How do you separate sawdust from salt paper clips and gravel?

Answer 1

You canseparate them with a liquid known a sulfuric acid. (it penetrates thought almost anything) Those things that are not soluble can be removed by filters, the sawdust, sand, rocks and iron. The salt and soluble iron will need to be removed chemically. You can evaporate the water and you'll have the salt after removing any iron chemically.

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The question didn't say anything about destroying any of the materials! Sulphuric Acid is highly corrosive and would attack the iron and sawdust at least. And your skin if you splash it on yourself.

I'm not sure about the salt but it would not harm the sand (quartz, or silicon dioxide grains).

You can extract the rocks by sieving the mixture; and the iron (filings I presume) with a magnet. That's a start.

Now you can flood the mixture with water and let the sawdust float. Scoop it from the surface of the water, and dry it.

That leaves sand and salt. Dissolve the salt, filter the brine to remove the sand; dry the sand and evaporate the brine to leave the salt.

BTW I hope Dale and I were not helping someone cheat with what look suspiciously like a homework question....