A bent is a structural component under the superstructure of a bridge. Usually either multiple columns connected at the top or one column,(hammer head bent). These bridge columns sit on a pile cap or shallow spread footings. This foundation system is a bent foundation.
If the bent foundation is for a mill feed conveyor, I guess it must be the structure system to support the feed conveyor and the structure is to be supported by spread footing or pile caps. I am wondering if there will be a heavy lateral load applying to the foundation. Also since it is mentioned that weight of gallaries is 7 kN/m, how to calculate the vertical load applying to the footing or cap?
In your case the bents for a conveyor are usually pairs of columns, sometimes in the form of A-frames, and sometimes with bracing between the columns. The footings could be spread footings or piles, depending on the site conditions. And yes, there could be substantial lateral loading. The engineer who is designing the superstructure should give you the loads in order for you to do your work.