I agree with the advice above.
The best way to sort this problem out is with ventilation.
If the shaft starts at surface it is very easy, if underground maybe more difficult.
Basically you need a fan of some description and some ducting.
Very cheap ducting is available in the form of polythene packaging. It comes as a long, lay-flat sausage, on a roll. Maybe 100 metres on one roll. When they use it for packaging it is heat crimped and cut with goods inside, making a sealed bag. However, for us it is the cheapest ducting you can get and comes in many sizes and strengths.
Just lay out the ducting down the shaft and blow some air in, letting the foul air drift out. Join lengths with a cut off oil drum and jubilee clips.
Les