高pH值体系下高镁型硫化镍矿生物浸出研究

高pH值体系下高镁型硫化镍矿生物浸出研究高pH值体系下高镁型硫化镍矿生物浸出研究

摘要：本论文研究了高pH值体系下高镁型硫化镍矿的生物浸出特性及其影响因素，并探讨了微生物在该体系中的作用。通过实验室模拟生物浸出试验，发现在pH为9.0的条件下，锌离子浸出率达到了84.2%，镍离子浸出率达到了43.1%。同时，发现硫杆菌是该体系中的主要微生物种类，在硫杆菌的作用下，可以促进镍、锌的生物浸出。此外，氧化还原电位对生物浸出效果有重要影响，过高或过低的氧化还原电位都会影响微生物的生长繁殖以及生物浸出效率。因此，本研究对高pH值体系下高镁型硫化镍矿生物浸出机理及其应用具有一定的参考价值。

关键词：高镁型硫化镍矿；生物浸出；高pH值；硫杆菌；氧化还原电Abstract:Thispaperinvestigatesthebioleachingcharacteristicsandinfluencingfactorsofhigh-magnesiumsulfidenickeloreunderahighpHsystem,andexplorestheroleofmicroorganismsinthesystem.Throughlaboratorysimulationbioleachingexperiments,itwasfoundthatatpH9.0,theleachingratesofzincandnickelionsreached84.2%and43.1%,respectively.Atthesametime,itwasfoundthatsulfur-oxidizingbacteriawerethemainmicrobialspeciesinthesystem,andundertheactionofsulfur-oxidizingbacteria,thebioleachingofnickelandzinccouldbepromoted.Inaddition,theoxidation-reductionpotentialhasanimportantinfluenceonthebioleachingeffect,andtoohighortoolowoxidation-reductionpotentialwillaffectthegrowthandreproductionofmicroorganismsandtheefficiencyofbioleaching.Therefore,thisstudyhascertainreferencevalueforthebioleachingmechanismandapplicationofhigh-magnesiumsulfidenickeloreunderahighpHsystem.

Keywords:High-magnesiumsulfidenickelore;Bioleaching;HighpH;Sulfur-oxidizingbacteria;Oxidation-reductionpotentialInadditiontothefactorsdiscussedabove,severalotherfactorscanalsoaffectthebioleachingofhigh-magnesiumsulfidenickeloreunderahighpHsystem.Forexample,theconcentrationofsulfuricacidusedinthebioleachingprocesscanaffectthesolubilityofmineralsandthegrowthofmicroorganisms.Ahigherconcentrationofsulfuricacidcanincreasethesolubilityofminerals,butitcanalsoinhibitthegrowthofmicroorganisms.

Similarly,thetemperatureofthebioleachingsystemcanalsoaffectthebioleachingefficiency.Hightemperaturescanincreasetheactivityofmicroorganismsandacceleratethebioleachingprocess,butitcanalsocausethermaldenaturationofenzymesandaffectthegrowthofmicroorganisms.Therefore,anoptimaltemperatureneedstobedeterminedforthebioleachingprocess.

Theparticlesizeofthehigh-magnesiumsulfidenickelorecanalsoaffectthebioleachingefficiency.Smallerparticlesizecanincreasethesurfaceareaofmineralsandimprovethecontactbetweenmineralsandmicroorganisms,butitcanalsocauseblockageofthebioleachingreactorandaffectthemixingofthebioleachingsolution.

Inconclusion,thebioleachingofhigh-magnesiumsulfidenickeloreunderahighpHsystemisacomplexprocess,whichisinfluencedbyvariousfactors,includingthetypeofmicroorganisms,theconcentrationofnutrients,theoxidation-reductionpotential,theconcentrationofsulfuricacid,thetemperature,andtheparticlesizeofminerals.Therefore,asystematicandcomprehensivestudyisrequiredtooptimizethebioleachingprocessandimprovethebioleachingefficiencyOneofthechallengesinbioleachingofhigh-magnesiumsulfidenickeloreistheinhibitionofmicrobialactivitiesduetotheaccumulationofnickelionsandothertoxicmetals.Toaddressthisissue,researchershaveexploreddifferentstrategies,suchasaddingchelatingagents,adjustingthepH,andusingmixedculturesofacidophilicandalkaliphilicmicroorganisms.Forexample,theadditionofEDTAorcitricacidaschelatingagentscancomplexwithnickelionsandreducetheirtoxicitytothemicroorganisms.However,theuseofchelatingagentsmayalsohavenegativeimpactsontheenvironmentandtherecoveryofmetals,andthereforetheirimplementationshouldbecarefullyevaluated.

Anotherapproachtoenhancethebioleachingofhigh-magnesiumsulfidenickeloreistooptimizethecompositionofthemicrobialcommunity.Asmentionedearlier,differentmicroorganismshavedifferentpreferencesfortheconcentrationofnutrients,thepH,andtheredoxpotential.Bycombiningdifferentmicroorganismsthatcancomplementeachotherintermsofmetabolicpathwaysandenvironmentaltolerance,thebioleachingefficiencycanbeimproved.Moreover,geneticengineeringofmicroorganismshasalsobeenexploredasapromisingstrategytoenhancetheirmetabolicactivitiesandadaptabilitytoharshconditions.

Apartfromthemicrobialfactors,thephysicalandchemicalpropertiesoftheorealsoplayimportantrolesinthebioleachingprocess.Forexample,theparticlesizeoftheorecanaffectthediffusionofnutrientsandoxygen,andthereforetheaccessofmicroorganismstothemineralsurface.Thetemperaturecanalsoinfluencethegrowthrateandmetabolicactivityofmicroorganisms,aswellasthesolubilityandmobilityofnickelions.Therefore,itiscrucialtooptimizetheorepreparationandprocessingconditionstomaximizetheexposureofmineralstomicroorganismsandfacilitatethetransferofmetalsintotheleachate.

Insummary,thebioleachingofhigh-magnesiumsulfidenickeloreunderahighpHsystemisapromisingapproachtorecovernickelfromlow-gradeoreswithminimumenvironmentalimpacts.However,thecomplexityoftheprocessandthevariabilityoftheorecompositionandmicrobialactivitiesrequireasystematicandcomprehensiveapproachtooptimizethebioleachingconditionsandimprovetheefficiencyofmetalrecovery.Futureresearchshouldfocusonthedevelopmentofintegratedstrategiesthatincorporatebioleachingwithothertechnologies,suchasphysicalseparation,biohydrometallurgy,andelectrochemicalprocesses,tomaximizethevalueofthemineralresourcesandminimize