avoid object overlaping

dear community¡¡

I am still in the theorical stage so I can't upload anything yet, and the question is this:

In a random object distribution in a 3d domain, is there any way to avoid object overlaping?

i.e. modeling concrete grain so no single grain would intersect each other, they must stay tangent at much (if it's well said...english corrections wellcome)

I could compute the intersection curve, and move one of the itersecting object through the curve's surface normal vector, but it could intersect with its adjacent grain object, so it would be recursive..

Maybe it is simple, but I don't see the way¡¡

Thank you.