Equipment and method for recovering refined lead from high-bismuth lead-bismuth alloy

Abstract

The present invention provides a device and method for recovering refined lead from a high-bismuth lead-bismuth alloy, comprising a lead electrolysis system and a bismuth electrolysis system. The lead electrolysis system and the bismuth electrolysis system share a silicon rectifier. Both the lead electrolysis system and the bismuth electrolysis system comprise an electrolytic cell group, a high-level cell, a low-level cell, a circulating acid pipe and an acid pump. The electrolyte flows from the high-level cell into the electrolytic cell group through the circulating acid pipe, then flows from the electrolytic cell group into the low-level cell, and is pumped from the low-level cell into the high-level cell through the acid pump for circulation. The electrolytic cell group comprises electrolytic cells, inter-cell conductive copper plates and conductive large copper plates. The electrolytic cells between the inter-cell conductive copper plates are all connected in series to form a series. The bismuth electrolysis system realizes parallel connection of two series by adjusting the connection mode of the conductive large copper plates. The current density of the bismuth electrolysis system is 1 / 2 of that of the lead electrolysis system. The isolation and independence of the circulating electrolyte of the bismuth electrolysis system is realized by valve control. The invention can process lead-bismuth alloys containing 15-35% bismuth, produce refined lead containing less than 30 ppm bismuth, and produce anode mud with bismuth enriched to 50-80%.

Description

Technical Field

[0001] The present invention belongs to the field of recovering refined lead from high-bismuth lead-bismuth alloy, and in particular relates to a device and method for recovering refined lead from high-bismuth lead-bismuth alloy. Background Art

[0002] Some lead-containing materials contain a small amount of bismuth. After the lead-containing materials are oxidized and reduced by the crude refining system, electrolytically refined by lead, and then by the silver recovery system, the bismuth element is finally enriched with lead to form a lead-bismuth alloy, which generally contains 15-35% bismuth. The traditional vacuum furnace distillation method is used to enrich bismuth. When the alloy contains bismuth ≥ 80%, it can be sold as a crude bismuth product. This method is costly, the direct bismuth recovery rate is less than 70%, and the production cycle is long. Summary of the invention

[0003] In view of the problems existing in the prior art, the present invention provides a device and method for recovering refined lead from a high-bismuth lead-bismuth alloy. The specific scheme is as follows:

[0004] Equipment for recovering refined lead from high-bismuth lead-bismuth alloy comprises a lead electrolysis system and a bismuth electrolysis system. The lead electrolysis system and the bismuth electrolysis system share a silicon rectifier. Both the lead electrolysis system and the bismuth electrolysis system comprise an electrolytic cell group, a high-level cell, a low-level cell, a circulating acid pipe and an acid pump. The electrolyte flows from the high-level cell into the electrolytic cell group through the circulating acid pipe, then flows from the electrolytic cell group into the low-level cell, and is pumped from the low-level cell into the high-level cell through the acid pump for circulation. The electrolytic cell group comprises electrolytic cells, inter-cell conductive copper plates and conductive large copper plates. The electrolytic cells between the inter-cell conductive copper plates are connected in series to form a series. The bismuth electrolysis system realizes parallel connection of two series by adjusting the connection method of the conductive large copper plates. The current density of the bismuth electrolysis system is 1 / 2 of that of the lead electrolysis system. The circulating electrolyte of the bismuth electrolysis system is isolated and independent by valve control.

[0005] Furthermore, the capacity of the high-level tank of the bismuth electrolysis system is 6% of the electrolyte volume of the bismuth electrolysis system, and the capacity of the low-level tank of the bismuth electrolysis system is 10% of the electrolyte volume of the bismuth electrolysis system.

[0006] Furthermore, the acid pump flow rate is the amount of electrolyte in the bismuth electrolysis system / (2-2.5)h / 0.8.

[0007] A method for recovering refined lead from a lead-bismuth alloy containing high bismuth content is provided, wherein the lead-bismuth alloy containing high bismuth content is cast into an anode plate and then loaded into the lead-bismuth alloy containing high bismuth content to be electrolyzed and the refined lead is recovered. During the electrolysis process, an oxidation reaction occurs between lead and bismuth on the anode: Pb-2e=Pb 2+ , Bi-3e=Bi 3+ , a reduction reaction occurs at the cathode: Pb 2+ +2e=Pb, bismuth remains in the anode mud after oxidation, realizing the separation of lead and bismuth.

[0008] Furthermore, during the electrolysis process, the current density of the bismuth electrolysis system is controlled to be 85-95 A / m 2 , the cell voltage is controlled below 0.65V, and the power-on cycle is 4 to 6 days.

[0009] Furthermore, the mass concentration of the electrolyte components in the electrolysis process is controlled at 115-160 g / L H2SiF6 (total), Pb 2+ 45~80g / L, H2SiF6(free) 85~100g / L, electrolyte circulation volume is controlled at 15~20L / min.

[0010] 8. Furthermore, during the electrolysis process, beef glue and naphthol are added as additives, wherein the beef glue is 0.3-0.5 kg / t and the naphthol is 6-8 g / t.

[0011] Advantages of the present invention

[0012] The equipment and method for recovering refined lead from high-bismuth lead-bismuth alloy of the present invention realizes the electrolysis of high-bismuth lead-bismuth alloy to produce refined lead on the basis of lead electrolysis system. The equipment and method are suitable for treating lead-bismuth alloy containing 15-35% bismuth, and produce refined lead containing less than 30ppm bismuth, and at the same time produce anode mud enriched with bismuth to 50-80%. Compared with the traditional vacuum distillation and converter blowing method for enriching bismuth, the method does not require the investment of large plant, equipment and facilities, and can be conveniently switched back to the lead electrolysis system for normal lead electrolysis when it is stopped, which plays a great practicality in production, and greatly reduces production costs, with low investment costs and short production cycle. BRIEF DESCRIPTION OF THE DRAWINGS

[0013] Figure 1 The invention is a schematic diagram of the connection of the equipment for recovering refined lead from a lead-bismuth alloy containing high bismuth content.

[0014] Figure 2 The present invention provides a schematic diagram of the connection mode and current direction of the conductive large copper plates of the lead electrolysis system and the bismuth electrolysis system.

[0015] In the figure:

[0016] 1: High-level tank of lead electrolysis system; 2: Low-level tank of lead electrolysis system; 3: High-level tank of bismuth electrolysis system; 4: Low-level tank of bismuth electrolysis system; 5; Valve; 6: Electrolytic cell group; 7: Circulating acid pipe; 8: Large conductive copper plate; 9: Electrolytic cell; 10: Conductive copper plate between cells. DETAILED DESCRIPTION

[0017] The present invention is further explained and illustrated below in conjunction with the accompanying drawings and specific embodiments. It should be noted that this specific embodiment is not intended to limit the scope of rights of the present invention.

[0018] like Figure 1 and Figure 2 As shown, the equipment for recovering refined lead from high-bismuth lead-bismuth alloy provided in this specific embodiment includes a lead electrolysis system and a bismuth electrolysis system, and the lead electrolysis system and the bismuth electrolysis system share a silicon rectifier.

[0019] The lead electrolysis system comprises an electrolytic cell group 6, a lead electrolysis system high-level cell 1, a lead electrolysis system low-level cell 2, a circulating acid pipe 7 and an acid pump (not shown).

[0020] The bismuth electrolysis system includes an electrolytic cell group 6, a high-level cell 3 for the bismuth electrolysis system, a low-level cell 4 for the bismuth electrolysis system, a circulating acid pipe 7 and an acid pump (not shown). The capacity of the high-level cell 1 for the bismuth electrolysis system is 6% of the electrolyte volume of the bismuth electrolysis system, and the capacity of the low-level cell 2 for the bismuth electrolysis system is 10% of the electrolyte volume of the bismuth electrolysis system.

[0021] The electrolyte flows from the high-level tank 1 of the lead electrolysis system and the high-level tank 3 of the bismuth electrolysis system into the electrolysis cell group 6 through the circulating acid pipe 7, and then flows from the electrolysis cell group 6 into the low-level tank 2 of the lead electrolysis system and the low-level tank 4 of the bismuth electrolysis system, and is then pumped from the low-level tank 2 of the lead electrolysis system and the low-level tank 4 of the bismuth electrolysis system into the high-level tank 1 of the lead electrolysis system and the high-level tank 3 of the bismuth electrolysis system for circulation through the acid pump. The flow rate of the acid pump is the amount of electrolyte in the bismuth electrolysis system / (2-2.5)h / 0.8.

[0022] like Figure 2 As shown, the electrolytic cell group 6 includes an electrolytic cell 9, an inter-cell conductive copper plate 10 and a conductive large copper plate 8. The electrolytic cells 9 between the inter-cell conductive copper plates 10 are connected in series to form a series. The bismuth electrolysis system realizes the parallel connection of two series by adjusting the connection method of the conductive large copper plate 8. The current density of the bismuth electrolysis system is 1 / 2 of that of the lead electrolysis system. The isolation and independence of the circulating electrolyte of the bismuth electrolysis system is realized by controlling the valve 5.

[0023] Theoretical basis: According to the current density calculation formula: Dk = A / S, where Dk represents current density, A represents current intensity, and S represents the total effective cathode area in a single electrolytic cell. After the two series of bismuth electrolysis system are connected in parallel, the two series are taken as a whole, and the total effective cathode area is 2S. If the current intensity A remains unchanged, the current density is Dk / 2, that is, the current density of the bismuth electrolysis system is 1 / 2 of that of the lead electrolysis system.

[0024] A method for recovering refined lead from a high-bismuth lead-bismuth alloy, wherein the high-bismuth lead-bismuth alloy is cast into an anode plate and then loaded into a high-bismuth lead-bismuth alloy refined lead recovery device for electrolytic treatment to recover refined lead. During the electrolysis process, low current density is conducive to the diffusion of metal ions in the anode mud layer, reducing the increase in cell voltage caused by concentration polarization. Therefore, the current density of the bismuth electrolysis system is controlled to be 85-95A / m 2When the cell voltage is greater than 0.65V, the precipitation of bismuth and other impurity metals intensifies, causing the precipitation of lead impurities to exceed the standard. Therefore, the cell voltage value is controlled below 0.65V, and the power-on cycle is 4 to 6 days. The power-on time is finally determined by the cell voltage value. When the cell voltage value is 0.6-0.65V, the cell must be replaced with a new anode plate to ensure that the precipitation of lead is qualified. The mass concentration of the electrolyte components is controlled at H2SiF6 (total) 115-160g / L, Pb 2+ 45~80g / L, H2SiF6(free) 85~100g / L, electrolyte circulation volume is controlled at 15~20L / min, cow glue and naphthol are added as additives, cow glue is 0.3~0.5kg / t of precipitated lead, naphthol is 6~8g / t of precipitated lead, and the dosage of additives is adjusted according to the crystallization of precipitated lead to obtain a smooth and delicate precipitated lead.

[0025] Lead and bismuth undergo oxidation reaction at the anode: Pb-2e=Pb 2+ , Bi-3e=Bi 3+ , a reduction reaction occurs at the cathode: Pb 2+ +2e=Pb. Bismuth, due to its more positive charge than lead, remains in the anode mud after oxidation and does not form ions to enter the solution, thus achieving the separation of lead and bismuth.

[0026] The bismuth electrolysis system electrolytic cell can double the cathode current area, and the current density through the bismuth electrolysis system electrolytic cell is reduced to 1 / 2 of that of the lead electrolysis system. The normal current density of the lead electrolysis system is 170-190A / m 2 The current density of the bismuth electrolysis system is 85-95A / m 2 , under the condition of low current density, the electrolysis of high-bismuth alloy can produce refined lead, and according to the production scale of high-bismuth alloy, the number of energized cells in the bismuth electrolysis system can be reduced or expanded according to this method.

[0027] Experiment 1:

[0028] The above-mentioned equipment and method for recovering refined lead from high-bismuth lead-bismuth alloy are used to recover refined lead from high-bismuth lead-bismuth alloy. The grade of the lead-bismuth alloy anode plate is calculated by weight percentage: Pb 68.35%, Sb 6.11%, Bi 24.33%, and the current density of the bismuth electrolysis system is 85A / m 2 The electrolyte composition is controlled by mass concentration: H2SiF6 (total) 118.07g / L, Pb 2+ 46.77g / L, H2SiF6 (free) 85.33g / L, power-on time: 144 hours, lead precipitation by weight percentage: Bi 0.0021%, anode mud Bi 62.79%, Pb 9.71%, Sb 18.90%;

[0029] Experiment 2:

[0030] The above-mentioned equipment and method for recovering refined lead from high-bismuth lead-bismuth alloy are used to recover refined lead from high-bismuth lead-bismuth alloy. The grade of the lead-bismuth alloy anode plate is calculated by weight percentage: Pb68.35%, Sb6.11%, Bi24.33%, and the current density of the bismuth electrolysis system is: 90A / m 2 The electrolyte composition is controlled by mass concentration: H2SiF6 (total) 118.56g / L, Pb 2+ 47.64g / L, H2SiF6 (free) 85.21g / L, through time: 136 hours, precipitated lead by weight percentage: Bi 0.0023%, anode mud Bi 62.12%, Pb 9.11%, Sb 18.33%;

[0031] Experiment 3:

[0032] The above-mentioned equipment and method for recovering refined lead from high-bismuth lead-bismuth alloy are used to recover refined lead from high-bismuth lead-bismuth alloy. The grade of the lead-bismuth alloy anode plate is calculated by weight percentage: Pb68.35%, Sb6.11%, Bi24.33%, and the current density of the bismuth electrolysis system is: 95A / m 2 The electrolyte composition is controlled by mass concentration: H2SiF6 (total) 120.05g / L, Pb 2+ 48.08g / L, H2SiF6 (free) 86.39g / L, through-the-air time: 128 hours, precipitated lead by weight percentage: Bi 0.0026%, anode mud contains Bi 62.90%, Pb 9.02%, Sb 18%.

Claims

1. A device for recovering refined lead from a high-bismuth lead-bismuth alloy, characterized in that: The invention comprises a lead electrolysis system and a bismuth electrolysis system. The lead electrolysis system and the bismuth electrolysis system share a silicon rectifier. Both the lead electrolysis system and the bismuth electrolysis system comprise an electrolytic cell group, a high-level cell, a low-level cell, a circulating acid pipe and an acid pump. The electrolyte flows from the high-level cell into the electrolytic cell group through the circulating acid pipe, then flows from the electrolytic cell group into the low-level cell, and is pumped from the low-level cell into the high-level cell through the acid pump for circulation. The electrolytic cell group comprises electrolytic cells, conductive copper plates between cells and large conductive copper plates. The electrolytic cells between the conductive copper plates between cells are connected in series to form a series. The bismuth electrolysis system realizes parallel connection of two series by adjusting the connection mode of the large conductive copper plates. The current density of the bismuth electrolysis system is 1 / 2 of that of the lead electrolysis system. The circulating electrolyte of the bismuth electrolysis system is isolated and independent by valve control.

2. The equipment for recovering refined lead from high-bismuth lead-bismuth alloy according to claim 1, characterized in that: The capacity of the high-level tank of the bismuth electrolysis system is 6% of the electrolyte volume of the bismuth electrolysis system, and the capacity of the low-level tank of the bismuth electrolysis system is 10% of the electrolyte volume of the bismuth electrolysis system.

3. The equipment for recovering refined lead from high-bismuth lead-bismuth alloy according to claim 1, characterized in that: The acid pump flow rate is the amount of electrolyte in the bismuth electrolysis system / (2-2.5)h / 0.

8.

4. A method for recovering refined lead from a lead-bismuth alloy containing high bismuth content by using the equipment for recovering refined lead from a lead-bismuth alloy containing high bismuth content as claimed in claim 1, characterized in that: The high-bismuth lead-bismuth alloy is cast into an anode plate and then loaded into the equipment for recovering refined lead from the high-bismuth lead-bismuth alloy for electrolysis to recover refined lead. During the electrolysis process, lead and bismuth undergo an oxidation reaction on the anode: Pb-2e=Pb 2+ , Bi-3e=Bi 3+ , a reduction reaction occurs at the cathode: Pb 2+ +2e=Pb, bismuth remains in the anode mud after oxidation, realizing the separation of lead and bismuth.

5. The method for recovering refined lead from a lead-bismuth alloy containing high bismuth content according to claim 4, characterized in that: During the electrolysis process, the current density of the bismuth electrolysis system is controlled to be 85-95 A / m 2 , the cell voltage is controlled below 0.65V, and the power-on cycle is 4 to 6 days.

6. The method for recovering refined lead from a lead-bismuth alloy containing high bismuth content according to claim 4, characterized in that: The mass concentration of the electrolyte components in the electrolysis process is controlled within the range of 115-160 g / L for total H2SiF6 and 150 g / L for Pb 2+ 45~80g / L, free acid H2SiF685~100g / L, electrolyte circulation volume is controlled at 15~20L / min.

7. The method for recovering refined lead from a lead-bismuth alloy containing high bismuth content according to claim 4, characterized in that: In the electrolysis process, beef glue and naphthol are added as additives, wherein the beef glue is 0.3-0.5 kg / t and the naphthol is 6-8 g / t.

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