RE: Not16 Apr 2024 08:57
Another co. reporting concentrations and recovery rates that are far superior to COBR's. To re-cap COBR stated they had around 241ppm NdPr - RBW are today reporting that their latest survey shows they are sitting on between 1,116ppm and 1954ppm for NdPr at Uberaba, Brazil. Their stated recovery rate is also far superior to COBR's at between 31% and 65%. Certainly some very stiff competition for COBR.
Rainbow Rare Earths is pleased to announce the results of the mineralogy and hydrometallurgical test work recently carried out on phosphogypsum material from The Mosaic Company's ("Mosaic") Uberaba site in Brazil that is the subject of a memorandum of understanding ("MOU") between Rainbow and Mosaic.
As announced on 7 September 2023, Rainbow had assayed gypsum samples from different areas of the Mosaic stack, which were sent to SGS Laboratories in Lakefield, Canada for testing. The assays found to have the highest grade were those taken from the most recently deposited phosphogypsum material, which is the by-product of ongoing phosphoric acid production by Mosaic at the Uberaba site. This material demonstrated a grade of between 4,520 to 7,912ppm total rare earth oxides ("TREO"), with neodymium and praseodymium (together "NdPr") being 24.7% of the rare earths basket. The TREO grade thus being ca. 80% higher (based on current phosphogypsum material from the phosphoric acid plant at Uberaba) and the NdPr grade being ca. 50% higher than those at Phalaborwa. The Uberaba phosphogypsum stack has similar characteristics to Phalaborwa given that both stacks are based upon a hard rock carbonatite phosphate deposit. As such, the Uberaba material is amenable to direct acid leaching, which the testwork demonstrated can recover between 31% to 65% of the TREO.
Mineralogical evaluation of the leach residue carried out at SGS Laboratories in Lakefield, Canada, has revealed that 50% to 71% of the rare earth oxides are contained in monazite.
Due to mineralogy, a complementary route is being studied via hydrometallurgical and monazite concentration test work at Mosaic's lab in Brazil that will allow for increasing overall TREO recovery.
The phosphoric acid plant at Uberaba receives its phosphate rock feed from long life phosphate mines which offers the opportunity to recover rare earths from the current arisings of phosphogypsum from the phosphoric acid plant. The stack still represents a significant rare earths resource that can be addressed at a later date should the current arisings become the focus of the initial study.