There is no such thing as a "beard friendly dust mask". It can be a dust mask, or it can be beard friendly. If the latter, then it's a dust inhibitor, i.e. it will cut down on the amount of dust that will make it to your nose and mouth, but it WILL NOT seal nearly as well as a mask on a clean shaven face.
There's a reason that every European (and most other) army in the world went clean shaven about a century ago after centuries of martial facial hirsuteness. Gas masks don't seal on bearded faces. The various militaries, as well as legions of industrial safety folks, have been trying to develop an effective filtration mask for bearded folk since, and have yet to succeed. Thus, you've got three choices. Use whatever dust mask you'd like, knowing that it will operate less than optimally as long as you have a beard. Spend the coin for a hood setup, which WILL keep everything out. Shave.