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US20140311896A1 - Electrorecovery of gold and silver from thiosulphate solutions - Google Patents

Electrorecovery of gold and silver from thiosulphate solutions Download PDF

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Publication number
US20140311896A1
US20140311896A1 US13/992,713 US201113992713A US2014311896A1 US 20140311896 A1 US20140311896 A1 US 20140311896A1 US 201113992713 A US201113992713 A US 201113992713A US 2014311896 A1 US2014311896 A1 US 2014311896A1
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United States
Prior art keywords
silver
leaching
copper
solution
gold
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Abandoned
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US13/992,713
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English (en)
Inventor
Gretchen Terri Lapidus Lavine
Alejandro Rafael Alonso Gómez
Ricardo Benavides Pérez
Carlos Lara Valenzuela
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Universidad Autonoma Metropolitana (UAM)
Servicios Administrativos Penoles SA de CV
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Application filed by Individual filed Critical Individual
Assigned to SERVICIOS ADMINISTRATIVOS PENOLES, S.A. DE C.V., UNIVERSIDAD AUTONOMA METROPOLITANA reassignment SERVICIOS ADMINISTRATIVOS PENOLES, S.A. DE C.V. ASSIGNMENT OF ASSIGNORS INTEREST (SEE DOCUMENT FOR DETAILS). Assignors: ALONSO GOMEZ, ALEJANDRO RAFAEL, BENAVIDES PEREZ, RICARDO, LAPIDUS LAVINE, GRETCHEN TERRI, LARA VALENZUELA, CARLOS
Publication of US20140311896A1 publication Critical patent/US20140311896A1/en
Abandoned legal-status Critical Current

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    • 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
    • C25C1/22—Electrolytic production, recovery or refining of metals by electrolysis of solutions of metals not provided for in groups C25C1/02 - C25C1/20
    • 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
    • C25C1/20—Electrolytic production, recovery or refining of metals by electrolysis of solutions of noble metals
    • C—CHEMISTRY; METALLURGY
    • C25—ELECTROLYTIC OR ELECTROPHORETIC PROCESSES; APPARATUS THEREFOR
    • C25C—PROCESSES FOR THE ELECTROLYTIC PRODUCTION, RECOVERY OR REFINING OF METALS; APPARATUS THEREFOR
    • C25C7/00—Constructional parts, or assemblies thereof, of cells; Servicing or operating of cells
    • C—CHEMISTRY; METALLURGY
    • C25—ELECTROLYTIC OR ELECTROPHORETIC PROCESSES; APPARATUS THEREFOR
    • C25C—PROCESSES FOR THE ELECTROLYTIC PRODUCTION, RECOVERY OR REFINING OF METALS; APPARATUS THEREFOR
    • C25C7/00—Constructional parts, or assemblies thereof, of cells; Servicing or operating of cells
    • C25C7/06—Operating or servicing
    • 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
    • Y02P—CLIMATE CHANGE MITIGATION TECHNOLOGIES IN THE PRODUCTION OR PROCESSING OF GOODS
    • Y02P10/00—Technologies related to metal processing
    • Y02P10/20—Recycling

Definitions

  • the present invention is related to the mining industry and treatment of mineral and materials that contain gold and silver. Specifically, it is related to a process to recover gold and silver, from copper thiosulfate solutions with a autogenerated electrolysis process, in which the metallic values are recovered from the rich solution in the cathodic compartment. The barren solution is then used as the anolyte, re-establishing the copper concentration needed to be recycled back to the leaching stage.
  • gold and silver are obtained from their minerals, concentrates and other materials, using different processes. These processes are in function of the nature of the gold and silver containing material, as well as their grade. Accordingly, if it is a high grade material, smelting is employed. On the other hand, if the material contains only small amounts of gold and silver, a hydrometallurgical treatment is usually selected (leaching).
  • Direct electrodeposition used as a separation method, is a viable option, including from solutions with low concentrations of gold and silver, even when the copper ion concentration is more than 50 times greater than that of silver and over 100 times that of gold [Alonso-Gómez, A. R., Lapidus, G. T. and González, I., “Proceso de Lixivia Terms y Recuperaconstruconstru Plata y Oro con Soluations de Tiosulfato Amoniacales de Cobre, solicitud PCT/MX2009/000022, fecha 14 Mar. 2008 (WO20097113842, publicada 17 Sep. 2009)].
  • a rotating cylinder electrode was employed in a reactor with separate anodic and cathodic compartments in order prevent the oxidation of the thiosulfate and the re-oxidation of the deposited gold and silver.
  • deposits were obtained with less than 2% impurities [Alonso, A. R., Lapidus, G. T. and González, I. (2008), “Selective silver electroseparation from ammoniacal thiosulfate leaching solutions using a Rotating Cylinder Electrode reactor (RCE)”, Hydrometallurgy, 92 (3-4), 115-123].
  • the separated anodic and cathodic compartments allow, on one hand, the election of the substrate upon which the metal is deposited (similar to a conventional electrolysis), eliminated the contamination of the deposit.
  • the anode is in contact with a solution which is different from the one that contains the metallic ions to be deposited, it is also possible to tailor the anolyte composition according to the requirement of the process and in this manner modulate the reductive power of the system.
  • One objective of the present invention is to provide a selective separation process for gold and silver from thiosulfate solutions, at an increased velocity compared with copper cementation, without the use of electrical current.
  • Another objective is to accomplish the aforementioned task using the barren solution as the anolyte, conserving in this manner the level of soluble copper, in order to maintain the composition of the thiosulfate solution so that it can be recycled back to the leaching stage.
  • the present invention is designed to solve the problem of gold and silver separation from copper thiosulfate leaching solutions, providing an improvement over the traditional separation methods (cementation and external current-driven electrolysis).
  • This improvement is characterized by the use of a novel autogenerated electrolysis process, employing a commercial copper sheet as the anode and a titanium cathode, in a reactor with anodic and cathodic compartments separated by ion exchange membrane which prevents the contamination of the thiosulfate solution.
  • the membrane achieves the purpose of separating the anodic and cathodic sections, to prevent the solutions used in each confinesto from mixing. This is important to avoid cementation of gold and silver on the copper surface, which slows the process and contaminates the product.
  • the rich (pregnant) solution located in the cathodic compartment
  • the copper concentration in this solution is kept low and for this reason the membrane plays a double role.
  • FIG. 1 is a schematic diagram of the process for electrodepositing gold and silver in an electrochemical autogeneration cell.
  • FIG. 2 shows a schematic diagram of the electrochemical autogeneration cell
  • FIG. 3 corresponds to a graph indicating the change in the silver concentration during the electrolysis performed in Example 1.
  • FIG. 4 is a diagram of the recirculation process of lots A and B of the leaching solution, used in Example 2.
  • FIG. 5 shows a graphic representation of the silver concentration change during the first leach LA 1 , performed on lot A (solid lines and markers), as well as during the first autogenerated electrolysis Ca 1 (dotted line, hollow markers).
  • FIG. 6 is a series of graphs that compare the quantity of silver remaining in solution throughout the electrolyses Ca 1 , Ca 3 and Ca 5 performed on lot A (markers ⁇ , ⁇ and ⁇ , respectively).
  • FIG. 7 shows the lead concentration during the first leach LA 1 performed on lot A.
  • FIG. 2 The operation of the electrochemical autogeneration reactor is represented in FIG. 2 :
  • Composition of the solution used in the cathodic compartment of the autogeneration electrolytic reactor Component Composition (mol/L) Ag(I) 1 ⁇ 10 ⁇ 3 Na 2 S 2 O 3 0.2 CuSO 4 0.05 EDTA 4 ⁇ 0.025 (NH 4 ) 2 (HPO 4 ) 0.1 NH 3 0.6
  • the solutions were prepared with analytical grade reagents and deionized water (1 ⁇ 10 10 M ⁇ cm ⁇ 1 ). Once the solutions were placed in their respective compartments, the electrodes were connected in short circuit. Stirring in both compartments was maintained during the electrodeposition process. Samples of the solution were taken every 20 minutes for four hours, after which time the test was detained. The samples were analyzed for silver and copper with atomic absorption spectrometry.
  • FIG. 3 a graphic representation is shown of results of the electrodeposition process, performed in the reactor of FIG. 2 .
  • the decrease in silver concentration is constant from the beginning of the electrolysis, attaining 50% of its initial value after only 60 minutes. Subsequently, the descent is slower, typical of first order reaction kinetics in a batch reactor, reaching 4% after 4 hours.
  • the recirculation scheme used in the present invention employs two lots of the thiosulfate leaching solution, which are alternated in each one of the reactor compartments ( FIG. 2 ), as was mentioned in the Detailed Description section.
  • the same reactor was used as in Example 1, with a copper sheet as the anode and a titanium sheet as the cathode, both with an exposed geometric area of 60 cm 2 .
  • FIG. 4 a block diagram is shown ( FIG. 4 ), in which the passage through the process of lots A and B of the leaching solution are shown, without the solid streams.
  • stream Al enters the first leach (LA 1 ), and after separating out and discarding the solid residue, stream A 2 (pregnant solution) enters the cathodic compartment (Ca 1 ) of the electrolytic reactor, where the silver electrodeposition takes place; only in this stage of the process is synthetic solution (Stream S 1 ) used in the anodic compartment (An 1 ).
  • Stream A 3 stripped of its values, is placed in the anodic compartment of the reactor (An 2 ), where the first electrodeposit from the pregnant solution lot B (Ca 2 ) occurs.
  • Stream A 4 is sent back to a new leaching stage (LA 2 ), where it is contacted with fresh mineral.
  • the pregnant solution (A 5 ) is sent to the electrochemical reactor for silver recovery in the cathodic compartment (Ca 3 ).
  • the anodic compartment is occupied by the solution of lot B originating from Ca 2 .
  • stream A 7 is again introduced into the leaching stage with fresh mineral, obtaining a pregnant solution in stream A 8 .
  • Table 3 shows the initial composition used in the leaching solutions for both lots; the volume of each one was 250 mL.
  • FIG. 5 the silver concentration during the first leach is shown (solid lines and markers), as well as the electrodeposition process in the cathodic compartment Ca 1 (dashed line and hollow markers). It is important to consider that the silver content in this mineral is very high, explaining the reason for extractions above 200 ppm, a value close to the solubility limit for this metal ion in thiosulfate solutions. These high values of silver in solution are the reason that the silver concentration only decreases to 50% of its original value in the autogenerated electrolysis (Ca 1 ). Additionally, because of the high dissolved lead concentration (200 ppm), there is competition with the silver in the electrodeposition process. This could represent an enormous loss in the traditional cyanidation process; however, in this case, the thiosulfate solution is recycled back to the leaching stage, the gold and silver remaining in solution are separated in subsequent cycles.
  • FIG. 6 a comparison of the change in silver concentration during the autogenerated electrolyses for lot A is shown in FIG. 6 .
  • the electrolyses Ca 3 and Ca 5 present similar behavior to that registered for Ca 1 (first electrolysis of lot A).
  • the quantity of silver that remains after the electrolyses Ca 2 and Ca 3 is similar, indicating that there is no accumulation of silver ions in the recycling process; in other words, the silver extracted in the leach is separated in the autogenerated electrolysis stage.
  • the behavior of lot B during the electrolyses (data not shown here) is practically the same exhibited by lot A.
  • the lead concentration is shown during the first leach of lot A, where it can be appreciated that the concentration of Pb(II) is similar to that of silver. Also, in the corresponding electrolysis, the lead concentration decreases approximately 35% during the first 20 minutes. This competition (inexistent in Example 1 with the synthetic solution) could be the cause that the silver recovery did not exceed 60%. Additionally, it must be considered that treating such high grade silver minerals would originate solubility problems during leaching, as well as electrode saturation in the electrodeposition stage. In these cases, it is possible to increase the thiosulfate concentration to increase the solubility of the Ag(S 2 O 3 ) 2 3 ⁇ complex, even though a larger electroactive area for the cathode would be required.

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  • Chemical & Material Sciences (AREA)
  • Engineering & Computer Science (AREA)
  • Chemical Kinetics & Catalysis (AREA)
  • Electrochemistry (AREA)
  • Materials Engineering (AREA)
  • Metallurgy (AREA)
  • Organic Chemistry (AREA)
  • Electrolytic Production Of Metals (AREA)
  • Manufacture And Refinement Of Metals (AREA)
  • Water Treatment By Electricity Or Magnetism (AREA)
US13/992,713 2010-12-09 2011-12-09 Electrorecovery of gold and silver from thiosulphate solutions Abandoned US20140311896A1 (en)

Applications Claiming Priority (3)

Application Number Priority Date Filing Date Title
MXMX/A/2010/013510 2010-12-09
MX2010013510A MX2010013510A (es) 2010-12-09 2010-12-09 Electrorecuperacion de oro y plata a partir de soluciones de tiosulfato.
PCT/MX2011/000150 WO2012078019A2 (fr) 2010-12-09 2011-12-09 Électrorécupération d'or et d'argent à partir de solutions de thiosulfate

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US (1) US20140311896A1 (fr)
EP (1) EP2650403A2 (fr)
JP (1) JP2014501850A (fr)
CN (1) CN103842557A (fr)
AU (1) AU2011339119A1 (fr)
BR (1) BR112013014261A2 (fr)
CA (1) CA2821042A1 (fr)
CO (1) CO6801690A2 (fr)
MX (1) MX2010013510A (fr)
PE (1) PE20140643A1 (fr)
RU (1) RU2013131237A (fr)
WO (1) WO2012078019A2 (fr)

Cited By (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US9777346B2 (en) 2015-09-03 2017-10-03 Battelle Energy Alliance, Llc Methods for recovering metals from electronic waste, and related systems
US10807085B2 (en) * 2017-11-17 2020-10-20 University Of Massachusetts Silver recovery as Ag0nanoparticles from ion-exchange regenerant solution
CN114774686A (zh) * 2022-05-06 2022-07-22 河南理工大学 一种在硫代硫酸盐浸金体系中置换回收金的装置及方法
CN118007193A (zh) * 2024-01-12 2024-05-10 武汉理工大学 一种硫代硫酸盐电化学浸出-回收一体化短流程提取贵金属的方法
CN118345450A (zh) * 2024-04-03 2024-07-16 武汉理工大学 一种电化学还原回收硫代硫酸金中金的方法
PL448742A1 (pl) * 2024-05-29 2025-12-01 Sieć Badawcza Łukasiewicz - Instytut Metali Nieżelaznych Sposób rozdziału metali szlachetnych z roztworów tiomocznika z kwasem chlorowodorowym

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KR101349305B1 (ko) * 2013-05-24 2014-01-13 한국지질자원연구원 유로형 셀을 이용한 희유 금속의 전해 채취 장치, 및 그 방법
AU2015259608B2 (en) 2014-05-12 2019-10-03 Sumitomo Corporation Of Americas Brine leaching process for recovering valuable metals from oxide materials
CN104499003A (zh) * 2014-11-13 2015-04-08 黄石市英柯有色金属有限公司 从水溶液中提取金属的方法
WO2016168930A1 (fr) 2015-04-21 2016-10-27 University Of Saskatchewan Procédés de lixiviation et d'extraction simultanées de métaux précieux
CN104911351A (zh) * 2015-06-07 2015-09-16 长春黄金研究院 一种生物浸出金及浸出液中金自发电回收方法
CN108642091B (zh) * 2018-05-02 2021-03-30 江南大学 一种同步回收金属与单质硫的方法
CN108660314B (zh) * 2018-05-02 2019-11-26 江南大学 一步法回收金属的方法
CN108624912B (zh) * 2018-05-25 2020-04-24 王勇 一种贵金属元素电化回收工艺及系统
CN113621995B (zh) * 2021-07-16 2023-12-26 武汉理工大学 一种基于电化学联合催化技术回收硫代硫酸盐浸出液中贵金属的方法
CN115928150B (zh) * 2022-11-08 2025-07-15 重庆川仪自动化股份有限公司 一种从含银废料中回收银的方法
CN116334695B (zh) * 2023-02-20 2025-07-18 中国机械总院集团郑州机械研究所有限公司 一种熔盐电解制备银铜复合材料的方法及银铜复合材料

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US5100528A (en) * 1989-03-28 1992-03-31 Noranda, Inc. Continuous silver refining cell

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US3994789A (en) * 1974-10-02 1976-11-30 Progressive Scientific Associates, Inc. Galvanic cementation process
US5100528A (en) * 1989-03-28 1992-03-31 Noranda, Inc. Continuous silver refining cell

Cited By (8)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US9777346B2 (en) 2015-09-03 2017-10-03 Battelle Energy Alliance, Llc Methods for recovering metals from electronic waste, and related systems
US10378081B2 (en) 2015-09-03 2019-08-13 Battelle Energy Alliance, Llc Methods for recovering metals from electronic waste, and related systems
US11035023B2 (en) 2015-09-03 2021-06-15 Battelle Energy Alliance, Llc Reactor systems for recovering metals, and related methods
US10807085B2 (en) * 2017-11-17 2020-10-20 University Of Massachusetts Silver recovery as Ag0nanoparticles from ion-exchange regenerant solution
CN114774686A (zh) * 2022-05-06 2022-07-22 河南理工大学 一种在硫代硫酸盐浸金体系中置换回收金的装置及方法
CN118007193A (zh) * 2024-01-12 2024-05-10 武汉理工大学 一种硫代硫酸盐电化学浸出-回收一体化短流程提取贵金属的方法
CN118345450A (zh) * 2024-04-03 2024-07-16 武汉理工大学 一种电化学还原回收硫代硫酸金中金的方法
PL448742A1 (pl) * 2024-05-29 2025-12-01 Sieć Badawcza Łukasiewicz - Instytut Metali Nieżelaznych Sposób rozdziału metali szlachetnych z roztworów tiomocznika z kwasem chlorowodorowym

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RU2013131237A (ru) 2015-01-20
AU2011339119A1 (en) 2013-08-01
WO2012078019A3 (fr) 2012-12-06
CO6801690A2 (es) 2013-11-29
EP2650403A2 (fr) 2013-10-16
PE20140643A1 (es) 2014-06-02
BR112013014261A2 (pt) 2017-08-01
WO2012078019A4 (fr) 2013-01-24
JP2014501850A (ja) 2014-01-23
WO2012078019A2 (fr) 2012-06-14
CA2821042A1 (fr) 2012-06-14
MX2010013510A (es) 2012-06-08
CN103842557A (zh) 2014-06-04

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