In the world's skarn-type iron deposits, most of the useful minerals are magnetite. The high-sulfur magnetite contains sulfide ore, which makes the separation more difficult. If this ore is to be fully utilized, it must be desulfurized. Therefore, it is necessary to use the desulfurization and iron beneficiation process of magnetite containing sulfide ore.
The sulfur-bearing minerals of high-sulfur magnetite are mainly pyrite and magnetite. In fact, the processing technology of this kind of minerals is very simple. A single magnetic separation can obtain high-grade iron concentrate. However, the magnetic properties of pyrrhotite are also very high, and most of them will enter the iron concentrate during the magnetic separation process, which will affect the quality of the iron concentrate, and even make some high-grade iron concentrates become waste products.
So why do we have to desulfurize high-sulfur magnetite? This is because the sulfur in iron concentrate is very harmful, and sulfur forms SO2 during the sintering process of iron concentrate or rich ore powder is discharged from the flue gas, which not only pollutes the ecological environment, but also harms surrounding crops, and directly affects product quality, because sulfur is a more harmful element in steel, which causes steel to produce "hot brittleness", reduces the toughness and plasticity of steel, and deteriorates the quality of steel.
1. Stage grinding, stage desulfurization and iron separation process
The grinding fineness has a great influence on the beneficiation index. The products of different grinding fineness have different particle size compositions, thus affecting the monomer dissociation degree and selectivity of the minerals. Fine grinding can dissociate the iron ore monomers embedded with fine grains. Therefore, for iron ore with fine embedded particle size and single sulfur type (pyrite and pyrrhotite), stage grinding and stage separation process are usually used to achieve the purpose of iron extraction and sulfur reduction.
2. Magnetic separation-flotation combined desulfurization and iron separation process
The currently separated magnetite contains a large amount of pyrrhotite and pyrite due to its fine particle size, which makes the negative impact of magnetic agglomeration very obvious in the beneficiation process. It is more and more difficult to improve the concentrate grade of iron by a single magnetic separation method. Combining the magnetic separation method with anion reverse flotation can realize the complementary advantages in the separation process of magnetite ore, which is beneficial to improve the concentrate grade of magnetite ore separation. Therefore, the combined process of magnetic separation and flotation is one of the more effective processes for iron extraction and sulfur reduction in high pyrite.
3. Roasting-magnetic separation-flotation combined desulfurization process
The reduction roasting magnetic separation process of iron ore has not been widely used due to factors such as high cost and low iron concentrate grade. For weak magnetic iron ore with low theoretical grade and various types of sulfur content, iron ore concentrate with low impurity content can be obtained through the combined process of roasting, magnetic separation and flotation, which greatly improves the product quality.
Through the above introduction, we understand the effect of sulfur in iron concentrate on product quality, and introduce three effective desulfurization and iron separation processes. In recent years, the use of new beneficiation agents has also made the desulfurization and iron beneficiation work much simpler. No matter what method is used, the desulfurization of high-sulfur magnetite must be done, and it must not be sloppy. If you also need iron ore desulfurization, you can contact Xinhai, and we will discuss a suitable solution to help you improve the grade of iron ore concentrate and create higher profits.
