Hi, Mary. There are some things that you can try but all have some element of fire risk. Be sure that you read and follow the label directions. Leave all the rags you use outside for a couple of days to dry completely before you even think of bringing them inside.
The first thing that I would try would be Citristrip Adhesive Remover. Next would be mineral spirits. This will take a lot of rags. I would not use a solvent any more "active" than these.
I can imagine that you would go through a lot of expensive sanding belts if you had much of the black stuff left.