Sarissa Resources Inc (SRSR)

[Tom Orrow]

The 60 grit grinding of the ore is estabished as enough to expose the niobium grain among the gangue component? The beneficiation must have been done in the 50s at least on the bench and apparently in a pilot plant.

I understand the pre-oxidation is roasting of the exposed niobium at very high temperatures because the oxide can be dissolved in sulpheric acid. Not sure about the desliming, as I would expect the oxidized ore to still be dry sand at that point.

What are cocl2 and cacl4? Are they acids?

In my understanding, the oxidized niobium sand is submerged in a pool of dilute (35 - 50%) hot sulpheric acid that is semi-saturated with niobium. The concentration of the acid is controlled so that it doesn't react with the "alkeline earth metal" gangue but it does "digest" the niobium into a solution with the acid.

There are three stages of "digestion" -- after each, a centrifuge separates the acid from the ore, and after each the ore contains less and less niobium and the acid contains more and more niobium. The acid from the third stage is recycled into the first stage so the ore with the highest niobium is reacted with the acid that is most saturated with niobium.

I don't know why the acid is recycled that way.

I thought that the niobium was recovered from the acid by precipitating it with organic solvents. Is this what you meant by offgases? What is nbcl5?

I thought the precipitate would be Nb2O5.nH2O / niobic acid, that would be processed into niobium oxide.

Is this different than the chlorination / phosphogenation that is demonstrably operable in Chance's report?