• Godolphin Resources’ leach testing identifies conditions for optimal extraction of rare earths from its Narraburra project
  • Leach testing achieves 81% magnet REE extraction with limited deleterious element extraction and low acid consumption
  • Phase 3 metallurgical test work to be completed by early September, providing initial cost estimates for scoping study and enabling discussions with off-take partners

 

Special Report: Initial leach testing has identified the conditions for optimal extraction of rare earths from Godolphin Resources’ Narraburra project in NSW’s resource rich Lachlan Fold Belt.

The slurry leach phase of the Process Development Testing, which is itself part of the Phase 3 metallurgical testing, achieved 81% extraction rates of valuable magnet rare earths with limited deleterious element extraction and low (1-3.3kg/t) acid consumption.

Godolphin Resources (ASX:GRL) noted that the testing found the optimal leaching conditions to process Narraburra mineralisation are a 40wt% solid/liquid slurry density at pH 2.2 with 0.3-0.5M ammonium sulphate reagent at 50 degrees C over a 24 hour period.

This achievement is significant, as it represents a potential processing pathway for the project, which has an existing resource of 94.9Mt grading 739ppm total rare earth oxides, including a high-grade component of 20Mt at 1079ppm TREO.

Phase 3 metallurgical testing is designed to provide the required level of understanding of a mineral processing flow sheet for the project. It will also provide initial cost estimates to be used in a scoping study, while enabling the company to start discussions with potential offtake partners.

“We are excited to have completed the slurry leach phase of our Phase three metallurgical test work program at Narraburra. This is a critical step in understanding the optimal conditions to process the project’s REE mineralisation in an efficient and cost-effective manner,” managing director Jeneta Owens said.

“The results from the slurry leach phase have highlighted the optimal conditions required for processing the Narraburra rare earths mineralisation and demonstrated good MREO extraction with limited deleterious element extraction and importantly low acid consumption.

“These are critical factors when considering the economics of the project and will bode well for any future development initiatives.

“We are looking forward to the next steps of the metallurgical program, which include the solid/liquid separation and impurity removal steps, both of which are very important stages in processing REE mineralisation and the production of our first mixed rare earth carbonate or MREC sample, which will allow us to commence discussions with potential off take partners.”

 

Phase 3 testing

Phase 3 test work is being undertaken by the Australian Nuclear Science and Technology Organisation (ANSTO).

The slurry leach testing, which represents the first step of the program, had varied the temperature to understand its effect on MREO/impurity extraction percentage and process kinetics (time taken for optimised extraction).

While the best results were noted at 50C, the testing found that while MREO extraction was lower at 40C, the same was true of impurity extraction.

This will be investigated further in future studies to examine the trade-off between lower extractions, cost reduction from lower energy requirements and lower impurity levels in the mixed rare earth carbonate (MREC) product.

Slurry testing will be followed by solid/liquid separation, impurity removal and the production of a MREC product.

GRL expects to complete Phase 3 testing in early September, providing it with robust processing cost estimates, as well as an indicative MREC composition and value.

 

 

This article was developed in collaboration with Godolphin Resources, a Stockhead advertiser at the time of publishing.

This article does not constitute financial product advice. You should consider obtaining independent advice before making any financial decisions.

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