You could definitely "see" the world using only smells. However, touch would be a very necessary part of being able to make sens of the smells. In fact, touch is probably the most important sense for all animals (meaning it's always necessary, not that it's always the most developed) that can "visualize" their environment. Picture an organism with olfactory organs spread out along its body. By sensing the differences in each organ, they can get a rough idea of what is around them. But without touch, it wouldn't be very effective. This is because of wind.
Here is a list of pros and cons for different senses for visualizing an environment:
Light: Pros: Very fast. It works well for both very long and very short distances without losing much information. Cons: Very easy to form optical illusions, especially without depth perception.
Sound: Pros: Pretty fast. Work pretty well for long distances, and very well for short ones. Cons: Not as fast as light. Shape has significant effects on what "image" your "brain" will reconstruct.
Touch: Pros: Very Fast. Works very well for very short distances. Gives you a completely undistorted "map" of what you touch (most humans aren't highly attuned to seeing with their touch, so their brains' warp it into "seeing" what you think you are touching). Cons: Doesn't work well at all for long distances (except for vibrations). You nearly always have to touch something for you to have an image of what it looks like.
Electricity Pros: Fast. Works well in water. Good for semi-close distances. Cons: Doesn't work very well outside of water. Only works on things that give of a charge. Because of the nature of electricity, it's better for finding the general direction then creating an image of the world. Touch would be needed to get more then a general idea of your environment.
Taste Pros: Pretty fast. Gives you very detailed information on whatever you taste. Cons: Of no use for making an image without the sense of touch.
Smell Pros: Gives you detailed information on whatever you smell. Cons: Very slow when compared to the other senses. Of no use for making an image without the sense of touch. Even then, smells can only give you a very general view of the world. Touch would probably end up being dominant.
Note: Taste and smell senses differ only in that taste is generally sensing solids and smell is fluids (as used by me).
Or at least that's the way I perceive it. I tried to order them from most to least effective. The bottom three become much more effective when they are combined with touch.
Edit: If anything needs clarifying, ask, because I will otherwise assume you know what I meant.