The 3 steps that show the separation of sand and salt are:
1) Dissolving Process: Stirring a mixture of sand and salt in water.
2) Filtration: Filtering the resulting solution.
3) Evaporation: Heating the filtrate solution.
The idea inherent in sand and salt separation is the solubility of these materials in water. While salt is completely soluble in water, sand is not. The first step of the separation process is the gentle mixing of these materials in water, which will cause the salt to dissolve completely, while the sand will be left undissolved. The second step of filtration (through filter paper or piece of cloth) will separate the sand from the solution and all the sand will be retained on the filter paper. The filtrate (solution that has been filtered through the filter paper) will be the salt solution. The final step is the boiling of the solution so as to ensure complete evaporation of the water, which will leave only the salt behind.
This way we can separate out salt and sand in three simple steps.