Sulfur Content Reduction and Iron Grade Improvement of V-Ti Magnetite Concentrate by Combining Reverse Flotation and Magnetic Separation

Abstract

For low-grade iron ore, smelting costs and resource wastage will be increased. Product quality of such ore is affected adversely by an excessive amount of sulfur. This also causes environmental pollution. In accordance with the vanadium-titanium (V-Ti) magnetite concentrate properties with low iron grade and high sulfur content, the joint process of magnetic separation and flotation was carried out. Magnetic separation was conducted to increase the iron grade, while reverse flotation was used to reduce sulfur content. Results show that the feeding mainly contains titanomagnetite, hematite, and pyrite. The sulfur was primarily found in pyrite. The separation effect was influenced by the grinding fineness, magnetic intensity, collector type and dosage, and pH value. At a grinding fineness of −45 μm accounting for 87%, most of the iron minerals exhibited monomer dissociation. An open-circuit experiment was carried out under the best conditions of magnetic intensity, as well as collector and modifier dosage. Good experimental results were obtained as follows: the iron grade increased to 57.17%, iron recovery was 89.94%, sulfur content decreased from 0.66% to 0.26%, reverse flotation of sulfur foam concentrate contained almost 15.68% sulfur, the upgrade ratio was about 23, and the cobalt in the sulfur concentrate was enriched 20-fold. A method for improving the comprehensive utilization level and effect of mineral resources is provided in this study.