Current Developments in the Hydrometallurgical Treatment of ...
Current Developments in the Hydrometallurgical Treatment of ...
Current Developments in the Hydrometallurgical Treatment of ...
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<strong>Current</strong> <strong>Developments</strong> <strong>in</strong> <strong>the</strong> <strong>Hydrometallurgical</strong><strong>Treatment</strong> <strong>of</strong> Copper Ores and ConcentratesThe <strong>Hydrometallurgical</strong><strong>Treatment</strong> <strong>of</strong> Copper ConcentratesDavid Dreis<strong>in</strong>gerUniversity <strong>of</strong> British ColumbiaVancouver, Canada
<strong>Current</strong> <strong>Developments</strong> <strong>in</strong> <strong>the</strong> <strong>Hydrometallurgical</strong><strong>Treatment</strong> <strong>of</strong> Copper Ores and ConcentratesCopper Ore/Concentrate <strong>Treatment</strong>‣Focus on Sulfate Processes‣Variety <strong>of</strong> Process Options Available‣Key Factors– Copper Leach Extraction– Iron Precipitation– Precious Metal Recovery– Sulfur Deportment– Cost!
<strong>Current</strong> <strong>Developments</strong> <strong>in</strong> <strong>the</strong> <strong>Hydrometallurgical</strong><strong>Treatment</strong> <strong>of</strong> Copper Ores and ConcentratesProcess Options‣Copper Leach<strong>in</strong>g Issues;– Copper leach<strong>in</strong>g controlled by copperm<strong>in</strong>eral leach k<strong>in</strong>etics– Chalcopyrite passivates under mildconditions– Liquid sulfur wets unreacted m<strong>in</strong>erals andstops leach<strong>in</strong>g
<strong>Current</strong> <strong>Developments</strong> <strong>in</strong> <strong>the</strong> <strong>Hydrometallurgical</strong><strong>Treatment</strong> <strong>of</strong> Copper Ores and ConcentratesChalcopyrite Passivation‣Eh – pH Diagram Shows Many Phasesbetween CuFeS 2 (solid) andCuSO 4 (aqueous)‣Chalcopyrite Passivates by an Iron-Deficient Copper Sulfide (CuS n ) <strong>in</strong>Sulfate Based Leach<strong>in</strong>g Processes
<strong>Current</strong> <strong>Developments</strong> <strong>in</strong> <strong>the</strong> <strong>Hydrometallurgical</strong><strong>Treatment</strong> <strong>of</strong> Copper Ores and ConcentratesCu-Fe-S-H 2 O Diagram
<strong>Current</strong> <strong>Developments</strong> <strong>in</strong> <strong>the</strong> <strong>Hydrometallurgical</strong><strong>Treatment</strong> <strong>of</strong> Copper Ores and ConcentratesChalcopyrite Oxidation and SulfurElemental Sulfur Reaction Product4CuFeS 2 + 5O 2 (g) + 10H 2 SO 4 =4CuSO 4 + 2Fe 2 (SO 4 ) 3 + 10H 2 O + 20S(0.63 t O 2 /t Cu leached)Sulfate Sulfur Reaction Product4CuFeS 2 + 15O 2 (g) + 2H 2 O =4CuSO 4 + 2Fe 2 (SO 4 ) 3 + 2H 2 SO 4(1.89 t O 2 /t Cu leached)
<strong>Current</strong> <strong>Developments</strong> <strong>in</strong> <strong>the</strong> <strong>Hydrometallurgical</strong><strong>Treatment</strong> <strong>of</strong> Copper Ores and ConcentratesSulfur Chemistry‣Sulfur is formed from sulfide m<strong>in</strong>eralsdur<strong>in</strong>g leach<strong>in</strong>g‣Three temperature regimes‣Low T: < 119.3 C – SOLID (S 8 )‣Medium T: 119.3 C to 159 C – LIQUID(S 8 )‣High T: +159 C – LIQUID/POLYMER (S n )
<strong>Current</strong> <strong>Developments</strong> <strong>in</strong> <strong>the</strong> <strong>Hydrometallurgical</strong><strong>Treatment</strong> <strong>of</strong> Copper Ores and ConcentratesLOW T Leach<strong>in</strong>g‣Elemental sulfur forms porous productlayer‣K<strong>in</strong>etics can be slow due to diffusionthrough sulfur product layer
<strong>Current</strong> <strong>Developments</strong> <strong>in</strong> <strong>the</strong> <strong>Hydrometallurgical</strong><strong>Treatment</strong> <strong>of</strong> Copper Ores and ConcentratesMedium Temperature Leach<strong>in</strong>g‣Molten sulfur is dispersed by addition <strong>of</strong>a sulfur dispersant/surface active agent‣Lign<strong>in</strong> sulfonate and Quebracho are twocommon agents.‣Sulfide m<strong>in</strong>eral becomes sulfophobicand hydrophilic‣Sulfur liquid droplets are dispersed
<strong>Current</strong> <strong>Developments</strong> <strong>in</strong> <strong>the</strong> <strong>Hydrometallurgical</strong><strong>Treatment</strong> <strong>of</strong> Copper Ores and ConcentratesApparatus for <strong>in</strong>terfacial measurementPressure gaugeGas <strong>in</strong>letPlungerOutlet for gas bleed<strong>in</strong>gGlass tipLiquorsulfurScrew-drive syr<strong>in</strong>geThermowellSta<strong>in</strong>less steel bombGlass tipOpticalglass cellM<strong>in</strong>eralsampleAdjustable holderLightsourceLensSapphirew<strong>in</strong>dowOpticalglass cellAdjustableholderSapphirew<strong>in</strong>dowLensLensDigitalcamera
<strong>Current</strong> <strong>Developments</strong> <strong>in</strong> <strong>the</strong> <strong>Hydrometallurgical</strong><strong>Treatment</strong> <strong>of</strong> Copper Ores and ConcentratesSulfur Droplets <strong>in</strong> Acid Solution (150 C)0.05 g/L lign<strong>in</strong> sulfonate 0.1 g/L lign<strong>in</strong> sulfonate0.5 g/L lign<strong>in</strong> sulfonateSurfactant-free0.05 g/L Quebracho0.1 g/L Quebracho 0.5 g/L Quebracho
<strong>Current</strong> <strong>Developments</strong> <strong>in</strong> <strong>the</strong> <strong>Hydrometallurgical</strong><strong>Treatment</strong> <strong>of</strong> Copper Ores and ConcentratesCalculated Sulfur/AqueousInterfacial Tensions (γ SA )Concentration / g L -1 0 0.05 0.1 0.2 0.3 0.4 0.5Lign<strong>in</strong> sulfonate / mN m -1 55 43 35 31 29 29 29Quebracho / mN m -1 55 45 38 37 37 37 37
<strong>Current</strong> <strong>Developments</strong> <strong>in</strong> <strong>the</strong> <strong>Hydrometallurgical</strong><strong>Treatment</strong> <strong>of</strong> Copper Ores and ConcentratesSulfur Droplets <strong>in</strong> Acid Solution onChalcopyrite M<strong>in</strong>eral Surface (150 °C)0.05 g/L lign<strong>in</strong> sul<strong>of</strong>nate 0.1 g/L lign<strong>in</strong> sul<strong>of</strong>nate 0.5 g/L lign<strong>in</strong> sul<strong>of</strong>nateSurfactant-free0.05 g/L Quebracho 0.1 g/L Quebracho0.5 g/L Quebracho
<strong>Current</strong> <strong>Developments</strong> <strong>in</strong> <strong>the</strong> <strong>Hydrometallurgical</strong><strong>Treatment</strong> <strong>of</strong> Copper Ores and ConcentratesContact Angles (Θ)Concentration / g L -1 0 0.05 0.1 0.2 0.3 0.4 0.5Lign<strong>in</strong> sulfonate / 76 142 152 155 156 157 158Quebracho / 76 155 157 158 159 160 161Wa = γ SA (1+cos(Θ))Work <strong>of</strong> Adhesion (Wa)Concentration / g L -1 0 0.05 0.1 0.2 0.3 0.4 0.5Lign<strong>in</strong> sulfonate / mJm -2 68.3 9.1 4.1 2.9 2.5 2.3 1.9Quebracho / mJ m -2 68.3 4.3 3.0 2.7 2.4 2.2 2.0
<strong>Current</strong> <strong>Developments</strong> <strong>in</strong> <strong>the</strong> <strong>Hydrometallurgical</strong><strong>Treatment</strong> <strong>of</strong> Copper Ores and ConcentratesIron Precipitation‣ Dissolved iron will be oxidized andprecipitated as ferric hydroxide (undesirable),jarosite, goethite or hematite‣ Goethite forms at less than 140 C withhematite form<strong>in</strong>g above 140 C‣ Jarosite can form over wide temperaturerange‣ Basic ferric sulfate processes (Sepon)precipitate iron at high free acid and high T(220 C). Iron forms basic ferric sulfateswhich <strong>the</strong>n re-dissolve at atmospheric T+P.
<strong>Current</strong> <strong>Developments</strong> <strong>in</strong> <strong>the</strong> <strong>Hydrometallurgical</strong><strong>Treatment</strong> <strong>of</strong> Copper Ores and ConcentratesPrecious Metal Recovery‣ Au may be recovered by cyanidation <strong>of</strong> copper leachresidues.‣ However if S present <strong>the</strong>n form SCN and <strong>in</strong>crease<strong>the</strong> cost <strong>of</strong> Au recovery.‣ Ag <strong>of</strong>ten forms Ag-jarosite under copper leach<strong>in</strong>gconditions. May have to use lime boil to decomposeAg-jarosite prior to cyanidation.‣ Alternative strategy to use o<strong>the</strong>r reagents (eg. S 2 O 32-,SCN - or Cl - /Br - )‣ PGM Recoveries difficult from residues but possibledirectly (PLATSOL)
<strong>Current</strong> <strong>Developments</strong> <strong>in</strong> <strong>the</strong> <strong>Hydrometallurgical</strong><strong>Treatment</strong> <strong>of</strong> Copper Ores and ConcentratesS Deportment and Impurities‣ S oxidation forms sulfuric acid‣ Sulfuric acid may be a by-product as a weaksulfuric acid solution (economic credit)‣ Sulfuric acid neutralization consumeslimestone or lime (expense).‣ Impurities are generally removed byoxidation/pH adjustment as part <strong>of</strong> <strong>the</strong> leachor iron residue.
<strong>Current</strong> <strong>Developments</strong> <strong>in</strong> <strong>the</strong> <strong>Hydrometallurgical</strong><strong>Treatment</strong> <strong>of</strong> Copper Ores and ConcentratesProcess Examples‣GALVANOX‣Anglo American Corporation/University<strong>of</strong> British Columbia Process‣PLATSOL‣SEPON Copper Process
<strong>Current</strong> <strong>Developments</strong> <strong>in</strong> <strong>the</strong> <strong>Hydrometallurgical</strong><strong>Treatment</strong> <strong>of</strong> Copper Ores and ConcentratesGALVANOX‣Process developed by David Dixon andAla<strong>in</strong> Tshilombo <strong>of</strong> University <strong>of</strong> BritishColumbia‣Atmospheric leach<strong>in</strong>g <strong>of</strong> chalcopyriteconcentrates under mild, “galvanic”conditions to avoid passivation‣Follow<strong>in</strong>g slides from David Dixon
<strong>Current</strong> <strong>Developments</strong> <strong>in</strong> <strong>the</strong> <strong>Hydrometallurgical</strong><strong>Treatment</strong> <strong>of</strong> Copper Ores and Concentrates‣ Atmospheric Leach (~80 C)‣ No microbes‣ Pure sulphate medium (no chloride)‣ No f<strong>in</strong>e gr<strong>in</strong>d<strong>in</strong>g‣ Generates elemental sulfur (> 95%), low oxygen demand‣ No surfactantsGALVANOX FEATURES‣ Selective for chalcopyrite over pyrite (can cost-effectively treat lowgrade concentrates down to 9% copper or less)‣ Complete copper recovery, typically <strong>in</strong> less than 12 hours, andsometimes <strong>in</strong> as little as 4 hours‣ Fully compatible with conventional SX-EW‣ Conventional materials <strong>of</strong> construction
<strong>Current</strong> <strong>Developments</strong> <strong>in</strong> <strong>the</strong> <strong>Hydrometallurgical</strong><strong>Treatment</strong> <strong>of</strong> Copper Ores and Concentrates
<strong>Current</strong> <strong>Developments</strong> <strong>in</strong> <strong>the</strong> <strong>Hydrometallurgical</strong><strong>Treatment</strong> <strong>of</strong> Copper Ores and ConcentratesGALVANOX CHEMISTRY‣ GALVANOX takes advantage <strong>of</strong> <strong>the</strong> galvanic effect betweenchalcopyrite and pyrite.‣ Chalcopyrite is a semiconductor, and <strong>the</strong>refore corrodeselectrochemically <strong>in</strong> oxidiz<strong>in</strong>g solutions.‣ In ferric sulphate media, <strong>the</strong> overall leach<strong>in</strong>g reaction is as follows:CuFeS 2 + 2 Fe 2 (SO 4 ) 3 → CuSO 4 + 5 FeSO 4 + 2 S 0‣ This reaction may be represented as a comb<strong>in</strong>ation <strong>of</strong> anodic andcathodic half-cell reactions:Anodic: CuFeS 2 → Cu 2+ + Fe 2+ + 2 S 0 + 4 e –Cathodic: 4 Fe 3+ + 4 e – → 4 Fe 2+
<strong>Current</strong> <strong>Developments</strong> <strong>in</strong> <strong>the</strong> <strong>Hydrometallurgical</strong><strong>Treatment</strong> <strong>of</strong> Copper Ores and ConcentratesUNASSISTED CHALCOPYRITE LEACHINGSoCu2+4 e-4 Fe3+Fe2+CuFeS24 Fe2+Anodic SiteCathodic Site
<strong>Current</strong> <strong>Developments</strong> <strong>in</strong> <strong>the</strong> <strong>Hydrometallurgical</strong><strong>Treatment</strong> <strong>of</strong> Copper Ores and ConcentratesUNASSISTED CHALCOPYRITE LEACHING
<strong>Current</strong> <strong>Developments</strong> <strong>in</strong> <strong>the</strong> <strong>Hydrometallurgical</strong><strong>Treatment</strong> <strong>of</strong> Copper Ores and ConcentratesGALVANOX CHEMISTRY‣ Typically, chalcopyrite surfaces are passivated (i.e., <strong>the</strong>ybecome resistant to electrochemical breakdown) <strong>in</strong> ferric sulfatesolutions at even modest solution potential levels.‣ It is widely held that this results from <strong>the</strong> formation <strong>of</strong> some sort<strong>of</strong> passivat<strong>in</strong>g film on <strong>the</strong> m<strong>in</strong>eral surface that most likelyconsists <strong>of</strong> an altered, partially Fe-depleted sulfide layer.‣ Because <strong>of</strong> this, most <strong>in</strong>vestigators have assumed that it is <strong>the</strong>anodic half-cell reaction that limits <strong>the</strong> overall rate <strong>of</strong> leach<strong>in</strong>g.‣ However, we discovered that it is primarily <strong>the</strong> cathodic half-cellreaction (i.e., ferric reduction) that is slow on <strong>the</strong> chalcopyritesurface.
<strong>Current</strong> <strong>Developments</strong> <strong>in</strong> <strong>the</strong> <strong>Hydrometallurgical</strong><strong>Treatment</strong> <strong>of</strong> Copper Ores and ConcentratesGALVANOX CHEMISTRY‣ The presence <strong>of</strong> pyrite facilitates chalcopyrite leach<strong>in</strong>g byprovid<strong>in</strong>g an alternative catalytic surface for ferric reduction <strong>in</strong>electrical contact with <strong>the</strong> chalcopyrite‣ This essentially elim<strong>in</strong>ates cathodic passivation <strong>of</strong> chalcopyrite <strong>in</strong>ferric sulfate solutions.‣ Also, by ensur<strong>in</strong>g that chalcopyrite oxidation is rapid relative t<strong>of</strong>errous oxidation, <strong>the</strong> solution potential is ma<strong>in</strong>ta<strong>in</strong>ed at a levellow enough to prevent anodic passivation <strong>of</strong> <strong>the</strong> chalcopyrite‣ This also prevents anodic breakdown <strong>of</strong> <strong>the</strong> pyrite, whichrema<strong>in</strong>s more or less completely <strong>in</strong>ert.
<strong>Current</strong> <strong>Developments</strong> <strong>in</strong> <strong>the</strong> <strong>Hydrometallurgical</strong><strong>Treatment</strong> <strong>of</strong> Copper Ores and ConcentratesGALVANICALLY-ASSISTEDCHALCOPYRITE LEACHINGCu2+PyCp4 Fe3+4 e-4 e -4 Fe 2+Fe 2+Anodic SiteSoPyCathodic Site
<strong>Current</strong> <strong>Developments</strong> <strong>in</strong> <strong>the</strong> <strong>Hydrometallurgical</strong><strong>Treatment</strong> <strong>of</strong> Copper Ores and ConcentratesGALVANICALLY-ASSISTEDCHALCOPYRITE LEACHINGPartially leached particleCompletely leached particles
<strong>Current</strong> <strong>Developments</strong> <strong>in</strong> <strong>the</strong> <strong>Hydrometallurgical</strong><strong>Treatment</strong> <strong>of</strong> Copper Ores and ConcentratesGALVANOX CHEMISTRY‣ The ferric required for GALVANOX leach<strong>in</strong>g is regenerated <strong>in</strong> situ withoxygen gasFerric leach<strong>in</strong>g <strong>of</strong> chalcopyrite:CuFeS 2 + 2 Fe 2 (SO 4 ) 3 → CuSO 4 + 5 FeSO 4 + 2 S 0Oxidation <strong>of</strong> ferrous with dissolved oxygen gas:4 FeSO 4 + O 2 + 2 H 2 SO 4 → 2 Fe 2 (SO 4 ) 3 + 2 H 2 OOverall leach<strong>in</strong>g reaction:CuFeS 2 + O 2 + 2 H 2 SO 4 → CuSO 4 + FeSO 4 + 2 S 0 + 2 H 2 O
<strong>Current</strong> <strong>Developments</strong> <strong>in</strong> <strong>the</strong> <strong>Hydrometallurgical</strong><strong>Treatment</strong> <strong>of</strong> Copper Ores and ConcentratesCu RecoveryCHALCOPYRITE CONCENTRATE – 35% CuEffect <strong>of</strong> pyrite addition (50 g con, 65 g acid, 470 mV, 80 C)100%90%80%70%60%50%40%30%20%10%0%0 4 8 12 16 20 24Time (h)Py = 150 g (K5)Py = 100 g (K9)Py = 50 g (K6)Py = 25 g (K10)Py = 0 g (K1)
<strong>Current</strong> <strong>Developments</strong> <strong>in</strong> <strong>the</strong> <strong>Hydrometallurgical</strong><strong>Treatment</strong> <strong>of</strong> Copper Ores and ConcentratesCu RecoveryCHALCOPYRITE CONC 2 – 23.6% CuEffect <strong>of</strong> pyrite addition (30 g con, 120 g Py, 30 g acid, 480 mV, 80 C)100%90%80%70%60%50%40%30%20%10%0%Galvanox Leach<strong>in</strong>gNo Pyrite0 4 8 12 16 20 24Time (h)
<strong>Current</strong> <strong>Developments</strong> <strong>in</strong> <strong>the</strong> <strong>Hydrometallurgical</strong><strong>Treatment</strong> <strong>of</strong> Copper Ores and Concentrates
<strong>Current</strong> <strong>Developments</strong> <strong>in</strong> <strong>the</strong> <strong>Hydrometallurgical</strong><strong>Treatment</strong> <strong>of</strong> Copper Ores and ConcentratesCONTINUOUS PILOT PLANT RESULTSStageOperat<strong>in</strong>gHoursM<strong>in</strong>imum CuRecovery (%)Maximum Curecovery (%)Average CuRecovery (%)Plant Setup 0 -125 56.8 93.4 82.1100% Recycle40 hrsresidence time100% Recycle20 hrsresidence time200% Recycle20 hrsresidence timeEntire runexclud<strong>in</strong>g plantsetup125-325 92.7 97.1 95.3325-405 88.4 95.4 91.6405-464 96.6 97.9 97.3125-464 88.4 97.9 94.6
<strong>Current</strong> <strong>Developments</strong> <strong>in</strong> <strong>the</strong> <strong>Hydrometallurgical</strong><strong>Treatment</strong> <strong>of</strong> Copper Ores and ConcentratesAnglo American Corporation/University <strong>of</strong>British Columbia Process‣Chalcopyrite concentrates are f<strong>in</strong>elyground (
<strong>Current</strong> <strong>Developments</strong> <strong>in</strong> <strong>the</strong> <strong>Hydrometallurgical</strong><strong>Treatment</strong> <strong>of</strong> Copper Ores and ConcentratesCopper Extraction as a Function <strong>of</strong> Initial Particle Size150 C Leach<strong>in</strong>g <strong>of</strong> Chalcopyrite Concentrate with Surfactant AdditionCopper Extraction (%)100.0095.0090.0085.0080.0075.0070.00F<strong>in</strong>er Size5.28 um10.01 um13.04 um17.93 um65.0060.0055.0050.000 0.5 1 1.5 2 2.5 3 3.5 4Tim e (hr)
<strong>Current</strong> <strong>Developments</strong> <strong>in</strong> <strong>the</strong> <strong>Hydrometallurgical</strong><strong>Treatment</strong> <strong>of</strong> Copper Ores and ConcentratesFreeport-McMoRan <strong>Developments</strong> <strong>in</strong>Copper Concentrate Leach<strong>in</strong>g‣ John O. Marsden and John C. Wilmot‣ Freeport-McMoRan M<strong>in</strong><strong>in</strong>g Co.‣ Selected Slides from Copper 2007 Short Course,Toronto, August 2007
<strong>Current</strong> <strong>Developments</strong> <strong>in</strong> <strong>the</strong> <strong>Hydrometallurgical</strong><strong>Treatment</strong> <strong>of</strong> Copper Ores and ConcentratesMorenci “MT-DEW-SX” FlowsheetConcentrate1,000 mtpdPLV Conditions:~160 C200 psi O 2 overpressureLE Added to PLVWaterSlurryFormationSuper F<strong>in</strong>eGr<strong>in</strong>d<strong>in</strong>gPressureLeach<strong>in</strong>gLeanto PLV24331901.8Heap/Stockpile/Tank*Leach<strong>in</strong>gLeanBleedFeedFlashLet DownCoolantStreamsSolutionExtractionWaterLimeSolid/LiquidSeparationSolidsSolid/LiquidSeparation/WashSolids113110221.9SPLSWPLSElectrow<strong>in</strong>n<strong>in</strong>g1534.71.51.1Precious MetalsLeach<strong>in</strong>g/RecoveryGold/SilverBullion(optional)NeutralizationTail<strong>in</strong>gsDisposalLEGEND:Flow (m3/hr)Cu (g/L)H2SO4 (g/L)Fe (gpl)*Tank <strong>in</strong>cludes vat or agitatedor stirred leach<strong>in</strong>g vesselCathodeCopper
<strong>Current</strong> <strong>Developments</strong> <strong>in</strong> <strong>the</strong> <strong>Hydrometallurgical</strong><strong>Treatment</strong> <strong>of</strong> Copper Ores and ConcentratesMorenci Concentrate Leach Plant
<strong>Current</strong> <strong>Developments</strong> <strong>in</strong> <strong>the</strong> <strong>Hydrometallurgical</strong><strong>Treatment</strong> <strong>of</strong> Copper Ores and ConcentratesPLATSOL‣ PLATSOL Process– Simple process for one-step dissolution <strong>of</strong> baseand precious metals– Add 5-10 g/L Chloride to AC solution– Invented at Lakefield Research for BulkConcentrate <strong>Treatment</strong>– Tested via Batch and Cont<strong>in</strong>uous AutoclavePrograms at Lakefield– High levels <strong>of</strong> base (+95-99%) and preciousmetals (90-95%) recovery
<strong>Current</strong> <strong>Developments</strong> <strong>in</strong> <strong>the</strong> <strong>Hydrometallurgical</strong><strong>Treatment</strong> <strong>of</strong> Copper Ores and ConcentratesPressure Oxidation: Conventional andPLATSOL Metal Extractions (220 C)Element Conventional PLATSOL**Cu 99.3 99.6Ni 95.9 98.9Co >92 96Fe 11.5 11.5S 91.5 91.5Pt ~0 96Pd 61.1 94.6Au ~0 89.4** ACTUAL PILOT PLANT RESULTS FROM SGS LAKEFIELD
<strong>Current</strong> <strong>Developments</strong> <strong>in</strong> <strong>the</strong> <strong>Hydrometallurgical</strong><strong>Treatment</strong> <strong>of</strong> Copper Ores and ConcentratesAutoclave Leach<strong>in</strong>g Base MetalsChloride – Assisted Total Pressure OxidationChalcopyrite Oxidation/Iron Hydrolysis:CuFeS 2 + 4.25O 2 + H 2 O = CuSO 4 + 0.5Fe 2 O 3 +H 2 SO 4Pyrite Oxidation:FeS 2 + 3.75O 2 + 2H 2 O = 0.5Fe 2 O 3 + 2H 2 SO 4Pyrrhotite OxidationFe 7 S 8 + 16.25O 2 + 8H 2 O = 3.5Fe 2 O 3 + 8H 2 SO 4Nickel Sulfide Oxidation:NiS + 2O 2 = NiSO 4Basic Ferric Sulfate Formation:Fe O + 2H SO = 2Fe(OH)SO + H O
<strong>Current</strong> <strong>Developments</strong> <strong>in</strong> <strong>the</strong> <strong>Hydrometallurgical</strong><strong>Treatment</strong> <strong>of</strong> Copper Ores and ConcentratesAutoclave Leach<strong>in</strong>g Precious MetalsGold Oxidation/Chlorocomplex Formation:Au + 0.75O 2 + 4HCl = HAuCl 4 + 1.5H 2 OPlat<strong>in</strong>um Oxidation/ChlorocomplexFormation:Pt + O 2 + 6HCl = H 2 PtCl 6 + 2H 2 OPalladium Oxidation/ChlorocomplexFormation:Pd + 0.5O 2 + 4HCl = H 2 PdCl 4 + H 2 OTemperature <strong>of</strong> 220 to 230 C.
<strong>Current</strong> <strong>Developments</strong> <strong>in</strong> <strong>the</strong> <strong>Hydrometallurgical</strong><strong>Treatment</strong> <strong>of</strong> Copper Ores and ConcentratesBase and Precious Metal Recovery‣ Copper– Copper Solvent Extraction and Electrow<strong>in</strong>n<strong>in</strong>g toProduce LME Grade Copper Metal Cathode‣ Nickel/Cobalt– Variety <strong>of</strong> Processes Possible– Mixed Hydroxide Precipitation <strong>of</strong> Nickel and Cobalt– Nickel and Cobalt Hydroxide Ref<strong>in</strong>ed “Off Site”– SX-EW or SX-Hydrogen Reduction to Metal‣ Au-PGM– Precipitate under reduc<strong>in</strong>g conditions to make highvalue precipitate for ref<strong>in</strong><strong>in</strong>g
<strong>Current</strong> <strong>Developments</strong> <strong>in</strong> <strong>the</strong> <strong>Hydrometallurgical</strong><strong>Treatment</strong> <strong>of</strong> Copper Ores and ConcentratesBulk ConcentrateRegr<strong>in</strong>d<strong>in</strong>gPLATSOL ®NaClLSLeach ResiduePGM’s NaSH PrecipPGM ConcCu SX/EWBleed(Ni-Co recovery)
<strong>Current</strong> <strong>Developments</strong> <strong>in</strong> <strong>the</strong> <strong>Hydrometallurgical</strong><strong>Treatment</strong> <strong>of</strong> Copper Ores and ConcentratesApplications to O<strong>the</strong>rCu/Ni/PGM ConcentratesConcentrate TypesElementsD F G H I J K L MCu % 5.8 12.0 4.2 2.4 5.5 3.9 0.9 0.2 0.7Ni% 4.1 3.01 7.7 0.9 10.3 14.9 0.1 0.1 0.3Fe% 17.1 33.9 35.9 19.2 - 27.9 32.7 16.6 28.7S% 16.3 24.5 34.1 - 25.3 28.8 0.8 0.5
<strong>Current</strong> <strong>Developments</strong> <strong>in</strong> <strong>the</strong> <strong>Hydrometallurgical</strong><strong>Treatment</strong> <strong>of</strong> Copper Ores and ConcentratesApplications to O<strong>the</strong>rCu/Ni/PGM ConcentratesElements% RecoveryConcentrate TypeD F G H I J K L MCu 99.9 99.3 99.0 99.3 99.7 99.6 99.3 85.0 99.2Ni 99 93.8 99.6 98.7 98.9 98.7 96.7 - 95.5Au 99 97.1 84.3 96.0 97.9 82.9 91.5 96.4 53.6Pt 95 97.4 98.2 99.0 97.9 93.9 93.9 99.1 95.3Pd 94 98.1 93.9 98.4 96.2 95.6 94.9 96.3 96.3
<strong>Current</strong> <strong>Developments</strong> <strong>in</strong> <strong>the</strong> <strong>Hydrometallurgical</strong><strong>Treatment</strong> <strong>of</strong> Copper Ores and ConcentratesApplications to O<strong>the</strong>r Feeds‣Cu/Au concentrates‣Refractory Au Concentrates‣Cu/Ni/PGE mattes‣Pt Laterites‣Automobile catalysts
<strong>Current</strong> <strong>Developments</strong> <strong>in</strong> <strong>the</strong> <strong>Hydrometallurgical</strong><strong>Treatment</strong> <strong>of</strong> Copper Ores and ConcentratesO<strong>the</strong>r ApplicationsCu - Au concentrate(28.9% Cu,5.8 g/t Au)‣ PLATSOL TMrecovery99.7% Cu95.9% Au‣ No cyanide!
<strong>Current</strong> <strong>Developments</strong> <strong>in</strong> <strong>the</strong> <strong>Hydrometallurgical</strong><strong>Treatment</strong> <strong>of</strong> Copper Ores and ConcentratesO<strong>the</strong>r ApplicationsRefractory Au ores-concentrates(non-pregrobbers)FeS 2 - FeAsS conc19.9 Au, 19.4 g/t Ag‣ PLATSOL TM recoveryAu 96%, Ag 99.5%‣ No cyanide!
<strong>Current</strong> <strong>Developments</strong> <strong>in</strong> <strong>the</strong> <strong>Hydrometallurgical</strong><strong>Treatment</strong> <strong>of</strong> Copper Ores and ConcentratesSEPON Copper Process‣ Atmospheric leach<strong>in</strong>g process for whole oreto leach copper oxides/carbonates/secondary sulfides‣ After CCD wash, pyrite and sulfur are floatedas a concentrate and sent to a hightemperature autoclave for oxidation.‣ Autoclave is <strong>the</strong> “chemical eng<strong>in</strong>e” for <strong>the</strong>Sepon plant produc<strong>in</strong>g acid, ferric sulfate andheat to susta<strong>in</strong> <strong>the</strong> atmospheric leachprocess.
<strong>Current</strong> <strong>Developments</strong> <strong>in</strong> <strong>the</strong> <strong>Hydrometallurgical</strong><strong>Treatment</strong> <strong>of</strong> Copper Ores and ConcentratesAutoclave and Post-Autoclave ChemistryAutoclave formation <strong>of</strong> basic ferric sulfate (22O C)‣ 2FeS 2 (s) + 7.5O 2 + H 2 O = Fe 2 (SO 4 ) 3 + H 2 SO 4‣ S + 1.5O 2 + H 2 O = H 2 SO 4‣ Fe 2 (SO 4 ) 3 + 2H 2 O = 2Fe(OH)SO 4 (s) + H 2 SO 4Post Autoclave Re-Leach <strong>of</strong> Basic Ferric Sulfate(100 C)‣ 2Fe(OH)SO 4 (s) + H 2 SO 4 = Fe 2 (SO 4 ) 3 + 2H 2 O
<strong>Current</strong> <strong>Developments</strong> <strong>in</strong> <strong>the</strong> <strong>Hydrometallurgical</strong><strong>Treatment</strong> <strong>of</strong> Copper Ores and ConcentratesSEPONLOCALITYMAP
<strong>Current</strong> <strong>Developments</strong> <strong>in</strong> <strong>the</strong> <strong>Hydrometallurgical</strong><strong>Treatment</strong> <strong>of</strong> Copper Ores and ConcentratesCRUSHINGEXCESSPYRITEMILLINGWASHWATERPOX LEACHAUTOCLAVESTEAMSURGEDIRECT HEXSEPONPROCESS BLOCKFLOWSHEETFILTERFe AcidADDNSURGEATM LEACHSURGEHEXCOOLING TWRCLARIFICATIONSXEWRAF CCDWASH CCDWASHWATERCATHODEFLOTATIONWASH CCDFe AcidCu LOSSNEUTRALISATIONTAILINGS
<strong>Current</strong> <strong>Developments</strong> <strong>in</strong> <strong>the</strong> <strong>Hydrometallurgical</strong><strong>Treatment</strong> Next <strong>of</strong> Step Copper – ConstructionOres and ConcentratesExample: Sepon Copper and Gold OperationKhanong Copper OrebodyGold OperationPadan CampCopper Operation
<strong>Current</strong> <strong>Developments</strong> <strong>in</strong> <strong>the</strong> <strong>Hydrometallurgical</strong><strong>Treatment</strong> <strong>of</strong> Copper Ores and ConcentratesSepon Copper Ramp Up Plant designed for 60 ktpa Cu productionCommission<strong>in</strong>g commenced Oct 2004 Ore commission<strong>in</strong>g Feb 2005 First cathode harvested March 2005 2005 Production: 644kt milled, 30.5kt stripped 2006 Production: 1,231kt milled, 60.8kt stripped 2007 Production: 60-63kt Q1 2009 Second POX circuit on l<strong>in</strong>e
<strong>Current</strong> <strong>Developments</strong> <strong>in</strong> <strong>the</strong> <strong>Hydrometallurgical</strong><strong>Treatment</strong> <strong>of</strong> Copper Ores and ConcentratesConclusions‣ <strong>Hydrometallurgical</strong> <strong>Treatment</strong> <strong>of</strong> Copper Oresand Concentrates is Cont<strong>in</strong>u<strong>in</strong>g to Develop‣ New Chemistries and Process OptionsEmerg<strong>in</strong>g‣ Central use <strong>of</strong> SX-EW for Copper Recovery‣ Theory and Practice are Work<strong>in</strong>g toge<strong>the</strong>rHand-<strong>in</strong>-Hand
<strong>Current</strong> <strong>Developments</strong> <strong>in</strong> <strong>the</strong> <strong>Hydrometallurgical</strong><strong>Treatment</strong> <strong>of</strong> Copper Ores and ConcentratesThank You!Questions?
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