Prepared Mineral Samples
Measure gold in suitable prepared geological samples within a validated analytical range.
Gold Testing Method
PhotonAssay™ Gold Analysis
Non-Destructive Bulk Analysis of Suitable Prepared Gold-Bearing Samples
PhotonAssay™ uses high-energy X-rays and nuclear excitation to measure gold and other supported analytes in suitable prepared geological samples.
The prepared analytical sample remains intact, but method suitability still depends on the material, validated range and sampling relationship.
Bilex confirms service availability, the facility arrangement and accepted sample requirements before a PhotonAssay enquiry proceeds.
Bilex Sample Handling
What Is PhotonAssay™?
PhotonAssay uses high-energy X-rays to excite atomic nuclei within a suitable sample. Characteristic gamma-ray emissions produced as the excited nuclei change state are detected and used to determine supported analytes.
This is gamma activation analysis and is fundamentally different from ordinary X-Ray Fluorescence (XRF). XRF measures characteristic emissions associated with atomic electrons and normally samples a shallow surface region; PhotonAssay makes a bulk measurement through a comparatively large prepared geological sample.
PhotonAssay is proprietary technology developed by CSIRO and commercialised by Chrysos Corporation. The name is used here for accurate identification, not to imply that Bilex invented or owns the technology.
Applications
Where PhotonAssay™ Gold Analysis Is Used
Gold-Bearing Ore
Support bulk measurement of properly sampled and prepared ore material.
Coarse-Gold Material
Use a comparatively large analytical portion where the validated method suits coarse-gold mineralisation.
Suitable Concentrates
Analyse prepared concentrate material only where composition and range fit the confirmed procedure.
Repeat Measurement
Preserve the prepared analytical sample for storage or repeat measurement where applicable.
Suitable material
Materials and Sample Forms
- Prepared gold-bearing geological samples
- Prepared ore
- Coarse-gold mineralisation
- Suitable prepared concentrates within validated ranges
- Other supported geological material confirmed before testing
Before testing
Sample Requirements
- PhotonAssay normally measures a prepared sample in a geometry accepted by the applicable system and procedure.
- Published industry sample sizes do not establish Bilex-specific requirements. Bilex confirms the accepted mass, container and preparation for each enquiry.
- Finished bullion, intact doré bars and whole nugget parcels must not be assumed suitable without a documented validated application.
- Measuring a larger analytical portion does not automatically make it representative of a multi-kilogram lot. Sampling remains decisive.
Process
From Testing Question to Report
Define the Question
Describe the material, the result you need and how the information will be used.
Review Suitability
Bilex reviews the sample form, expected composition, required analytes and any restriction on alteration.
Agree the Scope
The method, representative sampling relationship, preparation requirements and reporting scope are confirmed before work begins.
Prepare & Analyse
An identified analytical sample is prepared and measured according to the applicable confirmed procedure.
Review the Result
The reported result is interpreted within the method, sample identity and limitations stated for the work.
What it contributes
Strengths
- Non-destructive measurement of the prepared analytical sample
- Bulk measurement through a comparatively large prepared sample
- Rapid instrumental analysis after sample preparation and intake
- Well established for suitable geological and mining samples
Scope
Limitations to Understand
- Application and calibrated range must suit the material
- Not automatically a method for finished bullion or intact doré
- Does not eliminate representative sampling requirements
- Full turnaround includes intake, preparation, review and reporting—not only instrument cycle time
- Service and equipment arrangement require Bilex confirmation
Method selection
How This Method Relates to Other Tests
PhotonAssay vs XRF
Both techniques use X-rays, but the similarity should not be overstated. XRF provides elemental information from a shallow surface region by exciting atomic electrons.
PhotonAssay uses much higher-energy X-rays to excite atomic nuclei and measures characteristic gamma emissions from a comparatively large prepared bulk sample.
PhotonAssay vs Fire Assay
PhotonAssay leaves the prepared analytical sample intact and provides rapid instrumental bulk measurement where the material and range are validated.
Fire Assay consumes the analytical portion and uses an established precious-metal collection and separation process. PhotonAssay should not be described as universally more accurate or as having replaced Fire Assay.
Questions
Frequently Asked Questions
Is PhotonAssay the same as XRF?
No. PhotonAssay uses high-energy X-rays to excite atomic nuclei and measures gamma emissions from a bulk prepared sample. XRF normally measures elemental information from a shallow surface region.
Is PhotonAssay non-destructive?
The instrumental measurement does not destroy the prepared analytical sample. Preparation and sampling may still alter the original material before it reaches the instrument.
Can PhotonAssay test ore?
Yes, it is established for suitable prepared gold-bearing geological samples, including ore, within the applicable validated range.
Can PhotonAssay test doré or bullion?
Do not assume so. Suitability depends on the system, calibration, sample geometry, concentration range and validated scope. Bilex must confirm the application before testing.
Can PhotonAssay represent an entire consignment?
Not automatically. The result describes the analytical sample measured. Applying it to a wider lot depends on whether the sampling procedure reasonably connects that sample to the defined material.
Related services
Compare Supporting Methods
Discuss the sample
Discuss PhotonAssay Testing
Tell us the material, available sample quantity and the information the result needs to establish.
The final method and sample requirements are confirmed after the material and testing objective have been reviewed.