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WO1999050465A1 - Procede d'extraction de metaux precieux et de cuivre dans des minerais de cuivre/d'or a l'aide de techniques utilisant des resines - Google Patents

Procede d'extraction de metaux precieux et de cuivre dans des minerais de cuivre/d'or a l'aide de techniques utilisant des resines Download PDF

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Publication number
WO1999050465A1
WO1999050465A1 PCT/AU1999/000221 AU9900221W WO9950465A1 WO 1999050465 A1 WO1999050465 A1 WO 1999050465A1 AU 9900221 W AU9900221 W AU 9900221W WO 9950465 A1 WO9950465 A1 WO 9950465A1
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WO
WIPO (PCT)
Prior art keywords
medium
copper
formula
aqueous solution
precious metals
Prior art date
Application number
PCT/AU1999/000221
Other languages
English (en)
Inventor
Alexander E. Jenkins
Tam Tran
Original Assignee
Golden Kingdom (No.2) Pty Limited
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 Golden Kingdom (No.2) Pty Limited filed Critical Golden Kingdom (No.2) Pty Limited
Priority to AU31278/99A priority Critical patent/AU765902B2/en
Priority to CA002326168A priority patent/CA2326168A1/fr
Priority to NZ507574A priority patent/NZ507574A/xx
Publication of WO1999050465A1 publication Critical patent/WO1999050465A1/fr

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Classifications

    • 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
    • C22B3/00—Extraction of metal compounds from ores or concentrates by wet processes
    • C22B3/20—Treatment or purification of solutions, e.g. obtained by leaching
    • C22B3/42—Treatment or purification of solutions, e.g. obtained by leaching by ion-exchange extraction
    • 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
    • C22B11/08—Obtaining noble metals by cyaniding
    • 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
    • C22B3/00—Extraction of metal compounds from ores or concentrates by wet processes
    • C22B3/20—Treatment or purification of solutions, e.g. obtained by leaching
    • C22B3/22—Treatment or purification of solutions, e.g. obtained by leaching by physical processes, e.g. by filtration, by magnetic means, or by thermal decomposition
    • C22B3/24—Treatment or purification of solutions, e.g. obtained by leaching by physical processes, e.g. by filtration, by magnetic means, or by thermal decomposition by adsorption on solid substances, e.g. by extraction with solid resins
    • 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 relates to a hydrometallurgical process for selectively recovering precious metals from a medium loaded with precious metals and base metals. Further, the present invention also relates to a process for eluting copper from a medium loaded with precious metals, copper and optionally, other base metals.
  • the adsorbent used for gold recovery from solution is "swamped" with copper. This copper is then co-eluted with gold in the next stage, rendering gold solutions containing a significant amount of copper, hindering the final stage of gold recovery by electrolysis or zinc cementation.
  • aqueous eluant containing high concentrations of simple anions such as cyanide, chloride, bisulphate, sulphate, nitrate or thiocyanate, wherein the strong affinity of the resin for the precious metal anions is overcome by the mass action impact of the eluant anions.
  • simple anions such as cyanide, chloride, bisulphate, sulphate, nitrate or thiocyanate
  • simple anions such as cyanide, chloride, bisulphate, sulphate, nitrate or thiocyanate
  • This use invariably involves heated aqueous solutions of sodium zinc tetracyanide operating in a closed electroelution 2 circuit where the eluate from the resin bed enters the electrowinning cell as the electrolyte, and emerges diminished in precious metal content to be recycled back to the resin bed once more as the eluant.
  • the precious metal elution efficiency is directly related to the operating efficiency of the electrowinning circuit wherein the return precious metal concentrations have to be reduced to very low values to increase the driving force of the elution process. Typically a period of between two to three days is required for the elution efficiency to reach 95 % .
  • the resin is saturated with adsorbed zinc tetracyanide to the extent that it has replaced all removed anions, for example 90 to 100 kg/t of dry resins.
  • adsorbed zinc tetracyanide has to be removed, generally by washing in a sulphuric acid solution.
  • the product is gaseous HCN and an acidic zinc sulphate solution which also contains HCN, and both products represent major economic and environmental problems.
  • the present invention provides an improved precious metal elution process. At least some of the advantages of the present invention arise through the penetration of complex eluting metal cyanions from the external liquid medium to replace the adsorbed precious metal anions resident within the charged liquid film at the resin surface. This penetration being greatly enhanced due to the eluting anions possessing a linear structure, thereby favouring faster exchange kinetics than that achieved with the bulkier and more slowly diffusing tetrahedral zinc tetracyanide anion. Also, the presence of a heavy transition metal ion within the complex eluting cyanions contributes to the attractive force developed between the fixed and mobile ions, in addition to the electrostatic forces between the oppositely charged entities at the resin surface.
  • the present invention adapts this concept to solving the problem of desorbing (eluting) adsorbed precious metal cyanions, and overcomes the following deficiencies in current practice:
  • a regeneration stage is required for each resin charge following elution operations, whether it be for base or precious metals, to wash off all residual adsorbed cyanides (copper, zinc, free cyanide or thiocyanate), before the resin is re-used in the next adsorption cycle.
  • cyanides copper, zinc, free cyanide or thiocyanate
  • a process for the selective recovery of precious metals from a medium loaded with precious metals and base metals wherein said selective recovery is achieved by exposing said medium to an aqueous solution containing a complex of formula MX 2 ", wherein M is a metal of group
  • a process for the elution of copper from a medium loaded with precious metals, copper and optionally other base metals wherein said elution is achieved by exposing said medium to an aqueous solution capable of oxidising Cu(I) to Cu(II), whilst not eluting said precious metals from said medium.
  • a process for the elution of copper from a medium loaded with precious metals, copper and optionally other base metals comprising:
  • a process for the selective recovery of precious metals from a medium loaded with precious metals and base metals wherein said process comprises: 4
  • the precious metal is gold, silver or platinum group metals.
  • the precious metals are present on the medium in the form of precious ⁇ o metal cyanoion complexes.
  • the precious metals are removed from the medium in the form of precious metal cyanoion complexes.
  • copper and other base metals are present on the medium in the form of copper and other base metal cyanoion complexes. 15 Typically, the copper and other base metals are removed from the medium in the form of copper and other base cyanoion complexes.
  • the base metals are selected from the group consisting of: copper, nickel, cobalt, zinc, iron and lead.
  • the medium is an ion exchange medium or activated carbon.
  • the ion- 20 exchange medium may be any commercially available ion exchange medium. More typically, the ion exchange medium may be of a salt, acid or base in nature, and is generally solid in form. Even more typically, the ion exchange medium is an anion exchange medium. Still more typically, the anion exchange medium is in the form of an anion exchange resin. 25 Still even more typically, the anion exchanger functional group of an ion exchange resin for use in the process of the present invention is a strongly basic benzyltrimethylammonium chloride.
  • the metal M is selected from the 30 group consisting of: copper®, gold(I), silver(I), cadmium(I) and mercury (I). More typically, in the complex anion of formula MX 2 ", the metal M is copper.
  • X corresponds to a monovalent anion selected from the group consisting of: halides, cyanide, thiocyanate and isothiocyanate.
  • the halide may be selected from the group consisting of: chloride, bromide, iodide and fluoride. Even more typically, X is 35 selected from cyanide and thiocyanate.
  • the complex anion of formula MX 2 - " is either Cu(CNS) ⁇ or Cu(CN) 2 ⁇ . Still even more typically, the complex anion of formula MX 2 " is Cu(CN) 2 " .
  • the aqueous solution of the complex anion of formula 40 MX 2 " also includes a counterion.
  • the counterion may be any counterion which does not 5 cause precipitation of the complex anion of formula MX 2 ⁇
  • a counterion may include an alkali metal cation, for instance, Na+ or K+, or an ammonium ion.
  • the aqueous solution containing a complex anion of formula MX 2 ⁇ also contains a salt of formula M'X, wherein said M' may be, but is not necessarily, the counter cation in relation to the complex anion of formula MX 2 ⁇ .
  • the amount of the salt of formula M'X is from about 0 to about 10 moles per mole of the complex anion of formula MX 2 " . More typically, the amount of the salt of formula M'X per mole of the complex anion of formula MX 2 " is in the range of between any one of the following: between about 0.1 to about 8 moles per mole, about 0.1 to about 6 moles per mole, about 0.1 to about 5 moles per mole, about 0.1 to about 4 moles per mole, about 0.1 to about 3 moles per mole, about 0.1 to about 2.5 moles per mole, about 0.1 to about 2 moles per mole, about 0.1 to about 1.5 moles per mole, about 0.1 to about 1 moles per mole, about 0.2 to about 5 moles per mole, about 0.2 to about 4 moles per mole, about 0.2 to about 3 moles per mole, about 0.2 to about 2.5 moles per mole, about 0.2 to about 2 moles per mole, about 0.5 to about 1.5 moles
  • the minimum amount of aqueous solution containing a complex anion of formula MX 2 * used in the present invention is that sufficient to elute the precious metals from the ion exchange medium or activated carbon medium.
  • the lower limit of the concentration of the complex anion of formula MX 2 ⁇ in the aqueous solution depends on the amount of precious metals to be eluted off the ion exchange medium or activated carbon medium, and the desired rate of elution.
  • MX 2 _ in the aqueous solution is that wherein the complex anion of formula MX 2 " remains soluble.
  • concentration of the complex anion of formula MX 2 _ in the aqueous solution wherein the complex anion of formula MX 2 " remains soluble is dependent upon a number of factors, including temperature and the X/M molar ratio. More typically, the concentration of the complex anion of formula MX 2 " in the aqueous solution is at least about 0.01M.
  • the concentration of the complex anion of formula MX 2 " in the aqueous solution is in the range of between any one of the following: about 0.01M to about 2M, about 0.01M to about 1.75M, about 0.01M to about 1.5M, about 0.01M to about 1.25M, about 0.01M to about 1M, about 0.01M to about 0.75M, about 0.01M to about 0.5M, about 0.05M to about 2M, about 0.05M to about 1.75M, about 0.05M to about 1.5M, about 0.05M to about 1.25M, about 0.05M to about 1M, about 0.05M to about 0.75M, about 0.05M to about 0.5M, about 0.1M to about 2M, about 0.1M to about 1.75M, between about 0.1M to about 1.5M, about 0.1M to about 1.25M, about 0.1M to about 1M, about 0.1M to about 0.75M, and 6 yet even still more typically, the concentration of the complex anion of formula MX " in the aqueous solution
  • the aqueous solution of the complex anion of formula MX 2 - is provided by preparing an aqueous solution of a salt M'X at the desired concentration, wherein M' is the desired counterion, and adding a salt MX in a sufficient quantity to provide the desired concentration of M, and hence the complex anion of formula MX 2 ⁇ , in solution.
  • an aqueous solution of MX may be prepared first, with subsequent addition of M'X, or both MX and M'X may be added to water together, or any combination of these steps may be used.
  • Other reaction conditions for carrying out the process of the present invention are not critical. The process may be carried out at ambient temperature, or elevated temperatures, but is typically carried out at ambient temperature.
  • the pH is usually the pH of the aqueous solution of the complex anion of formula MX 2 " as prepared, without any further pH adjustment.
  • the processes of the present invention are useful for mediums loaded with precious metal-cyano complexes via both clear and/or slurried solutions.
  • precious metals may then be cemented onto copper metal by methods generally known in the art.
  • Precious metal/copper cement can then be easily purified by dissolution of copper in a mixture of sulphuric acid and an oxidant (such as hydrogen peroxide or air), leaving behind a product rich in precious metals for smelting into dore. Further, methods for dissolution of copper from cement containing precious metals are also generally known in the art.
  • the process engineering conditions chosen for contacting the resin and solution will be a design variable but preferably will incorporate either a column resin packed bed or some suitable form of stirred liquid/solids reactor configured for either batch or continuous operation.
  • solution contacts the resin via either a series of elution cycles, or a continuous passage of recycled solution.
  • any base metal-cyano complexes are removed from the medium together with the copper metal-cyano complexes. More typically, the base metals are selected from the group consisting of: copper, nickel, cobalt, zinc, iron and lead.
  • the aqueous solution capable of oxidising Cu(I) to Cu(II) comprises an oxidising agent, together with an acid.
  • the oxidising agent is selected from the group consisting of: hydrogen peroxide, Caro's acid (H 2 SO 5 ) and acid ferric sulphate, and the acid is a mineral acid.
  • the mineral acid is selected from the group consisting of: sulphuric acid, hydrochloric acid and nitric acid.
  • the minimum amount of aqueous solution of oxidising agent used in the present invention is that sufficient to oxidise Cu(I) to Cu(II). More typically, the aqueous solution capable of oxidising Cu(I) to Cu(II) comprises between about 0.25-5% by weight 7 hydrogen peroxide and about 1-20% by weight sulphuric acid; more typically between about 0.25-4% by weight hydrogen peroxide and about 1-15 % by weight sulphuric acid; even more typically between about 0.25-3 % by weight hydrogen peroxide and about 1- 12% by weight sulphuric acid; still more typically between about 0.25-2.5 % by weight 5 hydrogen peroxide and about 1-10% by weight sulphuric acid; yet still more typically between about 0.25-2% by weight hydrogen peroxide and about 1-8% by weight sulphuric acid; even still more typically between about 0.35-2% by weight hydrogen peroxide and about 2-8% by weight sulphuric acid; yet still more typically between about 0.35-1.5 % by weight
  • the aqueous eluant contacts the loaded resin at ambient temperatures for periods up to about 8 hours, depending on the desired extent of copper elution. More typically, the contact time is between about 1 and 5 hours, even more typically between
  • the medium prior to exposing the medium to the aqueous solution capable of oxidising Cu(I) to Cu(II), the medium is contacted with a mineral acid.
  • the mineral acid is selected from the group consisting of: sulphuric acid, hydrochloric acid and nitric acid. Even more typically, the mineral acid is sulphuric acid.
  • the mineral acid may be present at between 1 to 10% by weight, more typically, between about 1 to about 7.5% by weight; even more typically, between about 1 to about 5 % by weight; still more typically, between about 1 to about 4% by weight; and still more typically, between about 1 to about 2.5% by weight.
  • washing the medium typically an anion exchange medium, in accordance with the second or third embodiments of the invention, is removed from the system, together with the acid solution, by passing the HCN gas directly into a solution of calcium or sodium hydroxide. More typically, the cyanide liberated as HCN from the adsorbed cyano complex is removed from the system by passing into an air purged volatilisation column wherein the
  • 35 HCN gas is removed into a caustic soda scrubbing tower for the regeneration of sodium cyanide.
  • the recovery of copper metal from resultant acid solution after exposing the medium in accordance with either the second or third embodiments of the invention may be facilitated using any commercially available technology in this field. More
  • recovery of copper metal from the resultant acid solution after exposing the 8 medium may be obtained by electrowinning to cathodic copper. Even more typically, the recovery of copper metal from the resultant acid solution after exposing the medium may be obtained by cementation on materials such as scrap ferrous metal, or recovered as copper hydroxide by precipitation in alkaline solution. Typically, the medium is not damaged or destroyed by repeated contact with the aqueous solution capable of oxidising Cu(I) to Cu(II).
  • Figure 1 illustrates gold elution from anion exchange resins using CuCN-NaCN mixtures.
  • Figure 2 illustrates silver elution from anion exchange resins using CuCN-NaCN mixtures.
  • Figures 3A and 3B respectively illustrate gold and silver elution incorporating continuous cementation using copper powder.
  • Figure 4 illustrates copper elution using H 2 SO 4 -H 2 0 2 mixtures.
  • Figure 5 provides a flow-chart illustrating the recovery of gold and silver using resin technology.
  • the present invention is concerned with procedures designed to elute precious metals, notably gold, silver and platinum group metals, from resins at any stage in the adsorption cycle, but particularly from resins that have reached a gold level of the order of 10 kg/tonne of dry resin.
  • the resins have possibly been subjected to several base metal elutions by procedures outlined in accordance with the second embodiment of the invention with regard to decoppering, because it would be usual to have conducted such procedures where the copper or other base metal concentrations were significantly higher than gold for example.
  • the present invention details a new procedure for eluting gold and other precious metals from such loaded resins that departs significantly from current practice. It will be appreciated that the current precious metal elution systems for strong base anion exchange resins rely on the ability of strong alkaline solutions containing the zinc tetrahedral tetracyanide anion to replace the linear precious metal cyanoanions from the resin. In one form of the invention it is proposed to use a typically linear singly charged anion to undertake the same task and at the same time remove the problem of having to cope with the very high introduced concentrations of the CN anion and the disposal of the remnant zinc cations so introduced to the system.
  • the present invention comprises a series of operations whereby the adsorbed precious metals, typically gold, silver and platinum group metals, are selectively removed from the loaded medium in a manner which delivers a strong aqueous solution of those metals in a form capable of being further treated by known electro or hydrometallurgical procedures for their recovery in metallic form.
  • the eluant consists of an aqueous solution containing a complex of formula MX 2 ", wherein M is a metal of group IB or IIB of the Periodic Table of Elements, and X is a monovalent radical.
  • the medium may be an ion exchange medium or activated carbon, wherein if an ion exchange medium, it may be of a salt, acid or base in nature, and is generally solid in form.
  • the ion exchange medium is an anion exchange medium, and is usually in the form of an anion exchange resin.
  • anion exchanger the functional group
  • anion exchange resin is affixed to the surface of an insoluble base support, frequently presented in the form of porous beads of cross linked polystyrene which leads directly to the commonly used term "anion exchange resin".
  • Strong base anion exchange resins are mostly based on porous styrene-DVB copolymers to which a charged functional group has been chemically attached, and for a typical Type 1 resin this group is tri-methyl ammonium chloride, N + (CH 3 ) 3 C1 " .
  • the positively charged tri-methyl ammonium entities are firmly bonded to the resin matrix, and the negative chloride anions are held by strong electrostatic forces within a thin diffuse aqueous layer, within which they, and other anions, are free to migrate under the restrictions imposed by the requirement to maintain a condition of electoneutrality.
  • the anion exchanger functional group of an ion exchange resin for use in the process of the present invention may be a strongly basic benzyltrimethylammonium chloride.
  • the Cl _ counter ion is exchanged with the various base and precious metal cyano complex anions.
  • This particular functional group is chemically one of the most stable of the many possible amine substitutional products in this group, and provides a highest degree of dissociation for the counter anions over a wide range of operating pH.
  • resin will be loaded with base and precious metals from a pregnant solution being passed over a resin bed in either a column contactor or stirred reactor mode.
  • a pregnant solution or slurry derived from the cyanide leaching of a suitable ore is passed through a resin filled column, or a cascade arrangement of stirred liquid/solid reactors resulting in the base metal and precious metal components being adsorbed onto a commercially available resin source, such as Dowex MSA1 (Dow Chemical Co., Midland, Michigan USA).
  • these strong base anion exchange resins When exposed to pregnant aqueous solutions bearing dissolved precious metals, these strong base anion exchange resins uptake the complex ions which displace the chloride or any other simple anion such as hydroxide, bisulphate or sulphate, which may be uptaken on the resin. 10 After adsorbing the required mass of precious metals, the mass is referred to as being "loaded” .
  • the mass of loaded resin contained within the column or stirred reactor is then isolated from the pregnant liquor stream for subsequent washing and elution in an aqueous eluant stream containing the complex anion of formula MX 2 ⁇
  • the complex anion of formula MX 2 _ is generally linear in nature, wherein the metal M is selected from the group consisting of: copper(I), gold(I), silver(I), cadmium(I) and mercury (I), and X corresponds to a monovalent anion selected from the group consisting of: halides, cyanide, thiocyanate and isothiocyanate.
  • the halide may be selected from the group consisting of: chloride, bromide, iodide and fluoride, and is generally cyanide or thiocyanate.
  • the complex anion of formula MX 2 " is either Cu(CNS) 2 " or Cu(CN) 2 " , but Cu(CN) 2 " is generally preferred.
  • the aqueous solution of the complex anion of formula MX 2 - also includes a counterion.
  • the counterion may be any counterion which does not cause precipitation of the complex anion of formula MX 2 ⁇
  • a counterion may include an alkali metal cation, for instance, Na + or K + , or an ammonium ion.
  • the aqueous solution containing a complex anion of formula MX 2 " also contains a salt of formula M'X, wherein said M' is the counter cation in relation to the complex anion of formula MX 2 _ .
  • the amount of the salt of formula M'X may range from between about 0 to about 5 moles per mole of the complex anion of formula MX 2 ⁇ , but is generally about 1 mole per mole of the complex anion of formula MX 2 " .
  • the minimum amount of aqueous solution containing a complex anion of formula MX 2 " used in the present invention is that sufficient to elute the precious metals from the ion exchange medium or activated carbon medium.
  • the upper limit of the concentration of the complex anion of formula MX 2 " in the aqueous solution is that wherein the complex anion of formula MX 2 _ remains soluble.
  • the concentration of the complex anion of formula MX 2 " in the aqueous solution is at least about O.OIM, but may range between about O.OIM to about 2M, to between about 0.1M to about 0.5M.
  • the aqueous solution of the complex anion of formula MX 2 " is provided by preparing an aqueous solution of a salt M'X at the desired concentration, wherein M' is the desired counterion, and adding a salt MX in a sufficient quantity to provide the desired concentration of M, and hence the complex anion of formula MX 2 ", in solution.
  • an aqueous solution of MX may be prepared first, with subsequent addition of M'X, or both MX and M'X may be added to water together, or any combination of these steps may be used.
  • a typical eluant is made from 0.5M CuCN and 1.0M NaCN, and may be passed through the column at for example, 4 bed volume/h, for a time period depending on the amount of gold loading, and the elution rate (for example 48 hours). The elution process may proceed as a series of elution cycles, or a continuous passage of recycled eluant solution.
  • CuCN - 1.0M NaCN contains a very high proportion of Cu(CN) 2 _ species.
  • This species is single-charged and linear in structure, and accordingly, easily displaces other single-charged complex ions, such as,
  • reaction conditions for carrying out the process of the present invention are not critical.
  • the process may be carried out at ambient temperature, or elevated temperatures, but is typically carried out at ambient temperature.
  • the pH is usually the pH of the aqueous solution of the complex anion of formula MX 2 - as prepared, without o any further pH adjustment.
  • Eluted liquor may then be passed onto a cementation cell.
  • Cementation is a redox 5 process in which a metal, such as zinc and/or copper, is used to remove precious metal ions, such as gold, silver and platinum groups metals, from solution.
  • precious metal ions such as gold, silver and platinum groups metals
  • precious metals may then be cemented onto copper metal by methods generally known in the art.
  • Precious metal/copper cement can then be easily purified by dissolution of copper in a mixture of 5 sulphuric acid and an oxidant (such as hydrogen peroxide or air), leaving behind a product rich in precious metals for smelting into dore. Further, methods for dissolution of copper from cement containing precious metals are also generally known in the art.
  • resin will be loaded with base and precious metals from a pregnant solution being passed over a resin bed in either a column contactor or stirred reactor mode.
  • these strong base anion exchange resins adsorb the complex ions which displace the chloride or any other simple anion such as 0 hydroxide, bisulphate or sulphate which may be adsorbed on the resin. 12
  • the resin capacity for the base metals will be reached and the flow will have to be terminated.
  • the loaded resin charge is then taken off line and subjected to a process to remove the base metal cyanides from the resin.
  • the resin is washed with water and then subjected to a sequence of elution cycles or a continuous passage of a recycled eluant solution depending on the objectives at the time.
  • the eluant may comprise an aqueous solution of 5% by weight sulphuric acid, with an addition of hydrogen peroxide as oxidant to a level which is consistent with the requirement to preserve the structural and chemical integrity of the anion exchange resin and the functional group attached.
  • the eluate produced from this operation is an acidic aqueous copper sulphate with relevant other base metal sulphates which, utilising known recovery procedures, may be treated to provide copper metal and return the acid to the elution circuit.
  • the acid serves to regenerate the stripped resin ready for its return to adsorption from the pregnant liquor streams.
  • an anion exchange resin loaded with copper, gold and silver cyano complexes is exposed in an appropriate manner to an aqueous solution containing hydrogen peroxide and sulphuric acid for a period of time sufficient to provide for the desired removal of a predetermined quantity of the adsorbed copper complex.
  • the process engineering conditions chosen for contacting the resin and solution will be a design variable but preferably will incorporate either a column resin packed bed or some suitable form of stirred liquid/solids reactor configured for either batch or continuous operation.
  • a preferred feature for the preparation of a satisfactory aqueous oxidising solution is a solution which will perform the Cu(I) to Cu(II) oxidation without in so doing irretrievably destroy either the anion exchange capacity of the resin functional group or the physical and mechanical properties of the resin.
  • copper is present in the lower oxidation state, as Cu(I), in the copper cyano complexes and the process provides for the direct chemical oxidation of the metal to the Cu(II) state and the destruction of the adsorbed copper cyano complexes attached to the resin active sites, and permitting a level of copper removal which approaches complete.
  • the copper is then free to enter the aqueous phase as the cation 13 Cu 2 + and accordingly is not available for capture by the strong base anion exchanger.
  • the recovery of copper metal from the resultant acid solution is then achieved by the application of known technology in this area, notably electrowinning to cathodic copper or cementation onto scrap ferrous metal or precipitation as copper hydroxide according to the scale and economics of the operation.
  • This decoppering stage of the present invention further provides for the control of the conditions for the recovery of the cyanide component of the copper cyano complexes either as a solution containing the less toxic cyanate anion CNO ⁇ or as the gas HCN.
  • the copper loaded resin may be contacted in the first instance with a mineral acid, preferably sulphuric acid at an aqueous concentration sufficient to provide a pH of less than between 6, whereby the copper cyano complex adsorbed onto the resin will have been converted to the CuCN and/or Cu(CN) 2 " state.
  • a proportion of the cyanide will have been liberated as HCN from the adsorbed copper cyano complex and this product is preferably removed from the system along with the acid solution for recovery of its cyanide by either passing directly into a solution of calcium hydroxide or optionally into an air purged volatilisation column where the HCN gas is removed into a caustic soda scrubbing tower for the regeneration of sodium cyanide.
  • Subsequent oxidation of the adsorbed copper cyano complex or CuCN left on the resin is performed as outlined in accordance with the second or third embodiments of the invention, in an oxidising solution which is optionally constituted in a different manner to take advantage of the higher copper to cyanide ratio in the adsorbed copper cyano complex or CuCN.
  • Optional features of this process provide for the use of oxidant solutions derived from Caro's acid (H 2 SO5), acid ferric sulphate and other solutions capable of converting the copper in the cyano complex from its Cu(I) univalent state to the cationic Cu(II) state without adversely affecting the physical and chemical properties of either the anion exchange functional group or its polymer base support.
  • oxidant solutions derived from Caro's acid (H 2 SO5), acid ferric sulphate and other solutions capable of converting the copper in the cyano complex from its Cu(I) univalent state to the cationic Cu(II) state without adversely affecting the physical and chemical properties of either the anion exchange functional group or its polymer base support.
  • Figure 5 provides a flow-chart describing typical major unit operations (adsorption, precious metal elution, copper elution and gold cementation) in the recovery of precious metals and copper from the medium, in this case, anion exchange resin.
  • HCN is generated mainly from base metal cyanides (Cu, Zn, etc.) and not from strong cyanide eluant solutions;
  • the precious metal containing eluant is suitable for a precious metal recovery stage to be conducted by simple cementation onto copper.
  • the loadings of metal ions after 24 hours are: 3.59 kg/t Au, 10.84 kg/t Ag, 34.2 kg/t Cu and 8.02 kg/t Zn from the original solution of 18.6 mg/L Au, 57.75 mg/L Ag, 30 172.6 mg/L Cu and 40.3 mg/L Zn.
  • the residual concentrations of the final solution are: 0.642 mg/L Au, 3.56 mg/L Ag, 1.61 mg/L Cu and 0.22 mg/L Zn, indicating conditions close to maximum loading capacity of the resin.
  • Loading capacity is calculated for each adsorbed species.
  • Single-charged ions has no. of milli-equivalent equal to no. of milli-mole whereas double-charged ions (Zn) have m.eq equal to 2xmilli-mole. 1 5
  • the total metal loading capacity is 0.900 m.eq/g resin. Taking into account the loading of free cyanide (1.38 m.eq/g resin) the total operating capacity is 2.38 m.eq/g, compared to the max. loading capacity quoted by the manufacturer (Dow Chemical Co., Midland, Michigan USA) as 4.0 m.eq/g resin.
  • Bottle roll tests were used for this experiment. Volume of eluant: 200 mL, Resin loading: lOg dry resin / L eluant, Resin used: Dowex MSA1. 15 Samples (4 mL each) taken at time intervals were analysed by AAS for Au, Ag, Zn and Cu. Free cyanide was determined by potentiometric titration.
  • the amount of gold eluted was 76% of the Au(I) loading 30 capacity of 0.0182 m.eq/g resin, equal to 0.0138 m.eq/g resin.
  • the high concentrations of gold in the final eluant (>20 mg/L Au(I)) probably prevented further gold being eluted. 1 6
  • Table 2 summarises the metal ion loadings of the original resin and the elution efficiency after 6 hours for comparison of the 4 eluant systems tested.
  • Soak resins (0.266-0.311 g) in various solutions as specified in Table 4 below for one hour. Conditions were not optimised. Samples were taken after 1 hour for analysis using atomic absorption spectrophotometer for dissolved Cu and Au analysis. The total amounts of Cu and Au in solution were used to calculate the percentage of elution
  • HNO 3 Nitric acid
  • HC1 Hydrochloric acid
  • H 2 S0 4 sulphuric acid
  • Mixture 1 is traditionally known as aqua regia, a powerful oxidising solution.
  • Solution 4 is concentrated nitric acid, also a strong oxidising acid.
  • Mixtures 2 and 3 were made with hydrochloric acid and sulphuric acid, respectively with hydrogen peroxide, H 2 O 2 as oxidising agent.
  • the copper cement containing gold was digested in 5 different acids (nitric acid and/or hydrogen peroxide/sulphuric acid to dissolve copper and silver and aqua regia to dissolve gold) and analysed to determine the masses of gold and silver in the cement for mass balance checking.
  • Samples of resins (about 0.2 g) were added to 100 mL of eluants in plastic bottles and rolled for 24 hours. Samples were taken after 210 minutes and at 24 hours for analysis of Cu and Au using AAS.
  • Results of the testwork after 210 minutes are summarised in Table 7 below.
  • Gold was eluted from the resins if nitric was used (up to 37.8% in 50 g/L nitric acid). In the case when sulphuric acid was used, minimum gold ( ⁇ 1.5%) was eluted after 210 minutes. 20
  • the present invention relates to a hydrometallurgical process for selectively recovering precious metals from a medium loaded with precious metals and base metals. Further, the present invention also relates to a process for eluting copper from a medium loaded with precious metals, copper and optionally, other base metals.

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Abstract

Cette invention concerne un procédé qui permet d'extraire de manière sélective des métaux précieux dans un milieu qui est porteur de métaux précieux et de métaux communs. Cette extraction sélective des métaux précieux se fait en exposant le milieu à une solution aqueuse qui contient un complexe correspondant à la formule MX2- où M est un métal du groupe IB ou IIB du tableau de classification périodique des éléments, tandis que X représente un radical monovalent. Une seconde invention concerne l'extraction du cuivre de ce milieu. L'élution du cuivre se fait en exposant le milieu à une solution aqueuse capable d'oxyder le Cu(I) en Cu(II) sans pour autant éluer les métaux précieux dudit milieu.
PCT/AU1999/000221 1998-03-27 1999-03-26 Procede d'extraction de metaux precieux et de cuivre dans des minerais de cuivre/d'or a l'aide de techniques utilisant des resines WO1999050465A1 (fr)

Priority Applications (3)

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AU31278/99A AU765902B2 (en) 1998-03-27 1999-03-26 Recovery of precious metals and copper from copper/gold ores using resin technology
CA002326168A CA2326168A1 (fr) 1998-03-27 1999-03-26 Procede d'extraction de metaux precieux et de cuivre dans des minerais de cuivre/d'or a l'aide de techniques utilisant des resines
NZ507574A NZ507574A (en) 1998-03-27 1999-03-26 Selective recovery of precious metals and copper from a medium loaded with precious metals and base metals

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AUPP2653 1998-03-27
AUPP2653A AUPP265398A0 (en) 1998-03-27 1998-03-27 Recovery of precious metals and copper from copper/gold ores using resin technology

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Cited By (9)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
RU2385961C2 (ru) * 2008-03-20 2010-04-10 Открытое акционерное общество "Иркутский научно-исследовательский институт благородных и редких металлов и алмазов" ОАО "Иргиредмет" Способ переработки золотомедистых руд
RU2418082C1 (ru) * 2009-11-12 2011-05-10 Открытое акционерное общество "Иркутский научно-исследовательский институт благородных и редких металлов и алмазов" (ОАО "Иргиредмет") Способ переработки сульфидных золотомедных концентратов с извлечением золота
RU2427655C1 (ru) * 2010-01-11 2011-08-27 Открытое акционерное общество "Иркутский научно-исследовательский институт благородных и редких металлов и алмазов" (ОАО "Иргиредмет") Способ извлечения золота из золотосодержащей медистой руды
RU2460814C1 (ru) * 2011-04-13 2012-09-10 Открытое акционерное общество "Ведущий научно-исследовательский институт химической технологии" Способ извлечения золота из цианидных растворов c присутствующей в них растворенной ртутью
CN103572068A (zh) * 2012-08-02 2014-02-12 厦门紫金矿冶技术有限公司 从含铜载金炭中回收铜的方法
RU2532579C2 (ru) * 2013-02-13 2014-11-10 Федеральное государственное автономное образовательное учреждение высшего профессионального образования "Уральский федеральный университет имени первого Президента России Б.Н. Ельцина" Способ извлечения золота из концентратов
RU2538435C2 (ru) * 2012-12-24 2015-01-10 Общество с ограниченной ответственностью "Управляющая Компания "АРИЭНТ" Способ извлечения золота из упорных руд кучным выщелачиванием
RU2603411C1 (ru) * 2015-07-17 2016-11-27 Федеральное государственное автономное образовательное учреждение высшего образования "Национальный исследовательский технологический университет "МИСиС" Способ интенсификации процесса кучного выщелачивания золота из руд
WO2023283700A1 (fr) * 2021-07-15 2023-01-19 Greengold Engineering Pty Ltd Circuit et procédé améliorés de récupération d'or et de cuivre

Citations (8)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2753258A (en) * 1953-01-19 1956-07-03 Nat Res Dev Method of recovering gold from cyanide solutions
US4069119A (en) * 1976-05-14 1978-01-17 Continental Oil Company Copper recovery by leaching and ion exchange
WO1982000478A1 (fr) * 1980-08-06 1982-02-18 Parker A Recuperation de metaux precieux
US4371506A (en) * 1981-06-18 1983-02-01 Himsley Engineering Limited Ammoniacal elution of copper from ion exchange resins
WO1991011539A1 (fr) * 1990-02-02 1991-08-08 Davy Mckee (Stockton) Limited Procede de separation
WO1994019500A1 (fr) * 1993-02-25 1994-09-01 Denis Keith Kidby Recuperation de zinc a partir d'une solution contenant de l'acide cyanhydrique
US5427606A (en) * 1990-11-15 1995-06-27 Bruno Sceresini Holding Pty. Ltd. Base metals recovery by adsorption of cyano complexes on activated carbon
WO1997010367A1 (fr) * 1995-09-12 1997-03-20 Henkel Corporation Recuperation d'or avec des reactifs d'extraction a fonctionnalite guanidyle

Patent Citations (8)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2753258A (en) * 1953-01-19 1956-07-03 Nat Res Dev Method of recovering gold from cyanide solutions
US4069119A (en) * 1976-05-14 1978-01-17 Continental Oil Company Copper recovery by leaching and ion exchange
WO1982000478A1 (fr) * 1980-08-06 1982-02-18 Parker A Recuperation de metaux precieux
US4371506A (en) * 1981-06-18 1983-02-01 Himsley Engineering Limited Ammoniacal elution of copper from ion exchange resins
WO1991011539A1 (fr) * 1990-02-02 1991-08-08 Davy Mckee (Stockton) Limited Procede de separation
US5427606A (en) * 1990-11-15 1995-06-27 Bruno Sceresini Holding Pty. Ltd. Base metals recovery by adsorption of cyano complexes on activated carbon
WO1994019500A1 (fr) * 1993-02-25 1994-09-01 Denis Keith Kidby Recuperation de zinc a partir d'une solution contenant de l'acide cyanhydrique
WO1997010367A1 (fr) * 1995-09-12 1997-03-20 Henkel Corporation Recuperation d'or avec des reactifs d'extraction a fonctionnalite guanidyle

Cited By (9)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
RU2385961C2 (ru) * 2008-03-20 2010-04-10 Открытое акционерное общество "Иркутский научно-исследовательский институт благородных и редких металлов и алмазов" ОАО "Иргиредмет" Способ переработки золотомедистых руд
RU2418082C1 (ru) * 2009-11-12 2011-05-10 Открытое акционерное общество "Иркутский научно-исследовательский институт благородных и редких металлов и алмазов" (ОАО "Иргиредмет") Способ переработки сульфидных золотомедных концентратов с извлечением золота
RU2427655C1 (ru) * 2010-01-11 2011-08-27 Открытое акционерное общество "Иркутский научно-исследовательский институт благородных и редких металлов и алмазов" (ОАО "Иргиредмет") Способ извлечения золота из золотосодержащей медистой руды
RU2460814C1 (ru) * 2011-04-13 2012-09-10 Открытое акционерное общество "Ведущий научно-исследовательский институт химической технологии" Способ извлечения золота из цианидных растворов c присутствующей в них растворенной ртутью
CN103572068A (zh) * 2012-08-02 2014-02-12 厦门紫金矿冶技术有限公司 从含铜载金炭中回收铜的方法
RU2538435C2 (ru) * 2012-12-24 2015-01-10 Общество с ограниченной ответственностью "Управляющая Компания "АРИЭНТ" Способ извлечения золота из упорных руд кучным выщелачиванием
RU2532579C2 (ru) * 2013-02-13 2014-11-10 Федеральное государственное автономное образовательное учреждение высшего профессионального образования "Уральский федеральный университет имени первого Президента России Б.Н. Ельцина" Способ извлечения золота из концентратов
RU2603411C1 (ru) * 2015-07-17 2016-11-27 Федеральное государственное автономное образовательное учреждение высшего образования "Национальный исследовательский технологический университет "МИСиС" Способ интенсификации процесса кучного выщелачивания золота из руд
WO2023283700A1 (fr) * 2021-07-15 2023-01-19 Greengold Engineering Pty Ltd Circuit et procédé améliorés de récupération d'or et de cuivre

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NZ507574A (en) 2004-03-26
CA2326168A1 (fr) 1999-10-07
AUPP265398A0 (en) 1998-04-23

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