You can use filtration to separate a mixture of a solid in a liquid or a solid in a gas.
Step-by-step explanation:
Filtration is a separation process in which a mixture is passed through a filter that allows one component to pass through uninhibited but blocks another component from passing through.
In general this method sorts by size, with the filter acting as a barrier that allows smaller particles to go through but keeps larger particles back.
Think of a colander separating spaghetti from water or a coffee filter holding back coffee grounds while water passes through.
In order to sort these mixtures, the components must be noticeably different in size/composition. Therefore the mixture must be heterogeneous.
Another example would be an air filter which helps to remove solids like dust or pollen in HCAC systems to give better air quality inside of your home.