Yes, an electrostatic separator can be used to separate gold nuggets from sands in placer mines. Placer mining is a method of extracting gold and other precious minerals from alluvial deposits, such as riverbeds and beach sands. In these deposits, gold nuggets are often found mixed with sand, gravel, and other materials.

Electrostatic separation is a process that utilizes the differences in electrical conductivity or electrostatic properties of particles to separate them. When an electric charge is applied to the particles, they become either positively or negatively charged, depending on their electrical properties. Once charged, the particles are subjected to an electric field, which causes them to move according to their charge and mass. Particles with different charges will experience different forces and directions of movement, allowing them to be physically separated.

In the case of placer mining, the gold nuggets and sands have different electrical properties, which can be exploited by an electrostatic separator for separation. Gold is an excellent conductor of electricity, while sands and other non-metallic particles have lower electrical conductivities. This difference in conductivity allows the gold nuggets to become charged differently from the sands when subjected to an electric field.

By passing the mixed materials through an electrostatic separator, the charged gold nuggets and sands will experience different forces, leading to their separation. The gold nuggets, being good conductors, will tend to move differently from the sands, which have lower conductivities.

It’s important to note that the efficiency of electrostatic separation depends on various factors, including the size and shape of the gold nuggets and sands, the moisture content, and the type of electrostatic separator used. In placer mining operations, electrostatic separation may be employed as part of a broader processing approach that also includes techniques like gravity separation, sluicing, and panning to efficiently recover gold and other valuable minerals.