Copper removal refining agent and production process of regenerated refined lead

Abstract

The invention discloses a copper removal refining agent and a production process of regenerated refined lead, and a preparation method of the copper removal refining agent comprises the following steps: mixing iron oxide / silicon dioxide composite powder and thiourea in a polyvinyl alcohol aqueous solution, drying, and annealing to obtain iron sulfide composite powder; the iron sulfide composite powder and the lead sulfide powder are subjected to ultrasonic mixing in a polyvinyl alcohol aqueous solution and then subjected to compression molding, annealing treatment, smashing, sieving and centrifugal separation, and a copper removal refining agent is obtained; the iron sulfide and the lead sulfide are compounded with the mesoporous silica and coated with the carbon layer, the contact time of the copper removal refining agent and the lead liquid is prolonged, and the iron sulfide is generated in a porous structure and has the advantages of high surface area, large contact area with the lead liquid, good copper removal efficiency and uniform compounding degree of the lead sulfide and the iron sulfide; and scum formed after copper removal is formed into slag under the promotion action of a slagging agent mesoporous silica, so that convenience is brought to fishing and slag removal, the lead content in the scum is reduced, and the economic benefit is high.

Description

Technical Field

[0001] The invention belongs to the technical field of recycled lead, and in particular relates to a copper removal refining agent and a production process of recycled refined lead. Background Art

[0002] There are usually two methods for removing copper from crude lead by pyrometallurgical refining: smelting and sulfur addition. The smelting method is used for preliminary copper removal, and the sulfur addition method is used for deep copper removal. In the copper removal process of crude lead pyrometallurgical refining, the most widely used method is to add copper removers to the crude lead liquid. The copper removers are mainly sulfur, pyrite, red phosphorus or high-quality lead concentrate (main component PbS). The main principle is that during the heating process, copper and sulfur elements react chemically to form copper sulfide. Since copper sulfide is insoluble in lead liquid, it will naturally settle to the bottom of the container or float to the surface to form scum. The scum is salvaged and removed to obtain a relatively pure lead product.

[0003] The Chinese invention patent application with publication number CN105063369A discloses a copper removal composition for secondary lead refining and its application, which is composed of 30-45wt% Fe, 40-55wt% S, 3-15wt% SiO2 and 0.002wt% lead powder, prolonging the reaction and processing time, which is beneficial to the salvage of copper slag and improving the copper removal efficiency. However, sulfur and iron are easily oxidized in the air, difficult to store, and have poor stability. After sulfur comes into contact with lead liquid, it is easy to react with oxygen to generate sulfur dioxide, reducing the sulfur content while generating harmful gases.

[0004] A Chinese invention patent application with publication number CN112695206A discloses a copper removal agent for pyrometallurgical refining of crude lead, a preparation method and an application thereof, which is composed of 50-70% pyrite, 10-30% sulfur, 1-20% silicate cement and 5-20% iron powder. The lead content in the slag is fully reduced by the synergistic reaction of pyrite and sulfur, slag making by silicate cement and replacement by iron powder, so as to fully remove the impurity copper in the crude lead liquid and reduce the loss of the lead liquid. However, the solution only stirs and mixes the formula components, so that the synergistic effect of pyrite and sulfur is small, the slag removal efficiency is not improved much, and the sulfur and iron powder are still difficult to store and have low stability. Summary of the invention

[0005] The purpose of the present invention is to solve the problem of how to improve the stability and copper removal efficiency of a copper removal refining agent, and to provide a production process of a copper removal refining agent and regenerated refined lead.

[0006] The purpose of the present invention can be achieved by the following technical solutions: A copper removal refining agent, the preparation method of which comprises the following steps: Step 1: Ultrasonically mix the iron oxide / silicon dioxide composite powder and thiourea in a 5-8wt% polyvinyl alcohol aqueous solution, filter to obtain a precipitate, vacuum dry the precipitate and place it in a tube furnace, heat it to 500-550°C at a rate of 5°C / min under nitrogen protection, anneal it for 3-4h, and then pulverize it through a 100-mesh sieve after cooling to obtain an iron sulfide composite powder.

[0007] Step 2: Ultrasonically mix the iron sulfide composite powder and the lead sulfide powder in a 5-8wt% polyvinyl alcohol aqueous solution, filter to obtain a precipitate, press the precipitate into a mold, vacuum dry it, place it in a tubular furnace, heat it to 250-350°C at a rate of 5°C / min under nitrogen protection, anneal it for 80-100min, and obtain a carbonized composite powder after cooling. The carbonized composite powder is crushed through a 100-mesh sieve to obtain a carbon / refining agent composite powder, and the pure carbon particles in the carbon / refining agent composite powder are removed by centrifugal separation. After vacuum drying, a copper-removing refining agent is obtained.

[0008] Furthermore, in step 1, the mass ratio of the iron oxide / silicon dioxide composite powder to thiourea is 6-10g:5-10g.

[0009] Further, the steps for preparing the iron oxide / silicon dioxide composite powder are as follows: The iron / silicon dioxide composite powder is heated to 400-450° C. at a rate of 5° C. / min in a tubular furnace and annealed in air for 3-4 hours to obtain an iron oxide / silicon dioxide composite powder.

[0010] Further, the iron / silicon dioxide composite powder is prepared by the following steps: In a reaction kettle, mesoporous silica, 2-aminoterephthalic acid and ferric chloride hexahydrate are stirred, dissolved and mixed in DMF for 30-40 minutes, heated to 120-130° C. and reacted for 20-24 hours. After cooling, the precipitate is filtered, washed and vacuum dried to obtain an iron / silicon dioxide composite powder.

[0011] Furthermore, the usage ratio of mesoporous silica, 2-aminoterephthalic acid, ferric chloride hexahydrate and DMF is 4-8 g: 4-6 g: 6-8 g: 200-300 mL.

[0012] Further, mesoporous silica is prepared by the following steps: In a reaction kettle, the PEG-PPG-PEG copolymer is stirred and dissolved in a 35-40wt% hydrochloric acid aqueous solution, n-butanol is added, and after stirring and mixing, ethyl orthosilicate is added dropwise, and the mixture is stirred for 2-4 hours. The mixture is heated to 90-100° C. and stirred for 20-24 hours. The precipitate is filtered and calcined in air at 500-550° C. for 7-8 hours to obtain mesoporous silica.

[0013] Furthermore, the usage ratio of PEG-PPG-PEG copolymer, hydrochloric acid aqueous solution, n-butanol and tetraethyl orthosilicate is 6-10 g: 300-400 mL: 20-25 mL: 30-35 mL.

[0014] Furthermore, the mass ratio of the iron sulfide composite powder to the lead sulfide powder is 6-10g:25-30g.

[0015] A production process for recycled refined lead comprises the following steps: S01. The crude lead is smelted in an oxygen-enriched side-blown furnace and enters the decontamination pot through a lead chute to obtain molten lead. When the temperature of the molten lead drops to 600-650°C, 0.01-0.015wt% of the total mass of the molten lead is added with flake caustic soda. The mixture is stirred for 2-3 hours and samples are taken for testing. When the content of elements such as antimony and tin reaches the requirements, stirring is stopped and the alkali slag is removed.

[0016] S02. When the lead liquid is cooled to 280-320℃, take samples to test the copper content, add copper removal refining agent 1.5-2 times the weight of the copper content, stir for 60-80 minutes, take samples for testing, and stop stirring when the content of copper and other elements reaches the requirements, and remove the copper slag.

[0017] S03, transfer the lead liquid into the finished product pot, heat it to 450-480℃, add 0.01-0.015wt% of the total mass of the lead liquid, start the mixer to wash the lead, and wait until the scum in the lead liquid is completely washed away. After 1-2 times of lead washing and scum removal, sampling and testing meet the standards, stop stirring, remove the scum, keep warm, cast ingots, and obtain recycled refined lead.

[0018] Beneficial effects of the present invention: (1) The copper removal refining agent prepared by the present invention is a composite mesoporous silica with iron sulfide and lead sulfide, and is coated with a carbon layer, which prolongs the contact time between the copper removal refining agent and the lead liquid. The iron sulfide is generated in a porous structure, has a high surface area, has a large contact area with the lead liquid, has a good copper removal efficiency, and has a uniform degree of composite of lead sulfide and iron sulfide. The slag removal agent mesoporous silica is used as a carrier. The slag formed after copper removal is slaged under the promotion of the slag removal agent mesoporous silica, which is convenient for slag removal, and reduces the lead content in the slag, thereby achieving high economic benefits.

[0019] (2) The copper removal refining agent prepared by the present invention utilizes the bonding ability of polyvinyl alcohol to uniformly compound the iron oxide / silicon dioxide composite powder with thiourea, and reacts thiourea with iron oxide at high temperature to generate iron sulfide. The iron sulfide is bonded to the surface of mesoporous silica using the carbon structure formed by carbonization of polyvinyl alcohol, and the bonding strength is high. In addition, thiourea also makes the formed carbon structure have the effect of sulfur doping, thereby obtaining an iron sulfide composite powder with iron sulfide and sulfur-doped carbon loaded on the surface.

[0020] (3) The copper removal refining agent prepared by the present invention combines the iron sulfide composite powder and the lead sulfide powder together under the bonding effect of polyvinyl alcohol, and presses them in a mold to make the iron sulfide composite powder and the lead sulfide powder evenly combined, and quickly carbonizes the polyvinyl alcohol under the protection of nitrogen. The carbonization effect of polyvinyl alcohol is used to coat the evenly combined iron sulfide composite powder / lead sulfide powder, and the carbon layer on the surface is used to extend the contact time between the iron sulfide composite powder / lead sulfide powder and the lead liquid, reducing the contact between the sulfur element and the air, thereby improving the copper removal efficiency. As the carbon layer decomposes at high temperature, the lead sulfide and iron sulfide composite powders come into contact with the lead liquid and react with the copper element in the lead liquid. The iron sulfide with a porous structure has a large contact area with the lead liquid, and the copper removal efficiency is high. DETAILED DESCRIPTION

[0021] The following will be combined with the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0022] Example 1: A copper removal refining agent is prepared by the following steps: S1. In a reactor, 6 g of PEG-PPG-PEG copolymer was stirred and dissolved in 300 mL of 35 wt% aqueous hydrochloric acid solution, 20 mL of n-butanol was added, and after stirring and mixing, 30 mL of tetraethyl orthosilicate was added dropwise at a rate of 1 mL / s, and the mixture was stirred and reacted for 2 h. The mixture was heated to 90 °C and stirred and reacted for 20 h. The precipitate was filtered and calcined in air at 500 °C for 7 h to obtain mesoporous silica.

[0023] S2. In a reaction kettle, 4 g of mesoporous silica, 4 g of 2-aminoterephthalic acid and 6 g of ferric chloride hexahydrate were dissolved and stirred in 200 mL of DMF for 30 min, the temperature was raised to 120° C. and the reaction was performed for 20 h. After cooling, the precipitate was filtered and washed with DMF and ethanol, and vacuum dried at 80° C. for 20 h to obtain an iron / silicon dioxide composite powder.

[0024] S3. In a tubular furnace, the temperature of the iron / silicon dioxide composite powder was increased to 400°C at a rate of 5°C / min, and annealed in air for 3 h to obtain an iron oxide / silicon dioxide composite powder; 6 g of the iron oxide / silicon dioxide composite powder and 5 g of thiourea were ultrasonically mixed in a 5 wt% polyvinyl alcohol aqueous solution, and the precipitate was filtered to obtain a precipitate; the precipitate was vacuum dried at 60°C for 4 h, and then placed in a tubular furnace; the temperature was increased to 500°C at a rate of 5°C / min under nitrogen protection, and annealed for 3 h; after cooling, the mixture was crushed and passed through a 100-mesh sieve to obtain an iron sulfide composite powder.

[0025] S4. 6 g of iron sulfide composite powder and 25 g of lead sulfide powder are ultrasonically mixed in a 5 wt % polyvinyl alcohol aqueous solution, filtered to obtain a precipitate, and the precipitate is pressed into a mold under a pressure of 80 MPa, vacuum dried at 60 ° C for 10 h, and then placed in a tubular furnace and heated to 250 ° C at a rate of 5 ° C / min under nitrogen protection for annealing for 80 min, and then cooled to obtain a carbonized composite powder, the carbonized composite powder is crushed through a 100 mesh sieve to obtain a carbon / refining agent composite powder, the carbon / refining agent composite powder is dispersed in deionized water, and the pure carbon particles in the carbon / refining agent composite powder are removed by centrifugal separation, and the remaining carbon / refining agent composite powder is vacuum dried at 60 ° C for 10 h to obtain a copper-refining agent.

[0026] A production process for recycled refined lead comprises the following steps: S01. The crude lead smelted in the oxygen-enriched side-blown furnace enters the impurity removal pot through the lead chute to obtain molten lead. When the lead liquid is cooled to 600℃, 0.01wt% of the total mass of the lead liquid is added with flake caustic soda. The mixture is stirred for 2h and samples are taken for testing. When the content of elements such as antimony and tin reaches the requirements, stirring is stopped and the alkali slag is removed.

[0027] S02. When the lead liquid is cooled to 280°C, take a sample to test the copper content, add a copper removal refining agent 1.5 times the weight of the copper content, stir for 60 minutes, take a sample for testing, and stop stirring when the content of copper and other elements reaches the requirements, and remove the copper slag.

[0028] S03. Transfer the lead liquid into the finished product pot, heat it to 450℃, add 0.01wt% of the total mass of the lead liquid, start the mixer to wash the lead, and wait until the slag in the lead liquid is completely washed away. After one lead washing and slag removal, take samples for testing and meet the standards, stop stirring, remove the slag, keep warm and prepare for ingot casting.

[0029] S04. Qualified refined lead liquid enters the fully automated ingot casting machine system through the lead discharge pipe at the bottom of the finished product pot. After completing mold placement, robot surface opening, immersion water cooling solidification, trimming, palletizing, packaging, metering and labeling on the automated ingot casting, the qualified refined lead product is transferred to the product area for placement to obtain recycled refined lead.

[0030] Embodiment 2: A copper removal refining agent is prepared by the following steps: S1. In a reactor, 8 g of PEG-PPG-PEG copolymer was stirred and dissolved in 350 mL of 37.5 wt% aqueous hydrochloric acid solution, 22.5 mL of n-butanol was added, and after stirring and mixing, 32.5 mL of tetraethyl orthosilicate was added dropwise at a rate of 1 mL / s, and the mixture was stirred for 3 h. The mixture was heated to 95 °C and stirred for 22 h. The precipitate was filtered and calcined in air at 525 °C for 7.5 h to obtain mesoporous silica.

[0031] S2. In a reaction kettle, 6 g of mesoporous silica, 5 g of 2-aminoterephthalic acid and 7 g of ferric chloride hexahydrate were dissolved and stirred in 250 mL of DMF for 35 min, the temperature was raised to 125° C. and the reaction was carried out for 22 h. After cooling, the precipitate was filtered and washed with DMF and ethanol, and vacuum dried at 85° C. for 22 h to obtain an iron / silicon dioxide composite powder.

[0032] S3. In a tubular furnace, the iron / silicon dioxide composite powder is heated to 425°C at a rate of 5°C / min, and annealed in air for 3.5 h to obtain an iron oxide / silicon dioxide composite powder; 8 g of the iron oxide / silicon dioxide composite powder and 7.5 g of thiourea are ultrasonically mixed in a 6.5 wt% polyvinyl alcohol aqueous solution, and the precipitate is filtered to obtain a precipitate; the precipitate is vacuum dried at 65°C for 5 h, and then placed in a tubular furnace; the temperature is increased to 525°C at a rate of 5°C / min under nitrogen protection, and annealed for 3.5 h; after cooling, the precipitate is crushed and passed through a 100-mesh sieve to obtain an iron sulfide composite powder.

[0033] S4. 8 g of iron sulfide composite powder and 27.5 g of lead sulfide powder are ultrasonically mixed in a 6.5 wt % polyvinyl alcohol aqueous solution, filtered to obtain a precipitate, and the precipitate is pressed into a mold under a pressure of 85 MPa, vacuum dried at 65 ° C for 11 hours, and then placed in a tubular furnace under nitrogen protection and heated to 300 ° C at a rate of 5 ° C / min for annealing for 90 minutes, and then cooled to obtain a carbonized composite powder, the carbonized composite powder is crushed through a 100 mesh sieve to obtain a carbon / refining agent composite powder, the carbon / refining agent composite powder is dispersed in deionized water, and the pure carbon particles in the carbon / refining agent composite powder are removed by centrifugal separation, and the remaining carbon / refining agent composite powder is vacuum dried at 65 ° C for 11 hours to obtain a copper-refining agent.

[0034] A production process for recycled refined lead comprises the following steps: S01. The crude lead smelted in the oxygen-enriched side-blown furnace enters the impurity removal pot through the lead chute to obtain lead liquid. When the lead liquid is cooled to 625℃, 0.0125wt% of the total mass of the lead liquid is added with flake caustic soda. Stir for 2.5h, take samples for testing, and stop stirring when the content of elements such as antimony and tin reaches the requirements, and remove the alkali slag.

[0035] S02. When the lead liquid is cooled to 300°C, take a sample to test the copper content, add a copper removal refining agent 1.75 times the weight of the copper content, stir for 70 minutes, take a sample for testing, and stop stirring when the content of copper and other elements reaches the requirements, and remove the copper slag.

[0036] S03. Transfer the lead liquid into the finished product pot, heat it to 465℃, add 0.0125wt% of the total mass of the lead liquid, start the mixer to wash the lead, and wait until the scum in the lead liquid is completely washed away. After 1.5 times of lead washing and scum removal, take samples and test them to meet the standards, stop stirring, remove the scum, keep warm and prepare for ingot casting.

[0037] S04. Qualified refined lead liquid enters the fully automated ingot casting machine system through the lead discharge pipe at the bottom of the finished product pot. After completing mold placement, robot surface opening, immersion water cooling solidification, trimming, palletizing, packaging, metering and labeling on the automated ingot casting, the qualified refined lead product is transferred to the product area for placement to obtain recycled refined lead.

[0038] Embodiment 3: A copper removal refining agent is prepared by the following steps: S1. In a reactor, 10 g of PEG-PPG-PEG copolymer was stirred and dissolved in 400 mL of 40 wt% aqueous hydrochloric acid solution, 25 mL of n-butanol was added, and after stirring and mixing, 35 mL of tetraethyl orthosilicate was added dropwise at a rate of 1 mL / s, and the mixture was stirred for 4 h. The mixture was heated to 100 ° C and stirred for 24 h. The precipitate was filtered and calcined in air at 550 ° C for 8 h to obtain mesoporous silica.

[0039] S2. In a reaction kettle, 8 g of mesoporous silica, 6 g of 2-aminoterephthalic acid and 8 g of ferric chloride hexahydrate were dissolved and stirred in 300 mL of DMF for 40 min, the temperature was raised to 130° C. and the reaction was performed for 24 h. After cooling, the precipitate was filtered and washed with DMF and ethanol, and vacuum dried at 90° C. for 24 h to obtain an iron / silicon dioxide composite powder.

[0040] S3. In a tubular furnace, the iron / silicon dioxide composite powder is heated to 450°C at a rate of 5°C / min and annealed in air for 4 hours to obtain an iron oxide / silicon dioxide composite powder; 10 g of the iron oxide / silicon dioxide composite powder and 10 g of thiourea are ultrasonically mixed in an 8 wt % polyvinyl alcohol aqueous solution, and the precipitate is filtered to obtain a precipitate; the precipitate is vacuum dried at 70°C for 6 hours and then placed in a tubular furnace; the temperature is increased to 550°C at a rate of 5°C / min under nitrogen protection and annealed for 4 hours; after cooling, the precipitate is crushed and passed through a 100-mesh sieve to obtain an iron sulfide composite powder.

[0041] S4. 10 g of iron sulfide composite powder and 30 g of lead sulfide powder are ultrasonically mixed in an 8 wt % polyvinyl alcohol aqueous solution, filtered to obtain a precipitate, the precipitate is pressed into a mold under a pressure of 90 MPa, vacuum dried at 70 ° C for 12 h, and then placed in a tubular furnace under nitrogen protection and heated to 350 ° C at a rate of 5 ° C / min for annealing for 100 min, and then cooled to obtain a carbonized composite powder, the carbonized composite powder is crushed through a 100 mesh sieve to obtain a carbon / refining agent composite powder, the carbon / refining agent composite powder is dispersed in deionized water, the pure carbon particles in the carbon / refining agent composite powder are removed by centrifugal separation, and the remaining carbon / refining agent composite powder is vacuum dried at 70 ° C for 12 h to obtain a copper-refining agent.

[0042] Principle of the invention: By synthesizing mesoporous silica, the adsorption capacity of mesoporous silica on scum is improved, the separation effect of copper slag and lead liquid is improved, and the slag cleaning effect of mesoporous silica is improved; using mesoporous silica as a carrier, a porous Fe-MOF is hydrothermally generated on the surface of mesoporous silica, and the Fe-MOF is oxidized to form iron oxide through annealing treatment. The iron oxide / silicon dioxide composite powder is uniformly compounded with thiourea by utilizing the bonding ability of polyvinyl alcohol, and thiourea and iron oxide are reacted at high temperature to form iron sulfide. The iron sulfide is bonded to the surface of mesoporous silica by the carbon structure formed by carbonization of polyvinyl alcohol, and the bonding strength is high. In addition, thiourea also makes the formed carbon structure have the effect of sulfur doping, so as to obtain an iron sulfide composite powder with surface loaded iron sulfide and sulfur-doped carbon; the iron sulfide composite powder and lead sulfide powder are then combined together under the bonding effect of polyvinyl alcohol, and pressed in a mold to make the iron sulfide composite powder and sulfur doped carbon. The lead sulfide powder is evenly combined and polyvinyl alcohol is quickly carbonized under nitrogen protection. The carbonization effect of polyvinyl alcohol is used to coat the evenly combined iron sulfide composite powder / lead sulfide powder to obtain a carbonized composite powder. The pure carbon particles generated in the crushing process are removed by crushing and centrifugation to obtain a copper removal refining agent. The copper removal refining agent uses the carbon layer on the surface to extend the contact time between the iron sulfide composite powder / lead sulfide powder and the lead liquid, reduces the contact between the sulfur element and the air, and improves the copper removal efficiency. As the carbon layer decomposes at high temperature, the lead sulfide and iron sulfide composite powders contact the lead liquid and react with the copper element in the lead liquid. The iron sulfide with a porous structure has a large contact area with the lead liquid and a high copper removal efficiency. Copper replaces the lead element and the iron element in the lead sulfide and iron sulfide to obtain insoluble copper sulfide. The copper sulfide floats to form scum. Under the promotion of the slag removal agent mesoporous silica, a scum with a low lead content is formed, thereby improving the copper removal efficiency and reducing the loss of lead liquid.

[0043] PEG-PPG-PEG copolymer is polyethylene glycol polypropylene glycol polyethylene glycol block, CAS number: 9003-11-6.

[0044] A production process for recycled refined lead comprises the following steps: S01. The crude lead smelted in the oxygen-enriched side-blown furnace enters the impurity removal pot through the lead chute to obtain lead liquid. When the lead liquid is cooled to 650℃, 0.015wt% of the total mass of the lead liquid is added with flake caustic soda. The mixture is stirred for 3h and samples are taken for testing. When the content of elements such as antimony and tin reaches the requirements, stirring is stopped and the alkali slag is removed.

[0045] S02. When the lead liquid is cooled to 320°C, take a sample to test the copper content, add a copper removal refining agent twice the weight of the copper content, stir for 80 minutes, take a sample for testing, and stop stirring when the content of copper and other elements reaches the requirements, and remove the copper slag.

[0046] S03. Transfer the lead liquid into the finished product pot, heat it to 480℃, add 0.015wt% of the total mass of the lead liquid, start the mixer to wash the lead, and wait until the slag in the lead liquid is completely washed away. After washing the lead twice and removing the slag, take samples and test them to meet the standards, stop stirring, remove the slag, keep warm and prepare for ingot casting.

[0047] S04. Qualified refined lead liquid enters the fully automated ingot casting machine system through the lead discharge pipe at the bottom of the finished product pot. After completing mold placement, robot surface opening, immersion water cooling solidification, trimming, palletizing, packaging, metering and labeling on the automated ingot casting, the qualified refined lead product is transferred to the product area for placement to obtain recycled refined lead.

[0048] Comparative Example 1: The difference from Example 1 is that in S2, mesoporous silica is replaced by silica powder (particle size 5-10 μm) to prepare a copper-removing refining agent, and the copper-removing refining agent is used to prepare recycled refined lead.

[0049] Comparative Example 2: The difference from Example 1 is that in S3, the polyvinyl alcohol aqueous solution is replaced by deionized water to prepare a copper-removing refining agent, and the copper-removing refining agent is used to prepare regenerated refined lead.

[0050] Comparative Example 3: The difference from Example 1 is that in S4, 6 g of iron sulfide composite powder and 25 g of lead sulfide powder are ultrasonically mixed in deionized water, filtered to obtain a precipitate, the precipitate is pressed into a mold under a pressure of 80 MPa, vacuum dried at 60° C. for 10 h, and crushed through a 100-mesh sieve to obtain a copper-removing refining agent, and the copper-removing refining agent is used to prepare recycled refined lead.

[0051] Comparative Example 4: The difference from Example 1 is that sulfur is used as a copper-removing refining agent, and the copper-removing refining agent is used to produce regenerated refined lead.

[0052] The performance test of the copper removal refining agent prepared in Example 1 to Example 3 and Comparative Example 1 to Comparative Example 4 was carried out. The processing amount of regenerated refined lead was 10 tons, and the copper content of the regenerated refined lead was 0.055wt%. The produced regenerated refined lead was tested according to the standard of GB / T 469 to test the copper content in the regenerated refined lead before and after copper removal, as well as the lead content in the slag. The results are shown in Table 1: Table 1

[0053] It can be seen from Table 1 that the copper refining agent prepared by the present invention can reduce the copper content in the recycled lead to 0.0006%, and the slag volume is small, the lead content in the slag is low, the lead loss is small, and the economic benefit is high.

[0054] Since the comparative example 1 uses the traditional slag-beating agent silicon dioxide powder, its effect of promoting slag formation is smaller than that of the embodiment 1, and its adsorption capacity is weaker, resulting in the slag being more dispersed, the total slag amount increasing, and the lead content of the slag increasing.

[0055] In Comparative Example 2, since the carbonization effect of polyvinyl alcohol was not used to fix the iron oxide powder during sulfidation, the generated iron sulfide had a weaker bonding force with the mesoporous silica, resulting in partial agglomeration of the iron sulfide and the mesoporous silica, weakening the slag removal effect and increasing the lead content in the slag, resulting in a copper removal efficiency lower than that in Example 1.

[0056] In Comparative Example 3, since only the iron sulfide composite powder and the lead sulfide powder are pressed into shape and compounded by physical action, the compounded iron sulfide composite powder and the lead sulfide powder are easy to fall off during the crushing process, and the protective effect of the carbon layer is lacking, the reaction time of the copper removal refining agent in the lead liquid cannot be extended, the total slag amount becomes less, but the lead content in the slag increases, indicating that the slag cleaning is incomplete and the copper removal efficiency is lower than that of Example 1.

[0057] In Comparative Example 4, sulfur is directly added. When the sulfur contacts the high-temperature lead liquid, it will burn and cause loss, which increases the copper content of Comparative Example 4. To further reduce the copper content, the amount of sulfur used needs to be increased, resulting in a significant increase in the amount of sulfur used, and the slag in the total slag has a high lead content, resulting in a large lead loss.

[0058] Although embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that various changes, modifications, substitutions and variations may be made to the embodiments without departing from the principles and spirit of the present invention, and that the scope of the present invention is defined by the appended claims and their equivalents.

Claims

1. A copper removal refining agent, characterized in that: The preparation method of the copper removal refining agent comprises the following steps: Step 1, ultrasonically mixing the iron oxide / silicon dioxide composite powder and thiourea in a 5-8wt% polyvinyl alcohol aqueous solution, filtering to obtain a precipitate, vacuum drying the precipitate and placing it in a tube furnace, heating it to 500-550°C at a rate of 5°C / min under nitrogen protection for annealing for 3-4h, cooling it and crushing it through a 100-mesh sieve to obtain an iron sulfide composite powder; Step 2: Ultrasonically mix the iron sulfide composite powder and the lead sulfide powder in a 5-8wt% polyvinyl alcohol aqueous solution, filter to obtain a precipitate, press the precipitate into a mold, vacuum dry it, place it in a tubular furnace, heat it to 250-350°C at a rate of 5°C / min under nitrogen protection, and anneal it for 80-100min, and obtain a carbonized composite powder after cooling. The carbonized composite powder is crushed through a 100-mesh sieve to obtain a carbon / refining agent composite powder, and the pure carbon particles in the carbon / refining agent composite powder are removed by centrifugal separation, and the copper-refining agent is obtained after vacuum drying.

2. A copper removal refining agent according to claim 1, characterized in that: The mass ratio of the iron oxide / silicon dioxide composite powder to thiourea in step 1 is 6-10g:5-10g.

3. A copper removal refining agent according to claim 2, characterized in that: The steps for preparing the iron oxide / silicon dioxide composite powder are as follows: The iron / silicon dioxide composite powder is heated to 400-450° C. at a rate of 5° C. / min in a tubular furnace and annealed in air for 3-4 hours to obtain an iron oxide / silicon dioxide composite powder.

4. A copper removal refining agent according to claim 3, characterized in that: The iron / silicon dioxide composite powder is prepared by the following steps: In a reaction kettle, mesoporous silica, 2-aminoterephthalic acid and ferric chloride hexahydrate are stirred, dissolved and mixed in DMF for 30-40 minutes, heated to 120-130° C. and reacted for 20-24 hours. After cooling, the precipitate is filtered, washed and vacuum dried to obtain an iron / silicon dioxide composite powder.

5. A copper removal refining agent according to claim 4, characterized in that: The usage ratio of the mesoporous silica, 2-aminoterephthalic acid, ferric chloride hexahydrate and DMF is 4-8g:4-6g:6-8g:200-300mL.

6. A copper removal refining agent according to claim 5, characterized in that: The mesoporous silica is prepared by the following steps: In a reaction kettle, the PEG-PPG-PEG copolymer is stirred and dissolved in a 35-40wt% hydrochloric acid aqueous solution, n-butanol is added, and after stirring and mixing, ethyl orthosilicate is added dropwise, and the mixture is stirred for 2-4 hours. The mixture is heated to 90-100° C. and stirred for 20-24 hours. The precipitate is filtered and calcined in air at 500-550° C. for 7-8 hours to obtain mesoporous silica.

7. A copper removal refining agent according to claim 6, characterized in that: The usage ratio of the PEG-PPG-PEG copolymer, the hydrochloric acid aqueous solution, n-butanol and tetraethyl orthosilicate is 6-10 g: 300-400 mL: 20-25 mL: 30-35 mL.

8. A copper removal refining agent according to claim 1, characterized in that: The mass ratio of the iron sulfide composite powder to the lead sulfide powder in step 2 is 6-10g:25-30g.

9. A production process for recycled refined lead, characterized in that: The steps include: S01, smelting crude lead in an oxygen-enriched side-blown furnace, which enters the impurity removal pot through a lead chute to obtain lead liquid. When the lead liquid is cooled to 600-650°C, 0.01-0.015wt% of the total mass of the lead liquid is added with flake caustic soda, stirred for 2-3h, and sampled for testing. When the content of elements such as antimony and tin reaches the requirements, stirring is stopped and the alkali slag is removed; S02, when the lead liquid is cooled to 280-320°C, sample and test the copper content, add a copper removal refining agent 1.5-2 times the weight of the copper content, stir for 60-80 minutes, sample and test, and stop stirring when the content of copper and other elements reaches the requirements, and remove the copper slag; S03, transfer the lead liquid into the finished product pot, heat it to 450-480℃, add 0.01-0.015wt% of the total mass of the lead liquid, start the mixer to wash the lead, and wait until the scum in the lead liquid is completely washed away. After 1-2 times of lead washing and scum removal, sampling and testing meet the standards, stop stirring, remove the scum, keep warm, cast ingots, and obtain recycled refined lead.

10. A production process for recycled refined lead according to claim 9, characterized in that: The copper-removing refining agent is the copper-removing refining agent according to any one of claims 1 to 8.

Images