Solid state chemistry Sedimentation rate

It is not entirely clear, sedimentation does not occur between true solutions, or do you mean the formation of a precipitate?

@argentum Yeah, I think so. The question was about reaction between to solutions, I think it implies formation of a new compound 

Unfortunately, the only true answer may be found in catalogs of constants. But you can safely say that compound must be formed with great energy benefits, molecule of reactants must have a greate mobility and the product must have a low compatability with solvent

@anastasiap I also have some questions. What is meant here by a true solution? How do the true solution and the deposition rate correlate? What does a chemical reaction have to do with it?

@damiryagudin I think in this case true solutions is the ideal ones. The most important part is that it doesn't have any particles for the start of sedimentation process

In any case, the particles of the dissolved substance will be located, for example, in water or another solvent.

Either colloidal solutions or suspensions. Then some kind of precipitation is possible.