Sulfuric acid normal pressure air efficient copper leaching method for bismuth matte

Abstract

The invention provides a method for efficiently leaching bismuth copper matte in sulfuric acid normal-pressure air, and belongs to the field of non-ferrous metal hydrometallurgy. According to the technical scheme, the method comprises the following steps that bismuth copper matte is crushed and finely ground, and then copper in the bismuth copper matte is rapidly and selectively leached out through sulfuric acid under the normal pressure condition with air as an oxidizing agent by means of a self-suction stirrer. The obtained leaching residues can be conveniently left in a lead anode slime workshop so as to further recover valuable elements such as gold, silver, antimony and bismuth in the leaching residues in a short process. The method has the advantages of mild technical conditions, low required equipment investment, compact equipment and simplicity and convenience in operation.

Description

Technical Field

[0001] The invention belongs to the field of metallurgy and chemical industry, and specifically relates to a method for efficiently leaching copper using bismuth matte, sulfuric acid and normal pressure air. Background Art

[0002] One of the important functions of the lead anode mud smelting workshop of the lead smelter is to recover the element bismuth in the lead anode mud and refine it into 99.99% purity bismuth. For this purpose, impurities such as copper, gold, and silver need to be separated from bismuth. At present, the method of making bismuth matte from crude bismuth is widely used. Bismuth matte is rich in elements such as copper, sulfur, gold, silver, tellurium, bismuth, antimony, lead, and arsenic. It is a high-value smelting intermediate material with extremely high comprehensive recovery value. The conventional method is to merge bismuth matte into the lead system smelting and copper removal process. Although it can open the copper circuit, it also causes the dispersion loss and backlog of bismuth, antimony, tellurium, gold, silver, etc. in bismuth matte. In addition, some people have studied the wet process for treating bismuth matte, mainly oxygen pressure sulfuric acid leaching-electrodeposition copper technology (a comprehensive recovery method for bismuth matte, CN105543479A), which can well separate copper and bismuth and convert copper into cathode copper products, but the investment in oxygen pressure sulfuric acid leaching is relatively large. Others have studied the chloride solution leaching method (Chen Peihuan. Research on the recovery of silver and other valuable metals from bismuth matte. Comprehensive Utilization of Mineral Resources, 1989, (6), 5). It can effectively leach copper, but the leached lead chloride has difficulty in market sales. Summary of the invention

[0003] The invention aims to provide a method for efficiently leaching copper using bismuth matte, sulfuric acid and atmospheric pressure air.

[0004] The object of the present invention is achieved in that the method for efficient copper leaching in bismuth matte with sulfuric acid and atmospheric pressure air comprises pre-treatment, leaching and post-treatment steps, specifically comprising: A. Pretreatment: crush and finely grind the bismuth matte to be treated to obtain material a; B. Leaching: 1) Add sulfuric acid solution to material a for slurry adjustment to obtain material b; 2) Directly introduce 180-220℃ high-temperature steam into material b to heat it and start the self-priming mixer to leaching for 3-10 hours to obtain material c. During the leaching process, adjust the steam introduction amount to maintain the leaching process temperature constant at 60-95℃ and ensure that the air content in the slurry is 8-15%; C. Post-processing: 1) subjecting material c to liquid-solid separation to obtain leachate d and leach residue e, wherein the leachate d is a copper sulfate solution; 2) The leached residue e is washed to obtain material f, and valuable metals are recovered from material f in the lead anode mud workshop.

[0005] The specific operations are as follows: S1) Crushing and fine grinding of bismuth matte. The specific conditions are: crushing bismuth matte to an average particle size of 2-5 mm, and then grinding to a particle size of -200 mesh with a proportion of not less than 86%, to obtain bismuth matte ore powder.

[0006] S2) Sulfuric acid atmospheric pressure air efficient copper leaching - water washing - liquid-solid separation. The specific conditions are: in the leaching tank, the bismuth matte powder obtained in step S1 is slurried with a sulfuric acid solution with a sulfuric acid concentration of 40-150g / L according to a leaching solid-liquid ratio (kg / L) of 1:5-10; then 200°C high-temperature steam is directly introduced into the leaching slurry for heating and the self-priming mixer is turned on at the same time (air can be sucked into the slurry in the leaching tank, and air is used as an oxidant for leaching copper); during the leaching process, the steam introduction amount is adjusted to maintain the leaching process temperature constant at 60-95°C and ensure that the air content in the slurry is 8%-15%. Under this condition; the leaching test can be terminated by continuous leaching for 3-10 hours; liquid-solid separation, the leaching solution is a copper sulfate solution, which can be used as the original feed solution for copper recovery, and the leaching slag is stirred and washed at 25°C according to a washing solid-liquid ratio of 1:3. The final slag obtained after washing can be left in the lead anode mud workshop to recover valuable metals such as bismuth, antimony, gold and silver.

[0007] The present invention finds that only a small part of the copper in bismuth matte exists in the form of metallic copper (copper that is easily leached by sulfuric acid at normal pressure), while most of the copper exists in the form of cuprous sulfide (copper that is difficult to be leached by sulfuric acid at normal pressure). In order to reduce the investment cost of treating bismuth matte with wet copper leaching technology, the present invention proposes a method for efficiently leaching bismuth matte with sulfuric acid and normal pressure air. In order to achieve the above-mentioned goal, a self-priming stirrer is particularly used. The specific process and process parameters are as follows: 1. Crushing and fine grinding of bismuth matte The specific conditions are: the bismuth matte is crushed to an average particle size of 2-5 mm, and then ground to a particle size of -200 mesh with a proportion of not less than 86% to obtain bismuth matte ore powder.

[0008] 2. High-efficiency copper leaching with sulfuric acid and atmospheric pressure air - water washing - liquid-solid separation The specific conditions are as follows: in a leaching tank, the bismuth matte powder obtained in step 1 is slurried with a sulfuric acid solution having a sulfuric acid concentration of 40-150 g / L according to a leaching solid-liquid ratio (kg / L) of 1:5-10; then 200°C high-temperature steam is directly introduced into the leaching slurry for heating and a self-priming agitator is simultaneously turned on (air can be sucked into the slurry in the leaching tank, and the air is used as an oxidant for leaching copper); during the leaching process, the steam introduction amount is adjusted to maintain a constant leaching process temperature of 60-95°C and to ensure that there is no air in the slurry. The gas content is between 8% and 15% (gas content = total volume of air in the leaching slurry in the leaching tank / total volume of slurry, total volume of slurry = the sum of the volumes of gas, liquid and solid phases in the slurry). Under this condition, the leaching test can be completed after continuous leaching for 3-10 hours. The liquid-solid separation is carried out, and the leaching liquid is a copper sulfate solution, which can be used as the original feed liquid for copper recovery. The leaching residue is stirred and washed at 25°C according to a washing solid-liquid ratio of 1:3. The final slag obtained after washing can be left in the lead anode mud workshop to recover valuable metals such as bismuth, antimony, gold and silver.

[0009] Furthermore, the concentration of the sulfuric acid solution in step 2 is preferably 60 to 80 g / L.

[0010] Furthermore, the solid-to-liquid ratio in step 2 is preferably 1:8-10.

[0011] Furthermore, the air content in the slurry as described in step 2 is preferably ensured to be 10%-13%.

[0012] The technology of the present invention adopts relatively mild process conditions and a short process to treat bismuth matte, requires less equipment investment, is compact and easy to operate, and can selectively remove copper from bismuth matte; in addition, the obtained leaching slag is convenient to be left in the lead anode mud workshop for further short-process recovery of valuable elements such as gold, silver, antimony and bismuth therein. BRIEF DESCRIPTION OF THE DRAWINGS

[0013] Figure 1 It is a schematic diagram of the process flow of the present invention. DETAILED DESCRIPTION

[0014] The present invention is further described below in conjunction with the embodiments, but the present invention is not limited in any way. Any changes or substitutions made based on the teachings of the present invention belong to the protection scope of the present invention.

[0015] The method for efficient copper leaching with bismuth matte, sulfuric acid and atmospheric pressure air of the present invention comprises pre-treatment, leaching and post-treatment steps, specifically comprising: A. Pretreatment: crush and finely grind the bismuth matte to be treated to obtain material a; B. Leaching: 1) Add sulfuric acid solution to material a for slurry adjustment to obtain material b; 2) Directly introduce 180-220℃ high-temperature steam into material b to heat it and start the self-priming mixer to leaching for 3-10 hours to obtain material c. During the leaching process, adjust the steam introduction amount to maintain the leaching process temperature constant at 60-95℃ and ensure that the air content in the slurry is 8-15%; C. Post-processing: 1) subjecting material c to liquid-solid separation to obtain leachate d and leach residue e, wherein the leachate d is a copper sulfate solution; 2) The leached residue e is washed to obtain material f, and valuable metals are recovered from material f in the lead anode mud workshop.

[0016] The crushing and fine grinding described in step A is to crush the bismuth matte to an average particle size of 2-5 mm, and then grind the particle size to -200 mesh with a proportion of not less than 86%.

[0017] B. The concentration of the sulfuric acid solution in step 1) is 40-150 g / L.

[0018] The concentration of the sulfuric acid solution is 60-80 g / L.

[0019] In step B 1), the solid-liquid ratio of material a and sulfuric acid solution is 1: (5-10) kg / L.

[0020] The temperature of the high temperature steam in step B2) is 200-220°C.

[0021] The temperature of the high-temperature steam is 200°C.

[0022] The air content in step B2) is 10-13%.

[0023] The washing in step C2) is performed by stirring and washing with water at a solid-liquid volume ratio of 1:(2-4).

[0024] The washing temperature is 24-26°C.

[0025] The present invention is further described below with specific implementation cases: Example 1 Bismuth matte (chemical composition: Cu19.35%, Ag 1.74%, Au 18g / t, Bi6.12%, Sb 1.95%, S18.10%, Fe 8.92, Pb22.65%, As 0.24%) was crushed to an average particle size of 3.5 mm, and then ground to a particle size of -200 mesh accounting for 91.34% to obtain bismuth matte ore powder.

[0026] In the leaching tank, bismuth matte powder is slurried with sulfuric acid solution with a sulfuric acid concentration of 85g / L according to a leaching solid-liquid ratio (kg / L) of 1:7; then 200°C high-temperature steam is directly introduced into the leaching slurry for heating and the self-priming agitator is turned on at the same time; during the leaching process, the steam introduction amount is adjusted to maintain the leaching process temperature constant at 90-95°C and ensure that the air content in the slurry is stable at 8%-9%. Under this condition; the leaching test can be ended after continuous leaching for 8.5 hours; liquid-solid separation, the leaching solution is a copper sulfate solution with the chemical composition of: Cu 17.90g / L, Ag 0.002g / L, Au 0g / L, Bi 1.21g / L, Sb0.025g / L, Fe4.10g / L, Pb 0.081g / L, As 0.035g / L) can be used as the original feed liquid for copper recovery. The leached residue is stirred and washed at 25°C according to the washing solid-liquid ratio of 1:3. After washing, the liquid-solid separation is carried out. The final residue can be left in the lead anode mud workshop to recover valuable metals such as bismuth, antimony, gold and silver in a short process. The leaching rates of Cu, Ag, Au, Bi, Sb, Fe, Pb and As are 92.51%, 0.11%, 0%, 19.77%, 1.28%, 45.96%, 0.36% and 14.58% respectively.

[0027] Example 2 Bismuth matte (chemical composition: Cu 26.37%, Ag 2.49%, Au 16g / t, Bi5.35%, Sb 2.10%, S15.84%, Fe5.28, Pb20.20%, As 0.36%) was crushed to an average particle size of 4.7 mm, and then ground to a particle size of -200 mesh accounting for 90.01% to obtain bismuth matte ore powder.

[0028] In the leaching tank, bismuth matte powder is slurried with sulfuric acid solution with a sulfuric acid concentration of 60g / L according to a leaching solid-liquid ratio (kg / L) of 1:9; then 200°C high-temperature steam is directly introduced into the leaching slurry for heating and the self-priming agitator is turned on at the same time; during the leaching process, the steam introduction amount is adjusted to maintain the leaching process temperature constant at 85°C-95°C and ensure that the air content in the slurry is stable at 9%-13%. Under this condition; the leaching test can be ended after continuous leaching for 9.2 hours; liquid-solid separation, the leaching solution is a copper sulfate solution, and the chemical composition is: Cu 23.61g / L, Ag 0.002g / L, Au 0g / L, Bi 0.89g / L, Sb 0.018g / L, Fe2.53g / L, Pb 0.064g / L, As 0.038g / L) can be used as the original feed liquid for copper recovery. The leached residue is stirred and washed at 25°C according to the washing solid-liquid ratio of 1:3. The final residue obtained after washing can be left in the lead anode mud workshop to recover valuable metals such as bismuth, antimony, gold and silver in a short process. The leaching rates of Cu, Ag, Au, Bi, Sb, Fe, Pb and As are 94.00%, 0.08%, 0%, 17.47%, 0.90%, 50.31%, 0.33% and 11.08% respectively.

Claims

1. A method for efficient copper leaching in bismuth matte with sulfuric acid and atmospheric pressure air, characterized in that: The method for efficient copper leaching with bismuth matte, sulfuric acid and atmospheric pressure air comprises pre-treatment, leaching and post-treatment steps, specifically comprising: A. Pretreatment: crush and finely grind the bismuth matte to be treated to obtain material a; B. Leaching: 1) Add sulfuric acid solution to material a for slurry adjustment to obtain material b; 2) Directly introduce 180-220℃ high-temperature steam into material b to heat it and start the self-priming mixer to leaching for 3-10 hours to obtain material c. During the leaching process, adjust the steam introduction amount to maintain the leaching process temperature constant at 60-95℃ and ensure that the air content in the slurry is 8-15%; C. Post-processing: 1) subjecting material c to liquid-solid separation to obtain leachate d and leach residue e, wherein the leachate d is a copper sulfate solution; 2) The leached residue e is washed to obtain material f, and valuable metals are recovered from material f in the lead anode mud workshop.

2. The method for efficient copper leaching with bismuth matte and sulfuric acid at normal pressure air according to claim 1, characterized in that: The crushing and fine grinding described in step A is to crush the bismuth matte to an average particle size of 2-5 mm, and then grind the particle size to -200 mesh with a proportion of not less than 86%.

3. The method for efficient copper leaching with bismuth matte and sulfuric acid at normal pressure air according to claim 1, characterized in that: B. The concentration of the sulfuric acid solution in step 1) is 40-150 g / L.

4. The method for efficient copper leaching with bismuth matte and sulfuric acid at normal pressure air according to claim 1 or 3, characterized in that: The concentration of the sulfuric acid solution is 60-80 g / L.

5. The method for efficient copper leaching with bismuth matte and sulfuric acid at normal pressure air according to claim 1, characterized in that: In step B 1), the solid-liquid ratio of material a and sulfuric acid solution is 1: (5-10) kg / L.

6. The method for efficient copper leaching with bismuth matte and sulfuric acid at normal pressure air according to claim 1, characterized in that: The temperature of the high temperature steam in step B2) is 200-220°C.

7. The method for efficient copper leaching with bismuth matte and sulfuric acid at normal pressure air according to claim 1 or 6, characterized in that: The temperature of the high-temperature steam is 200°C.

8. The method for efficient copper leaching with bismuth matte and sulfuric acid at normal pressure air according to claim 1, characterized in that: The air content in step B2) is 10-13%.

9. The method for efficient copper leaching with bismuth matte and sulfuric acid at normal pressure air according to claim 1, characterized in that: The washing described in step C2) is performed by stirring and washing with water having a solid-to-liquid ratio of 1:(2-4).

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