Because fine powder does not support any shear, a first order assumption is that fine powder behaves similar to liquids. You may be able to use a CDF code (Fluent or ANSYS) for your simulation.
Powders do support shear which is why you can have piles of powder while you cannot have piles of water. I don't think that you will be able to find any software that will be of any use unless it is based on empirical data that you collect in a laboratry on the exact powder that you will be using. It is often more expensive to collect this data than to use trial an error to solve your problem. Assuming that powder will behave as a fluid is one of those error that can add to cost. Powder and Bulk Magazine is an excellent source of information and it is free to the trade.
Toner can become aerated where it does behave like a liquid or or can become packed and behave like a solid mass, depending on how you treat it.