Very small insoluble particles in a liquid may be separated from it by using

Centrifugation is the most effective technique for separating very small insoluble particles from a liquid, especially when normal filtration is insufficient [1]. The process involves spinning the mixture rapidly in a centrifuge, where centrifugal force causes denser insoluble particles to move to the bottom of the tube, forming a pellet, while the lighter liquid remains at the top [1]. This method is specifically based on particle size, shape, and density [1]. In contrast, decantation is better suited for larger particles that settle quickly under gravity. Crystallization is used to separate dissolved solids from a solution rather than insoluble particles. Fractional distillation is employed for separating miscible liquids with different boiling points. Therefore, for very small insoluble particles that do not settle easily, centrifugation is the standard scientific method [1].

Sources

1. [1] https://satheejee.iitk.ac.in/article/chemistry/chemistry-decantation/