It seems you are using it correctly.
Basically, dt is the time per tick (in seconds per tick)
When you want to modify a value V (for exemple a distance in pixels) at a certain variation DV in unit_of_v / seconds (pixel per seconds in our exemple), since you are acting each tick, you have to apply each tick:
New_V (unit_of_V) = V (unit_of_V) + DV (unit_of_V / seconds) * dt (seconds/tick)
Basically 60*dt is an easier way of implementing it (since you won't see a difference at 60 fps, which means you are deplacing it in your case at 2 pixels per 1/60 seconds, which is considered the normal tick)