Assuming you're using DPM (the only model which can give an incomplete track) just create a second injection which uses a different material. You'll need to create the first injection to get anthracite in the materials list, copy it (don't overwrite) and adjust to suit. You can also copy the original injection and modify if you don't want to set up from scratch.
Incomplete is a different issue. The warning is triggered by particles remaining in the system for too long (read up on how it works). Look at the tracks (colour by residence time) to see where they're getting stuck. Then look at the flow field to see why. Post images for review/comment.
What mesh & turbulence model did you use?
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