Just to be clear, although I have some concerns regarding the...

Just to be clear, although I have some concerns regarding the duration and temperature of the leaching performed during the lab test work, overall, I'm pleased with the initial results.

I was extremely relieved when I first read the preliminary metallurgical test results. My greatest fear was that the recoveries would be derived from leaching using Aqua Regia solution.

For those unfamiliar: Higher pH = less acid = less expensive and more environmentally friendly (I.e., for leaching purposes, pH2 is better than pH1; pH4 is better than pH2, Etc.)

The pH of Aqua Regia is between 0 and 1; therefore, it is very very acidic. This is bad for three reasons:
1. The cost of extra acid required adds extra expense to the leaching process.
2. In addition to the REEs, the strong acid solution draws out other (unwanted) elements. These "impurities" then need to be removed at a later stage thereby adding additional complexity and expense to the process.
3. The extra acid is bad for the environment.

Had Narruburra required Aqua Regia solution for the leaching process, it almost certainly would have been uneconomic. Leaching at pH2, on the other hand, is pretty good!

The initial leaching results appear promising. The fact Aqua Regia was not involved means Narraburra lives to fight another day! We just need some clarification on the duration and temperature of the leaching process. As these are only preliminary results, I'm sure these issues will be addressed as the leaching process is refined through additional test work.

I'm very excited as I eagerly await further test work from the lab.