I would have thought NSL would tweak their product to a certain...

I would have thought NSL would tweak their product to a certain spec that's broadly accepted by the steel industry, and have that certified by a third party.

Something like the specifications at the bottom of this page:
http://www.ironorebuyers.com/submit-iron-ore-sample/

Interested parties would then go through a similar process listed on this page (http://www.ironorebuyers.com) to purchase initially a small amount for testing I would think? Followed by a larger purchase order.

Just my guess tho.

NSL could also be looking at supplying all their product out of the current plant to a specific customer. In which case, you would expect them to be working very closely with the client to test and ensure the specification is correct. However, it would appear this would tie the plant down to the consumer, requiring further tweaking if we decided to sell on the open market?

All IMO. I have no experience in this area.

PS. or they could just sell on Alibaba LOL https://www.alibaba.com/showroom/want-to-buy-iron-ore.html