A material preparation method and system for recovering complex zinc oxide ore by flotation method

Abstract

The present invention relates to a preparation method and system for recovering complex zinc oxide ores by flotation. The preparation method involves selective crushing, wet screening, primary slurry mixing and grading, selective grinding, and secondary slurry mixing and grading of the material to be processed, ultimately obtaining a qualified product for the flotation process. The present invention uses a high-pressure roller mill and a vibrating screen combination to replace the traditional three-stage crushing process, selectively crushing and grinding the zinc oxide ore, and then using an improved hydrocyclone to separate more than 50% of the minerals that meet the flotation requirements and directly enter the flotation system. Compared with the traditional sulfide ore flotation preparation process, the present invention not only saves three stages of crushing, but also avoids or reduces the over-grinding of these primary fine-grained minerals and micro-fine ore slimes when they enter the ball mill, reduces the generation of colloidal particles and soluble inevitable ions, and improves the efficiency and benefits of zinc oxide flotation.

Description

Technical Field

[0001] The present invention belongs to the technical field of mineral processing, and in particular relates to a material preparation method and system for recovering complex zinc oxide ore by flotation method. Background Art

[0002] With the rapid development of science and technology, the demand for zinc metal has been growing year by year. However, after years of mining, easily processed zinc sulfide ores have become increasingly scarce, and their grade has gradually declined. People have begun to pay attention to the utilization of low-grade zinc oxide ores. These zinc oxide ores, mostly with a zinc grade below 15%, mainly exist as smithsonite and hemimorphite. Due to their low grade, high impurities, high oxidation rate, large mud content, and poor, fine, and mixed characteristics, coupled with the lack of effective processing technology, they have not been properly utilized, resulting in a large amount of these mineral resources becoming hazardous waste, causing economic losses and environmental problems.

[0003] The comprehensive recovery and utilization of slag resources has long garnered significant attention and dedication from industry professionals. While some progress has been achieved, many areas remain unsatisfactory. Among various treatment methods, flotation is the most effective. Flotation utilizes differences in the physical and chemical properties of mineral surfaces to separate ores. The process primarily consists of material preparation and flotation. Material preparation primarily involves material crushing (coarse, medium, and fine), grinding, and slurry conditioning. As the front-end process of flotation, its ability to provide a slurry with the appropriate particle size, concentration, and minimal impurities directly impacts flotation efficiency and profitability.

[0004] At present, the zinc oxide flotation preparation process still uses the traditional sulfide ore flotation preparation process, such as Figure 3 Figure 4As shown, the ore is first coarsely crushed by a jaw crusher 10, and then the ore is medium-crushed and finely crushed by a 1# cone crusher 11 and a 2# cone crusher 12, respectively, to a size of -15mm or -10mm. The ore is then ground by a ball mill 6, and finally classified by a 3# hydrocyclone 14, thereby providing a pulp with the required particle size and concentration for flotation. After long-term experimental research, the industry believes that the content of fine particles, colloidal clayey ore and soluble inevitable metal ions in long-term weathered ores is relatively high. However, during the treatment process of this method, the minerals are easily over-grinded, resulting in a large amount of fine particles, colloidal clayey ore and soluble inevitable metal ions. The dissociation degree of zinc oxide mineral monomers is also low, which will seriously affect the subsequent zinc oxide flotation separation, resulting in poor flotation indicators (such as recovery rate and grade), and it is difficult to obtain ideal flotation technical and economic indicators; at the same time, the energy consumption and wear steel consumption of grinding using this method are high, the flotation agent consumption is large, and the production cost is high; in addition, due to the high water content of this type of ore, the traditional preparation process is used, and the preparation equipment is seriously blocked during the rainy season, making it difficult to carry out normal production; furthermore, the storage of waste slag and the discharge of mineral processing wastewater also pose safety and environmental risks to mining companies, which is difficult for the industry to accept.

[0005] Based on the above problems, the present invention proposes a material preparation process specifically for zinc oxide ore flotation to overcome the defects and problems of the existing sulfide ore flotation preparation process, improve the suitability of the ore pulp in the material preparation process, and improve the flotation efficiency and benefits. Summary of the Invention

[0006] In view of the above problems, the present invention provides a material preparation method and system for recovering complex zinc oxide ore by flotation.

[0007] The specific technical solution is:

[0008] A preparation method for recovering complex zinc oxide ore by flotation method comprises the following steps:

[0009] (1) Selective crushing of the material to be processed: The zinc oxide mineral material to be processed with a particle size of -250 mm is transported to the high pressure roller mill for crushing to obtain the desired product A;

[0010] (2) Wet screening: The product A obtained in step (1) is conveyed to a vibrating screen and subjected to strong dispersion and vibration screening using high-pressure water to obtain a +3 mm oversize product B and a -3 mm undersize product C. The oversize product B is returned to the high-pressure roller mill for cyclic crushing, and the undersize product C is conveyed to the 1# slurry pool;

[0011] (3) Primary slurry mixing and classification: Sodium carbonate is added to the No. 1 slurry pool and mixed with the undersize product C obtained in step (2) to mix the slurry. After the slurry mixing is completed, the slurry is transported to the No. 1 hydrocyclone through the No. 1 slurry pump for low-concentration classification. The classification obtains the -3mm to 0.074mm grit product D and the -0.074mm overflow product E;

[0012] (4) Selective grinding and secondary slurry adjustment and classification: The grit product D obtained in step (3) is transported to a ball mill, and sodium carbonate is added to the ball mill for grinding. After the ball milling is completed, it is transported to the No. 2 slurry pool for slurry adjustment. After the slurry adjustment is completed, it is transported to the No. 2 hydrocyclone through the No. 2 slurry pump for low-concentration classification to obtain a +0.074 mm grit product F and a -0.074 mm overflow product G. The grit product F is returned to the ball mill for re-grinding;

[0013] (5) The prepared products enter the flotation system: the -0.074 mm overflow product E and the -0.074 mm overflow product G obtained in step (3) and step (4) are transported to the flotation system equipment.

[0014] Furthermore, the amount of sodium carbonate added in step (3) is 2 kg per ton of dry ore.

[0015] Furthermore, the classification concentration of the 1# hydrocyclone in step (3) is 40% to 45%.

[0016] Furthermore, the amount of sodium carbonate added in step (4) is 1 kg of sodium carbonate per ton of dry ore.

[0017] Furthermore, the grinding concentration of the ball mill in step (4) is 50% to 55%.

[0018] Furthermore, the classification concentration of the 2# hydrocyclone in step (4) is 35% to 40%.

[0019] The present invention also provides a material preparation system for recovering complex zinc oxide ore by flotation method, comprising a high-pressure roller mill, wherein the discharge port of the high-pressure roller mill is connected to a No. 1 vibrating screen, the discharge port of the No. 1 vibrating screen is connected to the feed port of a No. 1 slurry pool, the discharge port of the No. 1 slurry pool is connected to the feed port of a No. 1 hydrocyclone via a No. 1 slurry pump, the grit outlet of the No. 1 hydrocyclone is connected to the feed end of a ball mill, the discharge end of the ball mill is connected to the feed port of a No. 2 slurry pool, the discharge port of the No. 2 slurry pool is connected to the feed port of the No. 2 hydrocyclone via a No. 2 slurry pump, the grit outlet of the No. 2 hydrocyclone is connected to the feed end of the ball mill, and the overflow port of the No. 1 hydrocyclone and the overflow port of the No. 2 hydrocyclone are connected to flotation system equipment.

[0020] Furthermore, the diameter of the 1# hydrocyclone is 500 mm, and the diameter of the sand settling port is 110 mm to 130 mm.

[0021] Furthermore, the diameter of the 2# hydrocyclone is 350 mm.

[0022] Beneficial effects of the present invention:

[0023] (1) The present invention adopts a combination of high-pressure roller mill and vibrating screen to replace the traditional three-stage crushing, selectively crushes the zinc oxide ore, and then uses an improved hydrocyclone to separate more than 50% of the minerals that meet the flotation requirements and directly enter the flotation system. Compared with the traditional sulfide ore flotation preparation process, it not only saves three-stage crushing, but also avoids or reduces the over-grinding of these original fine-grained minerals and fine-grained ore mud (including gangue minerals and useful minerals) when entering the ball mill, reduces the generation of colloidal particles and soluble inevitable ions, and improves the efficiency and benefit of zinc oxide flotation.

[0024] (2) The present invention adopts high-pressure roller mill for selective crushing, which improves the dissociation degree of zinc oxide ore monomers and increases its effective target points for adsorption and capture, providing good conditions for subsequent zinc oxide ore flotation, and can greatly improve the flotation recovery rate and grade of zinc oxide ore.

[0025] (3) The present invention adopts a small amount of sodium carbonate in stages, which effectively avoids the dissolution of calcium, magnesium, zinc, ferrous iron, and other ions through the common ion effect, reduces the non-selective flocculation and surface adsorption pollution caused by them, ensures the mineral surface is clean and fully dispersed, and is conducive to improving the subsequent flotation efficiency.

[0026] (4) The present invention improves the upper limit of water content in crushing feed, and the volumetric water content can reach 20% to 25%, thus avoiding the management and technical problems of abnormal production in the rainy season due to high water content.

[0027] (5) The material preparation method of the present invention can provide mineral materials that are more suitable for the flotation process, promote the flotation recovery rate and grade improvement, and is more conducive to the comprehensive and efficient recycling of resources, reducing resource waste and safety and environmental risks. It has good economic and social benefits and has a wide range of industrial and commercial application and promotion value. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] Figure 1 This is a flow chart of a material preparation method and system for recovering complex zinc oxide ore by flotation method of the present invention;

[0029] Figure 2 This is a diagram showing the equipment association of a material preparation method and system for recovering complex zinc oxide ores by flotation method according to the present invention;

[0030] Figure 3 This is a flow chart of the existing zinc oxide ore preparation method;

[0031] Figure 4 This is the equipment association diagram of the existing zinc oxide ore preparation system;

[0032] In the figure: 1-high pressure roller grinding mill, 2-1# vibrating screen, 3-1# slurry tank, 4-1# slurry pump, 5-1# hydrocyclone, 6-ball mill, 7-2# slurry tank, 8-2# slurry pump, 9-2# hydrocyclone, 10-jaw crusher, 11-1# cone crusher, 12-2# cone crusher, 13-2# vibrating screen, 14-3# hydrocyclone. DETAILED DESCRIPTION

[0033] In order to make the technical problems and technical solutions solved by the present invention more clearly understood, the present invention is further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not intended to limit the present invention. Example 1

[0034] like Figure 1 As shown, this embodiment provides a preparation method for recovering complex zinc oxide ore by flotation, comprising the following steps:

[0035] (1) Selective crushing of the material to be processed: The zinc oxide mineral material to be processed with a particle size of -250 mm is transported to the high pressure roller mill for crushing to obtain the desired product A;

[0036] (2) Wet screening: The product A obtained in step (1) is conveyed to a vibrating screen and subjected to strong dispersion and vibration screening using high-pressure water to obtain a +3 mm oversize product B and a -3 mm undersize product C. The oversize product B is returned to the high-pressure roller mill for cyclic crushing, and the undersize product C is conveyed to the 1# slurry pool;

[0037] (3) Primary slurry adjustment and classification: Sodium carbonate (2 kg of sodium carbonate per ton of dry ore) is added to the No. 1 slurry pool and mixed with the undersize product C obtained in step (2) for slurry adjustment. After the slurry adjustment is completed, the slurry is transported to the No. 1 hydrocyclone through the No. 1 slurry pump for low-concentration classification. The classification concentration is controlled at 40% to 45%. The classification obtains -3 mm to 0.074 mm sand product D and -0.074 mm overflow product E, of which the separated -0.074 mm overflow product E can reach a proportion of 70% to 75%;

[0038] (4) Selective grinding and secondary slurry adjustment and classification: The grit product D obtained in step (3) is transported to a ball mill, and sodium carbonate is added to the ball mill (1 kg of sodium carbonate is added for each ton of dry ore) and then ground. The grinding concentration is controlled at 50% to 55%. After ball milling, it is transported to the 2# slurry pool for slurry adjustment. After slurry adjustment, it is transported to the 2# hydrocyclone through the 2# slurry pump for low-concentration classification. The classification concentration is controlled at 35% to 40%, and a +0.074 mm grit product F and a -0.074 mm overflow product G are obtained. The grit product F is returned to the ball mill for regrinding, and the separated -0.074 mm overflow product G can reach a proportion of 80% to 85%.

[0039] (5) The prepared products enter the flotation system: the -0.074 mm overflow product E and the -0.074 mm overflow product G obtained in step (3) and step (4) are transported to the flotation system equipment.

[0040] Experimental Example 1.1

[0041] Three groups of zinc oxide ores of different grades were subjected to comparative preparation tests using the preparation method of the present invention (i.e., the method described in Example 1) and a conventional sulfide ore flotation preparation method. Flotation comparative tests were also conducted using the same flotation process and reagent dosage. The specific test data are shown in Table 1.

[0042] Table 1: Comparative test data of material preparation and flotation

[0043]

[0044] The data in Table 1 demonstrates that, compared to conventional sulfide ore flotation preparation methods, the flotation feed products obtained using the present invention's preparation method for zinc oxide ores of varying grades exhibit significantly lower ore slime content and soluble unavoidable ion content, significantly improving the degree of dissociation of zinc oxide monomers, and creating improved flotation conditions for zinc oxide flotation. Comparative flotation test data further demonstrate that, under identical flotation process and reagent dosage conditions, the flotation performance (including grade and recovery) of the products obtained using the present invention's preparation method significantly outperforms that of products obtained using conventional preparation methods. Furthermore, the flotation performance of products of varying grades is similar, demonstrating the method's ability to maintain stable flotation performance and achieve zinc recovery rates exceeding 80% for even low-grade zinc oxide ores. This demonstrates the present invention's stable and adaptable process, demonstrating its practical significance for the comprehensive recovery and utilization of low-grade zinc oxide waste resources and its potential for widespread industrial and commercial application.

[0045] This embodiment provides a preparation system for recovering complex zinc oxide ores by flotation. The system utilizes a high-pressure grinding roller 1 in combination with a first-stage vibrating screen 2 to replace the three-stage crushing in conventional sulfide ore flotation preparation systems. The system selectively crushes the raw zinc oxide ore, and then uses an improved first-stage hydrocyclone 5 to separate more than 50% of the minerals that meet flotation requirements and directly feed them into the flotation system. Compared to conventional sulfide ore flotation preparation systems, this system not only eliminates the need for three stages of crushing but also avoids or reduces the over-grinding of these primary fine-grained minerals and micro-grained slime (including gangue minerals and useful minerals) that would otherwise enter the ball mill 6. This system also reduces the generation of colloidal particles and soluble unavoidable ions, thereby improving the efficiency and benefits of zinc oxide flotation.

[0046] The material preparation system includes a high-pressure roller mill 1, the discharge port of the high-pressure roller mill 1 is connected to the 1# vibrating screen 2, the discharge port of the 1# vibrating screen 2 is connected to the feed port of the 1# ore pulp pool 3, the discharge port of the 1# ore pulp pool 3 is connected to the feed port of the 1# hydrocyclone 5 through the 1# ore pulp pump 4, the grit port of the 1# hydrocyclone 5 is connected to the feed end of the ball mill 6, the discharge end of the ball mill 6 is connected to the feed port of the 2# ore pulp pool 7, the discharge port of the 2# ore pulp pool 6 is connected to the feed port of the 2# hydrocyclone 9 through the 2# ore pulp pump 8, the grit port of the 2# hydrocyclone 9 is connected to the feed end of the ball mill 6, and the overflow port of the 1# hydrocyclone 5 and the overflow port of the 2# hydrocyclone 9 are connected to the flotation system equipment. Among them, the diameter of the 1# hydrocyclone is 500mm, and the diameter of the sand settling port is 110mm~130mm; the diameter of the 2# hydrocyclone is 350mm; a high-pressure water pipe can also be set on the upper part of the screen surface of the 1# vibrating screen 2 to facilitate the 1# vibrating screen to screen out fine-grained minerals.

[0047] Working principle: The zinc oxide mineral material with a particle size of -250mm to be processed is transported to the high-pressure roller mill 1 for crushing to obtain the required product A; the product A is transported to the 1# vibrating screen 2, and is strongly dispersed by high-pressure water for 1# vibration screening to obtain +3mm oversize product B and -3mm undersize product C. The oversize product B is returned to the high-pressure roller mill 1 for cyclic crushing, and the undersize product C is transported to the 1# pulp pool 4; sodium carbonate is added to the 1# pulp pool 4 and mixed with the undersize product C to prepare the slurry. After the slurry preparation is completed, the slurry is transported to the 1# hydrocyclone 5 through the 1# pulp pump 4 for low-concentration classification, and the classification obtains - 3mm~0.074mm grit product D and -0.074mm overflow product E; the grit product D is transported to the ball mill 6, and sodium carbonate is added to the ball mill 6 for grinding. After the ball milling is completed, it is transported to the 2# slurry pool 7 for slurry adjustment. After the slurry adjustment is completed, it is transported to the 2# hydrocyclone 9 through the 2# slurry pump 8 for low-concentration classification to obtain +0.074mm grit product F and -0.074mm overflow product G. The grit product F is returned to the ball mill 6 for regrinding, and the obtained -0.074mm overflow product E and -0.074mm overflow product G are transported to the flotation system equipment to enter the flotation process.

[0048] The present invention is described in detail above through specific and preferred embodiments, but those skilled in the art should understand that the present invention is not limited to the embodiments described above. Any modifications, equivalent substitutions, etc. made within the spirit and principles of the present invention should be included in the scope of protection of the present invention.

Claims

1. A preparation method for recovering complex zinc oxide ore by flotation, characterized in that: The steps include: (1) Selective crushing of the material to be processed: The zinc oxide mineral material to be processed with a particle size of -250 mm is transported to the high pressure roller mill for crushing to obtain the desired product A; (2) Wet screening: The product A obtained in step (1) is conveyed to a vibrating screen and subjected to strong dispersion and vibration screening using high-pressure water to obtain a +3 mm oversize product B and a -3 mm undersize product C. The oversize product B is returned to the high-pressure roller mill for cyclic crushing, and the undersize product C is conveyed to the 1# slurry pool; (3) Primary slurry mixing and classification: Sodium carbonate is added to the No. 1 slurry pool and mixed with the undersize product C obtained in step (2) to mix and mix. After the slurry mixing is completed, the slurry is transported to the No. 1 hydrocyclone through the No. 1 slurry pump for low-concentration classification. The classification concentration of the No. 1 hydrocyclone is 40% to 45%. The classification obtains the -3mm to 0.074mm grit product D and the -0.074mm overflow product E; (4) Selective grinding and secondary slurry adjustment and classification: The grit product D obtained in step (3) is transported to a ball mill, and sodium carbonate is added to the ball mill for grinding. The grinding concentration of the ball mill is 50% to 55%. After the ball milling is completed, it is transported to the 2# slurry pool for slurry adjustment. After the slurry adjustment is completed, it is transported to the 2# hydrocyclone through the 2# slurry pump for low-concentration classification. The classification concentration of the 2# hydrocyclone is 35% to 40%, and a grit product F with a diameter of +0.074 mm and an overflow product G with a diameter of -0.074 mm are obtained. The grit product F is returned to the ball mill for re-grinding. (5) The prepared products enter the flotation system: the -0.074 mm overflow product E and the -0.074 mm overflow product G obtained in step (3) and step (4) are transported to the flotation system equipment.

2. The method for preparing a complex zinc oxide ore for recovery by flotation according to claim 1, characterized in that: The amount of sodium carbonate added in step (3) is 2 kg per ton of dry ore.

3. The method for preparing a material for recovering complex zinc oxide ore by flotation according to claim 1, characterized in that: The amount of sodium carbonate added in step (4) is 1 kg per ton of dry ore.

4. The method for preparing a material for recovering complex zinc oxide ore by flotation according to claim 1, characterized in that: The method completes the processing through a material preparation system, which includes a high-pressure roller mill, a discharge port of the high-pressure roller mill is connected to a No. 1 vibrating screen, the discharge port of the vibrating screen is connected to a feed port of a No. 1 ore pulp pool, the discharge port of the No. 1 ore pulp pool is connected to a feed port of a No. 1 hydrocyclone via a No. 1 ore pulp pump, a grit port of the No. 1 hydrocyclone is connected to a feed end of a ball mill, the discharge end of the ball mill is connected to a feed port of a No. 2 ore pulp pool, the discharge port of the No. 2 ore pulp pool is connected to a feed port of a No. 2 hydrocyclone via a No. 2 ore pulp pump, the grit port of the No. 2 hydrocyclone is connected to a feed end of the ball mill, and the overflow port of the No. 1 hydrocyclone and the overflow port of the No. 2 hydrocyclone are connected to flotation system equipment.

5. The method for preparing a material for recovering complex zinc oxide ore by flotation according to claim 4, characterized in that: The diameter of the 1# hydrocyclone is 500mm, and the diameter of the sand settling port is 110mm-130mm.

6. The method for preparing a material for recovering complex zinc oxide ore by flotation according to claim 4, characterized in that: The diameter of the 2# hydrocyclone is 350 mm.

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