چكيده به لاتين
Researches have shown that the chemical composition of the feed entering the palletization plant specifically the Sulphur content influences the quality of the pellet, in as much as the allowable Sulphur content of the iron concentrate is 0.1 %. In this study, a pyrite-rich sample of magnetite iron ore from Gol-e-Gohar mine was considered to reduce its pyrite content down to less than 0.1 % through flotation process along with increasing the iron grade with magnetic separation process. In the first step, after characterization of the ore sample, initial iron grade of the ore and its Sulphur content were determined as 50.37 and 4.12 %, respectively. In the next step, after size classification of the ore sample, to determine the liberation degree, wet magnetic separation and microscopic analysis were done for three size fractions of the sample. The liberation degree for magnetite and pyrite in d80=106µ was obtained 80 and 85 %, respectively. Magnetic separation tests were conducted in d80=106µ with magnetic intensity, feeding time, feed water flowrate, and drum rotational speed of 800 G, 3 minutes, 4 liter/min and 54 RPM, respectively. An iron concentrate with iron grade of 63%, Sulphur content of 0.52% and recovery of 96%, was obtained. In order to reduce the Sulphur content to less than 0.52%, the concentrate was reprocessed by reverse flotation in which pyrite content was floated. Before conducting the flotation tests, a few preparation tests were done to achieve the optimum operational conditions. Finally, using a xanthate-type collector with 5 minutes preparation time in pH=9, Sulphur content was reduced to roughly 0.1%. Moreover, the yield and overall iron recoveries were obtained 95.96% and 94.9%, respectively. Furthermore, the possibility of using the saline water as an alternative to the currently used regular water in the flotation of pyrite with the aim of iron-concentrate desulphurization was investigated and results showed that at the present time the saline water is not a suitable possible option for this industry.
Keywords: Wet magnetic separation, Gol-e-Gohar iron ore, desulphurization, pyrite flotation.
