Based strictly on the OP data:
200 TPH = 400,000 Lb/Hr assuming 2000 pound Tons
400,000 Lb/Hr = 400,000/60 = 6666.67 Lb/min
Conveyors are uniformly loaded normally.
A belt speed at 160 FPM means in one minute, 6666.67 Lb of material is spread out over 160 feet
OR 6666.67/160 = 41.67 Say 42 PLF material load
This is most likely not conservative, because conveyors are run overloaded all the time in industrial operations.