The easiest way to use the heat from mining is for space heating or water heating. This will be a very simple and reliable system that does not require much knowledge from the operating personnel. And the more complex and expensive the system, the more problems in the future.
Water heating?
I don't see how the heat from mining will be enough to heat water. Only if it's on a small scale.
Do you know of any concrete reports about this that you can share?