Seems to me that this process is similar to extracting NaCl...

Seems to me that this process is similar to extracting NaCl (common salt) from water . This is reasonably straightforward - it deploys a process called fractional crystallisation. Issues we have in Australia with deposits of K2SO4 is their remoteness - not so with sites for extracting common salt.
Remoteness introduces issues of the rights of First Australians and transportation. Appropriate permissions etc with traditional land owners seem to have been granted but the transportation question remains unanswered
If/when we get this sorted then we are in business. I am optimistic.