Arafura Resources Limited’s (ASX:ARU) initial results from drilling at Nolans Bore Neodymium-Praseodymium (NdPr) deposit include 43.62 metres at 6.0% total rare earth oxide (TREO) and 28% phosphorous pentoxide (P2O5) from 19 metres.
The phase I drilling has targeted shallow indicated resources and material types in the Southeast Zone of the deposit, which forms part of the broader Nolans project in the Northern Territory.
This zone was primarily modelled and estimated using data from previous reverse circulation (RC) drilling campaigns.
Encouraging results
The 43.62-metre interval in Hole NBDH1103 was within a 60.63-metre intersection from 14.81 metres at 4.7% TREO and 22% P2O5.
Significant results for the initial batch of samples from the 2019 drill program.
Five shallow infill resource definition core holes were drilled across Southeast Zone in this phase to confirm detailed geological and material type information.
The results and data will ultimately be used to refine resource modelling and better inform mine planning.
Further assays expected
Assays have been received from the first two core holes and the results are consistent with expectations.
All drill samples, including those from four deep exploration holes drilled as phase II of the program, have been submitted for assay.
Assaying jobs are in progress with final assays expected from all remaining holes during the first quarter of 2020.
Schematic cross-section showing assay results and mineralised interval in NBDH1103.
Flotation test work
Representative core samples of mineralised material types 5A1 and 5A2 were also selected from the first three holes drilled for flotation variability test work.
These tests have validated the beneficiation performance of additional Nolans Bore mineralised material which was previously excluded from ore reserves for Nolans project.
This work, together with an evaluation of rare earth recovery and impurity deportment data, gives Arafura the required confidence to adjust the geometallurgical model to now include 5A2 material.
New reserves estimate
An updated geometallurgical model will be the foundation of a new estimate of ore reserves for the Nolans project and this is expected to be completed by the end of March 2020.
The implication of the tests is that a substantial proportion of the 8.7 million tonnes of 5A2 material that was forecast in the project’s DFS to be stockpiled during mining has potential to be processed and in so doing converted to ore reserves.
This scenario was described in the DFS as an upside case production schedule which could extend the processing life of the project and improve project economic outcomes.
The recent drilling and associated metallurgical program were highlighted in the use of funds from the company’s recently completed fully underwritten $23.2 million entitlement offer.
Arafura’s primary objective with these programs is to increase the mine life of the Nolans project beyond 23 years.