Rob
Ansys Employee
Anthracite is the default material as it was added when Fluent DPM was developed to burn coal.
Take a large step away from the computer. Get a sheet of paper and sketch out the geometry you want to model. Add any boundary information you have (inlet, outlet etc) and calculate the Reynolds Number. Post that image on here, and we'll be able to offer advice. Use engineering terms, don't worry about the CFD part. At the moment, you're asking the wrong questions, and it's difficult to help as we're not sure what you are trying to model.
One of the steps to learning to use CFD is to fully understand the physics of the application. Then you can figure out what models are suitable, and even whether you need to use CFD. We often work through problems by sketching out the system and applying a bit of experience. Only then do we switch on the software.