-intensity magnetic separation roughing concentrate 3 (d), and high-intensity magnetic separation roughing tailing 3 was fed into the zinc oxide high-intensity magnetic separation roughing operation 4. The magnetic field intensity of the zinc oxide strong magnetic roughing operation 4 is 1.7T, and the pulsation frequency is adjusted to 10 times / minute. The material enriched in the magnetic medium box is the strong magnetic roughing concentrate 4 (e), and the strong magnetic roughing tailings 4 are the magnetic tailings (X1).

[0050] The strong magnetic separation rougher concentrate 1, the strong magnetic separation rougher concentrate 2, the strong magnetic separation rougher concentrate 3 and the strong magnetic separation rougher concentrate 4 are combined, concentrated to a mass concentration of 60%, and added into a ball mill for fine grinding. The fineness of the grinding product is -0.074mm and the content is 60%.

[0051] The finely ground product is added to the hanging trough flotation machine. Sodium carbonate (g) is added in an amount of 1500g / t per ton of dry weight of the raw ore. After stirring for 2 minutes, water glass (h) is added in an amount of 1500g / t. After stirring for 2 minutes, sodium sulfide (i) is added in an amount of 3000g / t. After stirring for 1 minute, collector dodecylamine (j) is added in an amount of 60g / t. After stirring for 2 minutes, zinc oxide flotation roughing operation is carried out. The zinc oxide coarse concentrate (foam product) enters the zinc oxide flotation cleaning operation I, and the roughing tailings (in-tank product) enter the zinc oxide flotation scavenging operation I.

[0052] Based on the dry weight of each ton of raw ore, sodium carbonate (g) is added to the zinc oxide roughing tailings tank in an amount of 800g / t. After stirring for 2 minutes, water glass (h) is added in an amount of 800g / t. After stirring for 2 minutes, sodium sulfide (i) is added in an amount of 1000g / t. After stirring for 1 minute, collector dodecylamine (j) is added in an amount of 30g / t. After stirring for 2 minutes, the zinc oxide flotation scavenging operation is carried out. The zinc oxide scavenging concentrate (foam product) is returned to the zinc oxide roughing operation, and the scavenging tailings (product in the tank) enter the zinc oxide flotation scavenging operation II.

[0053] Based on the dry weight of each ton of raw ore, sodium carbonate (g) is added to the zinc oxide scavenging tailings tank in an amount of 300g / t. After stirring for 2 minutes, water glass (h) is added in an amount of 300g / t. After stirring for 2 minutes, sodium sulfide (i) is added in an amount of 400g / t. After stirring for 1 minute, collector dodecylamine (j) is added in an amount of 20g / t. After stirring for 2 minutes, the zinc oxide flotation scavenging operation is carried out. The zinc oxide scavenging concentrate (foam product) is returned to the zinc oxide scavenging operation in the first step. The scavenging tailings (product in the tank) are the flotation tailings (X2).

[0054] The zinc oxide rougher concentrate is added to the flotation cell, and sodium sulfide (i) is added at a rate of 500 g / t per ton of dry weight of the raw ore. After stirring for 1 minute, the zinc oxide flotation cleaning process (I) is carried out. The zinc oxide flotation cleaning process (I concentrate) (foam product) enters the zinc oxide flotation cleaning process (II concentrate), and the flotation cleaning process (I tailings) (in-tank product) is returned to the zinc oxide flotation rougher process. The zinc oxide flotation cleaning process (I concentrate) is added to the flotation cell, and sodium sulfide (i) is added at a rate of 200 g / t. After stirring for 1 minute, the zinc oxide flotation cleaning process (II concentrate) is carried out. The zinc oxide flotation cleaning process (II concentrate) (foam product) is zinc oxide concentrate (K), and the flotation cleaning process (II tailings) (in-tank product) is returned to the zinc oxide flotation cleaning process (I concentrate).

[0055] The specific process indicators of the above-mentioned embodiment 1 and embodiment 2 are shown in Table 1.

[0056] Table 1

[0057]

[0058] As can be seen from Table 1, the raw ore of Example 1 contained 1.18% Zn, the zinc oxidation rate was 97.68%, the zinc oxide concentrate obtained contained 28.18% Zn, and the zinc recovery rate was 81.28%. The coarse magnetic separation pre-discarding tailing rate was 60.46%, and the coarse magnetic separation pre-discarding tailing zinc loss rate was 15.95%. The raw ore of Example 2 contained 2.07% Zn, the zinc oxidation rate was 96.36%, the zinc concentrate obtained contained 29.79% Zn, and the zinc recovery rate was 84.16%. The coarse magnetic separation pre-discarding tailing rate was 61.87%, and the coarse magnetic separation pre-discarding tailing zinc loss rate was 12.87%.

[0059] Those skilled in the art can make various corresponding changes and modifications based on the above technical solutions and concepts, and all of these changes and modifications should be included in the scope of protection of the claims of the present invention.

Claims

1. A method for resource utilization of extremely low-grade zinc oxide ore, characterized in that: The steps include: S1. Coarse grinding: The crushed ore is mixed with water and then ground. The ore is crushed to less than 2mm, then mixed with water in a mass ratio of 2:1 and fed into the mill for grinding. The ore is ground to a fineness of -0.3mm, accounting for 60%; S2, zinc oxide strong magnetic separation roughing: the ground material obtained in step S1 is subjected to a multi-stage zinc oxide strong magnetic separation roughing operation, and the strong magnetic separation roughing tailings obtained in each stage of zinc oxide strong magnetic separation roughing operation are fed into the next stage of zinc oxide strong magnetic separation roughing operation, and the tailings obtained in the last stage of zinc oxide strong magnetic separation roughing operation are magnetic separation tailings; S3, combining the high-intensity magnetic separation roughing concentrates obtained from the high-intensity magnetic separation roughing operations of zinc oxide at each level in step S2 and then finely grinding them; S4, zinc oxide flotation roughing operation: Sodium carbonate as a conditioning agent, water glass, sodium sulfide as an activator, and dodecylamine as a collector are sequentially added to the finely ground product obtained in step S3, and then zinc oxide flotation roughing operation is performed. The resulting zinc oxide coarse concentrate enters the zinc oxide flotation cleaning operation I in step S7, and the resulting roughing tailings enter the zinc oxide flotation scavenging operation I in step S5; S5, zinc oxide flotation scavenging operation 1: sodium carbonate as a regulator, water glass, sodium sulfide as an activator, and dodecylamine as a collector are sequentially added to the roughing tailings obtained in step S4, and then zinc oxide flotation scavenging operation 1 is performed. The resulting zinc oxide scavenging concentrate is returned to the zinc oxide flotation roughing operation, and the resulting scavenging tailings are fed into zinc oxide flotation scavenging operation 2 in step S6; S6, zinc oxide flotation scavenging operation 2: sodium carbonate as a regulator, water glass, sodium sulfide as an activator, and dodecylamine as a collector are sequentially added to the scavenging tailings obtained in step S5, and then the zinc oxide flotation scavenging operation 2 is performed. The obtained zinc oxide scavenging concentrate is returned to the zinc oxide flotation scavenging operation 1, and the obtained scavenging tailings are the flotation tailings; S7, zinc oxide flotation and concentration operation 1: adding sodium sulfide as an activator to the zinc oxide rougher concentrate obtained in step S4, and then performing zinc oxide flotation and concentration operation 1. The obtained zinc oxide flotation and concentration concentrate 1 enters zinc oxide flotation and concentration operation 2, and the obtained concentration tailings 1 are returned to the zinc oxide flotation and concentration operation 2. S8, zinc oxide flotation and concentration second operation: add activating agent sodium sulfide to the zinc oxide flotation and concentration first concentrate obtained in step S7, and then carry out zinc oxide flotation and concentration second operation. The obtained zinc oxide concentration second concentrate is zinc oxide concentrate, and the obtained concentration second tailings are returned to the zinc oxide flotation and concentration first operation.

2. The method according to claim 1, characterized in that In step S2, the magnetic field strength of each level of zinc oxide strong magnetic roughing operation is 1.35-1.75T, and the pulsation frequency is adjusted to 10 times / minute.

3. The method according to claim 1, characterized in that In step S3, the high-intensity magnetic separation roughing concentrates obtained from the various levels of zinc oxide high-intensity magnetic separation roughing operations are combined and the pulp mass concentration is adjusted to 60%-65%, and the fineness of the finely ground product is -0.074mm and the content accounts for 55%-60%.

4. The method according to claim 1, wherein In step S4, based on the dry weight of each ton of raw ore, the amount of sodium carbonate used is 1200g / t-1500g / t, the amount of water glass used is 1200g / t-1500g / t, the amount of sodium sulfide used is 2000-3000g / t, and the amount of dodecylamine used is 40g / t-60g / t.

5. The method according to claim 1, wherein In step S5, based on the dry weight of each ton of raw ore, the amount of sodium carbonate used is 500g / t-800g / t, the amount of water glass used is 500g / t-800g / t, the amount of sodium sulfide used is 500g / t-1000g / t, and the amount of dodecylamine used is 20g / t-30g / t.

6. The method according to claim 1, characterized in that In step S6, based on the dry weight of each ton of raw ore, the amount of sodium carbonate used is 100g / t-300g / t, the amount of water glass used is 100g / t-300g / t, the amount of sodium sulfide used is 200g / t-400g / t, and the amount of dodecylamine used is 10g / t-20g / t.

7. The method according to any one of claims 1, 4-6, characterized in that: In steps S4, S5 and S6, the stirring time after adding sodium carbonate, water glass, sodium sulfide and dodecylamine is 2 minutes, 2 minutes, 1 minute and 2 minutes, respectively.

8. The method according to claim 1, characterized in that In step S7, the amount of sodium sulfide used is 300 g / t-500 g / t per ton of dry weight of the ore, and the mixture is stirred for 1 minute after adding the sodium sulfide.

9. The method according to claim 1, characterized in that In step S8, the amount of sodium sulfide used is 100 g / t-200 g / t per ton of dry weight of the ore, and the mixture is stirred for 1 minute after adding the sodium sulfide.

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