general discussion, page-1256

Thanks Ken,

I have been looking at processes for extracting Mg from ferro nickel slag for extent of similarity to the hydromet process. Looking at the literature:

1.https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6777126/

Xin Zhang, Foquan Gu*,Zhiwei Peng*, Liancheng Wang, Huimin Tang, Mingjun Rao, Yuanbo Zhang, GuanghuiLi, Tao Jiang, and Yang Wang(2019), Recovering Magnesium from Ferronickel Slagby Vacuum Reduction: Thermodynamic Analysis and Experimental Verification,

Recovery of magnesiumreached 97.74% however it looks like a fairly expensive process as it requiresaddition of about 50% Si and also CaO.

2. https://www.researchgate.net/publication/349165004_Magnesium_Extraction_of_Ferronickel_Slag_Processed_by_Alkali_Fusion_and_Hydrochloric_Acid_Leaching

Prasetyo, Agus Budi & Khaerul, A. & Mayangsari,Wahyu & Febriana, Eni & Maksum, Ahmad & Andinie, J. &Firdiyono, F. & Wahyuadi, Johny. (2021). Magnesium Extraction ofFerronickel Slag Processed by Alkali Fusion and Hydrochloric Acid Leaching.Journal of Mining and Metallurgy, Section B: Metallurgy. 57. 18-18.10.2298/JMMB200224018P.

The highestmagnesium extraction percentage is 82.67% that resulted from an optimum acidleaching condition with temperature of 80 C. This is a bit closer to the hydrometprocess in that after a sodium carbonate fusion they use acid leach.

3. https://www.researchgate.net/publication/313488782_Synthesis_of_Magnesium_Oxide_from_Ferronickel_Smelting_Slag_Through_Hydrochloric_Acid_Leaching-Precipitation_and_Calcination

Mubarok,Zaki & Yudiarto, A.. (2017). Synthesis of Magnesium Oxide from FerronickelSmelting Slag Through Hydrochloric Acid Leaching-Precipitation and Calcination.10.1007/978-3-319-52192-3_24.

Even closerto the hydromet process as it uses acid leach and calcining. By adjusting the Phto 11-12 after acid leach they could precipitate as Mg(OH)2 and then calcine itto MgO. Magnesium extraction of 97% was obtained from the slag leaching withHCl 8 molar, solid:liquid ratio 1:40 (g/ml) and temperature 80 °C after 24 h.

Given thatwe have acid leaching tanks as well as a calciner it seem s2 and 3 above are closest to the hydromet process and not a lot of difference between them

LMG must have done some comprehensive testing because why would they establish a binding MoU with Société Le Nickel (SLN), for the supply of 450,000 tonnes per annum of ferro-nickel slag over 20 years?(https://www.latrobemagnesium.com/projects). I would have thought they would have the process up on their website unless it’s in the process of seeking a patent.

Curious as to what their plans are.