PDF Publication Title:
Text from PDF Page: 014
integrated Dredging and Processing of Alluvial Mineral Deposits Maria C. Rockwell Technical University of Nova Scotia Abstract Alluvialdeposits,commonlytermed"placers,"are a naturallyliberatedresourceof preciousmetals, gemstonesandso-calledblacksandscontainingheavymineralsuchasmagnetitei,lmenitec,hromite, zircon,monaziteandrutile.Theinlanddepositshavelongbeenthetargetof mininganddredgingoperations. Howeverw,iththesteadydepletionofpotentiallyeconomicresourcesm,oreeffortsarenowbeingapplied towardexploratioandexploitatiotenchniqueinsa marinenvironmeanbtovebeachdepositso!rjustbelow offshoredeposits!the currentsea level. Thispaperreviewsthegenericdepositionandcharacteristipcropertiesof alluvialmineraldeposits.It highlighttsheirrecoverytechniquesr,ecentechnologicadlevelopmenatsndintegratedmineradlredgingand processingpracticesina marinenvironmenAt.lsopresentedisaninsightintothedevelopmenptotentiaolf Nova Scotia offshore gold deposits. Characterization of Alluvial Minerals Thealluvialmineralsaretheproductofa complexweatheringanderosionprocessoftheoutcroppingrocks. Thenaturallyliberatedmineral-ricshedimenmt ayaccumulatneearthesourcerockor enterintoa dynamic systemofredistributiong,ravitysortinganddepositioninenvironmentalflayvorablesettingsC.oncentrations ofalluvialmineraisarefoundinvariousamountsalongtherivervalleys,beaches,dunes,inestuarybasins and in offshoredrownedsystemscoveredwith sediments,as well as depositedin bedrockcrevices,pits and fractures.Theconcentratedlayersof heavymineralsmayhavethicknessesof severalmiilimetersto several metersdependingonthedepositionvolumeanditscompositionS.incethealluviaml ineradl epositsvaryin degreeofisolations,ize,ageandcompositions,eparatestudiesarerequiredtoassesstheeconomicvalue andthefuturedevelopmenptotentiaolfeachdepositOduntan1,984;HaleandMcLaren1,984;Chaziteo- dorou, 1977!. Fromthecommercialinterestvalue,thealluvialdepositsareclassifiedintotwogroups: ! relativelylarge volumeandlowunitvaluecommodities,e,g,sandsandgravels,and ! lowgrade,highvaluecommodities, e.g.noblemetalsp, recioustonesandso-calledblacksandswithmagnetiteil,meniter,utilez, irconm, onazite, chromite,cassiterite,etc,Intheformergroupallormostofthevolumeminedisutilized,whereasinthelatter grouponlya smaflrlactioncontainintghevaluablemineralsisutilizedT.hislattergroupo,rtheplacerminerals, is considered in this paper. TheeconomicimportanceoftheplacermineralsisexemplifiedintheirmanyusesandapplicationsTable 1! forwhichtherearelimitedor nosubstitutesT.hevalueof zircon,rutileandscheelitehaveincreasedmore than1.5times,andgoldandplatinummorethan6 times,between1958and1980 GomesandMartinez, 1981!,Theparticlesizeoftheplacermineralsrangesfroma fewmicronsuptocoarsenuggetsandcrystals Macdonald1,983!.Themaincharacteiisticpropertiesof someplacermineralsis shownin Table2. The differenceisn particlesize,shape,specificgravity,magneticandelectricpropertiess,urfacewetabilityand otherphysicaplropertiesareemployedinmineraplrocessintgechniquetsoseparatethevaluableminerals from each other and from the gangue minerals. Dredge Mining and Developments TheexploitatioonfplacerdepositshaslongattractedtheinteresotfmininganddredgingoperatorsW.hen thesupplyofwaterissufficientd,redgeminingprovedtobemoreefficienthanotherminingsystems Woodsend,1984;IHC,1983!.Table3 presentsa comparisonbetweendredgeminingandotherplacer mining systems. Afterananuvialdeposithasbeenexploredandaneconomicappraisalhasbeenmade,the selectionof a dredgeminingsystemdependson the analysisof severalfactors,suchas: ! the geologicaland topographicaclharacteristicsofthedeposit,! thediggingconditionsandrestraintsofthemarineenviron- ment, ! the technologicalimitationof the dredgingsystem,PDF Image | Dredging Applications of High Density Polyethylene Pipe
PDF Search Title:
Dredging Applications of High Density Polyethylene PipeOriginal File Name Searched:
tamuw86005_part1.pdfDIY PDF Search: Google It | Yahoo | Bing
Development of a solar powered Electric Ship The Electricship website originally started off as a project to develop a comprehensive renewable, affordable, modular electric ship... More Info
Modular Boat Hull Composite The case for a unsinkable, modular composite hybrid boat hull... More Info
MS Burgenstock Hybrid Electric Catamaran Lake Lucerne Unique shuttle servicing Lucerne to the Burgenstock Resort... More Info
Ground Power Unit GPU Powered by Lithium Ion Batteries The goal of the Ground Power Unit is to provide a readily accessible, modular, ready-to-power solution for remote power... More Info
| CONTACT TEL: 608-238-6001 Email: greg@electricship.com | RSS | AMP |