High-tension electrostatic separators utilize the electrical conductivity difference between the various minerals within an ore feed. The high-tension roll electrostatic separator (HTR) utilizes a grounded roll to transport feed material through the high voltage ionizing field (corona) where particles are charged by ion bombardment. Conducting particles pass their charge to the grounded carrier electrode (roll) and are therefore free to be thrown from the roll by centrifugal and gravity forces. Non-conducting particles are pinned to the carrier electrode and are transported further around the roll periphery, where they drop from the electrode surface, either because their charge dissipates, or by mechanical means, e.g. brush and high voltage AC wiper.

Throughput capacity of a high tension electrostatic separator is closely related to the roll speed, roll width, and characteristics of the feed material. For a roll with a smaller diameter, a higher rotation speed is required in order to maintain a substantial feed rate. However, at higher RPM, coarse, non-conductive particles tend to leave the roll surface too early due to the increase in centrifugal force resulting in a large portion of misplaced non-conductive particles in the conductor stream. Vice versa, under a low RPM condition, fine conductive particles do not gain enough inertia to be thrown off the roll, resulting in misplacement of the nonconductor stream. Therefore, for the treatment of particle mixtures with a range of physical characteristics, including conductivity, particle size, and density, it is necessary to adjust the roll speed and electrode positions to optimize the process.

Application Area of  high tension separator

The electric separator separate coltan and cassiterite by the difference electrical conductivity of the coltan particles and cassiterite particles. use high voltage electrod to attract the electric minerals, and dumped the non-electric minerals. This machines has been used to separate & refining the monazite, zircon, tin, ilmenite, tantalite, rutile and etc.
 

Detailed pictures of   ARC-type electrostatic separator