OA17808A - Devices and methods for smelterless recycling of lead acid batteries. - Google Patents

Abstract

Lead from lead acid battery scrap is recovered in two separate production streams as clean grid lead and as high-purity lead without smelting. In preferred aspects, lead recovery is performed in a continuous process that uses an aqueous electroprocessing solvent and electrorefining, and spent electroprocessing solvent can be recycled to the recovery process.

Description

DEVICES ΑΙ^ΜΤΗΟΒ FOR SMELTERLESS RECYCLIIYGOFLEAD ÀÇÏD BATTERIES [0001] This application ôlaiins priority tô.U.SÎ provisïgnal application with thé sérial ûtimbei 61/905941, which. ivas filed 19-Nov-13.

Field of the Invention [0002] The field of thé invention is reeÿcling of lead acid batteries, especially as it relates to devices and methods that utilize aqueous solutions and do not require smelting and that can be performed in continuons fashion.

Backgrtmnd of the Invention [0003] Tire background description includes information that may be useful in understanding the présent invention. It is not an admission that any of the information provided herein. is prior art or relevant to the presently claimed invention, or tirât any publication specifically or implicitly referenced is prior art.

[0004] Lead acid batteries (LABs) are the single largest class of batteries used today. They are essential for applications ranging from starting automobile eagines, providing emergency back-up power for data, centers, and powering industrial andrecreational vehicles such as fork lift tnicks and golf caris. Lmlike any other battery type, LABs are alrnost 100% recycled and this feature puis lead as the single most recycled commodity. While LAB production is increasing at an average rate of about 5% per year globallv, production of new lead from ore is becoming încreasingly difficult as lead rich ore deposits as depleted. Net surprisingly. new and more efficient methods for lead recyclai» are urgentiy needed.

[0005] Unfortimately, ail or alrnost ail of the current lead recycling from LABs is still based on lead smelting technology. originalïy developed over 2000 years ago to produce lead from ore bodies. Lead smelting is a pyro-metallurgical process in which lead, lead oxides, and other lead compounds are heated to about 1600 °F and then mixed with various reducing agents to remove oxides, sulfates, and other non-lead materials. Prior Art Figure 1 depicts a typical smelting operation starting with ground up LAB materials.

[0006] Unfortimately, lead smelting is a highly pollutingprocess. generating significant airborne waste (e.g., lead dust CO2, arsenic, SO2), solid waste (lead containing slag), and liquid waste (Ag., sulfigiç acid, arseniç_:salts)_f and pollution issues hayeforced the clpsure qf .many smelters în &e LIS and .other Western cousines. Migration.andejqjansion ©f smelters in less regulated counfei.es has restilted in large scale pollution and high levels of human lead coniamination.

.5 [0007] To complicate matters, obtaining pennifs foi lead smelters has become mereasingly difficulf and smelting plants are generally expensive to bmld and operate. Coiisequemly, profitable operation of smelters is a function of scale. As such, there is a drive towards larger and more centralized smelters, which is at odds with the logistics of the LAB industry that favors dîstributed recycling and production located close to concentrations of LAB use. As a > 10 resuit, only the largest LAB producing companies hâve been able to justify and operate smelters while other companies rely on secondary lead produeers to recycle their batteries and supply them with lead. This can make it difficult for LAB producers to meet increasingly stringent requirements for “cradle to grave” control of their products, such as the international standard ISO 14000.

[0008] On a more technical level. it should be appreciated that lead smelting was developed to produce lead fiom lead ore (primarily Galena or lead sulfide). However. tire chemistiy of recycled lead acid batteries is vastly different to the chemistry of lead smelting of ores. As such lead smelting is a fimdamentally inefficient process for lead recycling.

[0009] Varions efforts hâve been made to move away from smelting operations and to use more envfronmentally fiiendly solutions. For example, US 4927510 teaches recovering in pure métal form substantially ail lead firom battery sludge after a desulfurization process. Ail publications identified herein are incorporated by reference to the same extent as if each individual publication or patent application were specifically and individually indicated to be incorporated by reference. Where a définition or use of a term in an incorporated reference is inconsistent or contrary to the définition of that term provided herein. the définition of that tenu provided herein applies and tire définition of that tenu in the reference does not apply. Unforiunately, the ^£510 patent still requires use of a fluorine containing electrolyte, which is equally problematie.

[0010] To overcome some ofthe diffîciïlties associated with fluorine containing électrolyte, desulfurized lead active materials hâve been dissolved in œethaae suifbnic acid as described in US 5262020 and US5520794. However, as lead sulfate is rather poorly soluble in methane sulfonic acid, up-sfreatupre-desulfinizafion is still. neçessary andresithial insoluble materials typically reduced the overall yield. to. an economically rmaifractrve process. To miprove ai least sorne of the. aspects .associated with. lead sulfate, oxygen.and/or ferrie methane. sidfànate can be added as describedin WO 2Ô14/076544_ÿ or mixed oxides .can be produced as: tanght in .5 WO 2014/070547- However^ despite.the.m^royed. yield, seyeràl disadvsntages nevertheless fernain.. Among other thârgs, solvent reuse in these processes ofteii requires additional .effort» andresidual suffises are still lest as waste product: Morêoven, during process upsef conditionsor power outage (which is not uneommon in electroiytic lead recovery), the plated métairie lead will dissolve back into the électrolyte in conventional electroiytic recovery operations, 10 unless the cathode was removed and the lead peeled off, rendering batch operation at best problematic.

[0011] Thus, even though numerous methods for lead recycling are known in the art, ail or almost ali of triera, suffer from one or more disadvantages. Therefore, there is still a need for improved devices and method for smelterless recycling of lead acid batteries, especially in a 15 continuons manner.

Snmmarv of The Invention [0012] lire inventive subject matter is direeted tp varions devices, Systems, and. methods of lead materiel processing in which an.eleçtroproçessiüg solvent is used te selectively dissolve tire active material lead (e.g., PbO, PbO2 and.PbSQi) while eleanùrg and maintaining the 20 grid lead (e.g,,. battery gridsand lead contacts) in. solid form. The dissolved lead is then recoveredih an eleefrolyticcéll, preferably in a.continuons feshion, while clean solid grid. lead is recovered from the lead. iom-enriçhed electroprocessing solvent [0013] Ih one aspect ofthe inventive subjectmatter, the inventors contemplate a. method of processing various lead materials', and especially from.lead acid batteries in which. trie lead 25 materials (e.g., grid leadand active/material lead). are eontacted with an electroprocessing solvent to so selectively dissolve trie active material lead, thereby ibrming a lead ion-enriehed electroprocessing solvent and solid grid lead. In especially'' preferred aspects of contemplated methods, the electroprocessing solvent is an aqueous solution of an alkane sulfonic acid (e.g., methane sulfonic acid) and a chelator (e.g., EDTA). Once the active material lead is dissolved 30 at least some of the grid lead is removed from the lead ion-enriched electroprocessing solvent andïhe lead ions in the lead ion-enriched elecfroprocessingsolvent are reduced ©a a cathode, to foira high-purity lead and a.regenerated.elecfcoproce.ssmg solvent [0014] Wlülenotliœitmg-îq die. inventive subject watter, it js geneiuilyprefeiTed.tbat the active matériel lead has not updergone a desulfinîzationstep, butis directly obtained from .5 lead. acid battery scrap. It is ftiifher generally prefetred that the eleetropïocessing solvent include the.aikane sulfomc acid in au amount.of between 5 and 50 wt% andihe ehelafbr in an amount of between 0.5 and 20 wt%.

[0015] With respect to réduction it is especially preferred thatrediïçtign.is a. continuons process. For example, lead ions are preferably reduced on.one portion, ofthe cathode while at least some of the high-purity lead is recovered from another ροϊόοη of the cathode. Most.

typically, the lead ions are leduced under conditions thatpromote formation of a., micro- or nanoporous mixed matrix (containing molecularhydrogen and elecfrôpï ocessing soh'ënf) having a density of less than 5 g/em3, or a density ôf less than 3 g/cni3, or. a. density of less than 1 g/cm3.

[0016] While not limiting to the inventive subject matter, the cathode is moved relative to the lead ion-enriched electroprocessing solvent (e.g., as a rotating disk, a rotating cylinder, a rolling conveyor-type belt, or reciproeating plate) during the step of reducing the lead ions. Where desired, it is also contemplated that such methods may include a step of removing sulfate and/or a. métal ion other than lead (e.g., tin, silver calcium, arsenic) from the regenerated electroprocessing solvent, and./or a step of using at least some of the regenerated electroprocessing solvent in the step of contacting the lead materials with the electroprocessing solvent. Additionally., itis generally preferred that ali process steps are performed such as to allow processing of the lead materials in a. continuons fashion.

[0017] In another aspect ofthe inventive subject matter, the inventors contemplate a method of continuoiïsly and electrochemically producing high-purifr lead from a lead ion-enriched eleefroprocessing solvent. In such method, a lead ion-enriched electroprocessing solvent is provided and lead ions in the lead ion-enriched electroprocessing solvent are reduced on a cathode to so form adhèrent high-purity lead and a regenerated electroprocessing solvent Most typically, the adhèrent high-purity lead is then removed from one portion of the cathode while lead ions are reduced on another portion of the cathode. Ih fiirther contemplated aspects, at least some of the regenerated electroprocessing solvent is then contacted with lead materiab comprising gfid lead and active material lead to so produce at least a portion pf the lead.ion-einich.ed electroprocessing silvenL [0018] Such methods. will also include a step of dissolving active material lead in an electroprocessing solvent to so form file lead .ion-enriched eleciroprocessing solvent; Most .5 jypically. but not necessarily, the active material lead cari be used directly from lead acid battery scrap without.&rther processing.(e;g:. wiffiout prier desiilfiirization). As noted be&fô, it is generally preferred that the lead ion-enriched electroprocessing solvent inchides an alkane sulfonic acid (e.g., methane sulfonic acid) in an amount of between 5 and 50 wi% and a chelator (e.g.. EDTA) in an amount of between 0.5 and 20 wt%. Where desired, it is contemplated that sulfate and/or a métal ion other than lead is removed from the regenerated electroprocessing solvent [0019] hi further contemplated aspects, the cathode is moved relative to the lead ion-enriched electroprocessing solvent during the step of reducing the lead ions, and/or die high-puiity lead has a purity of at least 98%, more preferably at least 99%, and most preferably at least

99.5%. Among other options, it is generally preferred that the high-puiity lead is only weakly associated with tire surface of the cathode and can be readily removed by a harvestér surface in a non-peeling manner, and that the harvester surface is positioned proximal to the cathode. Thusly produced high-purity lead will typically be or comprise a micro- or naiioporous mixed matrix having a density of less than 5 g/cm3.

[0020] Therefore; and viewed from a different, perspective, the inventors also cojifemplate an.

electrolyzer for producing high-purity lead from a lead ion-enriched electroprocessing solvent. Most preferably, such electrolyzer will include a cell thaï contains a lead ionenriched electroprocessing solvent, an anode and a cathode, both of which are at least partially disposed in the cell to allow contact of the anode and cathode with the lead ion25 emiched electroprocessing solvent. It is still further generally preferred that die elecfrolyzer will further comprise a lead harvester' that is positioned proximally to a surface of the cathode and configured to collect weakly associated Irigh-purity lead from the surface of the cathode in a non-peeling manner.

£0021] Contempiafed electrolyzer may be configured in numerous manners. However. it is 30 typically preferred that the anode and cathode aie disposed in the same cell without a.

separator, that the anode is a titanium anode that is coated with. a métal oxide au example of which is lutheriium. oxide. and/or that the cathode rs an aluminum cathode. Moreover. ît is; generally preféned tirât the cathode is configured: to move relative to the lead.ipn-eariched eleçteprccessing solvent (e:g., configured as a rotating disk shaped cathode, preferably rotatable at. a. speed that allows formation of weakly associatedhigh-purity lead hi a micro- ;or .5 nanoporous mixed mairix;on the disk shaped cathode. Where_: desired, a.harvester surface maybe positioned proximal to the. cathode to remove adliëréntliigh-puritÿ lead üi a nonpèeiiiîgmamier. Additionally, it is contemplated tirât a solvent .conditioning unit.(e.g._$ ion exchange resin. ion sélective membrane, précipitation tank) is fiuidly coupled to the cell to allow for removal of sulfate and/or a métal ion other than lead firom the solvent.

[0022] Therefore, in a further aspect of the inventive subject matter, tire inventons also contemplate a production intennediate that comprises (a) an aqueous solution containing alkane sulfonic acid in an amount of between 5 and 50 wt% of the solution and a chelator in an amount of between 0.5 and 20 wt% of the solution, and (b) undissolved solid giid lead and dissolved active material lead. Most typically, the alkane sulfonic acid is methane sulfonic acid and is présent in an amount of between 15 and 35 wfti, and/or tire chelator is EDTA (ethylene diamine tetraacetic acid) and is présent in an amount of between 1 and 10 wt%. As noted before. it should be appreciated that the active material lead need not necessarily be desulfurized.

[0023] Additionallv, the inventons contemplais a lead composition that includes solid lead 20 having a purity of at least 98% (more typically at least 99%, most typically at least 99.5%), molecular hydrogen, and an electroprocessing solvent, wherein the solid lead the hydrogen, and the electroprocessing solvent form a micro- or nanoporous mixed matrix having a density of less than 5 gtom3, or of less than 5 g/cm3. or of less than 1 g/cm3. Most typically. the electroprocessing solvent comprises an alkane sulfonic acid (e.g., methane sulfonic acid) in 25 an amount of between 5 and 50 wt% ofthe solvent and a chelator (e.g., EDTA) m an amount ofbetween 0.5 and 20 wt% ofthe solvent [0024] Varions objects, féatares, aspects and advantages of&e mventfye subject mattei. will bec-orne more apparent from the folléw'mg detailed. description of préterrëd embodiments, along with thé àceômpanymg drawing figurés in. which like numéral® represent like

Brief Dfeseriptîon of feéDrawmg [0025] Prier Figure lA.isaschematicofaconventionalsmeltingprocessforgrorrndlead acid battery materials, [0026] Figure:'tB-rs an exemplary schematic of a smelter-less process fer gromid lead.aeid battery materials according to. the inventive subjeçt imiter, [0027] Figure IC is an exemplary schematic of an electrolyzer according to the inventive subject marier.

[0028] Figure 2A is an exemplary experimental set up for a process according to Figure IB.

[0029] Figure 2B is a detail view for an electrolyzer with a disc-shaped cathode and a lead product in a micro- or nanoporous mixed matrix.

[0030] Figures 3A-3C are graphs iUustratmg current efïïciencies (CE) as a firnction of lead concentration (3 A, 3C) and current density (3B) using an electrolyzer according to the inventive subject marier.

Detailed Description [0031] The inventera hâve now discovered that lead acid battery materials can be recycled ia a conceptirally simple, yet. effective manner where all.ïéad materials are tfeatëd with a multir functional eleetroprocessing solvent that helps cïéan gridlead materials, and espécrally grids aad contacts/bus bars, while at the same time dissolves ail active lead materials, iricliidirig lead oxide and lead sulfate. Moreover, the sanie solvent eàa. ùpon loading with lead ions due 20 to active materials dissolution, be subjected to an elecirolÿsis process thaï allows continûôus production of high-purity lead while regeneratirig &e elëcfroprocéssing solVent.Tôr a further cycle.

[0032] With respect to the continuous lead recovery it should be especially appreciated that Ireretofore known processes would plate metallic lead from an electrolyte onto a cathode in 25 an acidic solution. During process upset conditions or power outage (which. is not uneommon in electrolytrc lead recovery), the plated metallic· lead would dissolve back into tire electrolyte unless the cathode was removed and the lead removed. Still further, conventional electrolytic lead recovery processes deposit or plate lead as a sfrongly bound film to the cathode, which makes removal of ihe lêad làbor intensive. For examplè, lead can be peeled &om the cathode as sheets. However, srrch sheets bave, the teudency ta breakpr flake, and .lead. removal is thus incomplète and/or iaborsome. Jncontrast, the lead recoveryusing the devices and methods according to the inventive subjeet matter yvill allowrecovery of high purity lead în anon.5 peeling manner. For exampie, the lead product can be removed from die cathode as.anonfrim material.(e.g._s as amorphoùs micro- ornanoporousnrikëdrriatiix) using a wipër or scraper (preferably where the serapér does not dirëctly contact the cathode but is in close proximity, e.g., between 0.5 aud 5 mm)as a removal tool, which in tum allows continuons removal on one portion of the cathode while réduction is performed at another portion of the 10 cathode.

[0033] hi particularly preferred aspects of the inventive subject matter, the electroproeessing solvent comprises an alkaae sulfonic acid in combination with a chelator, and most preferably ' methane sulfonic acid and EDTA. The inventors suiprisingly discovered that ail relevant lead species found in active material lead are effecfively and quickly dissolved in MSA (methane 15 sulfonic acid) where die MSA includes substantial quantifies of a chelator at an acidic pH (i.e., ai a pH equal or less than 7.0, equal or less than 6.0. equal or less than 5.0, equal or less than 4.0, or equal or less than 3.0). For example an aqueous solution of MSA and EDTA did dissolve positive active material (e.g., lead sulfate, and especially tri/tetrabasic leadsulfate; PbSO4.3PbO.H2O/ PbSO4.4PbO.H2O) as well as négative active material (e.g., lead oxide 20 ranging from Pbfll) to Pb(IV) and multiple partial oxidation states between them). Moreover, it was observed that under dissolving conditions for the active material lead. grid lead (e.g., mefallic lead from contacts, bus bars, lead alloys for battery grids, etc.) is not dissolved but instead cleaned by the electroproeessing solvent. Such finding was particularly unexpected as known processes involving lead dissolution in MSA characterized lead sulfate as being only 25 sparsely soluble in MSA. Therefore, among other' benefifs of using a chelator (and especially

EDTA) in MSA, it should be noted that EDTA synergisticaliy and dramatically enlianced solubility of lead sulfates in MSA. Consequently, it should be recogmzed that using the electroproeessing solvent of the inventive subject matter, active material lead can be processed without the need for prior desulfurization.

[0034] Additionally, the inventors also unexpectedly noted that electroproeessing solvents comprising an alkane sulfonic acid and a chelator, and especially MSA and EDTA, were suitable for electrolytic recovery of lead on a cathode. Notably, such recovery;· could even be performed in an électrolytiç çéfi.withoat a separator and as such signifîeantly simplified the design, of suitable éleetrolyzers. Such fînding was particularly imexpectedas prior reports on lead açid batteries ’jiavmg MSÀ as eleçtrolyte (SLABs) notedtlrat layers of an. .insoluble fonn. of PbG2 ..would form on the anode, which effectiyely shuts down the SLAB battery. Without .5 use of the chelator, and especially ËDTA, nse&lness. of MSA. would. beJhmted elecfrolytic recovery of lead. as the.insoluble, âw ofPbO2 willbe présent iii at léast.somesciap materials from LABs.

[0035] While EDTA has been used to preferentialiy dissolve lead salis and to support lead etectrochemicai plating from. solution as described in US. 7368043, such plating requîtes a lû cômplexaiid expensive elecfrocheiineal cell withàmembrane separatoi^- fo inhibitdéstructibn of the EDTA. Still fhthër,. such process also. opérâtes : at high pH. (çaustic pH) and il would be impràctical to couvert ail of the active material from a LAB to caustic· on a commercial bàsis.. hi contràst, EDTA in combination with tlib MSA btacidic pH not only mcrëasedsolubility of most lead species, and especially lead sulfates, but also allowed for réduction, of ionic léàd to 15 ijn adhèrent, bût not plated form: As Used herein, thé térriis “àdliéréaf * of foveakïy associated” in conpmcfion with. metallic lead that. was formed by réduction bf ionic lead refera to a foim of lead that. is not a cohérent film over the surface of the cathode, but that is amoiphous and can be wiped off the cathode, fri other words, a weakly associated or adhèrent lead product does not form in a macroscopie dimension intermetalhc bonds between the cathode and the 20 lead product and will therefore not form a cohérent lead film on the cathode. For example, by observation in most experiments (e.g., see experimental descriptionbelow), lead formed in a spongy low⁷ density layer that was barelv attached to the cathode, floated off a static plate cathode, and could be washed off the surface of a rotating cathode if eleçtrolyte circulation is too aggressive. Moreover. the combination of the alkane· sidfonic acid (e.g., MSA) and chelator (e.g., EDTA) allowed for stable eleetrolytie recovery of lead without significant destruction of the alkane suïfonrc acid (e.g.. MSA) and chelator (e.g.. EDTA).

[0036] Therefore, it should be appreciated that lead acid batteries and battery materials can be processed as exemplarily depicted in Figur e IB by first crashing or grinding the battery or battery materials to a.relatively small size (e.g., averageparticle sizebetween0.1 and 1 cm, 30 or between I and 3 cm, or between 3 and 5 cm, or larger, in the largest dimension), followed by remctval of plastic parts and battery acid (which can be further recycled or processed). The so obtained lead scrap material willpredominaatly contain grid lead and active material lead, which is then. treated ih .a container with the electropr.oeessing solvent to clean the. grid lead. and to dissolve theactive material lead. After .a suitable period.of leaddissolution (or upon complété dissolution of the active injïterial lead). remaining cleaned solid grid lead. eau b.e^: extracted fronithe solution, optionally washed. and pressed into tead.éhips/ingots to. so. yield .5 grid lead that can be directly reused or: furtherrefîned. The reçîtefionof ranges of values hèreffit is merely intended to serve as a shorfiiand method of reièniugindividuaily to. each separate value falïing within the muge. ÛûÎess. otherwise indieated herein, each individual · value is incorporated into the spécification as if ii were individually recited herein.

[0037] The so obtained lead ion-enriched solution may then be treated to remove other non10 lead ions (e.g., zinc, calcium, tin, silver, etc.), which may be performed using a sélective ion exchange resin, other sélective adsorbent. sélective electrodeposition, liquid chromatography and/or précipitation. Of course, it should be recognized that such step may also be perfbnned after electrolytic recovery of lead. Regardless ofany optional pre-processing, tire lead ionemîched solution is then fed to an electrolyzer to recover the lead in metallic form. While any 15 type of electrolyzer is generally’’ contempiated, especially preferred electrolyzers will include those without separator or membrane between the cathode and the anode, and with a cathode that moves relative to the electrolyte. After réduction of the lead ions, the process will yield a high-purity lead (i.e., at least 98% purity, or at least 99% purity, or ai least 99.5% purity).

Where the electrolyzer has one or more nioving électrodes, and especially rotating disk électrodes, lead is being deposited as adhèrent but non-fîhn forming lead.

[0038] Surprisingly, the inventors discovered that the so formed lead formed a micro- or nauoporous mixed matrix ia which the lead formed micro- or nanometer sized structures (typically needles/wires) that trapped some of the elecfroprocessing solvent and a substantiel quantity of molecular hydrogen (i.e., H2). Most notably, such matrix had a black appearance 25 and a remarkably low bulk density. Ihdeed, in most. of the experimental test nuis, the matrix did float on the solvent and had a. density of less than 1 g/cni3. Upon pressing die matrix or application of other force, the density increased (e.g., 1-3 g''cm3, or 3-5 g/cm3, or higher) and a metallic silvery sheen appeared.

[0039] Additionally, it was uaexpectedly observed that the reduced lead ions did not form a 30 tightly bonded film on the cathode, but could be readily removed from the cathode, simply by wiping the cathode with a material to which the lead could adhère (e.g., plastic, lead-film, etc.). Therefore, lead recovery can be perfonned in a continuons manner. Particularly where

a. rotating orreciproeating electrodewasemployed, lead ions cpuldbe reduced one part, of an. electrode or electrode. assembly,. while metalHc leadcan beremcfv'edfrom.another.part ofthe electrode or eleetnxfe assembly.

[0040] hr yet a forther advantageousaspect ofthe.inventive subject matter. ifahould also.be .5 recognized that the eiectipprocessing solvent can be reused after sufficient quantifies of lead had been removed via réduction. Most notablyi themvenfors discovered foat both MSA and EDTA were remarkably stable under the conditions used (see experimental below), and that the spent electroprocessing solvent could be processed by mechanical processing (e.g., filter., centrifuge, hydrocycioae, etc.) to remove any solids, and/or chemical processing (e.g., by 10 précipitation of sulfates, for example, to produce calcium or strontium sulfate), and/or adsorptive processing (e.g., activated charcoal. ion exchange resin, etc.). So processed solvent can then be reused in the next cycle of processing lead materials. .

[0041] With respect to the alkane sulfonic acid it should be appreciated that numerous alkane sulfonic acids are deemed suitable for use herein. However, MSA is especially preferred as 15 this compound is environmentally fiiendly and stable under electrolytic conditions used.

However, other suitable alkane sulfonic acids include ethyl sulfonate, proplyene sulfonate, trifîuro methyl sulfonate (triflic acid), sulfamic acid, etc. In most circumstances, the MSA or other alkane sulfonic acid will be présent in a significant concentration, typically at least 1-5 wt%, more typically 5-15 wt%. even more typically 25-50 wt%, and most typically between 20 15 and 35 wt% of the electroprocessing solvent. Thus, suitable concentrations will typically be between 5 and 50 wt%, or between 20 and 30 wt% of the electroprocessing solvent. The pH of the electroprocessing solvent is most preferably acidic as noted above, and most typically between pH 5-7, or between pH 1-3, or between pH 3-5. Viewed form a different perspective, the pH of the electroprocessing solvent will be less than 7, or equal or less than 25 5, or equal or less than 3.

[0042] Similarly, the nature of the ehelator may vary considerably. However, it. is generally preferred that the ehelator is a ehelator that is sélective or prefereutial for divalent cations. Therefore, EDTA may be partially or eompletely replaced by other chelating agents such as NTA (nitrilotriacetic acid), IDA (iminodiacetic acid), DTPA (diethyleneüiaminepentaaeetic 30 acid), etc. Regardless ofthe particular type ofehelator, if. is preferred that the ehelator is typically présent in an amount of at least 0.1-1 wt%, more typically 1-3 wt%, even more typically 3-10 wt%, and most typically between 2 and 8 wt% of the electroprocessing solvent.

Furthermore,. it is. noted fhatthe chélatpr may be provided in ïôrm of a sait where the ehelator has otherwise redirçe.d.solubilify in acidiçsbhïtioBXé.g., NtiZ^EDTA). It should be noted that. sarch. çonceniratioris may even exçeed tire solubiiiiyrliniit ofthe ehelator. Smfable solvent ai^ preferably aqueous and will most preferably be prepared fromdeionized water. Howeyer, additional co.-solyents are also deerned suitable and include alcohols, various pôlÿols (propylene giycal, polyethylene. glycôï, etc.), brighteners, etc.

[0043] Of course, if. should be noted that the particular size/dimensions of the electrolytic cell may vary considerably aad that the spécifie process conditions and operating parameters will at least in part détermine the size and volume of the electrolytic cell. hr especially preferred ' 10 aspects, however, die electrolytic cell is opérable without the need for a membrane separator.

Viewed from. another perspective, the cell need not be separated in fluidly distinct catholyte and anolyte compartments. Moreover, it should be appréciated that the electrolytic cell need only be fluidly coupled to the container in which the lead materials are being dissolved and'br cïeaned. Where treatment of the elecfropiocessmg solvent is considered, rt should be noted that the type of treatment will détermine the location of such treatment unit, and that the skilled artisan will be readily appraised ofthe suitable location. However, preferred locations are those where treatment is performed on the lead ion-enriched solvent or the at least partially depleted solvent. As used herein, and unless the context dictâtes otherwise, the term coupled to” is intended to include both direct coupling (in which two éléments that are coupled to each other contact each other) and indirect coupling (in which at least one additional element is located between the two éléments). Therefore, the tenus coupled to” and coupled with are used synonymously.

[0044] In other coritemplated aspects ofthe inventive subjeetmatter, and with further respect to the électrodes in the electrolyzer it should be appreciaied that mimerons électrodes are25 deerned suitable for use herein. Indeed, it should be noted that ail conductive materials are considered suitable for use in conjunction with the teacliiags herein so long as such materials are· compatible with the electrochemical conditions use in the process. Therefore, and among other contemplated materials, suitable anodes include various metals, carbon (typically graphite, glassv carbon, or graphene) anodes, matrices comprising at least one polymer and one form of carbon and especially preferred anodes will be titanium anodes, which may be coated with ruthénium oxide (or other métal oxide). Notably, aluminum has been found not to dissolve in the lead-ion enriched elechoprocessing solvent and as such aluminum coated with a conducting and non-passtyatiug material snçh as nithenmm oxide is conteinplated as an anode material. Alternatiÿely Magneli.Phase sub-oxides of titanium (of tire formula: TixO(2xr l) where x is an. mïeger between 4 and '11 j bave been discovered to be stable anode: materials in electroiytes :of similar: composition to the electroprocessing -solvent and are .5 confemplated.foruse as anqde.inaterials andpassivatiofiresisiasî coatings. onanodes.

[9045] More notably, however, the .inventors. dîseovered tirât the lead recovery process, when using the lead ion-enriched electroprocessing solvent, would lead to the formation of a low density lead composition tirât included lead at a very high purity and that included some of the solvent and hydrogen produced ai the cathode. Most remarkably, most if not ail of the so ‘ 10 formed lead composition was black in color, did not plate and bond as an elecùochemically bound film to the cathode, but floated onto the surface upon moderate to strong agitation of the solvent. When pressed into a smaller volume, the hydrogen and electroprocessing solvent was expelled and the remaining lead returned to a metallic appearance. Unexpectedly, less than 10% (e.g., between 5-9%), more typically less than 7% (e.g., between. 2-6%), even more typically less than 5% (e.g., between 1-4%), and most typically less than 3% (e.g., between 0.01-2%) of the total lead formed ai the cathode was found as plated and strongly adhèrent lead on thé cathode, wtiile die remainder of the lead remained in the low density form. While not wishïng to be bound by any theory or hypothesis, the inventors contemplais tirai the lead ia dre low density lead materials formed a micio- or nanopor ous mixed matrix comprising micrometer or even nanometer-sized lead filaments to foim a porous material in which hydrogen and the solvent were trapped.

[0046] Upon further study, the inventors noted that low density and high-purity lead could be obtained from multiple cathode materials, regardless of cathode shape or relative movement of the solvent against the cathode. However, vigorous agitation or movement of the cathode relative to Oie electroprocessing solvent did simplify ‘harvest’ of the floating low density lead composition. Therefore, and anrong other suitable choices, preferred cathode materials include various metals, and especially aluminum. Altenratively, carbon (e.g. graphite, diamond like carbon, graphene, etc.,) matrices comprising at least one polymer and one form of carbon, Magneli Phase sub-oxides of titanium (ofthe formula TixO(2x-l) where x is an integer between 4 and 11) bave been discovered to be stable cathodes materials in the electroprocessing solvent and are contemplated for use as cathode surfaces.

[0047] 'WliUe alackof platipg is typically undesirable in. ail or most elecfro\yinuing methods, theinventors now tiiscoyered that such îack of plafing will enable a continuons lead recycling process in which lead can be ççntinuously removed from the cathode on pne segment while

X additional lead; isfoimed on another segmentof the cathode. Removal.of fhe: adherent/weakly .5 assoçiat:e4 lead is typically done using a.meehanical implement (e.g;, a tv^mg.surface, blade, or other tool in close pioxiœity to the cathode, etc;), hôwevër, remoyal can also be peiiormed wa.nOn-meehanicaltooiâ (e.g.,viajettïng elecfroptocessirig.solvent against fhe cathode,, or sparging gas against the cathode, etc.). Moreover, it should be noted that the removal may not use an implement at ail, but merely by doue by passive release of the low density lead material from the cathode and flotation to the surface of tire eïectrochemical cell (where an overflow weir or harvesting will receive the lead materials).

[0048] Therefore, in at least some preferred aspects, the cathode comprises one or more diskshaped aluminum cathodes that are rotatably coupled to the electrolytic cell and that are in close proximity to the cathodefs). Figure 2A is a photograph of a. small-scale experimental 15 eïectrochemical device in winch lead acid battery scrap materials (predommantly grid lead and active materials lead) are contacted in a digestion tank. Solid materials are then removed as needed and the lead ion enriched electroprocessing solvent is then fed into the electrolytic cell where low density lead materials are plafed on the disk shaped electrode. As needed in the process, at least a portion of the elecfropiOcessing solvent is fed to the recovery unit in 20 which an ion exchange resin and a précipitation stage periodically remove sulfate ions aud other non-métal ions. Figure 2B is a photograph showing a more detailed view of a pair of disk-shaped cathodes and wiper surface that is proximally positioned to the cathodes to so wipe the low-density lead material from tire cathode surface in a non-peeling manner (i.e., without lifting a cohérent lead sheet or cohérent lead film from the cathode in a pulling motion). Figure 2C is more schematic exemplary depiction of an electrolyzer according to the inventive subject matter where electrolyzer 100 has a cell 110 that contains a lead ionenriched electroprocessing solvent 112. Anode 120 and rotating disk-shaped cathode 130 are at least partially disposed in the cell to contact fhe lead ion-enriched electroprocessing solvent 112 and to promote formation of low density lead product 142 that is taken up by lead harvester 140 (typically a plastic· wiper or otherwise proximally positioned surface). Most notably, the- inventais realized that cell 110 can be operated without significant anodic destruction (e.g., less than 10% chelator loss per 12hr continuous operation) of the chelator.

even. inthe. absence a. membrane or. other separator. Solvent conditioning unit 15Qis fluidlv coupled to thte cell ta receive solvent,and proyide back condîtioned solvent.

[0049] Of course,. it should be appreciated. (bat the inventive subject mafter is not limited ta use. of a disk-shaped elechOde, but that ia lâct ail eleçfrodes are deemcd sui table that allow .5 acfive(e.g,, usinga wipingblade or surface) orpassive removal (e.g.. via. bubbles, solvent jetting, or flotation) of higlppurity lead from the cathode. Thus, suitable électrodes may be configured as simple plates that may be ststic relative to the solvent or moved in a reciprocal manner, or eleefrodes that can be contmuously moved and that are configured to allow réduction of lead ions on one portion and lead removal on another portion. For example, 10 suitable electrode configurations include conducfive disks, cylinders, spheres, belts, etc.

Likewise, it should be recognized that. the number of cathodes may vary considerably, and that most typically multiple cathodes are operated in parallel (or serially, especially where the cathodes are stafic relative to the solvent [0050] Solvent processing can be performed in numerous manners and may'· be continuons or 15 baîch-wise. Most typically, processing the solvent includes a step of fîltering to remove ai least some ofthe particulates, a step of sulfate removal (e.g., via lime précipitation, reverse osmosis. ion exchange, electro-osmosis, sait splitting, liquid chromatography, liquid/liquid extraction etc.,), and-'or a step ofnon-lead métal ion removal (e.g.. ion exchange). Where the process is operated in a batch mode, collection of multiple sfreains of solvent is especially 20 preferred, and a surge or holding tank may therefore be added to the system. On Aie other hand. where the system is continuously operated, multiple sfreains may be combined and then processed to reduce redundancy and plot, space.

[0051] Lastly, with respect to the grid lead recovered from the lead ion-enriched solvent, it should benoted that the grid lead may be washed, compacted, and ingoted or be further 25 refined to increase purity where desired. Residual plastic materials are preferably’· collected from the scrapping operation and recycled in a separate process sfreaar using conventional plastic recycling methods.

Experimental Data and Considérations [0052] Ail methods described herein can be performed in any suitable order uuless otherwise 30 indicated herein or otherwise clearly contradicted by context. The use of any and ail exemples, or exemplary language (e.g. '“such as”) provided with respect to certain embodiments herein is intendedmerely to befter.i.llrïminate the. invention and. does not pose a limitation: onîhe scope of the inwntion otherwise elaimed. No language in.the. spécification, should be construed as mdieatmg any non-claimed:ele.œent essentiel to the practice of the invention.

.5 [0053] in a first set of experiments,. the inventors investigated.the: ability of a. solvent to digest.

varions components of a. lead acid battery and in a second _;set ofexperiments to inyesf igàte the ability to electroplate or reduce the dissolved lead (optionally after filtration). Digestion of the various components was initially carried out using only MSA in concentrations rangiiig from 1-50 wt%. At ail concentrations the majority of the lead oxides were extremely soluble.

However, the inventors did not attempt to isolate and test insoluble forms of PbOj in the initial work because it was quickly apparent, that lead sulfate (PbSO4) did not digest very well. Although soluble, the overall concentration of lead sulfate was low (as measured by solution density). tire rate of digestion was also slow (upwards of 24 hours), and digestion required agitation and heat. With the addition of disodium ethylenediamine tetraaeetic acid (EDTA), both tire concentration and digestion rate were vastly improved. The density increased from 1.2 g/cc to greater than 2.1 g/cc. More importanüy andunexpectedly, lead was easilÿ elecfroplated/reduced from this solution, in acid conditions and without the need for a membr ane.

[0054] hr a preferred set of experiments, the MSA concentration was approximately 25 wfr» 20 (+/- 5) MSA in combination with approximately 5 wt% disodium EDTA. For example, a typical solution was made up as follows: 100 L of 98% MSA, 20 kg of Disodium EDTA, the remainder of water filled to 450L total volume. However, tire actual amounts used may vary by as much as 10%. Notably, this solution was able to digest approximately 33kg of mixed battery materials in a 12 hour period without heating or significant agitation The starting density was l.lg/cc and the maximum, density achieved was 1.6 g/cc. It should be appreciated that some of the EDTA did not dissolve (possibly due to reaching saturation concentration in the acidic solution), and it is estimated tirât about 2 to 5 kg of the disodium EDTA did not fiüly dissolve and was captured as tank scaling or on the fîlters during recirculation. Therefore, inmostpraetical examples, preferred eleefroprocessmg solvents will include 2030 30% MSA. 2-8% EDTA, with the remainder deionized water.

[0055] Remarkably, the bulk of lead oxide and sulfate are highly soluble in confemplated elecfroprocessing solvents while metallic lead (and solid lead alloys from lead grids) did not

-dissolve and was sti'ippedcleaii of contamination; under most experimental conditions, 6090% ouïrent ef^ckæey was. observed -wifii a low voltage needed.. Dos- to sélective dissdlving of the positive and. négative active maierials (PAM and.NÂM), .substantially less energy for overalllead recycling is required.

[0056] Using a réclamation set up as. shown in Figure 2 A, and a. total swept cathode area of Û.252 lut and a tank size 10 US gallon^ the following data ia Tablé I and 2 were. obtained:

Biitch	Situ	RPAI	Seraper	A	A'm2 Cathode	Vi	Vf	T
1	1	5.00	OU	50.00		197.72	3.00	3.50	10.00
1	•7	5.00	on	100.00		395.44	3.90	4.10	10.00
1	3	5.00	on	150.00		593.16	4.40	4.60	10.00
1	4	5.00	on	50.00		197.72	3.10	3.40	10.00
2	1	5.00	on	150.00		593.16	4.40	4.50	5.00
2	X>	5.08	ou	150.00		593.16	4.50	4.50	5.00
2	3	10.00	on	150.00		593.16	4.50	4.60	5.00
3	1	10.00	on	100.00		395.44	3.70	3.80	5.00
3	2	10.00	on	100.00		395.44	3.80	4.10	5.00
3		10.00	on	100.00		395.44	3.90	4.10	5.00
3	4	10.00	on	215.00		850.20	5.00	5.00	5.00
3	5	2.00	on	100.00		395.44	3.80	3.80	5.00
3	δ	1.00	at end	93.00		367.76	3.80	3.80	5.00
3	•7	1.00	ai end	90.00		355.90	3.80	3.80	5.00
4	1	L00	at end	400.00		1581.76	6.40	6.60	5.00
5	1	1.00	at end	200.00		790.88	4.60	4.60	5.00
5	•t Xr		OU	200.00		790.83	4.80	4.80	5.00
5	3		ou	200.00		790.88	4.70	4.70	5.00
5	4		on	200.00		790.38	4.80	4.80	5.00
5	5		ou	200.00		790.83·	4.60	4.60	6.20
5	6		on	200.00		790.88	4.70	4.70	5.00
5	•T l		on	200.00		790.88	4.70	4.70	5.00
Table 1
Battit	Rua	wet g	dry g	gdir	g/Àh	kg.di.'in2	Pb (gzl) at start	CE % Tlieory
1	1		30.41	1S2.43	3.55	0.72	10.03		0.96
1	•7		50.39	382.32	3.02	1.20	9.22		0.30
1	3		49.69	298.14	1.99	1.18	7.89		0.52
1	4	32.89	22.37	134.24	2.68	0.53	6.58		0.71
2	i	48.77	31.17	374.04	2.49	1.48	10.03		0.66
2	2	40.77	28.74	344.88	2.30	1.36	9.27		0.61
2	3	40.26	29.47	353.64	2.36	1.40	8.49		0.62
3	1		22.18	26'6.16	2.66	1.05	10.03		0.70
3	2		26.64	319.68	3.20	1.26	9.44		0,84
3	3		20.82	249.84	2.50	0.99	8.74		0.66

3	4	37.78	453,36	2.11	1.79	8,19	•0.57
3	5J	20.30'	243.60	2.44.	0.96	.7.19.	.0.66.·
3	6	12.70	152,40	1,64	0,60	6.66	0,43
3	'7	10.38	124.56	1.38	Q;49	6,32	0.36
4	1 ·	56:79	6S148	1.70	2.69	10.03	0.45:
5	1	33.80	405.60	2,03	•1.60	10,03	0.53
5	7	3450	41400	2.07	1,64	9,12	0.55'
5	.3	30.48	3.65.76	1.83	1.45	831	J04&
:5	4	28.40	340.80	Î70'	1.35	7.56	0.45
5	5	31.70	306.77	1.53	1.21	6.73	0.40
5	6	'22.90	274.80	1.37	1.09	6.12	0.36
5	7	20.50	246.00	1.23	0.97	5.58	0,32

Table 2

Efficiencîes for plating are depicted in Figures 3A-3C, wherein Figure 3 A shows the entrent efficiency of lead production as a function of the initial lead concentration at 200A at a entrent density of 790A/m² and 1 rpm of the disk cathode. Figure 3B shows the entrent efficiency as a function of electrode carrent density. and Figure 3C plotted current efficiency against lead concentration.

[0057] As is shown in Table 3 below, high puiitv lead was obtained at. the cathode as a micro- or nanoporous mixed matrix having a density of less than. 1 g/cm³ (floating on the surface of the solvent). Moreover, the lead composition did not plate on the cathode as a solid and cohérent film but was recovered as amorphous soft and compressible mixed material that contained the methane sulfonic acid and hydrogen.

Element	Qusnt.	Def, Limit	Actual
Bismuth	ppm, (p©g)	0.1	1.3
Copper	ppm, (pg/g)	0.1	L1
Lead	ppm, (pg/g)	0.1	Major (99.5%+)
Potassium	ppm, (pg/g)	0.5	18
Sodium	ppm, (pg/g)	0,1	0.20
TÎH	ppm, (pg/g)	0.2	30

Table 3 [0058] Notably, the so obtained mixed material was different from conventional sponge lead that is noimally produced using foaming agents or gas injection during cooling of liquid lead 15 that was previously purified.

[0059] It should be apparent to those skilled in the art tha t many more modifica tions besides those already described are possible without departing from the inventive concepts herein.

The inventive subject matter, therefore, is not to be resfricted except in the spirit of the appended claims. Moreover, in inteipretiiig both the spécification and the claims, ali terms should.be inteipreted.in the broadest possible manner consistent with the eoafext. In. particplar, the terms ^comprises” and. “comprising” should be inteipreted as reieiring to éléments, components, or steps inanGOrexclusivemanner, indicating that the refèrenced éléments, components; or steps may be.présent or utilîzed, or combined with iother éléments, 5 components, çir:.steps that axe not expressly referenced. Where·: the spécification .claims refera tô at least çnë of something selected fiqm. the group consisting ofA, B, C .... and N, thé fext shauld be iiiterpreted as requiring only one element irai the group, not À plus if, or B plus N, etc.

Claims (29)

1. WhatiS: çlaiïiiëd is;·

   !.. acid·battenés/coHrprismg:

   grovidiüglead âëfiye^i^nal lead, rriieremihe.

   feadtç ..so fibpBia lead: ^olid gri$ lead;

   wherein the elecfropiocessing solvent is.an àqùèbus sdhriionofaualkariesMfcnie acid and a chelator having a pHof lesstlian7;:

   removing at least some of the grid lead fronf the lead ipn-^nri.ched eleçtrçproeessing solvent; and reducing lead ions in the lead ion-enriched: eleciKproeessmgsolverrton a cathode to. form high-purity lead and regen^atfidêlëçfroproçes^mgSôii^nL,.
2. 2. The method ofclaim 1 wherein the active nralefial leadfisnotpre^dously desulfinized;
3. 3. The method ofclaim 1 wherein the elecfroprpcessiHgjsôiyçnt&Gn^risesithé aitetfe sulfonic acid in an amount of between 5 and 50 wt% and the chelator in an amount. of between 0.5 and 20 wt.%.
4. 4. The method of claim 1 wherein reducing tire lead ions is performed concurrently with. a further step of removing at least some of the high-purity lead from the cathode.
5. 5. The method of claim 1 wherein reducing the lead ions is performed under conditions tirai form a micro- ornanoporous mixed matrix having a density ofless than 5 g/cni\
6. 6. The method of claim 1 wherein the cathode is moved relative to the lead ion-eariched electroprocessing solvent during the step of reducing the lead ions.
7. 7. The method of claim 1 further comprising a step of removing sulfate and'or a métal ion other than lead front the regenerated electroprocessing solvent
8. 8. The method of claim 1 ferther comprising a step of using at least some of the regenerated electroprocessing solvent in the step of eontactmg the lead materials with the electroprocessing solvent.

   ,maten.$s·. remoyîng at least sonie .of the gricl lead, and reducinglead:lions are·performed to aiïbty prpce&sgrgte

   W Amë&dpfiésùHàtippsfy'M^ ibn-enriçhed : elèefroprecessing solvent, comprising· . proyidiiig a lead iou-eniiclied eledfroproees^ fr çhelhtpr;:

   providing an electrolytic cell comprising au anode and a cathode, wherein the electrolytfc cell does not include a membrane or other separator between the anode sud the cathode;

   reducing lead ions in the lead ion-enriched elecfroprocessing solvent on the cathode to form adhèrent high-purity lead and a regenerated elecfroprocessing solvent without significant dégradation of the chelaior at the anode;

   removing the adhèrent high-purity lead froin one portion of the cathode while lead ions are reduced on another portion of the cathode;

   contacting at least some ofthe regenerated elecfroprocessing solvent with lead materials comprising grid lead and active material lead to so produce at least a portion of the lead ion-enriched elecfroprocessing solvent
9. 11. The method of claim 10 further comprising a step of dissolving active material lead in a elecfroprocessing solvent to so fonnthe lead ion-enriched elecfroprocessing solvent.
10. 12. The method of claim 11 wherein the active material lead is not previously desulfurized.
11. 13. The method of claim 1 i wherein the lead ion-enriched elecfroprocessing solvent includes an alkaae sulfonic acid in an amount of between 5 and 50 wt% and the chelator in an amount of between Û.5 and 20 wt%.
12. 14. The method of claim 11 wherein the cathode is moved relative to the lead ion-enriched elecfroprocessing solvent during the step of reducing the lead ions.
13. 15. The method of claim 11 wherein the high-purity lead has a purity of at least 98%.
14. 16. The method of claim 11 wherem tire adhèrent high-purity lead îs removed by a haivester surface in a uon-peeling manner, and wherein the harvester surface is positioned proximal to the cathode.

    .1?j fhepiefhgd ofçlaiin. i. T ^herein: jhe.

    inîxedmatax.haying .a.$esisify ÏS/i&me^dpfçlænîT l.ûtoher^ step gf rerngying ί Î9- A piOffection infenne&afe cpinprisürg (à) an. aqueous; solution contaimiig attome sulfesie acid in -an amount of bëiween 5^: and- 50 W%' of thë solution anda chelator in an amount of between 0.5 and 20 wt% of the solution, and (b) undissolved solid grid lead and dissolved active material lead comprising lead sulfate.
15. 20. The production intermediate of claim 19 wherein the alkane sulfomc acid is methane sulfonic acidand is présent in an amount of between 15 and 35 wt%.
16. 21. The production intermédiare of claim 19 wherein. the chelator is EDTA (etihyiene diamine tetraaeetic acid) and is présent in an amount of between I and 10 wt%.
17. 22. The production intermediate of claim 19 wherein the active material lead is not previously desulfiirized.
18. 23. A lead composition comprising solid lead having a purity of ai least 98%, molecular hydrogen, and an eleetropmcessing solvent, wherein the solid lead, the hydrogen, and the eïectroprocessing solvent form a micro- or naaoporous mixed matrix having a density of less than 5 g/cm⁵, and wherein the pH of flie eïectroprocessing solvent is less than 7.
19. 24. The lead composition of claim 23 wherein the mixed matrix has a density of less than 3 g'crn³.
20. 25. Tire lead composition of claim 23 wherein the mixed matrix has a density of less than 1 g/cm³.
21. 26. The lead composition of claim 23 whereiii the eïectroprocessing solvent comprises an alkane sulfonic acid in an amount of between 5 and. 50 wt% and a chelator in an amount. of between 0.5 and 20 wt%.
22. 27. The lead composition of claim. 26 wherein the alkane sulfonic acid is methane sulfonic acid and wherein the chelator is EDTA (ethylene diamine tetraaeetic acid).
23. 28;.^elec^lyzerf<piüduçïngipgh-piHltyIeadfiô^^ solvent, eoaiprisaig:

    a..çefâ:çofitain^ electroprocessing ^vrilféan^ri^gachelafoi?

    a» ©ièctidiy fie cell/cpniprisàig anode; aad a cathode, both. Mlëarfpariially {Ssposedm the eleeteoljÂc.cellto'alIôw^pütact'ofjiieaîiode .aiid.cathpdewtiththelead. kaï-eHridied ëlectippEocessingsolvent,· wheréh. thé eléctiolytic cell does ûof inchkfe::.àtiriembraîië ©p ©:tiiéP:sêpa£àtôî;^Uyeéa^: tlleanode and tiie; cathode;.

    a lead harvester operationaily coupled to the electroiyzer and positioned proxùaally to a surface ofthe cathode and configured to collect adhèrent high-purity lead from the surface of tire cathode ia a non-peeling manner and without significatif dégradation of the chelator.
24. 29. The electrolyzer of claim 28 wiierein the anode is a titanium anode that is coated with ruthénium oxide, and wherein the cathode is an aluminum cathode.
25. 30. The electrolyzer of claim 28 wherein fhe cathode is configured to move relative to the lead ioa-enriched electroprocessing solvent
26. 31. The electrolyzer of claim 28 wherein the cathode is a rotating disk shaped cathode.
27. 32. The electrolyzer of claim 28 wherein the cathode is rotatable at a speed effective to allow formation of adhèrent, high-purity lead in a micro- or naaoporous mixed matrix on ihe disk shaped cathode.
28. 33. The electrolyzer of claim 28 forther comprising a harvester surface positioned proximal to the cathode and configured to remove adhèrent high-purity lead in a non-peeling manner.
29. 34. The electrolyzer of claim 28 further comprising a solvent conditioning unit that is fluidly coupled to the cell and configured to allow for removal of sulfate and/or a. métal ion other than lead fiom the solvent