The flotation method is mainly used to separate fine-grained and particulate weak magnetic hematite ore, including two processes: positive flotation (positive flotation with anionic collectors) and reverse flotation (reverse flotation with cationic collectors). Commonly used collectors include animal and vegetable fatty acids (soap), oxidized paraffin soap, crude tar oil, chlorinated acid, oxidized kerosene, sodium petroleum sulfonate, corn starch, etc.

• Positive flotation: Hematite positive flotation is a method of using anionic collectors to float iron minerals from raw ore. The flotation method is simple in medicine and low in processing cost, and is especially suitable for single hematite ore. However, it takes several selections to obtain qualified hematite concentrate, and the foam is easy to stick, making the product difficult to concentrate and filter.
• Reverse flotation: Hematite reverse flotation is a method of using anionic or cationic collectors to float gangue minerals from raw ore. The reverse flotation of anionic collectors is mostly used when the pH value is 8-9. It is used to treat minerals containing quartz gangue. After activation by calcium ions, reverse flotation is carried out with fatty acid collectors to obtain hematite concentrate. Cationic collector reverse flotation, the flotation agent used at this time is amine collector, which is suitable for flotation of quartz gangue. The amine collector is ether amine as the first choice, followed by aliphatic amine. The inhibitor of iron ore adopts water glass, tannin and sodium lignosulfonate, and the inhibitory effect is the best when the pH value is 8-9.

From the ore properties of hematite itself, reverse flotation has more advantages than positive flotation. Because the object collected by the reverse flotation process is gangue, and the object collected by the positive flotation process is iron minerals. Therefore, it is difficult to obtain high-quality hematite concentrate for minerals with serious inclusion of gangue minerals.