Hi there and thanks in advance!

My name is Chris, I'm a chemist who's been put in charge of getting the boss's new salt plant running smoothly. He owns several small companies and I'm the closest thing to an engineer! But here is the basic setup I need help with:

We take wet salt, pass it through a 30 foot rotating tube furnace. Then it passes through a size screener, the large pieces go through a crusher and the smaller pieces move into a large hopper, which then loads the salt into a bagging machine and it's done. The salt has to dry in the furnace but cool down enough after the furnace to be bagged. The approximate temperatures are 200*F for drying and 160*F for bagging.

Here are some general questions that I would love some help/general equations for:

1. Given the furnace dimensions, what speed will the furnace have to rotate to move the salt at a certain speed?
2. Depending on the depth of the salt on the belt, approximately how fast can I expect the salt to cool related to atmospheric temperature? What about cooling in the large hopper? I imagine it will be very insulated.