Pantoro Reports on Prelimary PGM Results Generated by the Automated Mineralogy Incubator

Pantoro Limited (ASX:PNR) (Pantoro) is pleased to advise that it has the results of initial TESCAN TIMA, Scanning Electron Microscopy (SEM), on diamond core samples from the Lamboo PGE prospect at its Halls Creek Project (PNR 100%).

prelimary PGM results from Pantoro Ltd's Lamboo PGE prospect
Plates 1 and 2: Bright phase TIMA images for Platinum and Palladium provided by AMI.

The work was conducted by specialist group, Automated Mineralogy Incubator (AMI), at their Bentley laboratory in Perth. The work has successfully identified the occurrence and mineralogical association for a number of platinum group metals (PGM) and gold. The samples were all of oxide and transitional material. Fresh ore diamond core samples were not available for this work but fresh ore samples will be included in future geo-metallurgy studies.

The key aspect of this work was aimed at identifying minerals of the PGM group at a high resolution using the TESCAN TIMA instruments bright phase tool, which allows the reflectance of these minerals by electron backscatter.

The most common platinum group minerals found were, palladium, as native palladium, often with Fe and Cu; or as (Sb-Te)-palladinite, platinum and irarsite-ruarsite (iridium+rhodium and ruthenium sulphides). (Plates 1 and 2).

This geo-metallurgical work is preliminary in nature, and represents the first stage of Pantoro’s systematic approach to characterisation of the PGM material to guide future metallurgical test work programs.

Following the outstanding drill results reported in September and November 2021, the company has now prepared composite samples of both oxide/transitional and fresh PGM bearing material for submission to AMI. The next phase of work will entail pre-concentration and geo-metallurgical characterisation using the TESCAN TIMA Scanning Electron Microscopy in order to provide further insight into the mineral speciation and deportment of the PGMs especially in the fresh material.

Technical Background

Half core samples from diamond drill hole EDD18001 were submitted to specialist group AMI for preliminary mineralogical scanning utilising the TESCAN TIMA scanning electron microscope. Eleven samples of interest were selected. The samples were of oxide and transitional material, requiring the core to be resin impregnated and plugs extracted for mounting, polishing and carbon coating prior to the TESCAN TIMA scan. Scanning comprised a bright phase search targeting the platinum group minerals at a high resolution with a 1 μm pixel size and 10 μm neighbourhood search. In addition to this, a broader scan to establish modal mineral abundance was also conducted.

Due to nature of the sample locations and sizes being selective, the results of this work are considered to be indicative only in terms of the potential suite of PGM minerals identified. The PGM’s identified by this work were: platinum; palladium; palladium (Cu); palladanite (Sb-Te); irarsite; ruarsite and laurite. The last three minerals are arsenides of iridium+rhodium and ruthenium, which are other members of the platinum group. Assaying of these elements as well as osmium are currently being undertaken on a selection of the recent drill samples from the Lamboo drill program. (TESCAN TIMA images in Appendix 1).

Most PGM particles identified as part of this work are less than 8 μm in size, with the exception of a few palladium particles which reach a top size of 12 μm. Some palladium minerals were found where manganese oxides with chrome and nickel mineralisation were also present. Other minerals such as ruarsite and irarsite were found next to chromites within titanium rich chlorite laminations. Additionally gold, monazite, (Cr,Ni) Fe oxides, and galena seem to be the predominant phases identified with this tool.

Further Work

Separate composite samples of both fresh and oxide/transitional material have now been prepared for submission to AMI for an advanced mineralogy study, including a bulk mineralogy and deportment study of PGE’s and gold. This work will be on pulverised samples with grind establishment at P80 75 μm, and will involve pre concentration of the primary samples prior to the TESCAN TIMA SEM scan.

In addition to this geo-metallurgical work, samples of fresh material have been submitted for petrography which will form part of the lithological modelling for the Lamboo layered ultramafic. Oxide/transitional and fresh ore samples have also been submitted for full metal suite assays.

As announced on 22 November 2021 a rig was secured and has been able to drill unaffected by weather so far. The rig will continue to drill in advance of the pending wet season.

Appendix 1

prelimary PGM results from Pantoro Ltd's Lamboo PGE prospect
prelimary PGM results from Pantoro Ltd's Lamboo PGE prospect