Separating salt from gravel using solubility curves?

Hi guys,

Can anyone explain to me please how would I use solubility curves in separating a mixture of salt and gravel to prepare pure salt crystals?

I initially assumed to add water to the mixture and stir until all the salt had dissolved and then separate the mixture using a sive. Then I would slowly heat the brine mixture until all the water had evaporated producing the salt crystals.

But I dont know if this is the best method? Would the salt be considered pure crystal? And more importantly how would I incorporate the solubility curve in this process?

Thanks in advance.