Chemical (elemental) analysis

Chemical (elemental) analysis

Accurate assaying is critical a component of any iron ore testwork program and X-ray fluorescence spectrometry (XRF) by fused bead is the method of choice for the analysis of iron ore samples. Loss-on-ignition (LOI) determination by Thermogravimetric Analyser (TGA) is typically done in conjunction with XRF. The Iron Ore Technical Centre (IOTC) leverages off the vast state of the art facilities of the ALS Geochemistry division in Malaga together with the Metallurgy Assay Laboratory in Balcatta for analytical services. These extensive capabilities enable the IOTC to deliver fast and accurate assay services in support of metallurgical testing.

Análise química elementar

Iron ore chemical analysis services

The benefits of the XRF method for iron ore samples are as follows:

  • The elemental XRF spectrum is relatively simple. This results in very few spectral interferences.
  • XRF spectrometers are the most stable analytical instruments commonly available in laboratories.
  • Samples are presented to the instrument as fused disks. This eliminates solubility issues that may affect acid dissolution techniques.
  • The flux to sample ratio is relatively low, thus providing good sensitivity for the majority of elements.

A typical iron ore analysis should include a loss-on-ignition (LOI) determination at 371ºC-425°C, 550ºC-650ºC and 1000ºC, normally undertaken by Thermogravimetric Analyser (TGA). Determining the LOI over the above range of temperatures provides a guide to the actual minerals present in the samples. The lower temperatures of 371ºC-425°C will classify the loss of water of hydration (dehydroxylation) primarily from organics and goethite. Clays such as kaolinite in iron ores will lose hydroxyls at approximately 650ºC. At the higher temperature of 1000°C, dehydroxylation of micas and amphiboles will occur together with loss of CO2 from carbonates such as calcite and dolomite. The LOI may be offset to some extent by the weight gain due to oxidation of reduced iron and manganese mineral phases.


The detection limits and ranges of the XRF suite analytes are tabulated below.

Analytes & detection ranges (%)
Al₂O3 0.01–100 Cl 0.001 – 6 Fe 0.01 – 75 Na₂O 0.005 – 8 S 0.001 – 5 TiO₂ 0.01 – 30
As 0.001–1.5 Co 0.001 – 5 K₂O 0.001 – 6.3 Ni 0.001 – 8 SiO₂ 0.01 – 100 V 0.001 – 5
Ba 0.001 – 10 Cr₂O₃ 0.0006 – 10  MgO 0.01 – 40 P 0.001 – 10 Sn 0.001 – 1.5 Zn 0.001 – 1.5
CaO 0.01 – 40 Cu 0.001 – 1.5 Mn 0.001 – 25 Pb 0.001 – 2 Sr 0.001 – 1.5 Zr  0.001 – 1.5
Loss on Ignition (LOI) (0.01%) at 371°C, 425°C, 550°C, 650°C, and 1000°C / Moisture at 110°C

Other related services

Chemical analysis almost always occurs in conjunction with:

Don't quite see what you're looking for or need more information?

Chemical analysis isn't always prescribed, either insofar as the methodology or when and how to take a sample for assay. ALS is always flexible on chemical analysis and will be happy to advise on your assay requirements.


Please contact us for further details.

Here are some frequently asked questions

  • Will ALS treat hazardous samples?

    Generally, yes. ALS has facilities and procedures to treat fibrous and radioactive samples. Surcharges do apply, however, to cover safety equipment, monitoring and decontamination.: The HPGR is equipped with high powered dust extraction and can be fully enclosed via tailored tenting systems to allow for the evaluation of potentially hazardous ore types.

  • Our samples are from overseas, what do I do?

    ALS is a quarantine approved premises and treats many samples of oversea origin. Strict regulatory requirements are in needed around packaging and paperwork, however. ALS can advise you on these requirements.

  • Can my associates and I view the testwork at ALS’s laboratory?

    Yes, clients are always welcome to visit our facilities and observe samples or tests in progress. Inductions are required and other rules may apply to visitors.

  • Will ALS dispatch my samples to third parties?

    Yes, if a testwork program is in progress, ALS will happily dispatch testwork products and feed samples to vendors, third party laboratories, and customers as required. Fees apply.

  • Does ALS do design engineering and consulting?

    No, as it is not our core business and would put us in direct competition with many of our clients. In the case of HPGR testwork programs, KMA as equipment suppliers, provide engineering and consultancy for their industrial units and can provide relevant information for the manufacture and supply of appropriate Koeppern HPGR units.

Associated testwork services

Related testwork

HPGR test products can be utilized as part of larger metallurgical testwork programs in the production of suitably sized product for downstream testing including:

Click on the above links or contact us for further information. We can integrate a full program for you if required.