Well, there's 2 possible customers that we know of: HC Starck...

Well, there's 2 possible customers that we know of: HC Starck Tantalum and Niobium GmbH, and Global Advanced Metals Greenbushes Pty Ltd.

See previous Tawana announcement 25 Oct 2019 "Bald Hill JV Tantalum Concentrate Sales":
https://www.asx.com.au/asxpdf/20181025/pdf/43zlchp767c74d.pdf

There could also be other customers, we don't yet know.

One of the previous customers catches my attention, its called Greenbushes, and I believe it is just down the road, reachable by truck, one truck in fact should it be a 20-40 tonne truck.

Here's the details on Greenbushes:
https://www.globaladvancedmetals.com/our-operations/gam-resources/greenbushes-australia.aspx

I don't know that it was sold via Greenbushes, because why would one of the largest Lithium and Tantalum mines need our product? But, it has happened in the past, and as you say there wasn't a boat .. so ..

Although we wouldn't need a boat to ship 20 tonnes, could send that in containers by sea without booking an entire boat.

In fact, 20 tonnes could easily be sent via a single container, on any normal container shipment boat / truck / train / etc.

I guess we may never know...