Bulk commodity analysis

Iron Ore Analysis

Accurate assaying is critical to the success of any iron ore exploration, resource definition, and metallurgical test work programme. X-ray fluorescence spectrometry (XRF) from a lithium borate fused bead is usually the analytical method of choice for iron oxide ores. This method is often combined with Davis Tube Recovery methods, providing a lab-scale ore beneficiation process that separates magnetic from non-magnetic fractions. The separation by Davis Tube Recovery test is affected by the grinding specifications and the results can be used to infer the amenability of samples to large-scale beneficiation. The routine grind quality data produced by ALS as a standard part of all sample preparation is ideal for monitoring that grind size has stayed consistent and within method expectations.

Loss on ignition

LOI is a critical component of iron ore analyses, allowing for an improved understanding of mineral composition of the ore and how it can be expected to behave during processing. Single temperature or multi-temperature LOI determinations are available by furnace or Thermogravimetric Analyser (TGA). Temperatures can be customised as required. This information is particularly valuable when analysing Channel Iron Deposits and Marra Mamba type ores.

Bauxite Analysis

XRF is the industry-standard analytical method for the majority of bauxite analyses. Results are reported on a dry weight (110°C) basis by default. Additional characterisation methods such as organic carbon, reactive silica, and available alumina comply fully with the Brazilian Centro De Tecnologia Mineral (CETEM) performance criteria. Multi-screen sizing to determine the optimum screen size for recovery and subsequent wet beneficiation are also available.

Available alumina and reactive silica

ALS uses a microwave assisted leaching process using a sealed reaction vessel for tests can be carried out at either a low (145°C) or high (235°C) temperature depending on the composition of the bauxite. The microwave method employed by ALS for these tests allows for improved control and reproducibility of conditions than in traditional tests in sealed steel bombs.

The amount of silica associated with the mineral kaolinite can also be estimated using FT-NIR spectroscopy and a chemometric algorithm if sufficient samples analysed with an alternative technique are available.