For the dust, how about an old, large fan (or several)? Make an open ended box to put it in, and attach filter media to the inlet end. If there's an air conditioning suppliers near you, they'll sell filter media or be able to sugest somewhere that will & it's not really expensive. I'd recommend at least F4 & preferably F5 filtration.
Just stick 'em up in your smithy so the dirty air gets drawn over the filter & the clean air recirculates around the shop.
For the fumes, perhaps you could score an old fume cupboard or similar? Would running an extract fan with a water bath on the outlet side work, like some do with their coal forges? Sorry, I'm in A/C as you may have guessed, but fume extraction / treatment isn't something I've been involved in.