A method for leaching zinc phases in zinc ore

Abstract

The present invention discloses a method for leaching zinc phase in zinc ore, which adopts hydrochloric acid-stannous chloride solution to selectively dissolve the smithsonite phase. Stannous chloride can effectively inhibit the Fe 3+ The hydrochloric acid system avoids dissolving hemimorphite in the oxidation of sphalerite, ensuring the accuracy of the zinc content determination results in the smithsonite phase; a hydrogen peroxide solution is used to selectively dissolve sphalerite, avoiding the use of saturated bromine water as a leaching agent, making it more environmentally friendly, significantly shortening the subsequent leachate treatment time, improving detection efficiency, reducing the workload of detection personnel, and facilitating industrial on-site application; it is proposed that the zinc oxidation rate in zinc ore be calculated by dividing the sum of the zinc content in smithsonite and hemimorphite by the total amount of zinc in each phase of smithsonite, sphalerite and hemimorphite, rather than dividing by the total zinc content in the sample. Calculating the oxidation rate in this way can effectively eliminate the influence of systematic errors caused by the instruments and environment during the phase separation process.

Description

Technical Field

[0001] The invention relates to the technical field of hydrometallurgy, and in particular to a method for leaching zinc in zinc ore through phase diagnosis. Background Art

[0002] During zinc ore mining, different recovery processes are selected based on the type and occurrence characteristics of the zinc minerals, such as flotation, combined flotation-wet recovery, and direct wet leaching. Regardless of the recovery process employed, it is crucial to identify the zinc mineral types and the proportions of the various zinc mineral phases in the ore to guide the control of zinc recovery rates at the concentrator and to identify the cause of the high tailings grade.

[0003] Chemical selective diagnostic leaching is the most commonly used method in industry for analyzing the zinc content of various phases in ores. Currently, the diagnostic leaching method for zinc phases in ores is essentially based on the zinc phase analysis process outlined in the fourth edition of Rock and Mineral Analysis. Specifically, the zinc minerals in the ore are separated into four phases: zinc sulfate, zinc oxides, zinc sulfide, and hemimorphite. Zinc sulfate is leached using an aqueous solution; zinc oxides are leached using an acetic acid-ascorbic acid solution in a boiling water bath; zinc sulfide is leached using saturated bromine water; and hemimorphite is roasted at 600-650°C, followed by leaching of the zinc in the hemimorphite with acetic acid.

[0004] The problem with the above zinc mineral phase separation process is that natural ores generally do not contain zinc sulfate, so there is no need to carry out zinc sulfate phase; acetic acid-ascorbic acid solution is used as the leaching agent for zinc oxide minerals, and leaching is carried out in a boiling water bath. 3+ When it exists, sphalerite is easily dissolved in small amounts, and a large amount of hemimorphite is dissolved at the same time, which seriously affects the accuracy of the determination of zinc oxide mineral content. Summary of the Invention

[0005] In view of the shortcomings of the existing technology, the present invention aims to provide a method for leaching zinc from zinc ore by phase diagnosis.

[0006] In order to achieve the above object, the present invention adopts the following technical solutions:

[0007] A method for leaching zinc from zinc ore using a phase diagnosis method, the specific process is as follows:

[0008] S1. Grind the zinc ore into powder and mix thoroughly, then dry it in a vacuum drying oven and cool it to room temperature in a desiccator for later use;

[0009] S2. Selective dissolution of smithsonite: weigh the material obtained in step S1 into an iodine volumetric flask, add a mixed solution of hydrochloric acid and stannous chloride, leaching under shaking at room temperature, filter, acidify the filtrate, and determine the zinc content in the smithsonite by ICP-OES or AAS, which is recorded as m1;

[0010] S3, placing the residue obtained after filtering in step S2 into a beaker, adding a hydrogen peroxide solution, leaching, filtering, collecting the filtrate in a beaker, acidifying, and measuring by ICP-OES or AAS to obtain the zinc content in the sphalerite, recorded as m2;

[0011] S4, placing the filter residue obtained after filtering in step S3 in a beaker, adding nitric acid, hydrochloric acid, hydrofluoric acid and perchloric acid, heating on a hot plate to dissolve completely, and after acidification, using ICP-OES or AAS to determine the zinc content in the hemimorphite, which is recorded as m3;

[0012] S5. Calculate the zinc ore oxidation rate according to the following formula:

[0013] W 锌氧化率 =(m1+m 3) / (m1+m2+m3)*100

[0014] Among them, W 锌氧化率 is the proportion of zinc oxide minerals in total zinc minerals, %; m1 is the zinc content in smithsonite, %; m2 is the zinc content in sphalerite, %; m3 is the zinc content in hemimorphite, %.

[0015] Furthermore, in step S1, the particle size of the zinc ore powder is controlled to be no greater than 0.05 mm.

[0016] Furthermore, in step S1, the product is dried in a vacuum drying oven at 50° C. for 4-6 hours.

[0017] Furthermore, in step S2, 1 g to 3 g of the material obtained in step S1 is weighed into a 300 mL iodine volumetric flask, 50 mL to 100 mL of a mixed solution containing 5% to 10% hydrochloric acid and 5% to 15% stannous chloride by mass percentage is added, and the mixture is shaken and leached at room temperature for 30 min to 60 min.

[0018] Furthermore, in step S3, the residue obtained after filtering in step S2 is placed in a 400 mL beaker, 30 mL to 50 mL of a 10% to 20% by volume hydrogen peroxide solution is added, and the mixture is leached at 50° C. to 80° C. for 1 to 3 hours. The mixture is filtered and the filtrate is collected in a 500 mL beaker. After acidification, the filtrate is determined by ICP-OES or AAS to obtain the zinc content in the sphalerite, which is recorded as m2.

[0019] Furthermore, in step S4, the filter residue obtained after filtering in step S3 is placed in a 400 mL beaker, 2 mL of nitric acid, 6 mL of hydrochloric acid, 2 mL of hydrofluoric acid and 1 mL of perchloric acid are added, and completely dissolved on a hot plate at 180° C. After acidification, the zinc content in the hemimorphite is determined by ICP-OES or AAS, which is recorded as m3.

[0020] The beneficial effects of the present invention are:

[0021] (1) In the present invention, the zinc-containing mineral phase is divided into smithsonite phase, sphalerite phase and hemimorphite phase according to the mineral composition characteristics of general zinc ore. The smithsonite phase is selectively dissolved by hydrochloric acid-stannous chloride solution. Since stannous chloride has a strong reducing property, it can effectively inhibit the Fe 3+ The hydrochloric acid system avoids the dissolution of hemimorphite during the oxidation of sphalerite, ensuring the accuracy of the zinc content determination results in the smithsonite phase and effectively avoiding the phase channeling problem of the current industrial method. The method is stable and the data is accurate and reliable.

[0022] (2) The present invention adopts hydrogen peroxide solution to selectively dissolve sphalerite, avoiding the use of saturated bromine water as a leaching agent, making it more environmentally friendly, greatly shortening the subsequent leachate processing time, improving detection efficiency, reducing the workload of detection personnel, and facilitating industrial field application.

[0023] (3) The present invention proposes a method for calculating the zinc oxidation rate in zinc ore by dividing the sum of the zinc contents in smithsonite and hemimorphite by the total amount of zinc in each phase of smithsonite, sphalerite and hemimorphite, rather than dividing by the total zinc content in the sample. This calculation of the oxidation rate can effectively eliminate the influence of systematic errors caused by the instruments and environment during the phase separation process. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] Figure 1 Schematic diagram of the method flow of Examples 1-3 of the present invention. DETAILED DESCRIPTION

[0025] 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.

[0026] Example 1

[0027] This embodiment provides a method for leaching zinc from zinc ore using a phase diagnostic method. Figure 1 As shown, the specific process is as follows:

[0028] S1. Control the particle size of zinc ore powder to be no larger than 0.05 mm. After fully mixing, dry it in a vacuum drying oven at 50°C for 4 hours, place it in a desiccator and cool it to room temperature for use.

[0029] S2. Selective dissolution of smithsonite: 1.3482 g of material was weighed into a 300 mL iodine volumetric flask, 100 mL of a mixed solution of 5% hydrochloric acid and 10% stannous chloride was added, and the mixture was shaken and leached at room temperature for 45 min. The mixture was filtered, and the filtrate was acidified and determined by ICP-OES or AAS. The zinc content m1 in the smithsonite was 0.19%.

[0030] S3. The residue obtained by filtering in step S2 was placed in a 400 mL beaker, 30 mL of a 20% (volume ratio) hydrogen peroxide solution was added, and the mixture was leached at 50° C. for 1 h. The mixture was filtered and the filtrate was collected in a 500 mL beaker. After acidification, the filtrate was determined by ICP-OES or AAS to obtain a zinc content m2 of 1.74% in the sphalerite.

[0031] S4. The residue obtained by filtering in step S3 is placed in a 400 mL beaker, and 2 mL of nitric acid, 6 mL of hydrochloric acid, 2 mL of hydrofluoric acid, and 1 mL of perchloric acid are added. The mixture is completely dissolved on a hot plate at 180° C. After acidification, the zinc content m3 in the hemimorphite is measured by ICP-OES or AAS, and is 0.024%.

[0032] S5. Calculation formula for zinc ore oxidation rate:

[0033] W 锌氧化率 =(m1+m 3) / (m1+m2+m3)*100=10.84%

[0034] Where: W 锌氧化率 : The proportion of zinc oxide minerals to total zinc minerals, %;

[0035] m1: zinc content in smithsonite, %; m2: zinc content in sphalerite, %; m3: zinc content in hemimorphite, %.

[0036] Example 2

[0037] This embodiment provides a method for leaching zinc from zinc ore using a phase diagnostic method. Figure 1 As shown, the specific process is as follows:

[0038] S1. The particle size of the material should not be greater than 0.05 mm. After fully mixing, dry it in a vacuum drying oven at 50°C for 6 hours, place it in a desiccator and cool it to room temperature for use.

[0039] S2. Selective dissolution of smithsonite: Weigh 2.0921 g of material into a 300 mL iodine volumetric flask, add 50 mL of a mixed solution of 5% hydrochloric acid and 10% stannous chloride, and leaching at room temperature for 30 min with shaking. Filter, acidify the filtrate, and determine the zinc content m1 in the smithsonite by ICP-OES or AAS. The content is 0.17%.

[0040] S3. The residue obtained by filtering in step S2 was placed in a 400 mL beaker, 30 mL of a 10% (volume ratio) hydrogen peroxide solution was added, and the mixture was leached at 80° C. for 1 h. The mixture was filtered and the filtrate was collected in a 500 mL beaker. After acidification, the filtrate was determined by ICP-OES or AAS to obtain a zinc content m2 of 0.16% in the sphalerite.

[0041] S4. The residue obtained by filtering in step S3 was placed in a 400 mL beaker, and 2 mL of nitric acid, 6 mL of hydrochloric acid, 2 mL of hydrofluoric acid, and 1 mL of perchloric acid were added. The mixture was completely dissolved on a hot plate at 180° C. After acidification, the zinc content m3 in the hemimorphite was determined to be 0.01% by ICP-OES or AAS.

[0042] S5. Calculation formula for zinc ore oxidation rate:

[0043] W 锌氧化率 =(m1+m 3) / (m1+m2+m3)*100=52.30%

[0044] Where: W 锌氧化率 : The proportion of zinc oxide minerals to total zinc minerals, %;

[0045] m1: zinc content in smithsonite, %; m2: zinc content in sphalerite, %; m3: zinc content in hemimorphite, %.

[0046] Example 3

[0047] This embodiment provides a method for leaching zinc from zinc ore using a phase diagnostic method. Figure 1 As shown, the specific process is as follows:

[0048] S1. The particle size of the material should not be greater than 0.05 mm. After fully mixing, dry it in a vacuum drying oven at 50°C for 4 hours, place it in a desiccator and cool it to room temperature for use.

[0049] S2. Selective dissolution of smithsonite: 1.0915 g of material was weighed into a 300 mL iodine volumetric flask, 100 mL of a mixed solution of 10% hydrochloric acid and 15% stannous chloride was added, and the mixture was leached at room temperature with shaking for 60 min. The mixture was filtered, and the filtrate was acidified and determined by ICP-OES or AAS. The zinc content m1 in the smithsonite was 0.30%.

[0050] S3. The residue obtained by filtering in step S2 was placed in a 400 mL beaker, 30 mL of a 20% (volume ratio) hydrogen peroxide solution was added, and the mixture was leached at 60° C. for 1 h. The mixture was filtered and the filtrate was collected in a 500 mL beaker. After acidification, the filtrate was determined by ICP-OES or AAS to obtain a zinc content m2 in the sphalerite of 50.86%.

[0051] S4. The residue obtained by filtering in step S3 was placed in a 400 mL beaker, and 2 mL of nitric acid, 6 mL of hydrochloric acid, 2 mL of hydrofluoric acid, and 1 mL of perchloric acid were added. The mixture was completely dissolved on a hot plate at 180° C. After acidification, the zinc content m3 in the hemimorphite was determined to be 0.028% by ICP-OES or AAS.

[0052] S5. Calculation formula for zinc ore oxidation rate:

[0053] W 锌氧化率 =(m1+m 3) / (m1+m2+m3)*100=0.64%

[0054] Where: W 锌氧化率 : The proportion of zinc oxide minerals to total zinc minerals, %;

[0055] m1: zinc content in smithsonite, %; m2: zinc content in sphalerite, %; m3: zinc content in hemimorphite, %.

[0056] Table 1

[0057]

[0058] As can be seen from Table 1, the proportion of each phase of zinc minerals in the samples determined by the methods of the embodiments is basically consistent with the data measured by the chemical diagnostic leaching method, which further verifies that the zinc phase diagnostic leaching method in zinc ore of the embodiments is highly selective and the measured results are accurate and reliable.

[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 leaching zinc from zinc ore by phase diagnosis, characterized in that: The specific process is: S1. Grind the zinc ore into powder and mix thoroughly, then dry it in a vacuum drying oven and cool it to room temperature in a desiccator for later use; S2. Selective dissolution of smithsonite: weigh the material obtained in step S1 into an iodine volumetric flask, add a mixed solution of hydrochloric acid and stannous chloride, leaching under shaking at room temperature, filter, acidify the filtrate, and determine the zinc content in the smithsonite by ICP-OES or AAS, which is recorded as m1; S3, placing the residue obtained after filtering in step S2 into a beaker, adding a hydrogen peroxide solution, leaching, filtering, collecting the filtrate in a beaker, acidifying, and measuring by ICP-OES or AAS to obtain the zinc content in the sphalerite, recorded as m2; S4, placing the filter residue obtained after filtering in step S3 in a beaker, adding nitric acid, hydrochloric acid, hydrofluoric acid and perchloric acid, heating on a hot plate to dissolve completely, and after acidification, using ICP-OES or AAS to determine the zinc content in the hemimorphite, which is recorded as m3; S5. Calculate the zinc ore oxidation rate according to the following formula: W 锌氧化率 =(m1+m 3) / (m1+m2+m3)*100 Among them, W 锌氧化率 is the proportion of zinc oxide minerals in total zinc minerals, %; m1 is the zinc content in smithsonite, %; m2 is the zinc content in sphalerite, %; m3 is the zinc content in hemimorphite, %.

2. The zinc phase diagnostic leaching method in zinc ore according to claim 1, characterized in that: In step S1, the particle size of the zinc ore powder is controlled to be no greater than 0.05 mm.

3. The zinc phase diagnostic leaching method in zinc ore according to claim 1, characterized in that: In step S1, the product is dried in a vacuum drying oven at 50° C. for 4-6 hours.

4. The zinc phase diagnostic leaching method in zinc ore according to claim 1, characterized in that: In step S2, 1 g to 3 g of the material obtained in step S1 is weighed into a 300 mL iodine volumetric flask, 50 mL to 100 mL of a mixed solution containing 5% to 10% hydrochloric acid and 5% to 15% stannous chloride by mass percentage is added, and the mixture is shaken and leached at room temperature for 30 min to 60 min.

5. The zinc phase diagnostic leaching method in zinc ore according to claim 1, characterized in that: In step S3, the residue obtained after filtering in step S2 is placed in a 400 mL beaker, 30 mL to 50 mL of a 10% to 20% by volume hydrogen peroxide solution is added, and the mixture is leached at 50° C. to 80° C. for 1 h to 3 h. The mixture is filtered and the filtrate is collected in a 500 mL beaker. After acidification, the filtrate is determined by ICP-OES or AAS to obtain the zinc content in the sphalerite, which is recorded as m2.

6. The zinc phase diagnostic leaching method in zinc ore according to claim 1, characterized in that: In step S4, the filter residue obtained after filtering in step S3 is placed in a 400 mL beaker, 2 mL of nitric acid, 6 mL of hydrochloric acid, 2 mL of hydrofluoric acid and 1 mL of perchloric acid are added, and the mixture is completely dissolved on a hot plate at 180° C. After acidification, the mixture is determined by ICP-OES or AAS to obtain the zinc content in the hemimorphite, which is recorded as m3.

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