Some of us use perlite in potting mixes and for starting cuttings. It’s useful to improve drainage without adding weight. However most of the perlite contains too many fines. The fines are dangerous to breath and don’t serve the desired purpose of improving drainage and increasing aeration of our mixes.
So I made up a box with 1/8 inch hardware cloth on the bottom and sides about 4 inches high. This was used to screen the perlite to remove the dust and fines. The key to making this safe and easy was to use water as the separation agent. About 1 inch of pertile was placed in the screen box. Then the perlite was sprayed with water to wet the dust and agitate the fines down thru the screen. In no time the fines are gone without a dusty mess and with minimum breathing issues. I used a hose end nozzle with the adjustable spray pattern. Start with a wide pattern over all the perlite to wet it and knock down the dust. Then work back and forth over the material about twice with a strong tight spray. 100% of the fines are removed.
Fines on the left and course on the right. The fines are wet and clumped together. The course dries out in nothing flat.
I’d say about 10-20% of the initial volume of perlite was removed as fines.