Canyon Resources Ltd’s (ASX:CAY) advanced metallurgical program has shown consistent +90% available alumina from total alumina in samples from Minim Martap Project in Cameroon, differentiating the project from many other high-grade bauxites.
The outcomes of the testing confirm the very high grade of the Minim Martap bauxite and the high rates of conversion from total alumina to available alumina at low-temperature digestion conditions.
Results support the properties detailed in the previously released bauxite technical specification datasheet and reflect excellent conversion results of greater than 90% in all cases.
“A double bonus”
Director of projects Dr James Durrant said: “The testing confirms that not only would an offtake company receive a very high alumina content in their bauxite, but that the extractable alumina portion is also very high, at over 90%.
“This is a double bonus to any offtaker and one they can improve upon even further by optimising the digestion conditions from the laboratory conditions we’ve used in these standardised tests.
“Canyon’s laboratory partners for the metallurgical work, SGS Perth, are very pleased with the data correlation of the tests and the FTIR data-sets we’ve been building now give us a fast and effective test for metallurgical performance.
“The FTIR test methodologies are aligned to how the major bauxite and alumina producers are operating, which will support us now, through the development phase, and as an operating miner.”
Consistently high conversion results across the initial mining plateaux with high levels of statistical confidence - confirmed by SGS laboratories include:
- 91% conversion from Low-Temperature Microdigestion based on average total aluminium oxide of 53.6% and total silicate of 1.6%
- 91% conversion from Low-Temperature Autoclave digestion based on average total aluminium oxide of 56.9% and total silicate 0.8%; and
- 90% conversion from FTIR analysis based on average total aluminium oxide of 52.7% and total silicate of 1.8%.
These tests are designed to highlight the different properties of the bauxite and give a complete view of bauxite metallurgical properties and processability.
A total of 61 samples were analysed by micro digestion for Total Available Alumina (TAA) and Reactive Silica (RSi) at low temperature with 22 samples also analysed at high temperature by SGS Laboratories in Perth.
The test work has highlighted the consistency of the high-grade mineralogy with the presence of aluminium hydroxide (Gibbsite) as the most dominant mineral within all high-grade bauxite occurrences.
Advanced metallurgical testing allows Canyon to provide potential offtake partners with more detailed data on the performance of the bauxite, particularly regarding the high alumina recoveries and the optimal refinery conditions for the refining of the Minim Martap bauxite.