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4th Graphite and Graphene Conf. page 1 © DORFNER Analysenzentrum und Anlagenplanungsgesellschaft mbH
Making the most of your graphite
by Dorfner ANZAPLAN GmbH, D-92242 Hirschau, Germany4th Graphite & Graphene Berlin, December 9th 2014
4th Graphite and Graphene Conf. page 2 © DORFNER Analysenzentrum und Anlagenplanungsgesellschaft mbH
COPYRIGHT/DISCLAIMER
The graphics, tables, diagrams and other contents of this presentation are protected by copyright law. © Dorfner Analysenzentrum und Anlagenplanungsgesellschaft GmbH. All rights reserved. Neither this publication nor any part thereof may be copied, reprinted, sold, published or distributed without prior written permission. This presentation provides non-binding information only and we do not assume any liability for correctness, accuracy and completeness of the information provided. Dorfner Analysenzentrum und Anlagenplanungsgesellschaft GmbH makes every effort to provide timely and accurate information. Nevertheless, mistakes and confusions may occur. The information and statistical data herein have been obtained from sources we believe to be reliable. Nevertheless, such information has not been independently verified and we do not assume any liability. Any opinions or estimates herein reflect the judgment of Dorfner Analysenzentrum und Anlagenplanungsgesellschaft GmbH at the date of publication and are subject to changes at any time without notice. This applies especially to information reflecting estimations and technical standards since they are subject to changes over time. Dorfner Analysenzentrum und Anlagenplanungsgesellschaft GmbH does not intend, and does not assume any liability or obligation whatsoever, to update these forward-looking statements and/or estimations or to conform them to future events and developments.
4th Graphite and Graphene Conf. page 3 © DORFNER Analysenzentrum und Anlagenplanungsgesellschaft mbH
Dorfner Group of Companies
Founded 1895 More than 100 years
experience in mineralsprocessing
Family owned Independent
Renowned in the Specialty Minerals Business
4th Graphite and Graphene Conf. page 4 © DORFNER Analysenzentrum und Anlagenplanungsgesellschaft mbH
Dorfner Group of Companies
Day by day experience in mining and processing up to 1 Mio tons of industrial and specialty minerals every year
Mechanical, physical, thermal and chemical processing
Renowned in the Specialty Minerals Business
4th Graphite and Graphene Conf. page 5 © DORFNER Analysenzentrum und Anlagenplanungsgesellschaft mbH
Dorfner ANZAPLAN
Founded in 1985 to become the most independent venture within the Dorfner Group.
The leading European Service Company in Specialty Minerals and Metals
CC
4th Graphite and Graphene Conf. page 6 © DORFNER Analysenzentrum und Anlagenplanungsgesellschaft mbH
ANZAPLAN ServicesCombined Competencies
AnalyticsInternationally certified chemical and mineralogical analytics, ILAC accredited
Process EngineeringIndependent from any machinery manufacturer Anzaplan is committed to the best process design and innovative concepts in minerals processing.
4th Graphite and Graphene Conf. page 7 © DORFNER Analysenzentrum und Anlagenplanungsgesellschaft mbH
Process Engineering
Anzaplan is globally active in the core areas of: Valuation of mineral
deposits, Process development, Pilot Scale Processing, Economic Assessment
and Feasibility studies, and Engineering.
Commitment to strategic minerals and metals
… within the mineral segments of:Quartz - Rare Earths – Graphite – Lithium Minerals – Nb/TaHPA - Clay Minerals - Fluorspar – Mica - Diatomite
4th Graphite and Graphene Conf. page 8 © DORFNER Analysenzentrum und Anlagenplanungsgesellschaft mbH
Graphite Characteristics
Graphite Type Characteristics
Amorphous Amorphous is microcrystalline type of natural graphite, placed in seems with crystals not visible to the naked eye. Purity ranges 70 to 90%.
Flake Flake type is found as disseminated free flakes within a graphite deposit. Typical flake sizes range between 75 to 850 µm with grades ranging between 1 to 30%. Flotation produces concentrates typically +85%.
Vein Crystalline vein type consists of flake like to lumpy particlesup to large and jumbo sizes. Ore is typically in the range of 80 to +95%.
4th Graphite and Graphene Conf. page 9 © DORFNER Analysenzentrum und Anlagenplanungsgesellschaft mbH
Flake Size and Purity MattersTypical flake sizes
Jumbo flakes +35 mesh >500 µm Large flakes 35 to 50 mesh 300 to 500 µm Medium flakes 50 to 80 mesh 150 to 300 µm Fine flakes -80 mesh <150 µm
The larger the flakes the higher the selling price at comparable purity. Higher purity sells at higher price at same flake size.
… therefore processing needs to balance purity with flake size recovery –at reasonablecost !
4th Graphite and Graphene Conf. page 10 © DORFNER Analysenzentrum und Anlagenplanungsgesellschaft mbH
Graphite Processing
Ore Characterization
Chemical analysis of surface and drill core samples to determine ore grade.
Detailed mineralogical characterization of host rock and graphite ore samples to identify type of mineral impurities
Determination of primary flake size distribution
Graphite concentration
Quality but cost balanced design of tailored processes for optimum liberation of graphite flakes at maximum grade based on mineralogical and chemical results.
Specified particle size distribution and morphology
Pilot scale processing to provide concentrates for customer approval.
Advanced Purification
Chemical and/or thermal purification design to achieve 99,5 to +99,95%
Ensuring maximum performance in high end applications such as batteries and semicon-ductor manufacturing
Pilot scale processing for customer approval.
4th Graphite and Graphene Conf. page 11 © DORFNER Analysenzentrum und Anlagenplanungsgesellschaft mbH
Graphite ProcessingStandard Processing
Standard processing is built on several flotation and regrinding steps.
Standard process needs standard ore.
A quite unusual attempt in specialties minerals disregarding potential benefits of ore specifics.
4th Graphite and Graphene Conf. page 12 © DORFNER Analysenzentrum und Anlagenplanungsgesellschaft mbH
Standard circuitGraphite ProcessingFrom Standards to Specialties
In specialty minerals industry the ore should take the lead for defining the process.
Maximizing value by taking advantage of the ore´s benefits is achieved only by tailor made processing.
Tailored solutions base on detailed ore analyses and provide space for innovation and know how transfer from related industries.
4th Graphite and Graphene Conf. page 13 © DORFNER Analysenzentrum und Anlagenplanungsgesellschaft mbH
Graphite processingDealing with challenges in mineral processing
2)
3) 4)
1) Intergrowth with gangue minerals
2) Graphite patch on surface
3) Graphite sprinkled on surface
4) Gangue mineral masked by graphite (overgrinding)
Liberation is key for downstream separation
1)
4th Graphite and Graphene Conf. page 14 © DORFNER Analysenzentrum und Anlagenplanungsgesellschaft mbH
Challenges in mineral concentrationLiberation by conventional processing is limited
“Liberation is key for separation”
The finer the more liberated ... but sprinkling masking
may hamper concentration and fine grinding adds
processing costs and shifts flake size
distribution to less valued finer particles
4th Graphite and Graphene Conf. page 15 © DORFNER Analysenzentrum und Anlagenplanungsgesellschaft mbH
Selective FragmentationImproved Liberation
Material in a dielectric liquid will be fragmented using high voltage pulses pulse rise time in ns, voltage up to 400 kV.
Graphite’s mechanical, electrical and anisotropic properties contrast strongly with surrounding rock matrix.
Electrical discharge forms plasma channels preferably along grain boundaries (high permittivity contrast).
Plasma channel expansion due to Ohmicheating generates strongest internal shockwaves liberating minerals with high mechanical contrast.
4th Graphite and Graphene Conf. page 16 © DORFNER Analysenzentrum und Anlagenplanungsgesellschaft mbH
Graphite ProcessingFlowsheet Selective Fragmentation
4th Graphite and Graphene Conf. page 17 © DORFNER Analysenzentrum und Anlagenplanungsgesellschaft mbH
Determined C contentafter SELFRAG indicatesC deportment into500 micron ranges
Selective FragmentationLiberation of coarse flakes
0
5
10
15
20
25
0 200 400 600 800 1000
C [
wt.
-%]
Grain size [µm]
Selective fragmentationConventional comminution
4th Graphite and Graphene Conf. page 18 © DORFNER Analysenzentrum und Anlagenplanungsgesellschaft mbH
Flotation after Selective FragmentationFlotation results
High quality of graphiteconcentrate in earlyflotation stages in all fractions by leaving thecoarse flakes large.
0
10
20
30
40
50
60
70
80
90
100
C [
wt.
-%]
Flotation steps
start F1 F2
— 125 micron
— 300 micron— 800 micron
4th Graphite and Graphene Conf. page 19 © DORFNER Analysenzentrum und Anlagenplanungsgesellschaft mbH
Graphite flakes are liberated selectively along crystal boundaries
Host rock (gangue minerals) is comminuted
Selective fragmentation offers improved liberation and separation of graphite flakes after a first crushing step.
Selective fragmentation will largely avoid problems associated with fine grinding as e.g. surface masking of silicates.
Selective FragmentationBenefits of selective fragmentation
4th Graphite and Graphene Conf. page 20 © DORFNER Analysenzentrum und Anlagenplanungsgesellschaft mbH
SELFRAG Product Portfolio
Capacity Batch 100kg – 1tph 5‐10tph
Value proposition
PuritySelectivityBatch
PuritySelectivity
Continuous process
Coarse liberationEnergy saving
ApplicationsSample
preparationMining research
High purity glass recycling
Silicon crushingMining exploration
RecyclingMining
Lab system(batch)
Continuous systemLow‐throughput continuous systemSample production
4th Graphite and Graphene Conf. page 21 © DORFNER Analysenzentrum und Anlagenplanungsgesellschaft mbH
Shaking tableShaking table - a viable addition
Exploits the principle of specific gravity difference of graphite and silicates, instead of just surface properties used by flotation.
In addition graphite flakes float on the surface.
Gangue particles (even if masked with graphite) can be separated.
Source: www.met-solvelabs.com
4th Graphite and Graphene Conf. page 22 © DORFNER Analysenzentrum und Anlagenplanungsgesellschaft mbH
Graphite ProcessingFlowsheet Shaking Table
4th Graphite and Graphene Conf. page 23 © DORFNER Analysenzentrum und Anlagenplanungsgesellschaft mbH
Chemical Purification of Graphite ConcentrateChemical purification needs to be tailored
Graphite concentrate > 90% is obtained bycomminution andflotation
Chemical purificationopens furtherpossibilities to achievehighest standards.
Two principal routes areavailable: caustic oracidic treatment followedby acid washing
Caustic baking at elevated temperature dissolves impurities such as feldspar, quartz and mica followed by acid washing.
Alternative HF leaching followed by sulfuric acid washing step depending on nature and ultimate level of purity by efficient removal of silicates.
Graphite after incineration
Graphite before incineration
4th Graphite and Graphene Conf. page 24 © DORFNER Analysenzentrum und Anlagenplanungsgesellschaft mbH
Technical tests to prove transferability of laboratory results to pilot plant scale in the technical center
Processed samples are needed for downstream processdevelopment
Engineering parameters are picked up for upscalingequipment, throughput and chemicals consumption.
Customer approval and detailed feedback when samplesare presented.
Fixed pilot plant reduces flexibility during processdevelopment.
Pilot plant processingSized process approval of lab results
4th Graphite and Graphene Conf. page 25 © DORFNER Analysenzentrum und Anlagenplanungsgesellschaft mbH
Advanced Refinement Caustic baking Acid leaching Thermal treatment Hot chlorination Filtration and washing,
neutralisation Dewatering and drying Water treatment and
recycling
Mineral Concentration Conventional comminution Autogenous grinding and
selective fragmentation Classification Sensor based sorting Gravimetric separation Magnetic separation Electrostatic separation Ultrasonic processing Flotation
From Standards to SpecialitiesPilot Plant Processing
4th Graphite and Graphene Conf. page 26 © DORFNER Analysenzentrum und Anlagenplanungsgesellschaft mbH
ANZAPLAN ServicesProject Evaluation and Process Development