Rincon -"Use it or lose it!", page-240

Not necessarily.  Sentient can walk and chew gum at the same time.  My understanding is that Sentient control 90% of the 232 sq klm halitic zone or roughly 21,000 hectares of the Rincon salar with a defined M&I and inferred resource of 8.3 million tonnes. 

Number 1, they do not need all that brine - they will NEVER use it all. Number 2, they are seeking to contruct a processing plant which will utilise higher-risk, higher cost, processing technology than the traditional method AGY intends to employ at commercial scale. It would make sense for Sentient to diversify their Rincon risk. 

Hypothetically, a 20% equity holding in the Rincon project for X hectares of Rincon salar would still leave AGY with 70% of a project with a large resource which could sustain a plant at 20K+ BG LCE per annum for a very long time. If the LPI PEA is anything to go by, the big financial returns kick-in with economies of scale above 20k per annum. 

Food for thought.