Techniques for Rapid and Accurate Sample Analysis in the Field

Techniques for Rapid and Accurate Sample Analysis in the Field Aaron Baensch — Principal Geologist, International Mining Group

Dane Burkett — XRD Product Specialist

Olympus Scientific Solutions Americas (OSSA) – Monday, June 19, 2017

Webinar Agenda

§  Introduction to OSSA, the mining team, and analytical products §  Quick introduction to pXRF and pXRD §  Focus on pXRF

§  New Olympus Vanta™ pXRF analyzer §  Workflows and standard operating procedures (SOPs) §  Sample preparation, CRMs, QA/QC, and data

management §  References §  A selection of case studies and applications

§  Focus on pXRD §  Diffraction 101 §  Introduction to Olympus pXRD instruments §  A selection of studies and applications

OLYMPUS Scientific Solutions

Olympus’ Dedicated International Mining Group (IMG) ToddHoulahan—Director

• JoinedOlympusin2008• 17yearsportableXRFexperience• Globalminingsales,marketing,andapplications• BAppSc.UniversityofNewcastle,Australia,1993(soilsmajor)• BasedinLondon,UK

MarcusLake—GlobalBusinessDevelopmentManager

• JoinedOlympusin2008• Drilling&blastingandcommoditytradingbackground• GlobalBD,distributorandsaleschanneltrainingandKAM• BachelorofCommerce,UniversityofNSW,Australia,1994• BasedinHongKong

AaronBaensch—PrincipalGeologist

• JoinedOlympusin2008• 10+yearspriorasindustrygeologist• Productandapplicationdevelopment,keyaccounts,andstrategicpartners

• ManagingDETCRCLab-at-Rig®• BachelorofMineralExplorationandMiningGeology(Hons)fromWASchoolOfMines,Kalgoorlie• BasedinSydney,Australia

DaneBurkett—XRDProductandApplicationsSpecialist

• JoinedOlympusin2015• BusinessDevelopmentandSupportingXRDApplications

• CompletedPhDusingOlympuspXRF&pXRD@UniversityNewSouthWales(UNSW)• BSc.Geology/EarthScience(Hons)fromUniversityofNSW(UNSW)• BasedinSydney,Australia

Olympus and Olympus Scientific Solutions Americas (OSSA) § Olympus has a long history in optics, imaging, and sensor technology

–  40,000 employees, market cap of US$12B, founded in 1919 in Japan –  Core Businesses:

–  Cameras and audio –  Medical, surgical, and life sciences (End, GI, Gyn, Urol…etc.) –  Industrial = OSSA (HQ = Boston & Quebec)

»  Nondestructive testing (NDT) »  Ultrasonic »  Phased array »  Eddy current »  Advanced NDT solutions and systems »  Industrial borescopes and videoscopes

»  Microscopy and optical metrology »  Analytical instruments

»  X-ray fluorescence (XRF) »  X-ray diffraction (XRD)



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Quartz

Pentlandite

Violarite

Talc

Pyrrhotite

Pyrite

Anorthite

Chalcopyrite

Biotite

Cummingtonite

Mineral wt %

Combining XRD + XRF + Microscopy = Integrated Geoscience Solution


Olympus — XRF Products Overview (Chemistry)

All brand names are trademarks or registered trademarks of Olympus Corporation


Olympus — XRD Systems (Mineralogy) §  TERRA® analyzer = a truly portable XRD device

§ BTX II™ analyzer = small and cost-efficient benchtop XRD device

TERRA portable XRD analyzer

BTX II benchtop XRD analyzer

Web-based GUI


Olympus — Microscopes (Optical Mineralogy) § Olympus also has a full range of stereo and polarizing petrographic and

metallurgical microscopes

Stereo microscopes Polarizing microscopes

Metallurgical microscopes


Physics 101 — X-ray Fluorescence (XRF) and X-ray Diffraction (XRD)

R²=0.993

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LAB(%)

pXRF(%)

Fe

www.ruby.colorado.edu

www.mdpi.com

§ XRF yields elemental chemistry (energy dispersive spectroscopy)

§ XRD yields quantitative mineralogy (fundamental crystallography)


30+ Elements Down to PPM Level


Mining and

Geoscience

Universities, research groups,

and geological surveys

Mineral exploration

Mining and grade control

Mineral processing and geometallurgy

Environmental and mine closure

Fixed and mobile plant maintenance and construction (alloy, PMI, and

oil analysis)

Servicing the Entire Mining Value Chain


Focus on pXRF

§  Rugged §  IP65/67 rated — dust and water resistant §  High temperature rating: 122º F / 50º C (with optional fan) §  Drop tested §  Detector shutter

§  Revolutionary §  AxonTM Technology = High Count Rate §  Stable hardware and excellent resolution §  Precise and accurate §  Automated calibration, no cal check required §  Tool-less window change

§  Productive §  New detector pulse processor §  Optional Wi-Fi enables powerful cloud applications §  Embedded GPS §  New software, methods, modes, and GUI

Handheld XRF — Vanta™ Analyzer



Geoscience Week 2017 Feature: pXRF Best Practice Guide (Blog)


SOPs, Chain of Custody, and QA/QC (Fisher & Gazley, 2014)


Geoscience = Many Different Types of Samples


Sample Selection — Horizon, Grain Size, Bags, etc.



Site-Specific Calibration and Test Time Optimization (Client Samples)

XRF_Cal_ID Cu_Lab Cu_pXRF Fe_Lab Fe_pXRFSF01 0.02 0.02 11.13 12.38SF02 2.50 2.54 33.84 30.76SF03 5.09 4.91 35.42 35.24SF04 7.49 7.46 38.89 38.21SF05 10.00 9.67 28.58 27.48SF06 11.47 11.19 17.73 18.50SF07 12.45 11.88 14.50 15.73SF08 13.23 12.81 29.39 29.31SF09 15.20 14.56 16.09 17.39SF10 17.67 16.61 32.35 30.84SF11 21.72 19.40 31.19 29.41SF12 30.19 28.67 9.54 11.05SF13 32.60 30.98 10.25 11.26SF14 35.23 32.30 8.70 10.43SF15 37.51 35.79 8.52 9.78SF16 40.14 39.77 8.87 9.83SF17 42.50 39.20 7.94 8.19SF18 43.72 43.72 9.18 10.67SF19 45.02 42.54 7.33 8.50SF20 46.04 46.01 5.94 7.12SF21 47.55 47.64 7.33 8.94SF22 48.19 48.57 6.15 7.11SF23 50.10 50.25 7.27 8.02SF24 52.52 53.50 6.79 7.75SF25 53.01 52.08 5.91 7.00SF26 55.00 56.51 6.51 7.41SF27 57.04 57.59 5.87 6.75SF28 60.58 61.90 4.41 4.95SF29 64.67 65.64 5.93 5.57SF30 68.73 68.85 4.85 4.73

y=1.0062xR²=0.9961

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LabXR

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pXRF

Cu_pXRF

y=1.0029xR²=0.9874

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Fe_pXRF


Real-Time 3D Visualisation

http://www.leapfrog3d.com/online-resources/case-studies


Reporting (eg. JORC Code) — pXRF Referenced in Table 1



pXRF Benchmarking and Industry Reference (2010–2013)



GEEA pXRF Thematic Set — February 2016



Examples and Case Studies


2016 PDAC Short Course: Case Studies (Videos on YouTube) § Olympus-IMS Channel


Geological Surveys — GTK Special Publication — Novel Technologies



Geological Surveys: Litho-Geochemistry (Drill Chips and Cores)


Geoscience Research and Development


Geoscience R&D — Automated Geology


Soil and Regolith Geochemical Surveys


Soil and Regolith Geochemical Surveys — Rapid Multivariate Datasets


Soils — What can be achieved in one month with one instrument?

OLYMPUS Scientific Solutions Phoenix Copper, 2008.


Auger Drilling — Regolith Mapping for Gold (Au) in West Africa


Robust rock classification at

surface using a Ti-Zr classification diagram


Gold Exploration — Using Pathfinders and Geochemical Signatures


Gold Mine Case Study Published in GEEA

§ Paper published in Journal of Geochemical Exploration (2011)


Gold — Chemo-Stratigraphic Controls on Au Deposition

§ Using Au vs Cr to map and model mine stratigraphy and lode locations


Gold Processing — Modelling Recovery from Arsenic in Refractory Ores


Free Au

Aspy + Au

A

B


Textural and Structural Investigation Using a Camera and Collimator


§  pXRF (with in-line camera) for assessing Au in diamond drill cores


Iron Ore Grade Control with a High Count Rate (15 seconds)


90 Sec Test (30s B1/60s B2) vs. 15 Sec Test (5s B1/10s B2)

OLYMPUS Scientific Solutions OLYMPUS Scientific Solutions

Iron Ore Grade Control with a High Count Rate (15 seconds)

90 Sec Test (30s B1/60s B2) vs. 15 Sec Test (5s B1/10s B2)


Lithium Exploration Combining pXRF and pXRD

§ Current example — LCT pegmatite exploration – mineralogy is key! R²=0.9676

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Li2O(%

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pXRFRb(%)

LabLivspXRFRbMineralName Li2O(%)* ChemicalFormulaSpodumene 8.03 LiAl(SiO3)2Petalite 4.50 LiAlSi4O10

Eucryptite 11.86 LiAlSiO4

Amblygonite 7.40 (Li,Na)AlPO4(F,OH)

Lepidolite 7.70 K(Li,Al)3(Al,Si)4O10(F,OH)2Lithiophilite 9.53 LiMnPO4

Zinnwaldite 3.42 KLiFeAl(AlSi3)O10(OH,F)2Holmquistite 3.98 Li2(Mg,Fe2+)3Al2Si8O22(OH)2Triphylite 9.47 Li(Fe,Mn)PO4SOURCE:webminera l .com*Ca lculatedLi 2OContent


Focus on XRD

What is XRD?

§ X-ray diffraction (XRD)

§ Way of defining crystalline phases (minerals) –  E.g. quartz, magnetite, hematite, muscovite

§ Can identify mineral phases irrespective of reflectance

§ Can be used to identify and quantify minerals

TERRA® portable XRD analyzer

BTX-II™ benchtop XRD analyzer

How Does XRD Work?

§ Crystals have a defined structure that is like a fingerprint

§ X-ray diffraction characterises this crystal structure

www.ccp14.ac.uk

www.ruby.colorado.edu

www.spectraminerals.com

www.marinmineral.com www.mdpi.com

Conventional XRD Instruments

§ Goniometer

§  Large lab-based equipment

§ Energy intensive

§ External water source

www.sfu.ca/

Whitefield (2012) http://www.tulane.edu/

Sample Preparation

§ Pressed pellets

§ Dry, < 10 µm, approximately 300 mg

§ Need homogenous grain size

§ Assumes a random orientation

Whitfield (2012) Mdpi.com

Conventional XRD Sample Preparation

§ Careful sample preparation required (15 + minutes)

§ Micronized sample is recommended (<10 µm)

A very flat surface is required

XRD on Mars?

§ Conventional XRD is too large, sample preparation too onerous, and energy requirements too great

§ Need for an XRD instrument that was light, rugged, and did not require regular calibrations

Mars

XRD on Mars!

Termed “the ultimate exploration tool / robotic geologist on wheels…”

Sojourney (1997) 11.5 kg

MER (2004) 185 kg

MSL Curiosity (2012) 900 kg

•  Spirit •  Opportunity

CheMin — the Olympus Link

•  Chemistry = X-ray fluorescence (XRF) •  Mineralogy = X-ray diffraction (XRD)

Olympus XRD Instruments

§  Fully portable XRD

§  Fast, easy sample preparation

§ Energy efficient

§ No need for regular part alignments

12.5 kg 14.5 kg TERRA® portable XRD analyzer

BTX II™ benchtop XRD analyzer

Sample Preparation

§  15 mg of sample

§  2–4 minutes

§  < 150 µm

Crush

Sieve

15 mg of sample

Why Are Grain Size Requirements Not as Small for pXRD Compared to Lab XRD?

§ Conventional XRD recommends powdering to < 80 µm (preferably < 10 µm) –  Rotating sample in 1D with reflectance geometry –  Alleviate grain size effects and orientation effects

§ Portable XRD < 150 µm for soils, < 75 µm for sulfides and heavy mineral concentrates

–  Vibrating sample with transmission geometry

Grain-size effects Whitfield (2012)

Orientation effects prims.mit.edu pXRD debye rings

Portability

§  4-hour battery life with hot-swap capability

§ Rugged

§ Can run off A/C power

Patented Sample Vibration Holder — Orientation Effects

§ Vibrates the sample rather than rotating the detector and source

§ Eliminates orientation effects

Sararazin et al. 2005

Power Consumption and Maintenance

Olympus XRD Lab-based XRD Power consumption 100 W

Detector cooling 1000  W

Filtered water + tube < $15/year $5000/year

Tube power 10 W 1.2 kW Tube replacement $0/year* $2000/year

Requires skilled technician External water No Yes

* Assuming a 6-year tube life of 6000 hours a year (equal to 5 day work week at 8 hours of work per day)

What can be achieved with XRD?

§ Qualitative and quantitative mineralogical analysis –  For all minerals, irrespective of color –  Lower level of detection ~1–2 wt %

§ Quantify the amorphous content within a sample –  High chrysocolla-bearing ores

§ Crystallinity

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Carnallite

Lazulite

Sylvite

Halite

Eberl & Velde (1989)

Geology.com

Testing Procedure

§ Overall, no significant change in results with varying runtimes –  Effects the limits of detection

–  For > 5 wt % –  Simple mineralogy (2 minutes) –  Complex mineralogy (5 minutes)

–  For 1–2 wt % –  Simple mineralogy (7 minutes) –  Complex mineralogy (15 minutes)

Lab-based XRD, 5 mins, 10 mins, 20 mins, 40 mins Burkett et al. (2015)

Lab-based XRD, 5 mins, 10 mins, 20 mins, 40 mins

Runtime Analysis

Lab-based XRD, 5 mins, 10 mins, 20 mins, 40 mins

R2 = 0.80 R2 = 0.87

R2 = 0.92 R2 = 0.88

Data Processing

§ Semi-quantitative analysis –  Reference intensity ratio (RIR) –  OK when there is minimal overlap between minerals

I

2 θ

Data Processing

§ Quantitative analysis –  Rietveld refinement –  Many software packages available

–  We suggest Siroquant® software because it has a database which utilizes observed reference material (better for poorly crystalline material)

RIR vs. Rietveld

§ Porphyry copper deposit

§  4 to 9 phases per sample

y=1.0115x+0.0026R²=0.97925

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Lab-XRD

Siroquant-hkl

Rietveld Processing

§ A simple refinement of the hkls (peak positions) get you most of the way there

§ Can get better results if other parameters are refined (e.g. width)

y=0.9946x+0.0846R²=0.99212

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pXRD

Lab-XRD

Siroquanty=1.0115x+0.0026R²=0.97925

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Siroquant-hkl

XRD for Mineral Exploration: Current Methods for Mineralogical Characterization and Quantification

§ Core-logging using a hand lens –  Alteration is typically fine-grained

–  Often rely on color as a guide (three-way color split) –  Geologists typically use geochemical data to infer mineralogy rather

than quantify it directly

Can roughly estimate mineralogy

Fine-grained alteration Brathwaite et al. 2014

Current Methods for Mineralogical Characterization and Quantification

§ Petrography –  Expensive, time-intensive, and often the phases

are still too fine-grained to identify/quantify –  Hard to differentiate between species within

similar mineral groups –  Carbonates: calcite, dolomite, ankerite,

rhodocrosite, etc. –  Phyllosilicates: illite, muscovite, smectite,

interlayered clays, etc.

Fine-grained alteration

Quantitative XRD

Importance of XRD in Metal Exploration

§ Alteration studies –  Alteration assemblages used to guide towards orebodies –  Provide evidence to help constrain the geological environment

–  Temperature, pressure, fluid chemistry, etc.

Tosdal et al. 2009 Hedenquist et al. 2000

Integrating Mineralogical Data into the Logging Protocol Core-logging

XRD data

Core-logs with assay data

S (ppm)

20000 0

Uvarova et al. (2014)

Mineralogical data

Uvarova et al. (2014)

Gold Exploration — Wall Rock Alteration

Why is Mineralogy Important?

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Ore-zone

Edge of ore-zone

Barren

Assay data can take weeks to months to get back

Alteration Zonation — Fluid to rock buffered

Phyllic Illite Rock buffered

Potassic Adularia-illite-pyrite Zone of mixing

Epidote Adularia-epidote Fluid buffered Higher temperature

‘Burkett 2017’

20 minute dataset

Case Study — Reliability (Burkett et al. 2015)

§ Key findings –  Highest grades encountered in wall rock with a relative proportion

of 60–80% adularia to 40–20% clays

§  Fluid mixing

§ How do we know the results are reliable?

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Adularia/(Adularia + Total clays)

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(g/t)

Verification of Approach Quantification

XRD for Mineral Exploration

§ Graphite

§ Bauxite

§  Lithium

§ Copper

§  Iron ore

§ Potash

Graphite Exploration

§ Carbon cannot be analyzed with XRF

§ XRD can quantify graphite and carbonate minerals

–  Work out total carbon, total graphitic carbon, and total carbon in carbonates

Investorintel.com

Comparisons between lab assay data (x-axis) and estimates from XRD (y-axis)

Importance of XRD in Mineral Processing

§ XRD can aid: –  Comminution –  Flotation –  Leaching –  Pyrometallurgy (roasting and smelting)

§ Can help to optimize each of the above processes and also help improve blending strategies

http://thedictionaryprojectblog.com/

http://mining-technology.com

http://wealthdaily.com

http://metallurgist.in

XRD for Metallurgy Available on www.olympus-ims.com

The Future — Combining pXRF and pXRD


Complete pXRF and pXRD Integration Delivers Drill Logs of the Future


Further Reading:


Uvarova, Cleverley, Baensch & Verrall, Coupled XRF and XRD analyses for rapid and low-cost characterisation of geological materials in the mineral exploration and mining industry, AAG Explore Vol. 162, March 2014

Thank you for your attendance & attention


Olympus and TERRA are registered trademarks and BTX II and Vanta are trademarks of Olympus Corporation. Siroquant is a registered trademark of Sietronics Pty Ltd.