Ann: Rincon Lithium Project Drilling Update, page-81

Further to this, I think perhaps the bags may be being stored to offer a degree of contingency.

The company will be contractually obligated to deliver X tonnes per month, and having extra tonnes in the bank will help offset any unplanned downtime (maintenance, optimisation etc).

If the plant was to stop for whatever reason, the company would still need to deliver, or potentially pay penalties - I'm not saying this is the case for AGY, but it is often a clause in supply agreements.

I'm also not saying "contingency" is the reason for stockpiling the product, but it would be comforting to know that management were assessing the different types of risk and planning this far ahead.