What principle does electrostatic separation utilize?

Electrostatic separation operates on the principle that materials can be separated based on their electrical properties, specifically their charges. When materials are subjected to an electric field, those with different electrical charges will react differently: positively charged particles may be attracted to a negatively charged surface, while negatively charged particles may be attracted to a positively charged surface. This can effectively sort metals and other materials that exhibit different electrical conductivities or dielectric properties.

In this process, the materials are first charged, and then they are passed through a separation chamber where the electric field enables the charged particles to be directed towards specific collection points. This method is particularly useful in applications like recycling and mineral processing, where the separation of fine materials is required.

The other principles mentioned do not apply to electrostatic separation. Magnetic forces would be effective for materials with magnetic properties, gravity mainly separates materials based on density differences, and heat alters material properties but does not function to separate materials by charge.