fiberboard,vermiculite,cellulose,or polystyrene
You can use a magnet to take out the iron by passing it over and stirring it around the mixture. Then submerge the mixture in water to dissolve the salt then strain, and boil off the water to leave only salt. Then you could heat the remaining sand and vermiculite. Since the vermiculite should expand, you could filter/strain the sand out through a strainer.
Use a magnet to remove the iron filings first. Then pour boiling water into the sand/salt mixture and stir it until the salt is dissolved. Filter off the sand and set it aside, then boil the salt water until the water evaporates or leave it in an evaporating basin. You now have three separate piles of iron, sand and salt, although I doubt they'd be really pure. In the future, you can get a faster answer by searching questions that are already closed. (A search for sand, salt, iron brings up other chemistry students who have also asked this question.) Have fun!
