A simple Google search gave me:
Micro-particle 564,000 Micron-particle 309,000
Are they interchangeable or is there a difference between the two? Here is an example:
Air filters remove dust, pollen and other micro(micron) particles from the air.
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Micron is another term for a micrometre. If you look at your Google results for
"micron-particle" again, you'll see that the majority of the results are either referring to particles of a specified size measured in microns (e.g., a 0.5 micron particle or a 3 micron particle), or actually have the text sub-micron particle, not just micron particle. A sub-micron particle is a particle that is smaller than a micron in size.
A micro-particle is a particle of a size in the micro- scale. The exact range included in this is not well defined as far as I'm aware, but the Wikipedia article on microparticles claims that is between 0.1 and 100 μm in size, which is probably reasonable. In specific fields within science and engineering the use of the term may be more tightly defined.
If the term micron-particle is used (without being preceded by a measurement) then it might be interpreted equivalently to micro-particle, or it might be interpreted as similar but with a tighter range. However, as a reader I would consider it incorrect and therefore slightly jarring.
In your example, micro particle is the correct term to use, since you are not giving a specific value for the size of particle.
I should also note that outside of science and engineering, the micro- prefix might be used or interpreted with less precision, in which case a micro particle would just refer to a very small particle.