If you mix sawdust and sand together, how can you then separate them?

Answer 1

Put them in water. The sawdust will float and the sand will sink.

Answer 2

Alex, you ask the most interesting questions.

I'd winnow, like they do on the farm when separating the wheat from the chaff. Wheat being heavier than chaff, falls downward in a pile and chafe being lighter blows sideways in the air and away from the pile. Check this out:

"win·now (wn) KEY

VERB:
win·nowed , win·now·ing , win·nows
VERB:
tr.


To separate the chaff from (grain) by means of a current of air. " [See source.]

In your case, the sand is the wheat and would drop pretty much downward and the sawdust is the chaff and would blow off sideways. Find a nice drafty place. Put your mixture in a pile on a fabric. Grab the fabric on the four corners. Snap the fabric up and down so the pile levitates and comes back down repeatedly. During each levitation, the sawdust should be blow off and away from the fabric; while the sand come back to the fabric.

I am presuming, of course, that the sand has a higher drag to weight coefficient than your sand. But if your sand is very fine (very light) or your sawdust is large or wet (very heavy), this might not work.

Another way might be to float the sawdust off. Simply put the mixture in a bucket of water and skim off the sawdust that floats up to the top. But, beware, as the sawdust gets saturated with water it could sink to the bottom along with the sand. So be quick in your skimming.

A final try...simply put the mixture in a sieve with holes large enough to let the sand through, but small enough to keep the sawdust in. This assumes the cross sectional area of the sawdust is greater than that of the sand of course. If that's reversed, the sand will stay in and the sawdust will fall through. But in this later case, you'll have to do some major shaking of the sieve to encourage the sawdust to move downward among the sand. And I'm not sure that would happen.

Answer 3

you could spread the mixture in a thin film over a conveyor belt, pass the belt through a drying oven then blow the sawdust off and/ or spray ions onto the mixture and rely on the sand falling off the end whiile the sawdust sticks to the belt, ready to be scraped off later.

Best of Luck - Mike

Answer 4

Put the mixture in water. As sand is heavier than water, it will settle down to the bottom of vessel while saw dust being lighter will float on the surface.

First saw dust can be collected from the surface. Then drain the vessel and collect sand which is at the bottom.

Answer 5

Well, crush it with a hammer. The salt should shatter into tiny pieces and the sand should not. Then run that through a filter and the salt and sand should be separated.

Answer 6

If you vibrate the sample the mixture will separate into layers based on the density of each material.

You can basically use any differing physical property for separation and density looks like the best candidate.

Answer 7

Use a vaccum cleaner with high enough suction to draw the dust, but too weak to draw the sand.

Answer 8

Put them in water, the sawdust should float.

Or burn them and blow off the ashes.

Answer 9

The sand is both smaller and heavier, so it will sink to the bottom, especially when agitated, tossed, etc. Put a screen mid-way in a two-level container and you can find only sand below the screen.

It's how people panned for gold, or separated wheat from chaff, before higher tech methods.

Answer 10

Actually, this exact question has been asked and answered. Came across it in my research. Sorry.
Links below.