CN110079827B - Electrolysis purification method of lead based on sulfamic acid bath - Google Patents
Electrolysis purification method of lead based on sulfamic acid bath Download PDFInfo
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- CN110079827B CN110079827B CN201811463689.6A CN201811463689A CN110079827B CN 110079827 B CN110079827 B CN 110079827B CN 201811463689 A CN201811463689 A CN 201811463689A CN 110079827 B CN110079827 B CN 110079827B
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- C25—ELECTROLYTIC OR ELECTROPHORETIC PROCESSES; APPARATUS THEREFOR
- C25C—PROCESSES FOR THE ELECTROLYTIC PRODUCTION, RECOVERY OR REFINING OF METALS; APPARATUS THEREFOR
- C25C1/00—Electrolytic production, recovery or refining of metals by electrolysis of solutions
- C25C1/18—Electrolytic production, recovery or refining of metals by electrolysis of solutions of lead
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Abstract
The subject of the invention is: in the electrolytic purification of lead by an aminosulfonic acid bath, the generation of white residue is suppressed, and the decrease of the lead concentration in the electrolytic solution is suppressed. The solution is a method for electrolytic purification of lead by a sulfamic acid bath, wherein the electrolytic purification is carried out while controlling the decomposition rate of sulfamic acid to 0.06%/day or less.
Description
The present application is a divisional application of an application having a national application date of 2015, 12 and 3 (priority date of 2014, 12 and 3), a national application number of 201510875275.4, and an invention name of "method for electrolytic purification of lead based on sulfamic acid bath".
Technical Field
The present invention relates to a method for electrolytic purification of lead by a sulfamic acid bath, and more particularly, to a method for electrolytic purification of lead by a sulfamic acid bath for recovering lead contained in dry fumes generated from a melting furnace for recycling raw materials such as a color smelting furnace, a substrate (disc), and an electronic component, and a dry furnace for melting industrial waste.
Background
In order to recover lead contained in dry fumes from nonferrous smelting, from melting furnaces for recycling raw materials such as substrates and electronic components, and from dry furnaces for melting industrial wastes, the fumes are leached with sulfuric acid to produce lead sulfate, which is then reduced by melting in an electric furnace. The metal separated by the melting reduction is subjected to soda treatment, and then the metal is subjected to anode casting, followed by electrolytic purification in an aminosulfonic acid bath, thereby recovering lead.
As such electrolytic purification technology of lead, for example, patent document 1 discloses an electrolytic method of lead in which the current density at the 1 st stage is set to 50A/m in electrolytic purification using sulfamic acid bath2Electrolysis was carried out for 2 hours or more, and then as the 2 nd stage, electrolysis was carried out at 100A/m2Thereafter, electrolysis was performed to recover high-purity lead. And record, root ofWith this configuration, high-purity lead can be recovered even for a high-Bi-grade anode.
Documents of the prior art
Patent document
Patent document 1: japanese patent No. 5163988.
Disclosure of Invention
Problems to be solved by the invention
If the conventional electrolytic purification of lead by an aminosulfonic acid bath is performed, white residue is visible in the bath, and the lead concentration in the electrolytic solution is lowered. That is, the white residue is accumulated on the bottom of the electrolytic cell, and the white residue must be taken out of the electrolytic cell to some extent, so that the electrolysis must be stopped, and the frequency increases as the white residue increases. In addition, the electrodeposition condition of lead may be deteriorated when the lead concentration in the electrolyte is lowered. The reason for this is that: by the following reaction, sulfamic acid in the electrolytic purification of lead by a sulfamic acid bath is decomposed, and a white residue is deposited as lead sulfate, thereby lowering the lead concentration in the electrolytic solution.
SO3NH2 -＋H2O→SO4 2-＋NH4+
Pb2+＋SO4 2-→PbSO4↓
Means for solving the problems
The present inventors have made extensive studies to solve the above problems, and as a result, have found that: by controlling the decomposition rate of sulfamic acid to a predetermined value or less, the formation of white residue can be suppressed in electrolysis of lead by a sulfamic acid bath, and the decrease in the lead concentration in the electrolyte can be suppressed.
In one aspect of the present invention made in view of the above-described findings, the present invention is a method for electrolytic purification of lead by a sulfamic acid bath, the method for electrolytic purification of lead by a sulfamic acid bath using a lead anode, the method for electrolytic purification of lead by a sulfamic acid bath being performed while controlling the decomposition rate of sulfamic acid to 0.06%/day or less.
In one embodiment, the method for electrolytic purification of lead based on a sulfamic acid bath of the present invention performs electrolytic purification while adjusting the concentration of sulfamic acid in the sulfamic acid bath to a concentration 20 to 60g/L higher than the concentration of lead in the sulfamic acid bath.
The method for the electrolytic purification of lead based on a sulfamic acid bath of the present invention in another embodiment is to perform the electrolytic purification while adjusting the temperature of the electrolyte of the sulfamic acid bath to 15 to 30 ℃.
Effects of the invention
According to the present invention, in the electrolytic purification of lead by a sulfamic acid bath, the generation of white residue can be suppressed, and the decrease of the lead concentration in the electrolytic solution can be suppressed. The frequency of taking out the white residue from the electrolytic cell can thus be suppressed. Further, by suppressing the decrease in the lead concentration in the electrolytic solution, the control of the lead concentration becomes easy, and a good lead electrodeposition state can be obtained. And also has the effect of reducing the frequency of supplementation of sulfamic acid in the electrolytic purification.
Drawings
FIG. 1 is a graph showing the relationship between the concentration of sulfamic acid and the decomposition rate of sulfamic acid in example 1.
Fig. 2 is a graph showing the relationship between the electrolyte temperature and the decomposition rate of sulfamic acid in example 2.
Detailed Description
The present invention is described in further detail below.
In the method for electrolytic purification of lead by using sulfamic acid bath, the electrolytic purification is performed while controlling the decomposition rate of sulfamic acid to be less than 0.06%/day. It is further preferable to perform electrolytic purification while adjusting the concentration of sulfamic acid in the sulfamic acid bath to a concentration 20 to 60g/L higher than the concentration of lead in the sulfamic acid bath, and it is preferable to perform electrolytic purification while adjusting the temperature of the electrolyte in the sulfamic acid bath to 15 to 30 ℃.
In the electrolytic purification of lead based on sulfamic acid bath, the anodic and cathodic reactions are as follows:
anodic reaction: pb + 2SO3NH2-→Pb(SO3NH2)2＋2e-
Cathodic reaction: pb (SO)3NH2)2＋2e-→Pb＋2SO3NH2-
The raw material (lead-containing substance) to be electrolytically purified is not particularly limited, and examples thereof include lead-containing substances obtained by: copper ore is subjected to flash smelting furnace (autolysis furnace) treatment and converter treatment, then lead sulfate obtained after converter ash is treated with sulfuric acid is made into lead carbonate through sodium carbonate, then the lead carbonate is subjected to smelting reduction in an electric furnace, and the separated metal is treated with soda. The component of the raw material (lead-containing substance) to be electrolytically purified may be lead as a main component, but may be 60 mass% or more, and may be, for example, a lead-containing substance containing 70 to 90 mass% of lead, 0.04 mass% of tin, and 5 to 30 mass% of bismuth.
The lead-containing substance was cast into the shape of an anode and used as an anode for electrolytic purification. The size of the anode is smaller than that of the cathode, so that the edge effect can be prevented and the excellent electrodeposited lead can be smoothly recovered.
By controlling the decomposition rate of sulfamic acid in the electrolyte to 0.06%/day or less, the deposition of lead sulfate can be reduced. It is also possible to suppress a decrease in the lead concentration in the electrolytic solution. Further, deterioration of sulfamic acid in electrolytic purification of lead by a sulfamic acid bath can be favorably suppressed, and the frequency of replenishment of sulfamic acid can be suppressed. On the other hand, if the concentration exceeds 0.06%/day, the production of lead sulfate increases, and the lead from the anode does not dissolve out in time, resulting in a decrease in the lead concentration in the electrolyte. And the generation of a large amount of lead sulfate increases the frequency of discontinuing the electrolytic purification and removing the lead sulfate accumulated in the bottom of the electrolytic cell. If the decomposition of sulfamic acid proceeds, it is necessary to frequently replenish sulfamic acid in order to maintain a predetermined concentration of sulfamic acid. The decomposition rate of sulfamic acid is preferably 0.04%/day or less, more preferably 0.02%/day or less.
The decomposition rate (d) of sulfamic acid is represented by the following formula:
d=Ad/A0
·Ad: amount of decomposed sulfamic acid
Ad= residue weight. Pb grade X (97/207)
The above "97" is the sulfamic acid molecular weight, and the above "207" is the Pb atomic weight
·A0: initial amount of sulfamic acid
In the present invention, the decomposition rate of sulfamic acid per day is preferably calculated as the amount of decomposed sulfamic acid per 1 day by averaging the weight of residues after 5 days.
The concentration of sulfamic acid in the electrolyte is preferably adjusted to a concentration (hereinafter also referred to as excess) 20 to 60g/L higher than the concentration of lead (g/L) in the electrolyte. Regarding the sulfamic acid concentration in the electrolyte of the present invention, for example, when the lead concentration in the electrolyte is 80g/L, it is preferable to adjust the sulfamic acid concentration in the electrolyte to 100-140 g/L. The concentration of sulfamic acid is expressed as a concentration of moles relative to moles of lead, but the molecular weight of sulfamic acid is close to the atomic weight of lead, so there is no problem in actually comparing the concentration of sulfamic acid directly with the concentration of lead.
When the sulfamic acid concentration in the electrolyte is higher than the lead concentration (g/L) in the electrolyte by more than 60g/L, the decomposition rate of sulfamic acid increases, and it is difficult to control the concentration to 0.06%/day or less. Whereas below 20g/L, the effect of addition of sulfamic acid may be lost. Since the decomposition of sulfamic acid proceeds and the concentration continues to decrease during electrolysis, sulfamic acid may be added as needed to maintain 20g/L or more, but when the decomposition rate of sulfamic acid exceeds 0.06%/day, the addition frequency increases and the accumulation of lead sulfate increases.
The electrolyte temperature of the sulfamic acid bath is preferably 15 ℃ to 30 ℃. Above 30 ℃, the decomposition of sulfamic acid may increase in the electrolytic purification of lead by sulfamic acid bath, and further, the accumulation of lead sulfate may increase due to the increase in the decomposition of sulfamic acid, and the lead concentration in the electrolyte may decrease. However, since the electrolytic solution temperature is too low and the electrodeposition of lead may be deteriorated, it is preferably 15 ℃ or higher, and more preferably 20 ℃ or higher.
Preferably, the lead concentration in the electrolyte is 60-80 g/L. With this configuration, good electrodeposition of lead electrodeposited on the cathode by electrolytic purification can be obtained. When the decomposition rate of sulfamic acid exceeds 0.06%/day, the lead concentration in the electrolyte is lowered, and it is difficult to control the lead concentration within an appropriate range. Therefore, if it is 0.06%/day or less, the lead concentration in the electrolyte can be easily adjusted to a narrow range of 60 to 80 g/L. More preferably, the lead concentration in the electrolyte is 70 to 80 g/L.
As a smoothing agent as another component in the electrolyte, it is preferable to add 1 to 700mg/L of NOIGEN BN-1390 (hereinafter, "NOIGEN (ノイゲン)" is a registered trademark) or NOIGEN BN-2560. Thereby, good electrodeposited lead can be recovered more smoothly. NOIGEN BN-1390 and NOIGEN BN-2560 are nonionic surfactants containing polyoxyethylene mono-naphthyl ether as a main component, and are first industrial pharmaceutical products. NOIGEN BN-1390 is a nonionic surfactant containing 90% polyoxyethylene mono-naphthyl ether, the balance being water.
The current density of electrolysis is preferably controlled to 50-100A/m2. Thereby, good electrodeposited lead can be recovered more smoothly.
Examples
The following examples of the present invention are presented for a better understanding of the present invention and its advantages, and are not intended to limit the invention.
Example 1 Effect of sulfamic acid concentration)
As a composition of the electrolytic solution, NOIGEN BN-1390 was added as a smoothing agent to a solution adjusted to the concentrations described in table 1 so that the concentration thereof was 10 mg/L. A lead plate obtained by casting a lead-containing substance is used as an anode, a stainless steel plate is used as a cathode, and the lead plate and the stainless steel plate are alternately arranged in an electrolytic cell. The electrolyte is replenished into the electrolytic cell after the electrodes are charged, and the concentration distribution in the electrolytic cell is made uniform by feeding the electrolyte so that the residence time of the electrolyte in the electrolytic cell is about 1 hour. The electrolytic solution was purified by electrolysis for 5 days while adjusting the temperature of the electrolytic solution to the temperature shown in Table 1 and applying a current at the current density shown in Table 1, thereby recovering electrodeposited lead. In examples 1-2, 1-3, 1-4, and 1-5, the decomposition rate [% ] of sulfamic acid was controlled to 0.3% or less for 5 days.
As a result, the surface roughness of the electrodeposition film was significant in example 1-1, and the decrease in the lead concentration in the electrolytic solution was not suppressed in examples 1-6 and 1-7. The decomposition rate of sulfamic acid was 0.4% in examples 1 to 6, and 0.9% in examples 1 to 7. On the other hand, in examples 1-2, 1-3, 1-4 and 1-5, the formation of white residue was suppressed, and the decrease in the lead concentration in the electrolyte was suppressed. FIG. 1 is a graph showing the decomposition rates of sulfamic acid in examples 1 to 3 (30 g/L in excess of sulfamic acid concentration), examples 1 to 6 (80 g/L in excess of sulfamic acid concentration), and examples 1 to 7 (130 g/L in excess of sulfamic acid concentration). In tables 1 and 2, "sulfamic acid concentration (excess portion)" means "sulfamic acid concentration of electrolyte (portion in electrolyte that exceeds lead concentration)".
[ Table 1]
Example 2 influence of the Electrolysis temperature
As a composition of the electrolytic solution, NOIGEN BN-1390 was added as a smoothing agent to a solution adjusted to the concentrations described in table 2so that the concentration thereof was 10 mg/L. A lead plate obtained by casting a lead-containing substance is used as an anode, a stainless steel plate is used as a cathode, and the lead plate and the stainless steel plate are alternately arranged in an electrolytic cell. The electrolyte is replenished into the electrolytic cell after the electrodes are charged, and the concentration distribution in the electrolytic cell is made uniform by feeding the electrolyte so that the residence time of the electrolyte in the electrolytic cell is about 1 hour. The electrolytic solution was purified by electrolysis for 5 days while adjusting the temperature of the electrolytic solution to the temperature shown in Table 2 and applying a current at the current density shown in Table 2, thereby recovering electrodeposited lead. In examples 2-2 and 3-3, the decomposition rate [% ] of sulfamic acid was controlled to 0.3% or less for 5 days.
As a result, the electrodeposition of lead in example 2-1 was deteriorated. In examples 2 to 5 and 2 to 6, however, the decrease in the lead concentration in the electrolyte could not be suppressed. In examples 2 to 5, the decomposition rate of sulfamic acid exceeded 3.5%, and in examples 2 to 6, the decomposition rate of sulfamic acid exceeded 7%. In examples 2-2, 2-3 and 2-4, the formation of white residue was suppressed, and the decrease in the lead concentration in the electrolyte was suppressed. FIG. 2 is a graph showing the decomposition rates of sulfamic acid in examples 2-2 (electrolyte temperature 15 ℃ C.), examples 2-4 (electrolyte temperature 30 ℃ C.), and examples 2-6 (electrolyte temperature 50 ℃ C.).
[ Table 2]
Claims (1)
1. The electrolytic purification method of lead based on sulfamic acid bath is characterized in that:
in a method for electrolytic purification of lead by a sulfamic acid bath using a lead anode containing lead in an amount of 60 mass% or more, the sulfamic acid concentration in the sulfamic acid bath is adjusted to a concentration 30 to 60g/L higher than the lead concentration in the sulfamic acid bath, the lead concentration is adjusted to 60 to 80g/L, 1 to 700mg/L of NOIGEN BN-1390 or NOIGEN BN-2560 is added to the sulfamic acid bath, the decomposition rate of sulfamic acid is controlled to 0.06%/day or less over 5 days, sulfamic acid is supplemented to maintain the sulfamic acid concentration, and generation of white residue generated in electrolytic purification of lead by the sulfamic acid bath is suppressed,
electrolytic purification was performed while adjusting the electrolyte temperature of the sulfamic acid bath to 15-30 ℃.
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| Application Number | Priority Date | Filing Date | Title |
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| JP2014245302 | 2014-12-03 | ||
| JP2014-245302 | 2014-12-03 | ||
| JP2015-221585 | 2015-11-11 | ||
| JP2015221585A JP6453743B2 (en) | 2014-12-03 | 2015-11-11 | Method for electrolytic purification of lead using sulfamic acid bath |
| CN201510875275.4A CN105671590A (en) | 2014-12-03 | 2015-12-03 | Method for electrolytically refining lead in sulfamate bath |
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| JP2010248608A (en) * | 2009-03-23 | 2010-11-04 | Jx Nippon Mining & Metals Corp | Lead electrolytic method (1) |
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| US4098658A (en) * | 1974-07-25 | 1978-07-04 | Ginatta Marco | Method of extracting metals from spent electric storage batteries |
| JPS5964791A (en) * | 1982-09-30 | 1984-04-12 | Mitsubishi Metal Corp | Lead with low count number of radioactive alpha particle and electrolytic purification thereof |
| IT1245449B (en) * | 1991-03-13 | 1994-09-20 | Ginatta Spa | HYDRO-METALLURGICAL PROCEDURE FOR THE PRODUCTION OF LEAD IN THE FORM OF METAL FROM MATERIALS CONTAINING OXIDES, PARTICULARLY FROM THE ACTIVE SUBSTANCE OF THE ACCUMULATORS |
| JP2009242845A (en) * | 2008-03-31 | 2009-10-22 | Nippon Mining & Metals Co Ltd | Electrolytic process of lead |
| JP4979752B2 (en) * | 2009-03-23 | 2012-07-18 | Ｊｘ日鉱日石金属株式会社 | Electrolysis method of lead (6) |
| JP5163988B2 (en) * | 2009-03-23 | 2013-03-13 | Ｊｘ日鉱日石金属株式会社 | Electrolysis method of lead |
| CN103510109B (en) * | 2013-10-24 | 2016-03-02 | 北京化工大学 | The method of the leaded grid of waste lead acid battery is reclaimed from gravity contact electricity solution |
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| JP2010248608A (en) * | 2009-03-23 | 2010-11-04 | Jx Nippon Mining & Metals Corp | Lead electrolytic method (1) |
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| CN110079827A (en) | 2019-08-02 |
| CN105671590A (en) | 2016-06-15 |
| JP6453743B2 (en) | 2019-01-16 |
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