How to recycle 60 tons/hour of CaCO3?
60 tons on $\ce{CaCO3}$ per hour means half a million tons per year. That's quite some calcium carbonate.

Hens need $\ce{CaCO3}$ to produce eggs. So the most natural idea to recycle it is to produce feed lime.

Or consider producing agricultural lime. The annual consumption of agricultural lime is about 2.5 million tons in Germany, and about 25 million tons in Brazil. Your production is in this scale. The presence of 3% proteins is probably of little concern if not beneficial.