Help identify large white wheels
What you have there is a 6118 Wheel Hard Plastic Small (22mm D. x 24mm), and this wheel is pretty common, it features in 39 sets, but luckily for you only in 4 sets in the color White. These sets are:


1704-1  Ice Planet Satellite Plow - this set has 6 of these wheels.





6983-1 Ice Station Odyssey - this set has 10 of these wheels.





6814-1 Ice Tunnelator - this set has 4 of these wheels.





6898-1 Ice-Sat V - this set has 8 of these wheels.




If you count the number of wheels you have, you should be able to deduce which set they came from as each set has a different number of wheels.