Method for self-growth of antimony bismuth slag under composite seed crystal reinforced alkaline medium

Abstract

The invention discloses a method for self-growth of antimony bismuth slag under a composite seed crystal reinforced alkaline medium. The method comprises the following steps: S1, adding a seed crystal into a to-be-purified desorbed solution generated in the self-purification process of a copper electrolyte; s2, slowly dropwise adding a precipitator into a system in the step S1, adjusting the pH value to 11.0-13.5, and carrying out precipitation reaction; and S3, after the reaction is finished, standing and settling, and finally, carrying out solid-liquid separation to obtain large-particle-size antimony and bismuth settled slag and antimony and bismuth settled liquid. According to the method, the grain size of the antimony and bismuth precipitation slag is effectively increased through seed crystal induction in combination with ultrasonic-assisted strengthening, so that the slag-liquid separation efficiency is improved, and the production cost is reduced.

Description

Technical Field

[0001] This invention relates to the field of non-ferrous metal hydrometallurgy, specifically to a method for enhancing the self-growth of antimony-bismuth slag in an alkaline medium using composite seed crystals. Background Technology

[0002] In the copper electrolytic refining process, impurities such as antimony and bismuth in the electrolyte accumulate continuously. When the concentration exceeds a certain threshold, it will seriously affect the quality of the cathode copper. In industrial production, the copper electrolyte needs to be periodically purified through open circuit treatment. The main purification methods include chemical precipitation, ion exchange, and resin adsorption. Among them, antimony oxide purification of copper electrolyte has attracted much attention due to its excellent impurity removal effect and recyclability, as it does not introduce external impurity ions. However, research shows that during the desorption stage of the antimony oxide-supported adsorbent (the antimony oxide becomes the supported adsorbent after adsorption and impurity removal), under conventional stirring reaction conditions, the antimony bismuth precipitate formed has an excessively fine crystal size, mostly in a colloidal or micron-sized suspended state. This fine particulate material has an extremely low settling rate, poor filtration performance, high filter cake moisture content, and easily carries a large amount of electrolyte, which not only causes the loss of valuable metals but also increases subsequent treatment costs and environmental risks. On the other hand, existing auxiliary methods for promoting particle size growth (such as single ultrasonic treatment) have obvious limitations. If the ultrasonic power or treatment time is not properly controlled, it will not only fail to promote growth, but may also cause shearing and breakage of the already formed particles, further aggravating the problem of fine slag particles.

[0003] Therefore, it is of great significance to develop a new method that can effectively promote the growth of antimony-bismuth precipitated crystals, improve precipitation efficiency, and enhance product quality. Summary of the Invention

[0004] To address the shortcomings of existing technologies, this invention aims to provide a method for enhancing the self-growth of antimony-bismuth slag in alkaline media using composite seed crystals. Through seed-induced bonding and ultrasonic-assisted enhancement, the particle size of the antimony-bismuth slag is effectively increased, thereby improving slag-liquid separation efficiency and reducing production costs.

[0005] To achieve the above objectives, the present invention adopts the following technical solution: A method for enhancing the self-growth of antimony-bismuth slag in an alkaline medium using composite seed crystals includes the following steps: S1. Add seed crystals to the desorbed liquid to be purified generated during the self-purification process of copper electrolyte; S2. Slowly add the precipitant to the system from step S1, adjust the pH to 11.0-13.5, and carry out the precipitation reaction; S3. After the reaction is complete, the mixture is allowed to settle and then separated into solid and liquid phases to obtain large-particle-size antimony-bismuth precipitate slag and antimony-bismuth precipitate liquid.

[0006] Further, in step S1, the seed crystal includes one or more of antimony sulfate, bismuth sulfate, antimony oxide, bismuth oxide, bismuth carbonate, and bismuth carbonate.

[0007] Furthermore, in step S1, the amount of seed crystals used is 0.1%-5.0% of the mass of the liquid to be purified and desorbed.

[0008] Furthermore, in step S2, the precipitant includes one or more of sodium hydroxide and potassium hydroxide.

[0009] Furthermore, in step S2, the precipitation reaction temperature is 60-85℃, and the stirring rate is 100-300 r / min.

[0010] Furthermore, in step S2, an ultrasonic field is applied to the system after a set time has elapsed since the precipitation reaction began.

[0011] Furthermore, the total duration of the precipitation reaction is 1-5 hours. An ultrasonic field is applied 30 minutes after the start of the precipitation reaction, with an ultrasonic power of 50-100W. The ultrasonic field is applied in an intermittent mode, and the total duration of the ultrasonic field is 1 / 3 to 1 / 2 of the total precipitation reaction duration.

[0012] Furthermore, in step S3, the obtained antimony-bismuth precipitated solution is returned to step S2 to adjust the pH value of the desorbed solution.

[0013] The beneficial effects of this invention are as follows: (1) Controllable and stable growth of sludge particle size: Through seed induction and synergistic control of process parameters, the average particle size of antimony-bismuth sludge can be increased by more than 23% compared with the traditional seedless process. Without the addition of seed crystals, the average particle size of sludge is only 8.2 μm, while with the present invention, it can reach more than 11 μm, and the standard deviation of particle size distribution is reduced from 2.5 μm to less than 1.8 μm, and the particle uniformity is significantly improved.

[0014] (2) Significantly improved slag-liquid separation efficiency: The gravity settling speed of large-diameter sludge is significantly accelerated, and the settling rate can be increased from 65% in the traditional process to more than 90%, and the settling cycle is shortened by 20%-40%; during the solid-liquid separation process, the air permeability of the filter cake is improved, the filtration rate is increased by about 35%, and the filter cloth replacement cycle is extended by 1-2 times, effectively reducing the energy consumption and material costs of the separation process.

[0015] (3) Production costs are significantly reduced: The efficient separation process reduces the amount of reagents used in subsequent washing, filtration and other processes and the equipment maintenance costs, and avoids downtime losses caused by fine residue clogging the equipment. Attached Figure Description

[0016] Figure 1 The above are process flow diagrams for embodiments 1-7 of the present invention. Detailed Implementation

[0017] The present invention will be further described below with reference to the accompanying drawings. It should be noted that this embodiment is based on the present technical solution and provides detailed implementation methods and specific operation processes, but the protection scope of the present invention is not limited to this embodiment.

[0018] Example 1

[0019] This embodiment provides a method for enhancing the self-growth of antimony-bismuth slag in an alkaline medium using composite seed crystals, such as... Figure 1 As shown, it includes the following steps: 1) Take 1L of the desorbed liquid obtained after purifying and removing impurities from the copper electrolyte of a copper smelter and send it into the crystallization reaction tank; 2) Calculate the total mass of micron-sized seed crystals (antimony oxide) to be added based on 1% of the mass of the desorbed liquid. The total mass of seed crystals is 10g. Then add all the seed crystals to the crystallization reaction tank. 3) Adjust the pH of the system in the crystallization reaction tank to 13 with sodium hydroxide solution and stir evenly; raise the temperature to 70℃, set the stirring rate to 150r / min, and stir for 4 hours; 4) After the reaction is complete, stop heating and stirring, let it stand and cool to room temperature, take the supernatant to determine the antimony and bismuth ion removal rate, and take the bottom sediment to determine its particle size distribution using a laser particle size analyzer.

[0020] The antimony ion removal rate in this embodiment was 92.2%, and the bismuth ion removal rate was 92.8%. The average particle size (D50) of the antimony and bismuth slag was 11.8 μm, which is 43.9% higher than that of Comparative Example 1.

[0021] Example 2

[0022] This embodiment provides a method for enhancing the self-growth of antimony-bismuth slag in an alkaline medium using composite seed crystals, such as... Figure 1 As shown, it includes the following steps: 1) Take 1L of the desorbed liquid, the same as in Example 1, and send it into the crystallization reaction tank; 2) Based on 0.5% of the desorbed liquid mass, the total mass of micron-sized seed crystals (antimony oxide) to be added is 5g. All the seed crystals are added to the crystallization reaction tank. 3) Adjust the pH of the system in the crystallization reaction tank to 12.5 with sodium hydroxide solution; raise the temperature to 65℃, set the stirring rate to 120r / min, and start the precipitation reaction. After 30 minutes, turn on the ultrasound (power 80W). The ultrasound field adopts the intermittent action mode. The precipitation reaction lasts for 4 hours, and the total ultrasound action time is 2 hours. 4) After the precipitation reaction is completed, the performance of the sediment is tested in the same way as in Example 1.

[0023] The test results showed that the antimony ion removal rate was 95.5% and the bismuth ion removal rate was 94.9%. The average particle size (D50) of the antimony and bismuth slag was 12.5 μm, which was 52.4% higher than that of the control sample 1 (average particle size 8.2 μm) without seed crystals.

[0024] Example 3 This embodiment provides a method for enhancing the self-growth of antimony-bismuth slag in an alkaline medium using composite seed crystals, such as... Figure 1 As shown, it includes the following steps: 1) Take 1L of the desorbed liquid, the same as in Example 1, and send it into the crystallization reaction tank; 2) The total amount of seed crystals is calculated to be 6g based on 0.6% of the mass of the desorbed liquid. The seed crystals are obtained by mixing 3g of micron-sized bismuth oxide and 3g of micron-sized antimony oxide. All the seed crystals are added to the crystallization reaction tank. 3) Adjust the pH of the system in the crystallization reaction tank to 13.5 with sodium hydroxide solution, raise the temperature to 75℃, set the stirring rate to 180r / min, and allow the precipitation reaction to proceed for 4 hours.

[0025] 4) After the reaction is complete, the performance of the sediment is tested using the same method as in Example 1.

[0026] The test results showed that the antimony ion removal rate was 95.9% and the bismuth ion removal rate was 96.1%; the average particle size (D50) of the antimony and bismuth slag was 13.1 μm, which was 59.8% higher than that of Comparative Example 1.

[0027] Example 4

[0028] This embodiment provides a method for enhancing the self-growth of antimony-bismuth slag in an alkaline medium using composite seed crystals, such as... Figure 1 As shown, it includes the following steps: 1) Take 1L of the desorbed liquid, the same as in Example 1, and send it into the crystallization reaction tank; 2) The total amount of seed crystals was calculated to be 6g based on 0.6% of the mass of the desorbed liquid. The seed crystals were obtained by mixing 3g of micron-sized bismuth oxide and 3g of micron-sized antimony oxide, and then all the seed crystals were added to the crystallization reaction tank. 3) Adjust the pH of the system in the crystallization reaction tank to 13.5 with sodium hydroxide solution; raise the temperature to 75℃, set the stirring rate to 180r / min, and start the precipitation reaction. After 30 minutes, turn on the ultrasound (power 100W). The ultrasound field adopts intermittent action mode; the precipitation reaction lasts for 4 hours, and the total ultrasound action time is 2 hours. 5) After the reaction is complete, the performance of the sediment is tested using the same method as in Example 1.

[0029] The test results showed that the antimony ion removal rate was 98.9% and the bismuth ion removal rate was 98.1%; the average particle size (D50) of the antimony and bismuth slag was 15.1 μm, which was 84.1% higher than that of Comparative Example 1.

[0030] Example 5

[0031] This embodiment provides a method for enhancing the self-growth of antimony-bismuth slag in an alkaline medium using composite seed crystals, such as... Figure 1 As shown, it includes the following steps: 1) Take 1L of the desorbed liquid, the same as in Example 1, and send it into the crystallization reaction tank; 2) Calculate the total mass of micron-sized seed crystals (antimony oxide) to be added based on 0.1% of the mass of the desorbed liquid. The total mass of seed crystals is 1g. Then add all the seed crystals to the crystallization reaction tank. 3) Adjust the pH of the system in the crystallization reaction tank to 11 with sodium hydroxide solution and stir evenly; raise the temperature to 70℃, set the stirring rate to 100r / min, and start the precipitation reaction for 4 hours; 4) After the reaction is complete, stop heating and stirring, let it stand and cool to room temperature, take the supernatant to determine the antimony and bismuth ion removal rate, and take the bottom sediment to determine its particle size distribution using a laser particle size analyzer.

[0032] The test results showed that the antimony ion removal rate was 91.4% and the bismuth ion removal rate was 93.2%; the average particle size (D50) of the antimony and bismuth slag was 10.1 μm, which was 23.1% higher than that of Comparative Example 1.

[0033] Example 6

[0034] This embodiment provides a method for enhancing the self-growth of antimony-bismuth slag in an alkaline medium using composite seed crystals, such as... Figure 1 As shown, it includes the following steps: 1) Take 1L of the desorbed liquid, the same as in Example 1, and send it into the crystallization reaction tank; 2) Calculate the total mass of micron-sized seed crystals (antimony oxide) to be added based on 5% of the mass of the desorbed liquid. Then add all the seed crystals into the crystallization reaction tank. 3) Adjust the pH of the system in the crystallization reaction tank to 13 with sodium hydroxide solution and stir evenly; raise the temperature to 60℃, set the stirring rate to 180r / min, and start the precipitation reaction. After 30 minutes, turn on the ultrasound (power 50W) and use the intermittent action mode of the ultrasound field; the precipitation reaction lasts for 4 hours, and the total ultrasound action time is 1.4 hours. 4) After the reaction is complete, stop heating, stirring and sonication, let it stand and cool to room temperature, take the supernatant to determine the antimony and bismuth ion removal rate, and take the bottom sediment to determine its particle size distribution using a laser particle size analyzer.

[0035] The test results showed that the antimony ion removal rate was 95.4% and the bismuth ion removal rate was 94.6%; the average particle size (D50) of the antimony and bismuth slag was 13.7 μm, which was 67.1% higher than that of Comparative Example 1.

[0036] Example 7

[0037] This embodiment provides a method for enhancing the self-growth of antimony-bismuth slag in an alkaline medium using composite seed crystals, such as... Figure 1 As shown, it includes the following steps: 1) Take 1L of the desorbed liquid, the same as in Example 1, and send it into the crystallization reaction tank; 2) Calculate the total mass of micron-sized seed crystals (antimony oxide) to be added based on 2% of the mass of the desorbed liquid. Then add all the seed crystals into the crystallization reaction tank. 3) Adjust the pH of the system in the crystallization reaction tank to 12 with sodium hydroxide solution and stir evenly; raise the temperature to 85℃, set the stirring rate to 300r / min, and react for a total of 4 hours; 4) After the reaction is complete, stop heating and stirring, let it stand and cool to room temperature, take the supernatant to determine the antimony and bismuth ion removal rate, and take the bottom sediment to determine its particle size distribution using a laser particle size analyzer.

[0038] The test results showed that the antimony ion removal rate was 94.2% and the bismuth ion removal rate was 93.6%; the average particle size (D50) of the antimony and bismuth slag was 12.7 μm, which was 54.8% higher than that of Comparative Example 1.

[0039] Comparative Example 1 This comparative example aims to set up a control experiment without the addition of seed crystals. The steps are as follows: 1) Take 1L of the same desorption solution as in Example 1; 2) Adjust the pH of the solution to 13.0 with sodium hydroxide solution, transfer it into the reaction tank, heat it to 70℃, and stir it at 150r / min for 4 hours; 3) After the reaction, the antimony ion removal rate was 84.8%, the bismuth ion removal rate was 83.5%, and the average particle size (D50) of the sludge was 8.2μm.

[0040] Table 1 Comparison of antimony-bismuth ion removal rate and bismuth precipitate particle size in the examples and comparative examples Antimony removal rate (%) Bismuth removal rate (%) Slag particle size (D50, μm) Example 1 92.2 92.8 11.8 Example 2 95.5 94.9 12.5 Example 3 95.9 96.1 13.1 Example 4 98.9 98.1 15.1 Example 5 91.4 93.2 10.1 Example 6 95.4 94.6 13.7 Example 7 94.2 93.6 12.7 Comparative Example 1 84.8 83.5 8.2 As can be seen from the comparison between Examples 1-7 and Comparative Example 1, Examples 1-7, through seed induction and process parameter control, can effectively solve the problems of small particle size and low settling rate of antimony-bismuth slag under alkaline medium, significantly improve the slag-liquid separation efficiency, and have good industrial application prospects.

[0041] For those skilled in the art, various corresponding changes and modifications can be made based on the above technical solutions and concepts, and all such changes and modifications should be included within the protection scope of the claims of this invention.

Claims

1. A method for composite seed reinforced autogenous growth of antimony bismuth dross in alkaline medium, characterized by, Includes the following steps: S1. Add seed crystals to the desorbed liquid to be purified generated during the self-purification process of copper electrolyte; S2. Slowly add the precipitant to the system from step S1, adjust the pH to 11.0-13.5, and carry out the precipitation reaction; S3. After the reaction is complete, the mixture is allowed to settle and then separated into solid and liquid phases to obtain large-particle-size antimony-bismuth precipitate slag and antimony-bismuth precipitate liquid.

2. The method of claim 1, wherein, In step S1, the seed crystals include one or more of antimony sulfate, bismuth sulfate, antimony oxide, bismuth oxide, bismuth carbonate, and bismuth carbonate.

3. The method of claim 1, wherein, In step S1, the amount of seed crystals used is 0.1%-5.0% of the mass of the liquid to be purified and desorbed.

4. The method of claim 1, wherein, In step S2, the precipitant includes one or more of sodium hydroxide and potassium hydroxide.

5. The method of claim 1, wherein, In step S2, the precipitation reaction temperature is 60-85℃ and the stirring rate is 100-300 r / min.

6. The method of claim 1, wherein, In step S2, an ultrasonic field is applied to the system after the precipitation reaction has been set for a certain time.

7. The method of claim 6, wherein, The total duration of the precipitation reaction is 1-5 hours. An ultrasonic field is applied 30 minutes after the start of the precipitation reaction. The ultrasonic power is 50-100W. The ultrasonic field is applied in an intermittent mode. The total duration of the ultrasonic field is 1 / 3 to 1 / 2 of the total precipitation reaction time.

8. The method of claim 1, wherein, In step S3, the obtained antimony-bismuth precipitated solution is returned to step S2 to adjust the pH value of the desorbed solution.

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