RE:gspsw248, yes the K+S Bethune mine, and Mosaic Belle Plaine mine are solution mines in Saskatchewan however they do not horizontally target thin seams of Sylvinite. Instead they bring everything in the brine solution to the surface and process all the impurities out of the brine which costs substantially more to do.
As mentioned before.....Take a strawberry shortcake and and try to run a straw through the strawberry filling without touching and of the rest of the cake.
Here is a GSP presentation describing the differences in techniques
https://gensourcepotash.ca/wp-content/uploads/2015/08/GSP-PPT-Comparing-BP-vs-SMERP-Feb2015.pdf You may recognize the term SMERP in this Gensource 2015 presentation, as a year later some noteable names filed a patent on behalf of Innovare for a process called SMERP.
GSP would offer to buy out Innovare's principals a few years later for approx $11.5 million in shares