I recall that there are some folks researching into ways that they can either use the heat or generate some additional electricity from the mining heat by-product.
I have had some discussions with power station engineers. The crux of it is that low grade heat (anything that is not hot enough to boil water) is considered a waste product and dumped to the atmosphere. And these are fancy, high efficiency co-gen plants.
So it seems pretty unlikely that they will be able to generate electricity if not producing over 100 C (which I assume not).
My information is about 8 years old so it is possibly out of date.