Gold-Bearing Ore
Confirm a suitable representative portion and preparation approach for the material.
Fire Assay Laboratory Service
Fire Assay Gold Testing
Representative Gold Determination from a Prepared Sample
When a surface indication is not enough, Fire Assay provides gold determination from a prepared analytical sample.
Bilex Minerals EA provides Fire Assay testing for suitable gold-bearing materials where the testing requirement calls for analysis of a representative prepared portion.
Because the analytical portion is consumed during the process, sampling and testing requirements should be agreed before destructive work begins.
Inside the Bilex Fire Assay Laboratory
Actual laboratory footage
See part of the Fire Assay process.
The video shows the actual Bilex laboratory environment and part of the Fire Assay process. Fire Assay is fundamentally different from non-destructive XRF screening: the material must first be prepared into an analytical portion, and that portion is consumed during the analytical process.
The video demonstrates laboratory equipment and process, not a specific gold result or purity determination.
When Is Fire Assay Appropriate?
Fire Assay may be appropriate when a gold determination is required from a representative prepared sample rather than a surface indication.
Concentrates
Define the material or lot and keep the analytical portion connected to it.
Refinery Samples
Analyse an identified prepared portion within the agreed testing scope.
Representative Gold-Bearing Material
Use a documented sample intended to represent the defined material.
Prepared Analytical Samples
Confirm identity, preparation and the intended use before analysis begins.
Why Representative Sampling Matters
A precise analytical method cannot compensate for an unrepresentative sample.
The result describes the prepared portion entering the analytical process. The link between that portion and the defined material must remain clear.
- Define the material or lot
- Agree how the sample is collected
- Record the sample identity
- Arrange witnessed sampling where required
- Confirm any retained portion
- Record the intended use of the result
How Fire Assay Works
- 01
Sample Preparation
A representative portion is selected and prepared according to the applicable testing procedure.
- 02
Weighing & Fusion
The prepared portion is weighed and combined with suitable fluxes and a collector before controlled furnace fusion.
- 03
Cupellation
The lead button undergoes cupellation and precious-metal material is separated.
- 04
Finishing & Measurement
The resulting precious-metal material undergoes the appropriate finishing and measurement process.
- 05
Calculation & Review
The analytical result is calculated, reviewed and reported within the scope of the tested sample.
Why Clients Choose Fire Assay
Representative Prepared-Sample Analysis
The method examines an identified prepared portion intended to represent the defined material.
Established Gold Determination Method
Fire Assay uses controlled preparation, fusion, cupellation, measurement and review.
Suitable for Gold-Bearing Materials
It can be considered for suitable ores, concentrates, refinery samples and representative material.
Documented Analytical Result
The result is reported within the scope of the identified sample and agreed method.
Important before testing
Fire Assay Is Destructive
Understand this before authorising the test.
The analytical portion is consumed during Fire Assay. No destructive work should be assumed or authorised without agreement on the applicable sample and testing requirements.
- Portion to be tested
- Amount required for the agreed procedure
- Sampling procedure
- Witnessed sampling where applicable
- Retained sample requirements
- Intended use of the result
Fire Assay vs XRF
The right method depends on the question you need answered.
| Comparison | Fire Assay | XRF |
|---|---|---|
| Primary purpose | Representative prepared-sample determination | Rapid surface screening |
| Sample | Prepared analytical portion | Measured surface region |
| Destructive | Yes | Normally no |
| Speed | More involved | Rapid |
| Surface limitations | Less dependent on surface alone | Important |
| Sampling | Critical | Important |
| Best suited to | Representative determination | Screening and comparison |
If you need rapid information while preserving the item, XRF may be appropriate.
If you require a determination from a representative prepared analytical portion and destructive testing is permitted, Fire Assay may be appropriate.
What Can Affect a Fire Assay Result?
The final result applies to the sample that was actually prepared and analysed. It should not be expanded automatically to material that was never sampled.
- Representativeness
- Sample preparation
- Sample identification
- Material heterogeneity
- Analytical controls
- Quality checks
- Calculations and reporting
What to Expect Before Testing
Please do not travel with valuable material until the appointment and intake requirements have been confirmed directly by Bilex.
Where appropriate, an initial consultation may be arranged by phone, WhatsApp, video call or in person.
- Material type
- Approximate quantity or form
- Purpose of testing
- Sampling requirements
- Destructive-testing restrictions
- Retained or witnessed sample requirements
Gold Testing & Assaying
Related Testing Methods
01020304
XRF Analysis
Rapid surface-region screening for suitable intact items.
Learn MoreICP-OES
Quantitative multi-element analysis from a prepared sample.
Learn MoreAAS
Targeted instrumental determination that can serve as a Fire Assay finish.
Learn MoreMetallic-Screen Fire Assay
Specialised analysis for coarse and heterogeneous gold-bearing material.
Learn MoreCommon questions
Fire Assay FAQ
Is Fire Assay destructive?
Yes. The prepared analytical portion used for Fire Assay is consumed during the process. Sampling and testing requirements should be agreed before destructive work begins.
Can Fire Assay test gold doré?
Fire Assay may be used for a suitable representative prepared portion from gold doré where destructive testing is permitted and the sampling plan fits the intended use of the result.
Is Fire Assay more accurate than XRF?
The methods serve different analytical purposes. XRF measures selected surface regions for rapid screening and comparison. Fire Assay analyses a representative prepared portion. The appropriate method depends on the question and sample requirements.
Why is sampling so important?
The result describes the portion that was prepared and analysed. If that portion does not represent the material or lot, the analytical result cannot repair the sampling problem.
How long does Fire Assay take?
Timing depends on the material, sample preparation, batch requirements, quality checks and agreed scope. Bilex should confirm the expected timing for the specific enquiry.
Fire Assay enquiry
Need Fire Assay Testing?
If you need a gold determination from a representative prepared sample, contact Bilex Minerals EA to discuss the material and testing requirements.