I have a question, Robin.
"Potash" is the common name for potassium carbonate. In your discussion, you discuss isolating potassium chloride ...
(or muriated potash, which would be potash reacted with muriatic, that is hydrochloric, acid, which would give you the chloride, thus the name)
... is the mined chloride chemically modified on the site to the carbonate, or is this done somewhere else ???
The usual process involves reacting the chloride with carbon dioxide to produce potassium bicarbonate, which upon heating yields the carbonate.
(Sorry about the chemistry, but I am interested in the process! And yeah, I am a chemist!)
If done off site at another plant, it might also be interesting if you had your trains ship the chloride to that plant, where the actual potash was produced. Another model to build !!!
Great model of the mine, and a very interesting process!