عنوان مقاله [English]
Flotation is the most commonly used process for desulfurization of iron concentrates in iron beneficiation plants. The current study deals with improving the metallurgical performance of the flotation circuit at Sangan iron beneficiation plant. A plant survey indicated that sulfur content of iron concentrate is sometimes higher than that of the permitted limit used for the pelletizing plants (<0.25%). For this purpose, laboratory and full-scale experiments were carried out. In the batch flotation tests, the effect of collector dosage (65-105 g/t), frother dosage (45-75g/t), pH (6-10) and slurry solid content (27-33%) was examined against sulfur recovery. The results showed that the collector dosage, pH, frother dosage and slurry solids% are the most significant parameters in terms of sulfur recovery, respectively. The metallurgical performance improved with increasing the collector and frother dosage as well as reducing the pH. In the plant site tests, the influence of collector distribution method in the flotation circuit, collector dosage (65-105 g/t), frother dosage (37-85 g/t) and slurry solids% (25-33 g/t) on the flotation circuit performance was investigated. The results indicated that the optimum metallurgical performance was achieved when collector addition is divided into three parts: 50% was added to the rougher feed, 30% to the cleaner feed and 20% to the scavenger feed. Increasing the collector and frother dosage resulted in an increase in the sulfur recovery and a reduction in iron concentrate sulfur content. Increasing the slurry solids% was found to be beneficial to the sulfur recovery and detrimental to the quality of the product.