What is Selenium?

Selenium is a semi-metal from group six of the periodic system and is closely related to sulphur. It is found in small quantities throughout the whole world and has an affinity with sulphuric ores. Copper ores contain between 0 and 20 ppm selenium. In copper reprocessing selenium is treated in the same way as precious metals and is separated from the anode slimes as crude selenium. The annual production comes exclusively as by-product from copper production and totals approximately 2,500 mt/a. Although selenium is an essential trace element, without which the body could not function, it is very toxic in larger doses.