CA1310837C - Hydrometallurgic process for recovering in the metal form the lead contained in the paste of the exhausted batteries - Google Patents
Hydrometallurgic process for recovering in the metal form the lead contained in the paste of the exhausted batteriesInfo
- Publication number
- CA1310837C CA1310837C CA 522758 CA522758A CA1310837C CA 1310837 C CA1310837 C CA 1310837C CA 522758 CA522758 CA 522758 CA 522758 A CA522758 A CA 522758A CA 1310837 C CA1310837 C CA 1310837C
- Authority
- CA
- Canada
- Prior art keywords
- paste
- lead
- metal form
- recovering
- exhausted
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Expired - Fee Related
Links
- 238000000034 method Methods 0.000 title claims abstract description 26
- 230000008569 process Effects 0.000 title claims abstract description 19
- 239000002184 metal Substances 0.000 title claims abstract description 15
- 229910052751 metal Inorganic materials 0.000 title claims abstract description 15
- YADSGOSSYOOKMP-UHFFFAOYSA-N lead dioxide Inorganic materials O=[Pb]=O YADSGOSSYOOKMP-UHFFFAOYSA-N 0.000 claims abstract description 24
- MHAJPDPJQMAIIY-UHFFFAOYSA-N Hydrogen peroxide Chemical compound OO MHAJPDPJQMAIIY-UHFFFAOYSA-N 0.000 claims abstract description 23
- 239000002253 acid Substances 0.000 claims abstract description 12
- 238000000605 extraction Methods 0.000 claims abstract description 9
- 239000003792 electrolyte Substances 0.000 claims abstract description 8
- 239000000243 solution Substances 0.000 claims description 18
- 230000009467 reduction Effects 0.000 claims description 10
- 238000006243 chemical reaction Methods 0.000 claims description 9
- 238000002386 leaching Methods 0.000 claims description 9
- 239000007787 solid Substances 0.000 claims description 3
- 239000007864 aqueous solution Substances 0.000 claims description 2
- QVGXLLKOCUKJST-UHFFFAOYSA-N atomic oxygen Chemical compound [O] QVGXLLKOCUKJST-UHFFFAOYSA-N 0.000 claims description 2
- 239000012535 impurity Substances 0.000 claims description 2
- 229910052760 oxygen Inorganic materials 0.000 claims description 2
- 239000001301 oxygen Substances 0.000 claims description 2
- 238000009854 hydrometallurgy Methods 0.000 claims 1
- 238000005363 electrowinning Methods 0.000 abstract description 5
- 238000005868 electrolysis reaction Methods 0.000 abstract description 4
- 150000003839 salts Chemical class 0.000 abstract 1
- 239000000203 mixture Substances 0.000 description 8
- RAHZWNYVWXNFOC-UHFFFAOYSA-N Sulphur dioxide Chemical compound O=S=O RAHZWNYVWXNFOC-UHFFFAOYSA-N 0.000 description 6
- 230000002378 acidificating effect Effects 0.000 description 6
- QAOWNCQODCNURD-UHFFFAOYSA-L Sulfate Chemical compound [O-]S([O-])(=O)=O QAOWNCQODCNURD-UHFFFAOYSA-L 0.000 description 4
- 238000007792 addition Methods 0.000 description 4
- 238000001914 filtration Methods 0.000 description 4
- 229910021653 sulphate ion Inorganic materials 0.000 description 4
- QGZKDVFQNNGYKY-UHFFFAOYSA-O Ammonium Chemical compound [NH4+] QGZKDVFQNNGYKY-UHFFFAOYSA-O 0.000 description 3
- BVKZGUZCCUSVTD-UHFFFAOYSA-L Carbonate Chemical compound [O-]C([O-])=O BVKZGUZCCUSVTD-UHFFFAOYSA-L 0.000 description 3
- 229910004039 HBF4 Inorganic materials 0.000 description 3
- NINIDFKCEFEMDL-UHFFFAOYSA-N Sulfur Chemical compound [S] NINIDFKCEFEMDL-UHFFFAOYSA-N 0.000 description 3
- 239000005864 Sulphur Substances 0.000 description 3
- 229910052783 alkali metal Inorganic materials 0.000 description 3
- 150000001340 alkali metals Chemical class 0.000 description 3
- HTUMBQDCCIXGCV-UHFFFAOYSA-N lead oxide Chemical compound [O-2].[Pb+2] HTUMBQDCCIXGCV-UHFFFAOYSA-N 0.000 description 3
- 239000000463 material Substances 0.000 description 3
- 239000000843 powder Substances 0.000 description 3
- 238000012545 processing Methods 0.000 description 3
- 230000007928 solubilization Effects 0.000 description 3
- 238000005063 solubilization Methods 0.000 description 3
- 239000000126 substance Substances 0.000 description 3
- 239000004291 sulphur dioxide Substances 0.000 description 3
- 235000010269 sulphur dioxide Nutrition 0.000 description 3
- LSNNMFCWUKXFEE-UHFFFAOYSA-M Bisulfite Chemical compound OS([O-])=O LSNNMFCWUKXFEE-UHFFFAOYSA-M 0.000 description 2
- OKTJSMMVPCPJKN-UHFFFAOYSA-N Carbon Chemical compound [C] OKTJSMMVPCPJKN-UHFFFAOYSA-N 0.000 description 2
- 229910000003 Lead carbonate Inorganic materials 0.000 description 2
- 150000007513 acids Chemical class 0.000 description 2
- 238000001035 drying Methods 0.000 description 2
- 229910002804 graphite Inorganic materials 0.000 description 2
- 239000010439 graphite Substances 0.000 description 2
- 238000010438 heat treatment Methods 0.000 description 2
- 150000002611 lead compounds Chemical class 0.000 description 2
- 239000000047 product Substances 0.000 description 2
- 239000000376 reactant Substances 0.000 description 2
- 238000011084 recovery Methods 0.000 description 2
- 238000009877 rendering Methods 0.000 description 2
- 239000010802 sludge Substances 0.000 description 2
- 239000007858 starting material Substances 0.000 description 2
- LSNNMFCWUKXFEE-UHFFFAOYSA-L sulfite Chemical compound [O-]S([O-])=O LSNNMFCWUKXFEE-UHFFFAOYSA-L 0.000 description 2
- RPAJSBKBKSSMLJ-DFWYDOINSA-N (2s)-2-aminopentanedioic acid;hydrochloride Chemical class Cl.OC(=O)[C@@H](N)CCC(O)=O RPAJSBKBKSSMLJ-DFWYDOINSA-N 0.000 description 1
- ATRRKUHOCOJYRX-UHFFFAOYSA-N Ammonium bicarbonate Chemical compound [NH4+].OC([O-])=O ATRRKUHOCOJYRX-UHFFFAOYSA-N 0.000 description 1
- 241000518994 Conta Species 0.000 description 1
- 101100536354 Drosophila melanogaster tant gene Proteins 0.000 description 1
- 229920001875 Ebonite Polymers 0.000 description 1
- RRHGJUQNOFWUDK-UHFFFAOYSA-N Isoprene Chemical compound CC(=C)C=C RRHGJUQNOFWUDK-UHFFFAOYSA-N 0.000 description 1
- VMHLLURERBWHNL-UHFFFAOYSA-M Sodium acetate Chemical compound [Na+].CC([O-])=O VMHLLURERBWHNL-UHFFFAOYSA-M 0.000 description 1
- 241000282887 Suidae Species 0.000 description 1
- 230000009471 action Effects 0.000 description 1
- 239000003513 alkali Substances 0.000 description 1
- 150000008044 alkali metal hydroxides Chemical class 0.000 description 1
- 239000012670 alkaline solution Substances 0.000 description 1
- 239000001099 ammonium carbonate Substances 0.000 description 1
- 235000012501 ammonium carbonate Nutrition 0.000 description 1
- 229910052924 anglesite Inorganic materials 0.000 description 1
- 239000007900 aqueous suspension Substances 0.000 description 1
- ZETCGWYACBNPIH-UHFFFAOYSA-N azane;sulfurous acid Chemical compound N.OS(O)=O ZETCGWYACBNPIH-UHFFFAOYSA-N 0.000 description 1
- 229910052799 carbon Inorganic materials 0.000 description 1
- 239000003518 caustics Substances 0.000 description 1
- 230000008859 change Effects 0.000 description 1
- 239000003638 chemical reducing agent Substances 0.000 description 1
- 239000003245 coal Substances 0.000 description 1
- 238000000151 deposition Methods 0.000 description 1
- 230000008021 deposition Effects 0.000 description 1
- 238000010586 diagram Methods 0.000 description 1
- 238000006073 displacement reaction Methods 0.000 description 1
- 239000000428 dust Substances 0.000 description 1
- 239000003344 environmental pollutant Substances 0.000 description 1
- 239000003517 fume Substances 0.000 description 1
- 238000001033 granulometry Methods 0.000 description 1
- 150000002500 ions Chemical class 0.000 description 1
- 229910000464 lead oxide Inorganic materials 0.000 description 1
- WABPQHHGFIMREM-UHFFFAOYSA-N lead(0) Chemical compound [Pb] WABPQHHGFIMREM-UHFFFAOYSA-N 0.000 description 1
- 239000007788 liquid Substances 0.000 description 1
- 235000013379 molasses Nutrition 0.000 description 1
- 238000012544 monitoring process Methods 0.000 description 1
- YEXPOXQUZXUXJW-UHFFFAOYSA-N oxolead Chemical compound [Pb]=O YEXPOXQUZXUXJW-UHFFFAOYSA-N 0.000 description 1
- 239000002245 particle Substances 0.000 description 1
- 231100000719 pollutant Toxicity 0.000 description 1
- 239000002244 precipitate Substances 0.000 description 1
- 238000000746 purification Methods 0.000 description 1
- 238000000926 separation method Methods 0.000 description 1
- 239000001632 sodium acetate Substances 0.000 description 1
- 235000017281 sodium acetate Nutrition 0.000 description 1
- 239000008247 solid mixture Substances 0.000 description 1
- 238000003756 stirring Methods 0.000 description 1
- 229910052717 sulfur Inorganic materials 0.000 description 1
- 239000000725 suspension Substances 0.000 description 1
- VZGDMQKNWNREIO-UHFFFAOYSA-N tetrachloromethane Chemical compound ClC(Cl)(Cl)Cl VZGDMQKNWNREIO-UHFFFAOYSA-N 0.000 description 1
- 230000001988 toxicity Effects 0.000 description 1
- 231100000419 toxicity Toxicity 0.000 description 1
- 239000002699 waste material Substances 0.000 description 1
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 description 1
Classifications
-
- C—CHEMISTRY; METALLURGY
- C25—ELECTROLYTIC OR ELECTROPHORETIC PROCESSES; APPARATUS THEREFOR
- C25C—PROCESSES FOR THE ELECTROLYTIC PRODUCTION, RECOVERY OR REFINING OF METALS; APPARATUS THEREFOR
- C25C1/00—Electrolytic production, recovery or refining of metals by electrolysis of solutions
- C25C1/18—Electrolytic production, recovery or refining of metals by electrolysis of solutions of lead
-
- C—CHEMISTRY; METALLURGY
- C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
- C22B—PRODUCTION AND REFINING OF METALS; PRETREATMENT OF RAW MATERIALS
- C22B13/00—Obtaining lead
- C22B13/04—Obtaining lead by wet processes
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
- H01M10/00—Secondary cells; Manufacture thereof
- H01M10/54—Reclaiming serviceable parts of waste accumulators
-
- Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
- Y02W—CLIMATE CHANGE MITIGATION TECHNOLOGIES RELATED TO WASTEWATER TREATMENT OR WASTE MANAGEMENT
- Y02W30/00—Technologies for solid waste management
- Y02W30/50—Reuse, recycling or recovery technologies
- Y02W30/84—Recycling of batteries or fuel cells
Landscapes
- Chemical & Material Sciences (AREA)
- Engineering & Computer Science (AREA)
- Chemical Kinetics & Catalysis (AREA)
- Electrochemistry (AREA)
- Materials Engineering (AREA)
- Metallurgy (AREA)
- Organic Chemistry (AREA)
- Manufacturing & Machinery (AREA)
- Mechanical Engineering (AREA)
- General Chemical & Material Sciences (AREA)
- Electrolytic Production Of Metals (AREA)
- Manufacture And Refinement Of Metals (AREA)
Abstract
"HYDROMETALLURGIC PROCESS FOR RECOVERING IN THE METAL
FORM THE LEAD CONTAINED IN THE PASTE OF THE EXHAUSTED
BATTERIES"
Abstract A completely hydrometallurgic process is disclosed for recovering in the pure metal form the lead contained in the paste of the old batteries, separated from the other components, and desulphurized according to the known processes.
The paste is leached with an acid suitable to the electrowinning, the amount of hydrogen peroxide necessary to reduce all of the existing PbO2 being added.
A high extraction yield is obtained, without foreign salts being added to the electrolyte, which is then submitted to an electrolysis step, to recover Pb as cathodes.
FORM THE LEAD CONTAINED IN THE PASTE OF THE EXHAUSTED
BATTERIES"
Abstract A completely hydrometallurgic process is disclosed for recovering in the pure metal form the lead contained in the paste of the old batteries, separated from the other components, and desulphurized according to the known processes.
The paste is leached with an acid suitable to the electrowinning, the amount of hydrogen peroxide necessary to reduce all of the existing PbO2 being added.
A high extraction yield is obtained, without foreign salts being added to the electrolyte, which is then submitted to an electrolysis step, to recover Pb as cathodes.
Description
~L3~3~
"HYDROMETALLURGIC PROCESS FOR RECOVERING IN THE METAL
FORM THE LEAD CONTAINED IN THE PASTE OF THE EXHAUSTED
BATTERIES"
According to the various methods of desulphurization of the paste, by treating the sludge of the exhausted batteries with solutions of carbonate of alkali metals or of ammonium~ a solution is obtained, into ~hich practically all of the sulphur passes in the form of soluble sulphate (of alkali metal or of ammonium), as ~ell as a mixture of insoluble lead compounds which, after having been separated from the solution, and th~roughly washed with water, is practically free from sulphur.
Such a mixture can be easily reduced with coal at a relatively low temperature (800-900 C), without substantial emissions of sulphur dioxide, and without the : product;on of lead mattes~
The pyrometallurgic reduction of this product is thus the presently most used method~ also because of the advantages oF the h;gh productivity and of the long life of the reduction ovens and of the high yields of lead ~xtraction.
The pyrometallurgical processings of the lead-containing materials ;nvolve however particular precautions in the carriage and in the charging of the furnaces, and the possibility of emission, by the same furnaces~ of fumes and volatile dusts~
From here the need arises for the refiner to have available large filtering plants, and a wide and expensive system for the monitoring, as to the pollutant lead, of the working premises and of the surroundings of ~ 3 ~
"HYDROMETALLURGIC PROCESS FOR RECOVERING IN THE METAL
FORM THE LEAD CONTAINED IN THE PASTE OF THE EXHAUSTED
BATTERIES"
According to the various methods of desulphurization of the paste, by treating the sludge of the exhausted batteries with solutions of carbonate of alkali metals or of ammonium~ a solution is obtained, into ~hich practically all of the sulphur passes in the form of soluble sulphate (of alkali metal or of ammonium), as ~ell as a mixture of insoluble lead compounds which, after having been separated from the solution, and th~roughly washed with water, is practically free from sulphur.
Such a mixture can be easily reduced with coal at a relatively low temperature (800-900 C), without substantial emissions of sulphur dioxide, and without the : product;on of lead mattes~
The pyrometallurgic reduction of this product is thus the presently most used method~ also because of the advantages oF the h;gh productivity and of the long life of the reduction ovens and of the high yields of lead ~xtraction.
The pyrometallurgical processings of the lead-containing materials ;nvolve however particular precautions in the carriage and in the charging of the furnaces, and the possibility of emission, by the same furnaces~ of fumes and volatile dusts~
From here the need arises for the refiner to have available large filtering plants, and a wide and expensive system for the monitoring, as to the pollutant lead, of the working premises and of the surroundings of ~ 3 ~
2.
the factories. For this reason, very important are the processes for the recovery of lead of the paste in the metal form, which may constitute a valuable alternative to the pyrometallurgical processings, such as, above all, those processes which operate according to a completely hydrometallurgical route, such as the extraction processes by electrolytic way, or electrowinning.
The desulphurized paste has on the average the following composition:
- Lead carbonate (PbC03) 50 - 52%
- Lead sulphate (PbS04) 2.5 - 4%
- Lead peroxide (PbO2) 14 - 16X
- Lead oxide (PbO) 11 - 12%
- Metal lead (Pb3 5 - 7%
It is known that the practical problem of the hydrometallurgical processing of the paste of the old batteries ;s that of rendering soluble in the solution selected for the electrolysis all of the components of ; the mixture, in paticular PbO2, which is conta;ned in it in large percentages. In fact, the residual of the acidic ~; solubilization of the mixture must not constitute an intolerable loss of lead.
~ On the other hand, owing to the well-known ;~ insolubility of PbO2 in the normal acids suitable to the electrolytic process, without a preliminary treatment for PbO2 reduction, the residue of the acidic solubili~ation of the mixture is very rich in lead, and must be sent back to the pyrometallurgical recovery.
In accordance with the prior art, the solubilization of all of the components of the paste in the various electrolyt~s has been accomplished by various ways.
~' .
~ 3 ~ 3 ~
In chronological order~ the following patents may be cited:
; - C~E. Tucker in U.S.Pat. 1,148,062 suggests a heating of the battery sludge, to convert PbO2 into soluble PbO
and Pb20.
- W.C. Smith in U.S.Pat. 1,752~356, ~o solubilize PbO2 in view of the treatment with caustic alkali, submits the paste to a heating in a reducing environment ~PbO is formed).
- J.H. Calbeck in U.S.Pat. 1,911,604 carries out the Leaching of the battery paste by a sodium acetate solution. Lead oxide and sulphate are dissolved, whilst PbO2 is normally insoluble in that electrolyte.
~ 15 ~ut, ;n the presence of metal Pb and in the said ; elertrolyte, a local couple is established, so that PbO2 and an equivalent amount of metal lead are dissolved.
- A.F. 6~umann in U.S. Pat. 4,107,007 leaches the paste with a concentrated solution of alkaLi metal hydroxide~ to which molasses,or raw sugar, or the like, has been added.
In such a way, Pb oxide and sulphate are dissolved, and fed to the electrolysisu The behaviour of PbO2 is not detailed~
R.D. Prengaman in U.S.Pat. 4,229,271 proposes two ; methods of eliminating PbO2 from the paste, and rendering it wholly soluble in the customary acids for the electrowinning process:
a) a drying at 100 C of the paste, follo~ed by a roasting under a reduGing atmosphere at i ' ; temperatures comprised within the range of from 290 to 375C;
b) a trea~ment of the aqueous suspension of the paste ~ith sulphur dioxide, or with sulphite or bisulphite of alkali metal or of ammonium~
- U.Ducati in U.S.Pat. 4,460~442 reacts the paste of the battery, at 100-120 C, in the presence of a strongly alkaline solution, to obtain a red lead precipitate, which has the property of completely dissolving ;n the hot concentrated solutions of fluoboric acid or of fluosilicic acid.
-A.Y. Lee and E.R. Cole of Bureau of Mines suggest in R~I. 8857 two ways for reducing the PbO2 contained in the paste:
a) by the addition of Pb powder during the leaching -~ with fluosilicic acid of the paste already desulphurized with ammonlum carbonate;
b~ by the addition of ammonium bisulphite during the treatment of desulphurization with ammonium carbonate.
The suggested methods of thermal reduction of PbO2 under a reduc;ng atmosphere have the disadvantage of add;ng two steps to the working cycle: the drying and the - reducing roasting. These operation steps require a strict control of the operat;ng ronditions, and they must be furthermore carried out on a un;t tfurnace or roaster) euipped with an adequate dust exhauster. Moreover~ e~en ~ if the temperatures are low, moving dry material is : pollution-causinga The method of reduction during the high-temperature dissolving, by means of the add-ition of lead powder, 3 ~
;nvolves the transfer of a portion of produced lead, to convert ;t into powder; as a consequence, this is an expensive method.
The method of reduction with sulphur dioxide, sulphite or bisulphite before the carbonating involves a certain cost, due to the reactant, but, what's more important, it causes the consumption of carbona~e for the desulphurizing to increase by about 25%; the correspond;ng expense is not negligible; to date, the expense for the carbonate is the highest item of individual expenditure of the whole process.
Purpose of the present invention is to solve the above reminded problems concerning the processes of hydrometallurgical treatment by electrow;nning of the desulphurized paste of the exhausted batteries~
For such a purpose to be accomplished, the invention proposes a hydrometallurg;cal process for recovering, by extraction by electrolytic way, in pure metal form, the lead of the paste, or desulphurized paste, of the exhausted batteries~ characterized in that it comprises the steps of:
a) leach;ng said paste with an aqueous solution of an ac;d selected from those suitable to the electrolytic ~; extraction;
b) treating with hydrogen peroxide the leached paste as ~: of (a), with the concom;tant carrying out of the following reactions:
~1) Pb + H22 ~~~> Pb + 2 t 2H
(2) Pb ~ Pb4+ --~ 2Pb2+
up to the quantitative reduction of all of the lead dioxide contained in the sa;d paste, c) separation of the solid residue from the so-obtained dissolved lead-containing solution, which can be directly sent to the electrolytic lead extraction.
The process of the invention, as substantially 5defined above, is described in greater detail.
The starting material of the process is the paste already separated from the other components of the exhausted batteries, and which has already undergone the desulphurizing process in accordance with the known art.
10This material is leached with the aclueous solution of an acid suitable to the subsequent eletrolytic extraction ~preferably, either fluoboric or fluosilicic acid), to which such an amount of hydrogen peroxide is added, as to obtain the greatest solubilization of all of ~; 15the lead compounds present, and~ more specifically, of PbO2 and of metal Pb.
Dur;ng the acidic treatment of the desulphurized paste, the hydrogen peroxide causes the reaction:
Pb4 + H22 ~~~ Pb + 2 + 2H ~1) 20so that all of the PbO2 is reduced to PbO and dissolved by the present acid.
; The cons;dera~le amount of 2 which is liberated during reaction ~1) physicaLly actlvates the particLes of metal Pb present in the paste, so that the reaction:
25Pb ~ Pb4+ _ ~ 2Pb2~ t2) occurs more easily, and all of the metal Pb having the right granulometry is d;ssolved, allowing also the hydrogen peroxide, corresponding to the Pb4 ~hich is reduced, to be saved.
30After the acidic leaching with the addition of hydrogen peroxide, of the desulphurized paste only the .
3~
organic substances (thin scraps of separators and ebonite, f;bres and so forth), and Pb sulphate not conuerted in the desulphurizing step remain undissolved.
The reacted liquid/solid mixture is separated by filtration~ The solid residue from the filtration contains not more than 5% of the lead present in the starting material and, after a roasting to destroy the organic substances, it can be returned to the desulphuri2ing step.
The filtered solution contains all of the Pb in ionic form and does not normally require any purifications, because it is the same Pb powder, physically activated by the oxygen being evolved in reaction (11, ~hich carries out the displacement action ~also named as "cementation") of the impurities~ small amounts of which may haue been dissolued during the acidic leaching.
The self-purified solution can be then directly fed to the electrolytic extraction of lead, which is carried out in customary cells with insoluble graphite anodes and with cathodes made from thin lead sheets. `
~y operating under suitable conditions, a cathodic ; deposit of excellent quality and purity can be obtained, - ~ the deposition of PbO2 at the anode being prevented to the highest extent~
The small amounts of PbO2, which are sometimes unavoidably formed, must be returned to the step of acidic leaching with hydrogen peroxide. The cathodes, smelted into pigs, are marketed as electrolytic lead. The solution coming off the electrolysis returns back to the acid;c leaching of the paste.
8.
To the purpose of better understanding the characteristics and the advantages of the invention, a non limitative example of practical embodiment thereof is described in the following.
E X _ m e ' An amount of 980 9 of well washed desuLphurized paste, containing, as referred to the dry matter: Pb, 70.5%; Sb, 0.68%; S, 0.18%; has been leached with 5 l of exhausted electrolyte from the electrowinning, containing:
49 g/l of Pb 139 g/l of free HBF4 After a half an hour stirring at 50 C, hydrogen peroxide ~in the form of a solution at 35%) has been added in the amount of 4.6% of the processed paste, and has been allowed to react over a further half an hour.
By filtration, the following substances have been s_ parated:
80 g of insoluble residue having the composition:
Pb 34.2X
Sb 2.4%
S 2.2%
~ 5 l of lead-carrying electrolyte~ containing;
; 181.5 g/l of Pb ~+~
0.6 g/l of Sb 25.1 g/l of free HBF4 The leaching ~ith fluoboric acid and hydrogen peroxide has extracted 96.01% of the total Pb contained in the paste. All of the sulphur has remained in the residue.
By submitting the 5 l;tres o~f lead-carrying ~ 3 ~
electrolyte to electrowinning on a cell with graphite anodes (previously lined with PbO2) and cathodes of thin sheet of eLectrolytic lead, 630 9 of cathodic lead,as well as 9 g of PbO2 a~ the anode, have been produced.
The cell has been operating over 24 hrs at 7 A and 2.5 V.
The cathodic current density has been of 280 A/m .
The curren~ efficiency has been of 97%.
The smelted cathodic lead had the following composition:
Sb c 0.001;
As < 0.001;
Sn < 0.001;
8; < 0.~0~;
Cu = 0.0003;
Ag < 0~0005.
The exhausted electrolyte, to be returned back to ~he leaching of new paste, contained:
53 g/l of Pb 20 `` \ 131 g/l of free HBF4.
ln the attached drawing, a block diagram is reported, to exemplifying purposes, of the process of the ` invention.
In general, it can be observed that according to the invention the use of hydrogen peroxide offers the follow;ng advantages~ as compared with the other reducing agents as proposed by the known art for the reduction of PbO2:
~; - It does not show any toxicity.
- It does not supply foreign ions to the solution which has to be sent to the electrolysis, and which must be .
1 0 .
continuously recycled.
- It is a reactant easily availabLe from the market, at a not ~oo high price~
- it can be metered with precision, avoiding the wastes, because the end of PbO2 reduction is signalled by a ~ sharp turning of the colour of the suspension from a : brown-red to a brown-grey colour~ The change in colour can be easily detected visually.
- With a consumption of 4-5% of H202 (as a solution at 35%), an yield not lower than 95~ is reached in the extraction of Pb.
~ ' .
, ~:`
the factories. For this reason, very important are the processes for the recovery of lead of the paste in the metal form, which may constitute a valuable alternative to the pyrometallurgical processings, such as, above all, those processes which operate according to a completely hydrometallurgical route, such as the extraction processes by electrolytic way, or electrowinning.
The desulphurized paste has on the average the following composition:
- Lead carbonate (PbC03) 50 - 52%
- Lead sulphate (PbS04) 2.5 - 4%
- Lead peroxide (PbO2) 14 - 16X
- Lead oxide (PbO) 11 - 12%
- Metal lead (Pb3 5 - 7%
It is known that the practical problem of the hydrometallurgical processing of the paste of the old batteries ;s that of rendering soluble in the solution selected for the electrolysis all of the components of ; the mixture, in paticular PbO2, which is conta;ned in it in large percentages. In fact, the residual of the acidic ~; solubilization of the mixture must not constitute an intolerable loss of lead.
~ On the other hand, owing to the well-known ;~ insolubility of PbO2 in the normal acids suitable to the electrolytic process, without a preliminary treatment for PbO2 reduction, the residue of the acidic solubili~ation of the mixture is very rich in lead, and must be sent back to the pyrometallurgical recovery.
In accordance with the prior art, the solubilization of all of the components of the paste in the various electrolyt~s has been accomplished by various ways.
~' .
~ 3 ~ 3 ~
In chronological order~ the following patents may be cited:
; - C~E. Tucker in U.S.Pat. 1,148,062 suggests a heating of the battery sludge, to convert PbO2 into soluble PbO
and Pb20.
- W.C. Smith in U.S.Pat. 1,752~356, ~o solubilize PbO2 in view of the treatment with caustic alkali, submits the paste to a heating in a reducing environment ~PbO is formed).
- J.H. Calbeck in U.S.Pat. 1,911,604 carries out the Leaching of the battery paste by a sodium acetate solution. Lead oxide and sulphate are dissolved, whilst PbO2 is normally insoluble in that electrolyte.
~ 15 ~ut, ;n the presence of metal Pb and in the said ; elertrolyte, a local couple is established, so that PbO2 and an equivalent amount of metal lead are dissolved.
- A.F. 6~umann in U.S. Pat. 4,107,007 leaches the paste with a concentrated solution of alkaLi metal hydroxide~ to which molasses,or raw sugar, or the like, has been added.
In such a way, Pb oxide and sulphate are dissolved, and fed to the electrolysisu The behaviour of PbO2 is not detailed~
R.D. Prengaman in U.S.Pat. 4,229,271 proposes two ; methods of eliminating PbO2 from the paste, and rendering it wholly soluble in the customary acids for the electrowinning process:
a) a drying at 100 C of the paste, follo~ed by a roasting under a reduGing atmosphere at i ' ; temperatures comprised within the range of from 290 to 375C;
b) a trea~ment of the aqueous suspension of the paste ~ith sulphur dioxide, or with sulphite or bisulphite of alkali metal or of ammonium~
- U.Ducati in U.S.Pat. 4,460~442 reacts the paste of the battery, at 100-120 C, in the presence of a strongly alkaline solution, to obtain a red lead precipitate, which has the property of completely dissolving ;n the hot concentrated solutions of fluoboric acid or of fluosilicic acid.
-A.Y. Lee and E.R. Cole of Bureau of Mines suggest in R~I. 8857 two ways for reducing the PbO2 contained in the paste:
a) by the addition of Pb powder during the leaching -~ with fluosilicic acid of the paste already desulphurized with ammonlum carbonate;
b~ by the addition of ammonium bisulphite during the treatment of desulphurization with ammonium carbonate.
The suggested methods of thermal reduction of PbO2 under a reduc;ng atmosphere have the disadvantage of add;ng two steps to the working cycle: the drying and the - reducing roasting. These operation steps require a strict control of the operat;ng ronditions, and they must be furthermore carried out on a un;t tfurnace or roaster) euipped with an adequate dust exhauster. Moreover~ e~en ~ if the temperatures are low, moving dry material is : pollution-causinga The method of reduction during the high-temperature dissolving, by means of the add-ition of lead powder, 3 ~
;nvolves the transfer of a portion of produced lead, to convert ;t into powder; as a consequence, this is an expensive method.
The method of reduction with sulphur dioxide, sulphite or bisulphite before the carbonating involves a certain cost, due to the reactant, but, what's more important, it causes the consumption of carbona~e for the desulphurizing to increase by about 25%; the correspond;ng expense is not negligible; to date, the expense for the carbonate is the highest item of individual expenditure of the whole process.
Purpose of the present invention is to solve the above reminded problems concerning the processes of hydrometallurgical treatment by electrow;nning of the desulphurized paste of the exhausted batteries~
For such a purpose to be accomplished, the invention proposes a hydrometallurg;cal process for recovering, by extraction by electrolytic way, in pure metal form, the lead of the paste, or desulphurized paste, of the exhausted batteries~ characterized in that it comprises the steps of:
a) leach;ng said paste with an aqueous solution of an ac;d selected from those suitable to the electrolytic ~; extraction;
b) treating with hydrogen peroxide the leached paste as ~: of (a), with the concom;tant carrying out of the following reactions:
~1) Pb + H22 ~~~> Pb + 2 t 2H
(2) Pb ~ Pb4+ --~ 2Pb2+
up to the quantitative reduction of all of the lead dioxide contained in the sa;d paste, c) separation of the solid residue from the so-obtained dissolved lead-containing solution, which can be directly sent to the electrolytic lead extraction.
The process of the invention, as substantially 5defined above, is described in greater detail.
The starting material of the process is the paste already separated from the other components of the exhausted batteries, and which has already undergone the desulphurizing process in accordance with the known art.
10This material is leached with the aclueous solution of an acid suitable to the subsequent eletrolytic extraction ~preferably, either fluoboric or fluosilicic acid), to which such an amount of hydrogen peroxide is added, as to obtain the greatest solubilization of all of ~; 15the lead compounds present, and~ more specifically, of PbO2 and of metal Pb.
Dur;ng the acidic treatment of the desulphurized paste, the hydrogen peroxide causes the reaction:
Pb4 + H22 ~~~ Pb + 2 + 2H ~1) 20so that all of the PbO2 is reduced to PbO and dissolved by the present acid.
; The cons;dera~le amount of 2 which is liberated during reaction ~1) physicaLly actlvates the particLes of metal Pb present in the paste, so that the reaction:
25Pb ~ Pb4+ _ ~ 2Pb2~ t2) occurs more easily, and all of the metal Pb having the right granulometry is d;ssolved, allowing also the hydrogen peroxide, corresponding to the Pb4 ~hich is reduced, to be saved.
30After the acidic leaching with the addition of hydrogen peroxide, of the desulphurized paste only the .
3~
organic substances (thin scraps of separators and ebonite, f;bres and so forth), and Pb sulphate not conuerted in the desulphurizing step remain undissolved.
The reacted liquid/solid mixture is separated by filtration~ The solid residue from the filtration contains not more than 5% of the lead present in the starting material and, after a roasting to destroy the organic substances, it can be returned to the desulphuri2ing step.
The filtered solution contains all of the Pb in ionic form and does not normally require any purifications, because it is the same Pb powder, physically activated by the oxygen being evolved in reaction (11, ~hich carries out the displacement action ~also named as "cementation") of the impurities~ small amounts of which may haue been dissolued during the acidic leaching.
The self-purified solution can be then directly fed to the electrolytic extraction of lead, which is carried out in customary cells with insoluble graphite anodes and with cathodes made from thin lead sheets. `
~y operating under suitable conditions, a cathodic ; deposit of excellent quality and purity can be obtained, - ~ the deposition of PbO2 at the anode being prevented to the highest extent~
The small amounts of PbO2, which are sometimes unavoidably formed, must be returned to the step of acidic leaching with hydrogen peroxide. The cathodes, smelted into pigs, are marketed as electrolytic lead. The solution coming off the electrolysis returns back to the acid;c leaching of the paste.
8.
To the purpose of better understanding the characteristics and the advantages of the invention, a non limitative example of practical embodiment thereof is described in the following.
E X _ m e ' An amount of 980 9 of well washed desuLphurized paste, containing, as referred to the dry matter: Pb, 70.5%; Sb, 0.68%; S, 0.18%; has been leached with 5 l of exhausted electrolyte from the electrowinning, containing:
49 g/l of Pb 139 g/l of free HBF4 After a half an hour stirring at 50 C, hydrogen peroxide ~in the form of a solution at 35%) has been added in the amount of 4.6% of the processed paste, and has been allowed to react over a further half an hour.
By filtration, the following substances have been s_ parated:
80 g of insoluble residue having the composition:
Pb 34.2X
Sb 2.4%
S 2.2%
~ 5 l of lead-carrying electrolyte~ containing;
; 181.5 g/l of Pb ~+~
0.6 g/l of Sb 25.1 g/l of free HBF4 The leaching ~ith fluoboric acid and hydrogen peroxide has extracted 96.01% of the total Pb contained in the paste. All of the sulphur has remained in the residue.
By submitting the 5 l;tres o~f lead-carrying ~ 3 ~
electrolyte to electrowinning on a cell with graphite anodes (previously lined with PbO2) and cathodes of thin sheet of eLectrolytic lead, 630 9 of cathodic lead,as well as 9 g of PbO2 a~ the anode, have been produced.
The cell has been operating over 24 hrs at 7 A and 2.5 V.
The cathodic current density has been of 280 A/m .
The curren~ efficiency has been of 97%.
The smelted cathodic lead had the following composition:
Sb c 0.001;
As < 0.001;
Sn < 0.001;
8; < 0.~0~;
Cu = 0.0003;
Ag < 0~0005.
The exhausted electrolyte, to be returned back to ~he leaching of new paste, contained:
53 g/l of Pb 20 `` \ 131 g/l of free HBF4.
ln the attached drawing, a block diagram is reported, to exemplifying purposes, of the process of the ` invention.
In general, it can be observed that according to the invention the use of hydrogen peroxide offers the follow;ng advantages~ as compared with the other reducing agents as proposed by the known art for the reduction of PbO2:
~; - It does not show any toxicity.
- It does not supply foreign ions to the solution which has to be sent to the electrolysis, and which must be .
1 0 .
continuously recycled.
- It is a reactant easily availabLe from the market, at a not ~oo high price~
- it can be metered with precision, avoiding the wastes, because the end of PbO2 reduction is signalled by a ~ sharp turning of the colour of the suspension from a : brown-red to a brown-grey colour~ The change in colour can be easily detected visually.
- With a consumption of 4-5% of H202 (as a solution at 35%), an yield not lower than 95~ is reached in the extraction of Pb.
~ ' .
, ~:`
Claims (4)
1. A hydrometallurgical process for recovering in pure metal form lead contained in the paste or desulphurized paste of exhausted batteries, which comprises the steps of:
a) leaching said paste with an aqueous solution of fluoboric or fluosilicic acid;
b) treating with hydrogen peroxide the leached paste obtained in step (a), with the concomitant carrying out of the following reactions:
(1) Pb4+ + H2O2 ? Pb2+ + O2 + 2H+
(2) Pb + Pb4+ ? 2Pb2+
up to the quantitative reduction of all of the lead dioxide contained in said paste; and c) separating a solid residue from the dissolved lead-containing solution obtained in step (b), to obtain a purified solution containing dissolved lead;
and d) subjecting the purified solution containing dissolved lead obtained in step (c) to an electrolytic lead extraction, to recover lead in pure metal form.
a) leaching said paste with an aqueous solution of fluoboric or fluosilicic acid;
b) treating with hydrogen peroxide the leached paste obtained in step (a), with the concomitant carrying out of the following reactions:
(1) Pb4+ + H2O2 ? Pb2+ + O2 + 2H+
(2) Pb + Pb4+ ? 2Pb2+
up to the quantitative reduction of all of the lead dioxide contained in said paste; and c) separating a solid residue from the dissolved lead-containing solution obtained in step (b), to obtain a purified solution containing dissolved lead;
and d) subjecting the purified solution containing dissolved lead obtained in step (c) to an electrolytic lead extraction, to recover lead in pure metal form.
2. Process according to claim 1, wherein said reaction (2) of step (b) is activated by oxygen which is developed in reaction (1) of step (b).
3. Process according to claim 2, wherein in step (b) said metal Pb which is physically activted by the O2 evolved in reaction 1 causes cementation of existing impurities.
4. Process according to claim 1, wherein an exhausted electrolyte is obtained in step (d) and said exhausted electrolyte is recycled back to step (a).
Applications Claiming Priority (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| IT22892A/85 | 1985-11-19 | ||
| IT2289285A IT1188203B (en) | 1985-11-19 | 1985-11-19 | HYDROMETALLURGIC PROCESS TO RECOVER IN LEAD METALLIC FORM THE LEAD CONTAINED IN THE ACTIVE MASS OF THE EXHAUSTED BATTERIES |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CA1310837C true CA1310837C (en) | 1992-12-01 |
Family
ID=11201606
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA 522758 Expired - Fee Related CA1310837C (en) | 1985-11-19 | 1986-11-12 | Hydrometallurgic process for recovering in the metal form the lead contained in the paste of the exhausted batteries |
Country Status (6)
| Country | Link |
|---|---|
| JP (1) | JPS62120436A (en) |
| CA (1) | CA1310837C (en) |
| DE (1) | DE3637270A1 (en) |
| FR (1) | FR2590277B1 (en) |
| GB (1) | GB2183623B (en) |
| IT (1) | IT1188203B (en) |
Cited By (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| WO2016183428A1 (en) | 2015-05-13 | 2016-11-17 | Aqua Metals Inc. | Systems and methods for recovery of lead from lead acid batteries |
| US10316420B2 (en) | 2015-12-02 | 2019-06-11 | Aqua Metals Inc. | Systems and methods for continuous alkaline lead acid battery recycling |
| US10340561B2 (en) | 2013-11-19 | 2019-07-02 | Aqua Metals Inc. | Devices and method for smelterless recycling of lead acid batteries |
| US10689769B2 (en) | 2015-05-13 | 2020-06-23 | Aqua Metals Inc. | Electrodeposited lead composition, methods of production, and uses |
| US10793957B2 (en) | 2015-05-13 | 2020-10-06 | Aqua Metals Inc. | Closed loop systems and methods for recycling lead acid batteries |
Families Citing this family (8)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| IT1223314B (en) * | 1987-10-20 | 1990-09-19 | Engitec Impianti | HYDRO-METALLURGIC PROCESS TO RECOVER IN LEAD METALLIC FORM ALL THE LEAD CONTAINED IN THE ACTIVE MASS OF THE EXHAUSTED BATTERIES |
| IL116753A0 (en) * | 1996-01-14 | 1996-05-14 | Margulead Ltd | A process for the manufacture of pure lead oxide from exhausted batteries |
| ITVA20070007A1 (en) * | 2007-01-17 | 2008-07-18 | Millbrook Lead Recycling Techn | RECOVERY OF THE LEAD OF HIGH-PURITY CARBONATE UNIFORM PASTEL RECOVERY FROM THE CRUSHING OF EXHAUSTED LEAD ACCUMULATORS |
| ITMI20072257A1 (en) * | 2007-11-30 | 2009-06-01 | Engitec Technologies S P A | PROCESS FOR PRODUCING METALLIC LEAD FROM DESOLFORATED PASTEL |
| US9322104B2 (en) * | 2012-11-13 | 2016-04-26 | The University Of British Columbia | Recovering lead from a mixed oxidized material |
| ITUB20153182A1 (en) * | 2015-08-06 | 2017-02-06 | Pin Corp Ltd | HYDROTHERMAL PROCESS - ELECTROCHEMICAL FOR THE DIRECT RECOVERY OF METALLIC LEAD OR A MIXTURE OF METALLIC LEAD AND LEAD OXIDE (II) FROM ELECTRODIC BATTERY PASTES AT THE END OF LIFE OR FROM MINERALS OR WASTE OF PRODUCTION |
| CN107059053A (en) * | 2017-01-10 | 2017-08-18 | 富民薪冶工贸有限公司 | A kind of method that electrolyte being electrolysed for lead and its molten lead mend lead |
| IT201800003369A1 (en) | 2018-03-08 | 2019-09-08 | Engitec Tech S P A | PROCEDURE FOR RECOVERING LEAD FROM A LEAD PASTEL AND RELATIVE USE IN A PROCEDURE FOR RECOVERING THE COMPONENTS OF LEAD-ACID ACCUMULATORS. |
Family Cites Families (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US2328089A (en) * | 1940-09-14 | 1943-08-31 | Lillian R Birkenstein | Recovery of soluble lead salts from insoluble lead compounds |
| NZ183268A (en) * | 1976-02-19 | 1978-09-20 | Gould Inc | Process for recycling junk lead-acid batteries comprising the formation of lead carbonate lead monoxide |
| US4269811A (en) * | 1978-10-10 | 1981-05-26 | Nl Industries, Inc. | Production of lead monoxide from lead sulfate with acetic acid |
| US4229271A (en) * | 1979-05-24 | 1980-10-21 | Rsr Corporation | Method of recovering lead values from battery sludge |
| GB2073725A (en) * | 1980-04-11 | 1981-10-21 | Ass Lead Mfg Ltd | A Method of Recovering Lead Values from Scrap Batteries |
| WO1984001964A1 (en) * | 1982-11-18 | 1984-05-24 | Extramet Sa | Process for selectively extracting lead from lead sulphides |
-
1985
- 1985-11-19 IT IT2289285A patent/IT1188203B/en active
-
1986
- 1986-11-03 DE DE19863637270 patent/DE3637270A1/en not_active Ceased
- 1986-11-04 GB GB8626274A patent/GB2183623B/en not_active Expired - Fee Related
- 1986-11-12 CA CA 522758 patent/CA1310837C/en not_active Expired - Fee Related
- 1986-11-13 JP JP61270818A patent/JPS62120436A/en active Pending
- 1986-11-17 FR FR868615937A patent/FR2590277B1/en not_active Expired - Fee Related
Cited By (9)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US10340561B2 (en) | 2013-11-19 | 2019-07-02 | Aqua Metals Inc. | Devices and method for smelterless recycling of lead acid batteries |
| US10665907B2 (en) | 2013-11-19 | 2020-05-26 | Aqua Metals Inc. | Devices and method for smelterless recycling of lead acid batteries |
| US11239507B2 (en) | 2013-11-19 | 2022-02-01 | Aqua Metals Inc. | Devices and method for smelterless recycling of lead acid batteries |
| WO2016183428A1 (en) | 2015-05-13 | 2016-11-17 | Aqua Metals Inc. | Systems and methods for recovery of lead from lead acid batteries |
| US10689769B2 (en) | 2015-05-13 | 2020-06-23 | Aqua Metals Inc. | Electrodeposited lead composition, methods of production, and uses |
| US10793957B2 (en) | 2015-05-13 | 2020-10-06 | Aqua Metals Inc. | Closed loop systems and methods for recycling lead acid batteries |
| US11028460B2 (en) | 2015-05-13 | 2021-06-08 | Aqua Metals Inc. | Systems and methods for recovery of lead from lead acid batteries |
| US10316420B2 (en) | 2015-12-02 | 2019-06-11 | Aqua Metals Inc. | Systems and methods for continuous alkaline lead acid battery recycling |
| US11072864B2 (en) | 2015-12-02 | 2021-07-27 | Aqua Metals Inc. | Systems and methods for continuous alkaline lead acid battery recycling |
Also Published As
| Publication number | Publication date |
|---|---|
| IT1188203B (en) | 1988-01-07 |
| JPS62120436A (en) | 1987-06-01 |
| GB2183623B (en) | 1990-04-11 |
| GB2183623A (en) | 1987-06-10 |
| IT8522892A0 (en) | 1985-11-19 |
| FR2590277B1 (en) | 1990-05-11 |
| DE3637270A1 (en) | 1987-05-21 |
| FR2590277A1 (en) | 1987-05-22 |
| GB8626274D0 (en) | 1986-12-03 |
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