BEHAVIOR OF SELENIUM IN COPPER SMELTING SLAG

Selenium is a value added by-product of copper process. The lower recovery of selenium from the copper process is attributed to the high loss of selenium in the discarded slag. Knowledge of selenium behavior in slag is very important in the control of the selenium loss. The samples of slag and matte were collected from the smelter exit before their separation. The experiments involving slag-matte separation were performed at 1250 degrees C for 4 hours of soaking time under inert atmosphere in a vertical tubular furnace with the addition of selenium dioxide in different proportions. The association of selenium in various phases of the slag was determined using electron microscopic analysis. The selenium was found to be replacing the sulfur of the entrapped matte phase in slag. With an increase in selenium content, the size of entrapped matte phase decreased, thus causing high loss of copper in slag.