JP2013500566A - Method for reclaiming lead in the form of high purity lead compounds from recovered electrode paste slime or lead ore of waste lead-acid batteries - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a new lead recycling method.
SOLUTION: (a) Impure lead-containing material is suspended in an aqueous solution of sodium acetate, potassium acetate or ammonium acetate; (b) In this suspension, all lead oxide is converted into lead sulfate soluble in an acetate salt solution. Hydrogen peroxide, added to a sufficient amount of sulfuric acid, and adapted to convert total lead dioxide into lead oxide which is finally converted to soluble lead sulfate by sulfuric acid. Or slowly add either sulfite, or blow anhydrous sulfite into this suspension, and (c) add a clear acetate salt solution containing dissolved lead sulfate to all undissolved compounds and Separated from solid phase residues containing impurities, (d) precipitates high purity lead carbonate / lead oxycarbonate or lead oxide or lead hydroxide, respectively, while forming soluble cation sulfate in acetate salt solution Lead sulfate separation solution to Add either carbonate or hydroxide of the same cation as the acetate salt of the lead sulfate-soluble solution, and (e) precipitate high purity lead from an acetate salt solution containing the same cation sulfate as the acetate salt. A method for regenerating lead comprising separating compounds.
[Selection] Figure 1

Description

      The present invention relates to a technology for regenerating a high-purity lead compound from a contaminated mixture such as a recovery electrode paste slime or lead ore of a waste lead-acid battery (battery).

      Conventionally, a method of regenerating useful lead-containing material from a recovery electrode paste slime or lead ore of a waste lead storage battery that has been performed for a long time has been based on a calcination method. A novel method based on wet processing is disclosed. In the method disclosed in Patent Document 1, the amount of hazardous residue discarded is drastically reduced, and the recovery electrode paste slime of a waste lead storage battery that can produce high-purity lead carbonate in a high yield while using reagents efficiently. It consists of a wet processing method for lead ore. Nevertheless, in order to use recycled lead for the manufacture of new battery pastes, the lead carbonate must be decomposed into lead oxide by heating the lead carbonate to a temperature of about 400-450 ° C. This method is costly due to the huge energy consumption.

      According to the method disclosed in US Pat. No. 6,057,089, starting materials in the form of electrode paste slime or finely ground and finally pretreated lead ore are leached with an acid different from sulfuric acid, and hydrogen peroxide or other reductions are made. Add lead dioxide and sulfuric acid that may be contained in the agent or starting material. Sulfuric acid converts all lead compounds to insoluble lead sulfate. This insoluble lead sulfate is separated with other insoluble materials and then selectively dissolved in an aqueous solution of a solubilizer. The carbonate solution for precipitation of lead carbonate / oxycarbonate is added to the separated clear solution of lead sulfate.

      Finally, in addition to the energy required to convert carbonate to lead oxide, the acid leaching step of the contaminated starting material is not only costly, but also the processing plant is complicated.

Special Table 2010-516891 (PCT / IT2008 / 000022)

      The object of the present invention is to significantly reduce the lead regeneration cost converted to the plant configuration of the processing vessel and related stirrer, heater or cooler, filter, etc., the complexity of the processing plant, transportation and energy costs, etc. It is an object to provide a novel lead regeneration method that can significantly and effectively simplifies the efficient all wet lead regeneration process.

      To solve the above problem, the suspended starting material is suspended directly in an aqueous solution of acetate in lead sulfate, and all the lead dioxide that appears to be present in the contaminated starting material is reduced to lead oxide. Add suitable hydrogen peroxide or sulfite, or alternatively blow sulfurous anhydride into this suspension, and leave all lead oxide dissolved in the selected lysis solution A new and highly efficient lead regeneration method comprising adding sulfuric acid compatible with conversion to

      The clear solution containing dissolved lead sulfate is then separated from the solid phase residue. The solid phase residue contains all undissolved impurities contained in the contaminated starting material.

      Depending on the origin of the contaminated starting material to be treated, it must not be dissolved in a specific lead compound or acetate solution, such as oxysulfate, with a solid phase of any insoluble material separated from the lead sulfate dissolved acetate solution. There may be other oxides that may be present.

      Even the lead of these compounds that are not dissolved by the acetate solution can eventually be regenerated if there are other reasons that are considered economically or that it is desirable to do so. This suspends a separated solid phase consisting of insoluble compounds of impurities and lead in a concentrated solution of hydroxide of the same cation (cation) of acetate that decomposes these compounds and converts them to soluble namalidate. This can be done by turbidity. Numarite can be dissolved in the hot hydroxide solution and then separated from the remaining insoluble impurities. A hydroxide solution containing residual lead separated from a solid phase of impurities previously separated is introduced into a lead sulfate-containing acetate aqueous solution, a hydroxide having the same cation as the acetate is introduced, and the acetate salt is introduced. Lead contained in the aqueous solution as lead sulfate is precipitated as lead oxide or lead hydroxide.

      Next, precipitation of the high purity lead compound from the clear lead sulfate solution (1) lead sulfate for precipitation of lead insoluble carbonate / oxycarbonate as contemplated by the method disclosed in US Pat. The same cationic carbonate of acetate used for selective dissolution is added to the solution, or (2) more preferably, according to another embodiment, a clear solution of lead sulfate instead of carbonate salt Depending on the temperature of the precipitation bath, the same cationic hydroxide of the acetate used for the selectively dissolved lead sulfate to cause precipitation of either lead oxide or hydroxide. This is done by adding. Thus, the extra burden of having to convert the regenerated lead carbonate to lead oxide by finally heating the carbonate in an oven is avoided.

      The inventors have found that the precipitation of all lead in solution as a high purity lead compound is indeed complete, whether or not carbonate or hydroxide is used to cause precipitation. did. Thus, the solid phase separation of the high purity lead compound from the acetate solution is performed from the same acetate solution in which the contaminating starting material is suspended.

      A clear solution of acetate salt gradually increases the sulfate of the same cation of the acetate salt used to selectively dissolve lead sulfate, but the concentration of sodium sulfate is maintained below the saturation point. As long as it can be reused in the suspension step of the contaminated starting material. When the sulfate concentration of the clear acetate salt solution approaches the saturation point, the solution is cooled to about 10 ° C. to selectively crystallize the solid phase composed of the sulfate salt of the acetate salt used. And precipitate. This solid phase is separated by filtration. The clear acetate salt solution from which the sulfate has been removed can then be recycled to the contaminated starting material suspension bath.

      Preferably, the solid phase constituted by the sulfate salt of the acetate salt cation used is more widely marketed prior to cooling the clear solution of the acetate salt for selective crystallization and precipitation. To produce a lead-free sulfate salt as an acceptable byproduct, the acetate solution is filtered through a column filled with a chelating resin to sequester all residual lead ions in the solution prior to solution cooling.

      As described above, according to the present invention, the lead regeneration cost converted into the plant configuration of the processing vessel and related stirrer, heater or cooler, filter, etc., the complexity of the processing plant, transportation and energy costs, etc. Can be significantly reduced, and a new lead regeneration method is obtained which significantly and effectively simplifies the efficient all wet lead regeneration process.

Major steps of the process of regenerating high purity lead oxide from waste storage battery electrode slime or lead ore to produce either pure lead carbonate / lead oxycarbonate or pure lead oxide / lead hydroxide of the present invention This is a flow sheet. A plant for regenerating high purity lead oxide from waste storage battery electrode slime or lead ore to produce either pure lead carbonate / lead oxycarbonate or pure lead oxide / lead hydroxide according to the flow sheet of FIG. FIG.

      Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings.

      Reference is made to the flow sheet of FIG. 1 according to a first embodiment of the method of the present invention. This embodiment is ultimately useful for electrode paste slime recovered from pulverized waste storage batteries or finely pulverized lead ores (eg, for converting lead sulfite to lead sulfate, which is useful with very little suitability). Are particularly suitable for the treatment of galena, lead sulfate, low-grade general minerals, etc.) generally roasted. The contaminating starting solid material is suspended in an aqueous solution of a salt capable of dissolving lead sulfate, such as, for example, sodium, ammonium, potassium, urea, mono-, di-, tri-ethanolamine salts of acetic acid.

      To this suspension is gradually added an amount of sulfuric acid necessary to convert all the oxides present in the starting material to sulfate and a reducing agent selected from hydrogen peroxide, sulfite and anhydrous sulfite. Or, in a suspension bath, blow in the amount necessary to reduce all lead dioxide that would be contained in the starting material (as in the case of slime from a waste lead acid battery) to lead oxide. .

      Accordingly, in the first step (1) of the process flow sheet of FIG. 1, a chemical reaction occurs in the starting material suspension bath as described in detail below. A chemical reaction occurs in which all lead compounds are simultaneously converted to sulfate dissolved in an aqueous solution containing the specific soluble salt.

Is free lead oxide, which was originally intimately bound to the electrode paste by dissolving lead sulfate, the type of compounds such as 3PbOPbSO ₄ and 4PbOPbSO ₄ as a result of itself oxide reacts rapidly converts to sulfate the In view of the fact that it produces, the reaction described below can clearly recognize the presence of synergy that results in a substantial increase in the rate of the chemical conversion process. The sulfate is then dissolved in an acetate salt solution such as sodium acetate, while lead dioxide physically embedded in the oxysulfate coagulum becomes more easily reached by the reactive species. As a result, it is more easily reduced to lead oxide.

      In the following reaction, lead sulfate is present as a major component (about 60% by weight) in a contaminated starting material and dissolved in an aqueous solution of sodium acetate. It relates to an exemplary embodiment.

Reaction 1: Lead sulfate dissolved PbSO ₄ (insoluble) + 4CH ₃ COONa → PbSO ₄ soluble complex

Reaction 2: Dissolution of lead oxide 2CH ₃ COONa + H ₂ SO ₄ → 2CH ₃ COOH + Na ₂ SO ₄
PbO (insoluble) + 2CH ₃ COOH → Pb (CH ₃ COOH) ₂ (soluble) + H ₂ O
Pb (CH ₃ COOH) ₂ + Na ₂ SO ₄ → PbSO ₄ (insoluble) + 2CH ₃ COONa
PbSO ₄ (insoluble) + 4CH ₃ COONa → soluble complex of PbSO ₄

Reaction 3: Reduction and dissolution of lead dioxide 2CH ₃ COONa + H ₂ SO ₄ → 2CH ₃ COOH + Na ₂ SO ₄
PbO ₂ (insoluble) + H ₂ O ₂ → PbO (insoluble) + H ₂ O + 1 / 2O ₂
PbO (insoluble) + 2CH ₃ COOH → Pb (CH ₃ COOH) ₂ (soluble) + H ₂ O
Pb (CH ₃ COOH) ₂ + Na ₂ SO ₄ → PbSO ₄ (insoluble) + 2CH ₃ COONa
PbSO ₄ (insoluble) + 4CH ₃ COONa → soluble complex of PbSO ₄

(Optional) Reaction 4: Solubilization of insoluble lead compounds that may be present in contaminated starting materials separated with regenerative impurities such as small amounts of lead 4PbOPbSO ₄ (insoluble) + 12NaOH → 5Na ₂ PbO ₂ ( Soluble) + Na ₂ SO ₄ + 6H ₂ O

      As an example, an aqueous solution of sodium acetate trihydrate dissolved in water at a concentration in the range of 37.5 wt% to 54.5 wt% to treat electrode paste slime recovered from ground waste lead acid batteries Can be used perfectly. An amount corresponding to or just exceeding the stoichiometric requirement to convert all lead oxide to lead sulfate, as previously assessed for the contaminating starting material to be processed. Add sulfuric acid. Preferably, after the required amount of sulfuric acid has been added, the suspension bath is charged with an amount of hydrogen peroxide pre-converted to the stoichiometric requirement to reduce lead dioxide contained in the starting material. Added.

      The amount of electrode paste that can be processed in a particular volume of solution will vary depending on the solubilization capacity of lead sulfate and the amount of sulfuric acid added to the selected lead acetate solution. The ability of an acetate (acetic acid) salt solution to dissolve lead sulfate varies depending on its salt concentration. As an example, 1 liter of sodium acetate having a concentration of 37.5% by weight can dissolve 100 g of lead sulfate. By increasing the concentration of sodium acetate, the amount of lead sulfate that can be dissolved also increases in direct proportion. The temperature at which the reaction can be carried out in the suspension bath is in the range of 10 ° C. to boiling point. The suspension can be stirred by hand or a turbine mixer to facilitate the collapse of the lead compound aggregates.

      The combination of selected operating conditions (eg, starting solid raw material type and fineness, lead sulfate solubilized salt solution type and concentration, final lead dioxide reducing agent addition, temperature, agitation method, etc.) is fully wet regenerated Affects the time required to complete the first step (1) of the method. The sulfuric acid used to sulfidize all lead oxide in solution should preferably have a high concentration so as not to over-dilute the lead sulfate solubilizing solution.

      A clear acetate solution containing lead sulfate from a solid phase residue, for example, by filtration, after a reaction time in the range of 6 to 15 minutes has elapsed, which varies depending on the combination of a number of parameters. Can be separated. Accordingly, all insoluble impurities and insoluble materials are separated from the solution (see step (2) of the flow sheet in FIG. 1).

      Step (3) of the flow sheet of FIG. 1 at a temperature high enough to ensure that all the lead present in the solution is in the form of PbO (yellow appearance) instead of in the form of lead hydroxide (white appearance). In the starting material in the form of lead sulfate by adding a hydroxide of the same cation of the selected acetate salt (ie either sodium, potassium or ammonia) to the solution according to the preferred alternative contemplated for Subsequent reactions conducted in clear acetate solutions containing almost all of the lead component selectively precipitate lead oxide due to its solubility much lower than that of lead sulfate. Generally, the critical temperature is around 70 ° C. Thus, precipitation can be carried out at about 72 ° C. to 73 ° C. (if for some reason it is not desired to recover high purity lead hydroxide that can ultimately be thermally converted to lead oxide).

      Another alternative contemplated for step (3) of the flow sheet of FIG. 1 was chosen instead of hydroxide in an aqueous acetate solution containing almost all the lead component of the starting material in the form of lead sulfate. It consists of adding a carbonate of the same cation as the acetate salt (ie either sodium, potassium or ammonia). This selectively precipitates lead carbonate or a mixture of lead carbonate and lead oxycarbonate. The reason is that their solubility is significantly lower than that of lead sulfate. In this alternative method, precipitation can occur at any temperature comprised between room temperature and boiling point.

      When the reaction of step (3) is completed, in step (4) of the flow sheet of FIG. 1, the precipitated lead oxide or lead hydroxide or carbonate / oxycarbonate is separated from the solution by filtration. On the other hand, the hydroxide cation sulfate or carbonate used to precipitate lead as an insoluble oxide (or hydroxide) or carbonate (or oxycarbonate) remains in solution.

      A clear acetate solution containing the same cation as the acetate salt, as long as the sulfate content is maintained below the saturation point (this saturation point varies depending on the type and processing conditions of the dissolved salt solution of lead sulfate) Can be integratively recycled (recycled) into the selective dissolution suspension bath of lead sulfate (see step (1)) of the process of the present invention.

      Needless to say, precipitation of excess sulfate salts with lead oxide or lead hydroxide or carbonate / oxycarbonate must be prevented. Therefore, the excess sulfate salt should preferably be finally removed from the solution before approaching the saturation point (see step (8) of the flow sheet of FIG. 1). This can be done easily. For example, utilizing different solubilities at the temperature of the sulfate salt (ie, sodium sulfate, potassium sulfate or ammonium sulfate) different from the temperature of the corresponding acetate salt used for selective crystallization of the sulfate and its separation from the acetate solution. Is done.

      The concentration of the solubilized salt aqueous solution and the temperature at which lead sulfate is dissolved in the solubilized salt aqueous solution are not essential parameters. This is because these parameters have little effect on the time required to complete the reaction and the quality of lead sulfate to be dissolved in the aqueous solubilized salt solution. In fact, after the dissolved lead has been precipitated as oxide or hydroxide or carbonate / oxycarbonate, the solubilized solution is recycled. Therefore, when operating with a recirculating solution, the solubilized solution must be recirculated (recycled) many times to completely dissolve the lead sulfate of a given quality.

      The method of the present invention is suitable for the treatment of electrode paste slime in which the amount of the three main lead compounds (ie, lead sulfate, lead oxide and lead dioxide) varies around an average value up to a variability range of about 2% by weight. It proved to be extremely suitable. This variation in the amount of major lead compounds, as a practical matter, hinders accurate calculation of the amount of sulfuric acid solution required to convert all the lead oxide present in the contaminated starting material to sulfate.

      Nevertheless, when carrying out the process of the present invention, if an excess of sulfuric acid is added than is stoichiometrically required, a hydroxide or carbonate of the same cation as the selected acetate salt is obtained. After precipitation of the pure lead compound by addition, an excess of carbonate sulfate of the addition compound is produced compared to the exact amount for precipitation of lead sulfate. The reason is that free sulfuric acid exists in the solution. Conversely, if an amount of sulfuric acid that is less than the stoichiometrically required amount is added, the conversion of the oxide to sulfate will be incomplete, so that when solid impurities are separated, A quantity of oxide remains undissolved in the acetate solution. If such a situation occurs unintentionally, the separated solid phase may simply be reintroduced into the suspension bath, and finally converted to sulfate by introducing an excessive amount of sulfuric acid.

      When the sulfate concentration in the clear acetate salt solution approaches the saturation point, the solution is filtered continuously or intermittently through a column packed with a chelating resin to isolate all residual lead ions in the solution. (See step (5) of the flow sheet in FIG. 1). The solution is then cooled to about 10 ° C. to precipitate a crystalline solid phase composed of the sulfate salt of the used acetate salt (see step (6) of the flow sheet in FIG. 1). The solid phase is then recovered by filtration (see step (7) of the flow sheet in FIG. 1). The clear acetate salt solution without sulfate salts is then recycled to the contaminated starting material suspension bath, while lead-free sulfate salts are utilized as a marketable by-product.

      Expressed as a metal equivalent, 80 g of recovered dry electrode paste slime having a lead content of 72% is stirred, and at a temperature of 83 ° C., 12.2 g of concentrated sulfuric acid having a concentration of 94 wt. Treated with 1000 mL of an aqueous solution of 5 wt% sodium acetate trihydrate. Subsequently, a concentration of 32% by weight of hydrogen peroxide was slowly added to the suspension (as added dropwise over about 10 minutes) and continued to be added until no further clarification of the suspension was observed. .

      The warm suspension was then filtered to separate the solid phase. This solid phase contains various additives used to form insoluble lead compounds and lead compound coagulates, electrode grid fragments and electrode pastes {eg carbon black, barium sulfate, fibers and impurities (eg sand, plastics). Material) etc.}. The amount of this obtuse solid phase was about 4-12% based on the weight of the solid mass of the dry electrode paste.

      Sodium hydroxide was added to the filtered clear solution containing lead sulfate at 83 ° C. with stirring, and continued to be added until lead in the form of lead oxide was almost completely precipitated. The suspension was then filtered to separate the precipitate from the sodium acetate solubilized solution. This solubilized solution contained a large amount of sodium sulfate at this point and was recycled to the stirred lead sulfate dissolution bath as long as the sodium sulfate content in the solution was maintained below the saturation point.

      When the sodium sulfate content in the sodium acetate solution approaches the saturation limit, the solution is filtered, for example, through a column packed with a chelating resin marketed under the trade name Chelex-100 or Dowex A-1. Of course, resins other than those described above can also be used. The resin filler was almost completely sequestered even with trace amounts of lead ions present as a residue in the sulfate solution.

      Subsequently, the purified sulfate solution (actually lead-free) was slowly cooled to 10 ° C. with slow stirring to precipitate a crystalline solid phase composed of sodium sulfate. The crystalline solid phase was then recovered by filtering the suspension, while the clear solution was recycled to the lead sulfate dissolution bath.

      The filtered lead oxide was rinsed strictly with deionized water and dried at 160 ° C. until the weight reached a constant.

      The separated pale solid phase was suspended in sodium hydroxide having a concentration of 40% by weight at 50 ° C. for 15 minutes. The separated clear liquid phase was introduced into the clear acetate solution. In view of the fact that this acetate solution also converts lead itself present in the solution as sodium namalite to lead oxide (or lead hydroxide) (according to a preferred embodiment) lead oxide or hydroxide. It contains lead sulfate as part of the amount of sodium hydroxide required to precipitate all the lead in solution as lead.

      At the end of the test, the following mass balance was recorded.

      Of the 80 g of recovered electrode paste used in the experiment, there was 4 g of an obtuse insoluble substance containing metallic lead and foreign substances (eg sand, carbon black, barium sulfate and a small amount of other substances).

      The calculated maximum amount of lead oxide that was recoverable was 62.05 g, while the amount of lead oxide that was effectively recovered was 62.03 g. Therefore, the recovery yield was 99.96%.

      Chemical analysis of the recovered solid product revealed that this solid product was exclusively composed of 99.99% pure PbO, while the final recovered sodium sulfate had a purity of about 99.90%. It was confirmed that there was.

      Table 1 below summarizes the relevant experimental conditions, characteristics and results of other exemplary Examples 2-4 of the process of Example 1 above. However, the indicated alternative conditions and the results obtained always used the same lot of electrode paste recovered from the pulverized waste storage battery as the starting material.

Table 1

Examples Lead sulfate dissolution Reaction time For precipitation Obtained purification yield
No. Solution and temperature compound lead compound %
2 Concentration 37.5 wt% 10 min NaOH Pb (OH) ₂ 99.94
Sodium acetate 65 ° C
1000mL

3 Concentration 40.0% by weight 8 minutes NaOH PbO 99.95
Sodium acetate 90 ° C
1000mL

4 concentration 40.0% by weight 12 minutes Na ₂ CO ₃ PbCO ₃ 99.91
Sodium acetate 45 ° C
1000mL

      Lead oxide produces a new storage battery electrode paste (whether produced directly by a fully wet process or by heating lead carbonate / lead oxycarbonate produced by a fully wet process). Are perfectly suitable.

      Implementation of the method of the present invention using lead ore or a mixture of lead ores as starting materials can be carried out in much the same way as in the previous embodiment. An essential pre-step is to convert as much as possible all the different salts of lead present in the ore to lead sulfate or lead oxide. For example, in the case of galena, which is the most common lead ore, the ore must be heated in air until lead sulfite is oxidized to lead sulfate by a common technique of roasting. Other common ores, such as lead sulfate ore, are already composed of lead sulfate, so no pretreatment is required. Needless to say, the ore must be pulverized to facilitate these processes.

      Figure 2 shows an industrial plant that regenerates variable lead in the form of high-purity compounds from finely pulverized lead ores that have been pretreated to convert the waste electrode storage electrode paste or as much lead compound as possible to lead sulfate. It is a block diagram of an example.

      The block diagram of FIG. 2 provides an illustration of a number of embodiments of the processing alternative described above. However, in the block diagram of FIG. 2, sodium is commonly exemplified as the selective cation of the acetate salt and the alternative cation of the alternative compound added for precipitation of the desired pure compound of lead by various alternative methods. .

      In operation, the plant always requires three agitators and a temperature controlled reactor. The first reactor RAC (1), in which the contaminating starting material is suspended in an aqueous acetate salt solution, has a first solid-solid solution for separating solution-containing lead sulfate from a solid phase constituted by insoluble impurities of the contaminating starting material. A liquid separator F (1) is attached.

      For the second reactor to precipitate the desired lead compound of high purity, indicated in any of the reactors RAC (2), RAC (3) and RAC (4) in the many alternatives of FIG. A second solid-liquid separator, namely F (2), F (3) and F (4) is associated.

      The third and last reactor RAC (5) and the third and last solid-liquid separator F (5) associated therewith at least periodically (more preferably continuously) recycled acetate salt solution. And is recycled to the first sulfate dissolution reactor RAC (1). This treatment consists of selective crystallization utilizing the significant difference between the solubility of the acetate salt and the solubility of the sulfate of the same cation as the acetate salt. For example, it may be introduced into a second reactor to precipitate the desired lead compound and removed from the apparatus. This step must be carried out (continuously or intermittently) to prevent saturation of the recycled acetate salt solution with sulfates of the same cation. When the recycled acetate salt solution is saturated with sulfates of the same cation, the acetate salt coprecipitates with the lead sulfate, making the purification process useless.

      In accordance with a preferred embodiment, the plant of FIG. 2 is filled with a suitable chelating resin in order to render the “by-product” sulfate salt (eg, sodium sulfate) generally lead-free and, consequently, commercially available. Exchange resin column C (1). When the solution is oriented (whether continuous or intermittent) to the selected sulfate crystallization reactor RAC (5), the solution passes through this exchange resin column C (1) into the solution. Isolate any residual lead ions that may be present.

      Needless to say, the chelating resin filler gradually loses its activity. Therefore, it is necessary to periodically extract the solubilized lead ions by circulating acetic acid through the column C (1) in a predetermined cycle. The lead-extracted solution of acetic acid used for the periodic reactivation of the exchange resin (ie, the solution containing lead acetate) is simply the first reactor RAC (1 ) Can be “disposed”.

      The block diagram of the multi-embodiment compatible plant of FIG. 2 also illustrates the optional reactor RAC (2bis). This optional reactor RAC (2bis) could not be dissolved during the processing of the contaminating starting material in the first reactor RAC (1), if desired, taking into account the composition of the contaminating starting material to be treated. The remaining amount of lead that accompanies the separated solid phase of impurities in the form of compounds or coagulum is treated. The separated solid phase is suspended in a warm concentrated solution of hydroxide of the same cation as the selected acetate that also dissolves these compounds of lead or coagulum thereof. The attached solid-liquid separator F (2bis) can separate all the lead-free impurities from the hydroxide solution containing dissolved sodium namalite. This hydroxide solution is added according to a preferred embodiment in a second reactor RAC (2) or RAC (3) that can be used to precipitate all the lead in the solution as lead oxide or lead hydroxide. It can be conveniently used as part of the hydroxide.

      The above description relates to one embodiment of the present invention, and those skilled in the art can consider various modifications of the present invention, all of which are included in the technical scope of the present invention. The The numbers in parentheses described after the constituent elements of the claims correspond to the part numbers in the drawings, are attached for easy understanding of the invention, and are used for limiting the invention. Must not. In addition, the part numbers in the description and the claims are not necessarily the same even with the same number. This is for the reason described above. With respect to the term “or”, for example, “A or B” includes selecting “both A and B” as well as “A only” and “B only”. Unless stated otherwise, the number of devices or means may be singular or plural.

Figure 1:

Step ← Material delivery; → Material removal
(1) Reduction, ← Raw material electrode slime sulfate, ← Sodium acetate preparation Solubilization ← Sulfuric acid
← Hydrogen peroxide
← Acetate saturated solution recirculation

(2) Filtration → Insoluble compounds and solid impurities

(3) Oxide generation ← Sodium hydroxide> 72 ° C to 73 ° C
Hydroxide generation ← Sodium hydroxide <72 ° C-73 ° C
Carbonate production ← Sodium carbonate

(4) Filtration → Lead oxide or
→ lead hydroxide or
→ Lead carbonate

(5) Solution purification → Lead acetate (To step (1))
← Acetic acid

(6) Crystallization

(7) Filtration → Lead sulfate

(8) Solubilized salt solution recirculation (To step (1))

(2bis) ← Sodium hydroxide insoluble compounds and solid impurities from step (2)

(2bis) filtration → insoluble compounds
→ Soluble lead namalite (To step (3))

Figure 2:

Legend: Stirred Reactor: (RAC) Heated Stirred Reactor
(RAF) Cooling and stirring reactor □ \: Solid / liquid separator (F)

RAC (1) ← Raw material electrode slime, hydrogen peroxide, sodium acetate, sulfuric acid

F (1) → solid impurities; RAC (2bis) ← sodium hydroxide

RAC (2) ← Sodium hydroxide; ← Lead namalite

F (2) → lead oxide; F (2bis) → solid inert impurities

RAC (3) ← Sodium hydroxide

F (3) → Lead hydroxide

RAC (4) ← Sodium carbonate

F (4) → Lead carbonate

Exchange resin column C (1) ← acetic acid; → lead acetate (to RAC (1))

RAF (5) → acetate solution recirculation; → sodium sulfate

Claims (12)

A method of regenerating a lead component of a contaminated electrode paste or slime or lead ore from a waste storage battery in the form of a high-purity lead compound,
(a) suspending the impure lead-containing material in a lead sulfate-soluble aqueous solution of acetate belonging to the group consisting of sodium acetate, potassium acetate and ammonium acetate;
(b) Sufficient sulfuric acid is added to the suspension to convert all the lead oxide to lead sulfate soluble in the acetate salt solution, and all the lead dioxide is added to the suspension. Add either hydrogen peroxide or sulfite slowly, or add anhydrous sulfite into this suspension, which is mainly compatible with conversion to lead oxide which is finally converted to soluble lead sulfate by sulfuric acid Step to blow,
(c) separating a clear acetate salt solution containing dissolved lead sulfate from a solid phase residue containing all undissolved compounds and impurities;
(d) In order to precipitate high-purity lead carbonate / lead oxycarbonate or lead oxide or lead hydroxide, respectively, while producing sulfate sulfate soluble in acetate salt solution, Adding either the carbonate or hydroxide of the same cation as the acetate salt of the lead-soluble solution;
(e) separating a precipitated high-purity lead compound from an acetate salt solution that also contains a sulfate of the same cation as the acetate salt,
A method for regenerating lead. Recycling the acetate salt solution, which also contains a sulfate salt of the same cation as the acetate salt separated from the lead precipitation compound, to the step (a) to cause selective precipitation of a sulfate salt of the same cation as the acetate salt; Then, to remove it as a by-product, at least a portion of the solution separated from the precipitated lead compound is continuously or periodically cooled to saturate the increase in sulfate content of the same cation in this solution. Keep below the limit,
The lead recycling method according to claim 1. Before cooling to selectively precipitate the sulfate salt of the same cation as the acetate salt, all lead ions from the solution for selective precipitation of the generally cation-free sulfate salt of the same cation as the acetate salt after cooling Bringing this solution into contact with a chelating resin suitable for isolating
The lead recycling method according to claim 2, wherein: Selective dissolution of lead sulfate is carried out in an aqueous solution of sodium acetate having a concentration of 10 g to 120 g of salt in 100 g of water, at a temperature in the range of 20 ° C. to boiling point, with a stirring time in the range of 5 minutes to 180 minutes, Done by suspending impure material,
The lead recycling method according to claim 1. Selective dissolution of lead sulfate is carried out in an aqueous solution of ammonium acetate having a concentration of 20 g to 120 g of salt in 100 g of water, at a temperature in the range of 20 ° C. to boiling point, with a stirring time in the range of 5 minutes to 180 minutes, Done by suspending impure material,
The lead recycling method according to claim 1. Selective dissolution of lead sulfate is carried out in an aqueous solution of potassium acetate having a concentration of 20 g to 120 g of salt in 100 g of water, at a temperature in the range of 20 ° C. to boiling point, with a stirring time in the range of 5 minutes to 180 minutes, Done by suspending impure material,
The lead recycling method according to claim 1. (f) Contains all undissolved compounds and impurities to convert lead compounds that could not be dissolved in acetate solution or its coagulum into hydroxide cation namalidate form and dissolve. Suspending the separated solid phase residue in a warm concentrated hydroxide of the same cation as the selected acetate salt;
(g) separating the alkaline solution containing lead namalite from the solid phase of impurities contained in the starting material;
(h) adding the separated lead-containing solution to the separated acetate solution to precipitate all renewable lead as high purity lead oxide or lead hydroxide;
The lead recycling method according to claim 1, further comprising: A plant that regenerates the lead component of contaminated electrode paste or slime or lead ore from waste storage batteries in the form of high-purity lead compounds,
(a) a first reactor (RAC (1));
This first reactor controls stirring and heating means for suspending impure materials in a lead sulfate-soluble aqueous solution of a salt belonging to the group consisting of sodium acetate, potassium acetate and ammonium acetate, and sulfuric acid. And means for adding while controlling a reagent belonging to the group consisting of hydrogen peroxide, sodium sulfite and anhydrous sulfite.
(b) a first solid-liquid separator (F (1));
This first solid-liquid separator separates insoluble lead compounds or lead compounds and undissolved solids of impurities from a clear acetate salt solution and lead sulfate solution.
(c) a second reactor (RAC (2), RAC (3), RAC (4));
This twenty-first reactor is adapted to hold a clear aqueous solution of acetate salt and a lead sulfate solution, has stirring and heating means, and insoluble lead carbonate / lead oxycarbonate or lead oxide or hydroxide. Adding either a carbonate or hydroxide of the same cation as the acetate salt for precipitating each lead, and forming a sulfate of the same cation as the acetate salt that is soluble in aqueous solution.
(d) a second solid-liquid separator (F (2), F (3), F (4));
The second solid-liquid separator separates a solid phase composed of the precipitated lead compound from an aqueous solution of an acetate salt that also contains a sulfate of the same cation as the acetate salt.
(e) means for recycling the separated solution to the first reactor (RAC (1));
(f) a third reactor (RAC (3));
This third reactor comprises a stirring means and a continuously or periodically treated part of the recirculating solution in order to selectively crystallize the same cation sulfate as the acetate salt contained in the solution. Means for cooling or heating while controlling
(g) a third solid-liquid separator (F (5));
This second solid-liquid separator separates the crystallized sulfate of the same cation as the acetate salt of the treated portion of the recycled solution that is recycled to the first reactor (RAC (1)). To
A lead recycling plant characterized by comprising: (h) further comprising a column packed with a chelate resin;
This column contains a continuous or periodic treatment portion of the recirculated solution to the fourth reactor (RAC (5)) for selective crystallization of the same cation sulfate as the acetate contained in the solution. Prior to introduction, a continuous or periodic treatment portion of the recirculating solution is passed to sequester residual lead ions from the solution;
The lead regeneration plant according to claim 8, wherein: (i) means for periodically extracting isolated lead ions from the chelate resin by circulating acetic acid in the column; and
(j) further comprising means for introducing a circulated amount of acetic acid into the first reactor (RAC (1)).
The lead regeneration plant according to claim 9. (k) a fourth reactor (RAC (2bis));
This fourth reactor suspends the separated solid phase consisting of insoluble lead compounds or undissolved solids of lead compounds in a hot concentrated hydroxide of the same cation as the selected acetate salt, and Having a stirring means and a heating means for converting the lead compound or the undissolved coagulum of the lead compound into a soluble namalite,
(l) a fourth solid-liquid separator (F (2bis)) for separating the lead-containing alkaline solution from the solid phase of impurities;
(m) Lead-containing alkaline solution is introduced into the second reactor (RAC (2), RAC (3)) in order to precipitate all renewable lead in the form of high purity lead oxide or lead hydroxide And means for
The lead regeneration plant according to claim 8, wherein: (n) when the separated lead compound is in the form of lead carbonate, lead oxycarbonate or lead hydroxide, further comprising an oven for decomposing the separated lead compound into lead oxide, lead dioxide or water, respectively;
The lead regeneration plant according to claim 8, wherein:

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