LongonjoMagnetMetalsProject
MetallurgicalDesktopStudy
ASXRelease
23November2016
ASXcode:“RVY”
BoardofDirectors:
RiftValleyResourcesLimited(“RiftValley”or“Company”)(ASX:RVY)ispleasedto
announce the completion and positive outcome of the Metallurgical Desktop
StudyintotheLongonjoMagnetMetalsProjectinAngola.Thecompanyengaged
renowned rare earth metallurgist Mr Gavin Beer to develop the metallurgical
flowsheet and undertake a Metallurgical Desktop Study into the viability of the
company’s70%ownedLongonjoMagnetMetalsprojectinAngola.
Mr Stephen Dobson said “We are very pleased with the positive outcome of the
studyandareveryconfidentthatthedemandformagnetmetalswillcontinueto
grow.Wearenowplanningthenextstageofworkrecommendedfromthestudy
that encompasses building a financial model that takes into consideration
estimatedcapitalexpenditure.“
MrStephenDobson
Non-ExecChairman
GeoffGilmour
ManagingDirector
GregCunnold
TechnicalDirector
GraemeClatworthy
Non-ExecutiveDirector
AkramAziz
Non-ExecutiveDirector
HIGHLIGHTS
• Beneficiationtestworkproducedhighgradeconcentratesofup
to19.44%rareearthoxides(REO)
• Subsequent leach testwork on concentrates achieved >89%
extractions of the Magnet Metals neodymium and
praseodymium
• Ametallurgicalflowsheethasbeendevelopedutilisingproven
technologies of flotation and acid baking to produce a mixed
rareearthcarbonate(REC)product
• StrategicGovernmentpartnerFerrangolP&PSA
• Excellent accessibility to Road, Rail, Hydroelectric Power and
DeepSeaPort
Tel+61892210090
Fax+61892210095
• 75% In-situ value magnet metals neodymium and
praseodymium
ABN86121985395
• CapitalExpenditureEstimateandFinancialModeladvancing
ProjectDevelopment
Explorationandevaluationactivitiesundertakentodateincludes:
•
Geochemicalsamplingundertaken
•
Mappingofthe3.5kmx1.7kmGeochemicalAnomaly
•
RABDrillingconductedoveranominal500mx600marea
- MineralizationfromsurfacetoBladerefusal–Average35meters
•
TrenchingCompletedforBulkSampleMaterial
•
BeneficiationTestWork
- Concentrategradesofupto19.44%REOachieved
•
MetallurgicalTestWork
- HighValueNeodymiumandPraseodymiumrecoveries(4XheadGrade)
- Sulphuric Acid Bake and Water Leach Recovery Test Work achieved 89% Extraction of High
ValueNeodymiumandPraseodymium
•
DesktopStudy
- HighlyPositiveOutcome
MovingForward
AbouttheLongonjoMagnetMetalProject
TheLongonjoprospectislocatedwithintheOzangoProjectarea50kmwestoftheregionalcityofHuambo.Itis
located proximal to good infrastructure including roads, towns and recently recommissioned railway
infrastructurewhichlinkstothedeepwaterAtlanticportofLobito.
Figure1:locationofOzangoProjectcontainingLongonjoREEprospect
The Ozango Project consists of a single Exploration Licence (N°013/03/09/T.P/ANG-MGM/2015) that covers a
large area of 3,670 square kilometres. The property extends for 100 kilometres in an east-west direction and
variesbetween28to46kilometresinwidth.Thenortheastcornerofthepropertycomestowithin17kilometres
ofHuambo.
TheProjectareacoverssome3,670km2ofArchaean/Paleoproterozoicgreenstonerocksthathavebeenintruded
by Cretaceous felsic volcanics, carbonatites and kimberlites. These rocks are considered highly prospective for
REE,phosphate,copper,ironoreandgold.Todate,however,thisareahasseenverylittlemodernexploration.
The geology is typical of REE mines and prospects globally including Lynas Corp’s Mt Weld deposit in Western
AustraliaandPeakResources’NgualladepositinTanzaniaandsimilartoArfura’sNolansBoreProject.
Figure2CarbonatiteVent–NationalHighwaytoPort(300km)
MetallurgicalDrillingandTrenching
A soil geochemical sampling program undertaken at Longonjo over an area of 6km2 defined a large and robust
3.5km long and 1.7km wide +0.5% REO anomaly which remains open to the west. A follow up trenching and
pittingprogramcarriedouttotestthebedrockwithinthesoilanomalyreturnedhighlyencouragingresultsofup
to18.9%TREOfromthepitbedrocksamples.
First pass exploratory drilling conducted at the Company’s Longonjo prospect in 2014 (see ASX announcement
“Initial Metallurgical Results from Longonjo Prospect – 7th May 2014”) tested the centre of the geochemical
anomaly and returned high grade rare earth assays from every hole. From a total of 168 composite samples
generated during the campaign, the highest grade returned was 11.32%, the lowest 0.45%, with an average of
2.96%TREOoverallthesamples.
Thedistributionofthehighvalueneodymiumandpraseodymiumrareearthsinthemineralisationwasfound
tobesubstantial,accountingformorethan75%ofthein-situvalueasshowngraphicallyinFigure3.
Figure3–In-SituValueDistribution
(Source:MetalsPages–16thNovember2016)
NeodymiumandPraseodymiummetalsareessentialfortheproductionofhighstrengthpermanentmagnets.
They are used in wind turbines, MRI machines, electric motors, drones, mobile phones, computers and many
moretechnologyandindustryapplications.
Followingonfromtheseencouragingresults,asurfacetrenchsamplingprogram(seeFigure4)wasundertakento
provideasuitablesampleformetallurgicaltestwork.Theprogramprovidedacompositeofapproximately58kg
sampled from 4 to 6 metres in depth (below the top soil) along an 80 metre long trench. Analysis of the
homogenised trench sample returned a grade of 6.47% REO. Mineralogical examination confirmed the rare
earthstobeprimarilyhostedwithinmonazite.
Figure4:TrenchingatLongonjo
ScopeoftheStudy
ThecompanyengagedSpecialistMetallurgicalConsultant,MrGavinBeer,tointerpretpreviousmetallurgical
testworkandundertakeaMetallurgicalDesktopStudy(DesktopStudy).
Thestudyencompassed:
•
Interpretationoftheprevioustestworkundertaken.
•
Developmentandrecommendationofaprocessflowsheet.
•
Developapreliminarymassandenergybalance.
•
Developmentofthepreliminaryequipmentlist.
•
Determinemajorequipmentrequired.
MetallurgicalTestwork
Beneficiation testwork was undertaken on the trench composite sample (see ASX announcement
“MetallurgicalTestworkUpdateLongonjoProspect–27thAugust2015”)andsuccessfullydemonstratedthat
themineralizationcanbephysicallyupgradedproducingconcentrategradesofupto19.4%REO.
Abeneficiationprocess(Figure5)wassubsequentlydevelopedthatincorporatingthefollowingstages:
•
Crushingandgrinding.
•
De-sliming.
•
Flotation.
ROM Ore
Crushing
Milling
De-sliming
Slimes
Flotation
Tails
Combined Tailings
Concentrate
S
Drying
L
Recycle Water
Flotation
Concentrate
Figure5:Blockflowdiagramofthetestedbeneficiationflowsheet
Hydrometallurgicaltestworkwasundertakenonacompositeflotationconcentrateevaluatingvariousextraction
routes. As the rare earths are largely associated with refractory monazite minerals, a “cracking” process is
requiredinordertoextracttherareearths.Twocrackingprocessesweretested:
•
Asulphuricacidbakeatelevatedtemperaturesfollowedbywaterleaching.
•
Acausticconversionusinghotcausticsodafollowedbyhydrochloricacidleaching.
The results are summarised in Table 1 with respect to the dissolution, or “recovery”, of key rare earths and
gangueelementstotheleachsolution.
Table1:AcidBakeandCausticConversionResults
AcidBakeRoute
REO
(%)
83.7
CeO2
(%)
77.5
Nd2O3
(%)
89.1
CausticConversionRoute
64.1
27.5
90.1
LeachDissolution
Pr6O11
Fe2O3
(%)
(%)
89.0
14.7
90.0
76.4
U3O8
(%)
45.0
ThO2
(%)
39.5
70.2
56.8
Theacidbakeroutewasselectedforthefollowingreasons:
• AchievedgooddissolutionofthehighvalueNdandPrrareearths
• Lowerdissolutionofganguemetalssuchasiron,thoriumanduranium
• Lowerreagentconsumption
• Simpleandprovenflowsheetthathasbeendemonstratedcommercially
ThesimplifiedhydrometallurgicalrouteisshowninFigure6.
Flotation
Concentrate
Acid Baking
Rare Earth
Uranium
Precipitation
Removal
RE Carbonate
Dewatering
Off-site Resin
Treatment
Water Leach
Purification
Leach
Residue
Iron
Impurity
Rare Earth
Carbonate
Product
Figure6:Blockflowdiagramoftherecommendedhydrometallurgicalflowsheet
(testedstagesshaded)
TheoverallrecommendedflowsheetisshownpictoriallyinFigure7overleaf.
The proposed final product is a mixed rare earth carbonate that will be sold or toll treated at a third party
refinery.Thereisalsothepotentialtocreategreaterrevenueshouldthecompanydecidetobuildanextraction
facilitytoproduceseparatedrareearthoxidesonthebackoftheproposedhydrometallurgicalplant.
Figure7–OverallFlowsheet
CautionaryStatement
TheDesktopStudyreferredtointhisreportisbasedonhighleveltechnicalandeconomicassessments,andisinsufficientto
support estimation and economic assessments, and is insufficient to support estimation of Ore Reserves or to provide
assurance of an economic development case at this stage, or to provide certainty that the conclusion of the study will be
realised.
CompetentPersonStatement
TheexplorationresultscontainedwithinthisASXReleaseisbasedonandfairlyrepresentsinformationcompiledbyMrGreg
Cunnold who is a member of the Australian Institute of Mining and Metallurgy. Mr Cunnold is a director of Rift Valley
Resources Ltd and has consented in writing to the inclusion in this ASX Release of matter based on the information so
compiledbyhimintheformandcontextinwhichitappears.MrCunnoldhassufficientexperiencerelevanttothestyleof
mineralisationandtypeofdepositunderconsiderationtobequalifiedasaCompetentPersonasdefinedbythe2012Edition
ofthe“AustralianCodeforreportingofExplorationResults,MineralResourcesandOreReserves”.
TheinformationinthisreleasethatrelatestoMetallurgicalTest-workisbasedonandfairlyrepresentsinformationcompiled
and/orreviewedbyMrGavinBeerwhoisaMemberofTheAustralasianInstituteofMiningandMetallurgyandaChartered
Professional. Mr Beer is a Consulting Metallurgist and a full-time employee of Met-Chem Consulting Pty Ltd. Mr Beer has
sufficientexperiencerelevanttotheactivitywhichheisundertakingtoberecognisedascompetenttocompileandreport
suchinformation.MrBeerconsentstotheinclusioninthereportofthemattersbasedonhisinformationintheformand
contextinwhichitappears.
ForFurtherInformationContact:
MrStephenDobson (0414166560) MrGeoffGilmour
(0412155512)