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
  • C22B23/00—Obtaining nickel or cobalt
  • C22B23/04—Obtaining nickel or cobalt by wet processes
  • C22B23/0453—Treatment or purification of solutions, e.g. obtained by leaching
• • 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 directed toward a continuous ion exchange process for recovering nickel from a mixed metal product liquor solution.
• CIX processes are used to recover metals from product liquor solutions (PLS), see for example WO 1996/20291 and C. Bailey et al., Removal of Nickel From Cobalt Sulphate Electrolyte Using ISEPTM Continuous Ion Exchange.
• PLS product liquor solutions
• CIX processes involve the use a metal recovery circuit including of a plurality of ion exchange beds, commonly arranged in carousal, which repetitively cycle through individual process zones including metal loading and elution.
• US 7594951 describes a CIX process that includes an integrated electro- winning loop for recovering copper from the eluate.
• interfering ions e.g. iron, sulfate
• the described process is applicable for recovery of other metals such as nickel.
• the present invention includes a system and method for recovering nickel from a mixed metal product liquor solution containing nickel and at least copper or iron comprising passing the product liquor solution through a plurality of ion exchange beds containing nickel selective ion exchange resin that pass through process zones as part of a repeating nickel recovery circuit.
• the method includes the steps of: (a) passing the product liquor solution through an ion exchange bed to load nickel onto the ion exchange resin, and (b) passing a sulfuric acid solution through the loaded ion exchange bed to strip nickel from the ion exchange resin and produce an eluate having a pH less than 3.
• the method is characterized by the additional steps of: (c) recovering the effluent and removing a portion of sulfuric acid sufficient to raise the pH of the effluent above 3, (d) electro- winning the eluate to produce electro-won nickel and a nickel-depleted raffinate, (e) combining at least a portion of the nickel-depleted raffinate with product liquor solution and repeating steps (a) through (d).
• Figure 1 is schematic view of an embodiment the subject invention.
• Figure 2 is a schematic view of an embodiment of a continuous exchange process applicable to the subject invention.
• the present invention includes a system and method for recovering nickel from a mixed metal product liquor solution, sometimes also referred to as "pregnant leach solution,” hereinafter collectively abbreviated as "PLS".
• PLS mixed metal product liquor solution
• the source of the PLS is not particularly limited but is typically produced by heap leaching, vat leaching or pressure leaching lateritic ores.
• the PLS includes a sulfuric acid solution including at least copper or iron, nickel and other acid soluble impurities.
• the PLS preferably has a pH of less than 3, but more preferably less than 2.3 (e.g. from 1.3 to 2.2).
• PLS is subject to continuous ion exchange (CIX) including the step of passing PLS through a plurality of ion exchange beds containing nickel selective ion exchange resin.
• the beds pass through individual process zones as part of a repeating nickel recovery circuit that is described below.
• the subject method further includes an integrated electro-winning cycle loop.
• FIG. 1 provides a schematic overview of an embodiment of the invention including an integrated CIX and electro-winning system generally shown at 10.
• the system includes a CIX unit (12) with multiple beds of nickel selective ion exchange resin for treating PLS (13), an acid removal unit (14) capable of removing a portion of sulfuric acid from the nickel eluate (16) exiting the CIX unit (12) in sufficient quantity to raise the pH above 3 (more preferably at least 3.2, 3.5 or even 4.0), an optional iron/copper removal unit (18) capable of removing a portion of iron or copper present in the pH adjusted eluate (20), and a nickel electro-winning unit (22) capable of electro-winning nickel from the eluate (24) resulting in a high grade nickel product (26) and a nickel depleted raffinate (28).
• an acid removal unit (14) capable of removing a portion of sulfuric acid from the nickel eluate (16) exiting
• the nickel depleted raffinate is recycled back to the CIX unit (12) and may be optionally supplemented with sulfuric acid (30).
• the system (10) may optionally include an acid recovery unit (32) for recovering sulfuric acid from the acid removal unit (14) and returning the acid to the CIX (12), recycling back to the PLS (13), for storage or disposal.
• FIG. 2 is a schematic overview of a CIX unit generally shown at 36 and adapted for use in the present method.
• the unit includes a plurality of ion exchange beds containing nickel selective ion exchange resin (e.g. DOWEXTM M4195) that sequentially pass through individual process zones (e.g. A, B, C) as part of a nickel recovery circuit.
• Each zone preferably includes at least one ion exchange bed or column, and in practice may include a plurality of individual beds.
• the method includes the following sequential steps: (a) passing the PLS (13) through an ion exchange bed (zone A) to load nickel onto the ion exchange resin and produce a raffinate solution (38), and
• the method may include additional process zones as is well known in the art, e.g. rinsing, washing, scrubbing.
• additional process zones as is well known in the art, e.g. rinsing, washing, scrubbing.
• optional Zone B is depicted as a rinsing step.
• PLS, rinse solution (e.g. water), elution solution (e.g. 20% sulfuric acid) may be maintained in tanks, 13, 40, and 42 respectively. The tanks are in selective fluid communication with the ion exchange beds.
• Fluid flow is controlled by a plurality of values and a control panel (not shown) as the beds cycle through the individual process zones (A, B and C).
• CIX equipment for performing the subject method is available from PuriTech (e.g. IONEXTM), Ionex Separations and Calgon Carbon (e.g. ISEPTM) and is also described in US 7594951.
• Suitable nickel selective ion exchange resins include DOWEXTM M4195 and XUS-43578 chelating resins available from The Dow Chemical Company. These resins include a styrene-divinylbenzene copolymer matrix with bis-picolylamine functional groups.
• the acid removal unit (14) is not particularly limited and may include an acid retardation unit including a fixed bed of suitable anion exchange resin (e.g. AMBERSEPTM 4200 Sulfate or DOWEXTM 21K XLT Sulfate resins). See for example: M. J. Hatch, J. A. Dillon, Acid Retardation. Simple Physical Method for Separation of Strong Acids from Their Salts, Ind. Eng. Chem. Process Des. Dev., 1963, 2 (4), pp 253-263.
• the acid removal unit (14) may include an engineered membrane system as described in Nystrom et al, MEMBRANE
• the iron or copper removal unit (18) is not particularly limited and preferably includes an ion exchange resin, chelating resin or adsorbent that is selective for the metal or impurity of interest but is relatively non-selective for nickel.
• the unit (18) may include a mixed bed of copper and iron selective resin such as AMBERLITE 747 or DIPHONIXTM resins.
• the system operates according to a method characterized by the integration of CIX and electro-winning unit operations into a single continuous process with cost effective recycling of nickel-depleted raffinate (28) and optionally, acid (32). More specifically, the subject method includes the sequential steps of:
• step (e) combining at least a portion of the nickel-depleted raffinate (28) with PLS (13) and repeating steps (a) through (d).
• step (c) further includes the step of removing a portion of at least one of copper and iron (18) from the effluent (20), such as by way of ion exchange, chelation or adsorption.

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• Engineering & Computer Science (AREA)
• Chemical & Material Sciences (AREA)
• Mechanical Engineering (AREA)
• Manufacturing & Machinery (AREA)
• Materials Engineering (AREA)
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• Organic Chemistry (AREA)
• Geochemistry & Mineralogy (AREA)
• Geology (AREA)
• General Life Sciences & Earth Sciences (AREA)
• Environmental & Geological Engineering (AREA)
• Life Sciences & Earth Sciences (AREA)
• Manufacture And Refinement Of Metals (AREA)
• Treatment Of Water By Ion Exchange (AREA)

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Cited By (2)

Citations (4)

• 2013
  • 2013-07-30 WO PCT/US2013/052608 patent/WO2014025568A1/fr not_active Ceased

Patent Citations (4)

Non-Patent Citations (2)

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