Skarn iron ore is a type of iron ore deposit related to contact metamorphism of intermediate-acidic intrusive rock bodies. The ore minerals of this type of iron ore deposit are mainly magnetite, and hematite, siderite, specularite, etc. can be seen. The gangue minerals are skarn mineral combinations, such as garnet, diopside and hematite. Skarn iron ore is an important iron ore resource. The selection of mineral processing procedures and equipment is an important link to improve the quality of iron concentrate. This article introduces the main mineral processing procedures and key equipment.
The beneficiation process of skarn iron ore usually adopts a combined process of magnetic separation + flotation + magnetic separation. The main operation stages include crushing and screening, grinding and separation, and dehydration. The ultimate goal of this process is to effectively separate iron minerals from gangue and other harmful impurities to obtain high-grade iron concentrate. The process flow of the three stages is as follows:
1.Crushing and screening process
Crushing and screening is the preparatory work before mineral processing, and its purpose is to crush large pieces of ore to a particle size suitable for grinding. This stage adopts a three-stage one closed circuit + water washing process. First, the ore is coarsely crushed by a jaw crusher, and then sent to a hydraulic standard cone crusher for medium and fine crushing. Finally, it is screened by a vibrating screen and washed at the same time to remove the dirt and fine gangue on the surface of the ore.
2.Grinding and separation process
Grinding and separation is the core of the entire mineral processing process. Its purpose is to separate iron minerals from gangue by grinding, and then enrich iron minerals through separation operations. The grinding stage adopts a two-stage closed circuit method, consisting of an overflow ball mill and a hydrocyclone. The crushing and screening products are first coarsely ground by a grate ball mill, and then classified by a high weir double spiral classifier and a submerged double spiral classifier. The slurry after classification enters the mixed flotation stage, and the flotation tailings are fed to the magnetic separation.
Magnetic separation is a process of separation using the magnetic difference of iron minerals. After the magnetic concentrate is finely screened, it is subjected to three stages of magnetic separation and filtration to finally obtain the iron concentrate. The medium ore in the fine screen and magnetic screen is dehydrated and magnetically separated, then returned to the regrinding mill for regrinding, and then returned to the magnetic separation process.
3.Dehydration process
The dehydration process is the last stage of the mineral processing process, and its purpose is to remove excess water from the iron concentrate for transportation and subsequent processing. The weak magnet concentrate is filtered by the inner filter drum filter, while the strong magnet concentrate is filtered after being concentrated by the concentrator. After the tailings are concentrated, they are sent to the tailings pond or filling station by the isolation diaphragm pump.
Jaw crusher: used for coarse crushing of ore, with the characteristics of large crushing ratio and high output. The coarsely crushed ore is fed to the cone crusher for medium crushing.
Hydraulic standard cone crusher: used for medium and fine crushing of ore, with adjustable discharge port size, strong adaptability, and used in conjunction with vibrating screen.
Vibrating screen: used for screening and washing of ore, which can effectively remove soil and fine gangue on the surface of ore.
Grate ball mill: used to receive ore after crushing and screening, and further coarse grinding of ore, used in conjunction with classifier.
High weir double spiral classifier and submerged double spiral classifier: used for classification after grinding, which can effectively separate ore particles of different particle sizes.
Overflow ball mill: used for grinding ore, which can achieve fine grinding of ore and improve the dissociation degree of minerals, and used in conjunction with hydrocyclone.
Hydrocyclone: used for slurry classification, which can divide the slurry into overflow and sedimentation parts according to the particle size.
Magnetic separator: used for magnetic separation of iron ore, which can effectively separate according to the magnetic difference of iron ore.
Internal filter drum filter and concentrator: used for dehydration of iron ore concentrate, which can effectively remove moisture from the concentrate.
In short, skarn iron ore is an important iron ore resource. Making full use of this resource and obtaining high-grade iron ore concentrate is of great significance for resource development. In actual production, it is recommended to conduct mineral processing tests, and the ready-made mineral processing process cannot be applied, because the mineral composition of each mine is different. Xinhai Mining can provide mining companies with mineral processing tests, scheme design, equipment installation, plant construction and operation and other mining industry chain services. If you have mineral processing needs, please contact us.
