I've just designed a beauty. Balls are delivered in drums; drums are taken to the mill area by fork lift truck & placed on a platform from where they are taken by a drum tippler to the mill spout.

I was surprised by the simplicity of it all.

Conveyors should not be used under any circumstances in a congested area & as for ball counting...assume n balls per drum & multiply that by the number of empty drums at the end of the shift. Some humans are quite good at counting. ■