چكيده به لاتين
Abstract
In this study, iron recovery from tailing of iron ore concentrate plant of Sangan iron ore mine located at 335 kilometers southeast of Mashhad was studied. A significant amount of iron ore concentrate tailings containing pyrite, hematite and magnetite has been stored around the mine. This work focused on the recovery of iron from tailing by reduction roasting using lime and graphite.. Roasted tailings were further concentrated by magnetic separation method. The roasting of tailing in the presence of lime was conducted under various conditions to evaluate the effects of tailing- lime ratio, temperature and time on the roasting rate and iron recovery efficiency. The results revealed that by increasing time, rates of roasting with lime is decreased while roasting rate increases as temperature increases up to 475 oC. and shows a maximum value at this temperature. It has also been shown that the rate of magnetic roasting in the presence of carbon has been increased by increase of temperature up to 1000 oC.
The optimumroasting conditions of tailing in the presence of lime and carbon are as follows: a) lime-tailing ratio of 1 to 1.7, roasting time is 60 min and temperature is 475 oC; b) for magnetic roasting with graghite: reduction time is 30 min, temperature is 1000 oC and tailing-graphite ratio is obtained as 3 to 1.
Under the above roasting conditions, the efficiency of iron recovery of 67 percent has been obtained compared with recovery efficiency of 27% for unroasted sample.
Keywords: Iron, Tailing, Roasting, Iron Ore, Sangan Khaf, limestone, graphite
