[go: up one dir, main page]

WO1987003623A1 - Procede electrolytique permettant d'obtenir simultanement un depot d'or et la regeneration de l'iode elementaire - Google Patents

Procede electrolytique permettant d'obtenir simultanement un depot d'or et la regeneration de l'iode elementaire Download PDF

Info

Publication number
WO1987003623A1
WO1987003623A1 PCT/US1985/002426 US8502426W WO8703623A1 WO 1987003623 A1 WO1987003623 A1 WO 1987003623A1 US 8502426 W US8502426 W US 8502426W WO 8703623 A1 WO8703623 A1 WO 8703623A1
Authority
WO
WIPO (PCT)
Prior art keywords
gold
iodine
lixiviant
iodide
cathode
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.)
Ceased
Application number
PCT/US1985/002426
Other languages
English (en)
Inventor
Jack W. Murphy
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Eneos Corp
In Situ Inc
Original Assignee
Nippon Mining Co Ltd
In Situ Inc
Priority date (The priority date 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 date listed.)
Filing date
Publication date
Application filed by Nippon Mining Co Ltd, In Situ Inc filed Critical Nippon Mining Co Ltd
Priority to PCT/US1985/002426 priority Critical patent/WO1987003623A1/fr
Priority to JP61500200A priority patent/JPS63502358A/ja
Priority to AU52071/86A priority patent/AU577173B2/en
Publication of WO1987003623A1 publication Critical patent/WO1987003623A1/fr
Anticipated expiration legal-status Critical
Ceased legal-status Critical Current

Links

Classifications

    • C—CHEMISTRY; METALLURGY
    • C01—INORGANIC CHEMISTRY
    • C01G—COMPOUNDS CONTAINING METALS NOT COVERED BY SUBCLASSES C01D OR C01F
    • C01G7/00—Compounds of gold
    • 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
    • C22B11/00—Obtaining noble metals
    • C22B11/04—Obtaining noble metals by wet processes
    • 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
    • E—FIXED CONSTRUCTIONS
    • E21—EARTH OR ROCK DRILLING; MINING
    • E21B—EARTH OR ROCK DRILLING; OBTAINING OIL, GAS, WATER, SOLUBLE OR MELTABLE MATERIALS OR A SLURRY OF MINERALS FROM WELLS
    • E21B43/00—Methods or apparatus for obtaining oil, gas, water, soluble or meltable materials or a slurry of minerals from wells
    • E21B43/28—Dissolving minerals other than hydrocarbons, e.g. by an alkaline or acid leaching agent

Definitions

  • This invention lies in the field of hydrometallurgy.
  • it involves the simultaneous electrolytic recovery of gold and restoration of elemental iodine in spent lixiviant solutions used, for example, in in situ mining, heap-leach mining, or agitated-leach recovery processes.
  • the object of the present invention is to provide an economic process for recovering gold from an iodine- containing lixiviant in a one-step process in which gold and iodine are electrolytically reduced simultaneously with the oxidation of iodide. Iodine is produced at a rate sufficient to provide for a recycle leaching of gold.
  • a further object of the invention is to prevent iron fouling of the electrolysis.
  • Fig. 1 is a schematic drawing of a laboratory set-up in which iodine/iodide lixiviant solution is sprinkled onto a column of crushed auriferous ore, and the column effluent is passed through an electrochemical cell for removal of gold and regeneration of iodine before being recycled back onto the ore column.
  • An improved process for recovering gold from gold- containing materials including auriferous ores by iodide/iodine leaching wherein the pregnant lixiviant containing dissolved gold and iodine is treated in an electrolytic cell to reduce gold in solution to elemental gold for recovery and simultaneously reduce iodine to iodide at the cathode, so as to prevent iodine from interfering with subsequent gold recovery processes.
  • iodide present at the anode is oxidized to elemental iodine to regenerate the leach solution to the desired iodide:iodine weight ratio, e.g. about 2:1 to about 10:1.
  • Gold is precipitated in the cathode co - partment, and if desired, the cathode effluent may be treated for further removal of traces of gold before being passed to the anode compartment.
  • a method for preventing iron contamination of the cathode is also provided comprising buffering the lixiviant solution to a pH of about 5.
  • the process described herein involves the simultane ⁇ ous electrolytic reduction of iodine and reduction and precipitation of gold at a cathode, preferably a stain- less steel cathode, with concomitant reoxidation of iodide to iodine at the anode, preferably a carbon anode, of the same cell.
  • the cathode effluent is subjected to a process for removal of gold, such as by being passed through a bed of activated carbon or anion exchange resin to remove traces of gold before passing into the anode compartment.
  • iodine in the solution entering the ore zone is reduced to iodide either in the ore zone or in the cathode compartment of the electrolytic cell, and is then completely replenished by oxidation in the anode compartment of the cell. Since no iodine is present in the cathode effluent, no iodine is available for adsorption onto the carbon bed or anion exchange resin in the modified process.
  • the current in the cell is adjusted to generate the desired concentration of elemental iodine in the anode effluent.
  • the total combined iodine and iodide concen ⁇ tration depends on the characteristics of the material being leached (3 gpl is a typical total iodide-iodine concentration for use in in situ mining) .
  • the iodide to iodine ratio in the regenerated lixiviant is also a function of the qualities of the feed material, however when too low an iodide to iodine ratio, i.e., too much iodine, is produced, the rate of solubility of iodine at the anode will not keep pace with iodine generation and cause iodine to crystallize on the anode and interfere with the process. If the iodide to iodine ratio is too high, i.e. , too little iodine, the iodine may be exhausted before the gold leaching is completed, causing gold to redeposit in the feed material.
  • an iodide ratio of at least about 2:1 is desirable, and ratios up to about 10:1 are generally useful.
  • the quantity of oxidized iodine in the cathode compartment will be insufficient to carry the total current used to regenerate the iodine in the anode compartment.
  • the remainder of the current must then be carried by some other cathode half-reaction; usually this additional half-reaction will be the reduction of water to hydrogen gas (in addition to the small contribution from the reduction of gold complex to elemental gold) .
  • the cell voltage necessary to be applied to effect the gold- recovery/iodine regeneration is then the difference in half-cell potentials between the iodide/iodine oxidation and the reduction of water at-the cathode pH, plus any cathode overvoltage for the water reduction plus the ohmic drop in the cell. Algebraically, this may be expressed as:
  • E app E l " /I 2 + E H 2 0/H 2 + IR cell + E cath,over
  • lixiviant solution When lixiviant solution first contacts a pyrite ore zone, it is common for extensive interaction between the iodine and the pyrite to take place rapidly because of the presence in the ore of finely divided pyrite parti ⁇ cles.
  • the pH can drop rapidly to about three or less and a considerable quantity of iron can be solubilized. The high concen- trations of iron thus produced will then be transported to the cathode where undesirable electrode reactions or chemical precipitations can occur.
  • the lixiviant solution may be buf ⁇ fered with a non-reducing buffer, preferably sodium acetate/acetic acid, to a pH sufficient to prevent iron dissolution, preferably at least about 5; this keeps the iron concentration to a low enough level that it inter ⁇ feres very little with the operation of the electrolysis cell. Buffering the lixiviant also retards dissolution of the stainless steel cathode, the degradation of the cathode being a hundred times faster at pH 3 than at pH 5.
  • a non-reducing buffer preferably sodium acetate/acetic acid
  • Fig. 1 depicting a preferred embodiment of this invention, shows original or regenerated lixiviant containing an optimum iodide:iodine ratio at reservoir R, being pumped into an ore column, from which pregnant lixiviant containing dissolved gold and reduced iodine, i.e. a higher iodide:iodine ratio than present in the original or regenerated lixiviant, flows into reservoir R 2 ⁇
  • the pregnant lixiviant is conducted to the stainless steel mesh cathode of an electrolytic cell equipped with a conventional power supply where gold is reduced to elemental gold and precipitated onto the cathode, and substantially all the iodine present in the lixiviant is reduced to iodide.
  • the cell is shown with a Nafion (Du Pont Co.) membrane separating the anode and cathode compartments.
  • This membrane is a sheet of cation exchange material which is impervious to water and anions but permits passage of cations from the anode compartment to the cathode compartment.
  • This arrangement prevents mixing of anolyte and catholyte while still permitting maintenance of electro-neutrality in the cell compart ⁇ ments as the electrode reactions take place.
  • the gold- barren cathode effluent containing virtually no iodine is collected at reservoir R 3 from whence it may be conducted in the modified path to an activated carbon bed for removal of traces of gold, and then be conducted to the graphite rod anode compartment of the electrolytic cell.
  • the gold- and iodine-barren lixiviant may be conducted from 3 via the primary path directly to the anode compartment.
  • iodide is oxidized to iodine in an amount sufficient to provide a regenerated lixiviant for reuse, and the regenerated lixiviant is conducted to R,' and recycled.
  • Example 1 In a typical laboratory-scale embodiment of this process, unbuffered solution containing 9 grams/liter ionic iodide and 1 gram/liter elemental iodine was pumped from a reservoir at 75 ml./min. into a glass column 23 cm. wide by 30 cm. long containing approximately 15 kg. of pyritic gold ore. Effluent from the column was depleted somewhat in iodine and contained gold ranging in concentration 10 to 0.1 mg./liter. This effluent solution was pumped into the cathode compartment of the electroly ⁇ sis cell and reduced at 1.0 amp of current using an applied voltage of 2.0 volts. No gold or elemental iodine was detected in the cathode effluent.
  • the cathode effluent was then pumped into the anode compartment of the same electrolysis cell wherein iodide was oxidized to elemental iodine at such a rate that the anode effluent was replenished to 1 gram/liter iodine. A cell current efficiency of 95 percent was achieved.

Landscapes

  • Chemical & Material Sciences (AREA)
  • Engineering & Computer Science (AREA)
  • Organic Chemistry (AREA)
  • Life Sciences & Earth Sciences (AREA)
  • Metallurgy (AREA)
  • Geology (AREA)
  • Mining & Mineral Resources (AREA)
  • Materials Engineering (AREA)
  • Chemical Kinetics & Catalysis (AREA)
  • Geochemistry & Mineralogy (AREA)
  • Physics & Mathematics (AREA)
  • Electrochemistry (AREA)
  • General Life Sciences & Earth Sciences (AREA)
  • Fluid Mechanics (AREA)
  • Environmental & Geological Engineering (AREA)
  • Manufacturing & Machinery (AREA)
  • Mechanical Engineering (AREA)
  • Inorganic Chemistry (AREA)
  • Electrolytic Production Of Metals (AREA)
  • Electrolytic Production Of Non-Metals, Compounds, Apparatuses Therefor (AREA)
  • Manufacture And Refinement Of Metals (AREA)

Abstract

Procédé amélioré de récupération d'or à partir de substances contenant de l'or par lessivage d'iodure/iode, où l'agent lessivant chargé contenant l'or et l'iode solubilisés est traité dans un élément électrolytique pour réduire l'or en solution en or élémentairte en permettant l'extraction et pour réduire l'iode en iodure au niveau de la cathode, de manière à empêcher toute interférence de l'iode avec les étapes successives d'extraction d'or, et pour réoxider simultanément l'iodure présent au niveau de l'anode en iodure élémentaire pour régénérer la solution de lessivage au rapport pondérable iodure:iode désiré, par exemple entre 2:1 et 10:1 environ. L'or est précipité dans le compartiment de cathode, et si on le désire, l'effluent de la cathode peut être traité en vue d'une extraction ultérieure des traces d'or avant de le faire passer dans le compartiment d'anode. Est également décrit un procédé empêchant la contamination de la cathode par du fer, consistant à tamponner la solution d'agent lessivant à un pH d'environ 5.
PCT/US1985/002426 1985-12-06 1985-12-06 Procede electrolytique permettant d'obtenir simultanement un depot d'or et la regeneration de l'iode elementaire Ceased WO1987003623A1 (fr)

Priority Applications (3)

Application Number Priority Date Filing Date Title
PCT/US1985/002426 WO1987003623A1 (fr) 1985-12-06 1985-12-06 Procede electrolytique permettant d'obtenir simultanement un depot d'or et la regeneration de l'iode elementaire
JP61500200A JPS63502358A (ja) 1985-12-06 1985-12-06 金電着と元素状沃素再生を同時に行う電解方法
AU52071/86A AU577173B2 (en) 1985-12-06 1985-12-06 An electrolytic process for the simultaneous deposition of gold and replenishment of elemental iodine

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
PCT/US1985/002426 WO1987003623A1 (fr) 1985-12-06 1985-12-06 Procede electrolytique permettant d'obtenir simultanement un depot d'or et la regeneration de l'iode elementaire

Publications (1)

Publication Number Publication Date
WO1987003623A1 true WO1987003623A1 (fr) 1987-06-18

Family

ID=22188967

Family Applications (1)

Application Number Title Priority Date Filing Date
PCT/US1985/002426 Ceased WO1987003623A1 (fr) 1985-12-06 1985-12-06 Procede electrolytique permettant d'obtenir simultanement un depot d'or et la regeneration de l'iode elementaire

Country Status (3)

Country Link
JP (1) JPS63502358A (fr)
AU (1) AU577173B2 (fr)
WO (1) WO1987003623A1 (fr)

Cited By (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS6417827A (en) * 1987-07-14 1989-01-20 Tanaka Precious Metal Ind Refining device for gold and refining method for gold using said device
CN104294313A (zh) * 2014-10-20 2015-01-21 常州钇金环保科技有限公司 黄金电化学溶解装置及其方法
US10526682B2 (en) 2017-07-17 2020-01-07 Enviroleach Technologies Inc. Methods, materials and techniques for precious metal recovery
US10563283B2 (en) 2016-06-24 2020-02-18 Enviroleach Technologies Inc. Methods, materials and techniques for precious metal recovery

Families Citing this family (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE3815487A1 (de) * 1988-05-06 1989-11-16 Basf Ag Verfahren zur niederdruckcopolymerisation von ethylen mit (alpha)-olefinen und ethylencopolymerisate mit niederem restmonomerengehalt
JP4788998B2 (ja) * 2005-12-28 2011-10-05 Ｊｘ日鉱日石金属株式会社 エッチング廃液からの金の回収方法

Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2304823A (en) * 1940-07-03 1942-12-15 Thomas M Courtis Method of treating ore and treatment agent therefor
DE1269362B (de) * 1964-12-09 1968-05-30 Mo Sawod Wtoritschnych Drogoze Verfahren zum Abloesen einer Goldschicht, die auf einer Unterlage aus Bunt- und seltenen Metallen und ihren Legierungen aufgetragen ist
JPS5141625A (fr) * 1974-08-05 1976-04-08 Beisaido Rifuainingu Ando Chem
US4557759A (en) * 1984-04-10 1985-12-10 In-Situ, Inc. Iodine leach for the dissolution of gold

Patent Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2304823A (en) * 1940-07-03 1942-12-15 Thomas M Courtis Method of treating ore and treatment agent therefor
DE1269362B (de) * 1964-12-09 1968-05-30 Mo Sawod Wtoritschnych Drogoze Verfahren zum Abloesen einer Goldschicht, die auf einer Unterlage aus Bunt- und seltenen Metallen und ihren Legierungen aufgetragen ist
JPS5141625A (fr) * 1974-08-05 1976-04-08 Beisaido Rifuainingu Ando Chem
US3957505A (en) * 1974-08-05 1976-05-18 Bayside Refining And Chemical Company Gold reclamation process
US4557759A (en) * 1984-04-10 1985-12-10 In-Situ, Inc. Iodine leach for the dissolution of gold

Cited By (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS6417827A (en) * 1987-07-14 1989-01-20 Tanaka Precious Metal Ind Refining device for gold and refining method for gold using said device
CN104294313A (zh) * 2014-10-20 2015-01-21 常州钇金环保科技有限公司 黄金电化学溶解装置及其方法
US10563283B2 (en) 2016-06-24 2020-02-18 Enviroleach Technologies Inc. Methods, materials and techniques for precious metal recovery
US10526682B2 (en) 2017-07-17 2020-01-07 Enviroleach Technologies Inc. Methods, materials and techniques for precious metal recovery

Also Published As

Publication number Publication date
JPS63502358A (ja) 1988-09-08
AU577173B2 (en) 1988-09-15
JPH0211675B2 (fr) 1990-03-15
AU5207186A (en) 1987-06-30

Similar Documents

Publication Publication Date Title
US4734171A (en) Electrolytic process for the simultaneous deposition of gold and replenishment of elemental iodine
US8388730B2 (en) Process of leaching gold
DE69511536T2 (de) Verfahren zur hydrometallurgischen extraktion
EP3655557B1 (fr) Procédé de récupération de métaux précieux
JP2014501850A (ja) チオ硫酸塩溶液からの金および銀の電気的回収
US20190233917A1 (en) Methods, Materials and Techniques for Precious Metal Recovery
US5401296A (en) Precious metal extraction process
US3767760A (en) Process for recovery of precious metals from copper containing materials
US10563283B2 (en) Methods, materials and techniques for precious metal recovery
JPS59501370A (ja) 鉱石および精鉱からの銀および金の回収
GB2299201A (en) Method for removal of technetium from radio-contaminated material
US4026772A (en) Direct electrochemical recovery of copper from dilute acidic solutions
US5039337A (en) Process for producing electrolytic lead and elemental sulfur from galena
AU577173B2 (en) An electrolytic process for the simultaneous deposition of gold and replenishment of elemental iodine
US5156721A (en) Process for extraction and concentration of rhodium
US4895626A (en) Process for refining and purifying gold
JPS6338538A (ja) ニツケル硫化物からのニツケルの回収方法
US4028202A (en) Direct electrochemical recovery of copper from dilute ammoniacal solutions
US5997719A (en) Electrochemical process for refining platinum group metals with ammonium chloride electrocyte
JP2001192878A (ja) 金属組成物からの貴金属回収法
JPH08158088A (ja) 白金族金属の回収方法
AU679356C (en) Hydrometallurgical extraction process
PL111091B1 (en) Process for recovering the high purity copper from diluted ammonia solution
JP2006016679A (ja) 硫化銅鉱からの貴金属回収方法
JPH03104894A (ja) スクラップからの貴金属回収方法

Legal Events

Date Code Title Description
AK Designated states

Kind code of ref document: A1

Designated state(s): AU JP