Hematite ore has the wide distribution and involves many kinds of minerals. Therefore, the hematite ore separation methods are not single, mainly including flotation process, magnetic separation process, gravity separation process and roasting magnetic separation process.
Hematite flotation process
back to top
Flotation process is mainly used for the separation of fine and micro-fine weak magnetic hematite, including positive flotation process (positive flotation of anionic collector) and reverse flotation process (negative flotation of cationic collector). Commonly used collectors include tallow fatty acid (soap), vegetable fatty acid (soap), paraffin soap oxidated, acid chloride, oxidized kerosene, sodium petroleum sulfonate, corn starch, etc.
1. Positive flotation process
Hematite positive flotation process is a method of using anionic collectors to float iron ore from raw ore. It can achieve discarding tailings under the coarse particles without desliming.
Hematite positive flotation process is featured with simple dosage, low processing cost, which is especially suitable for a single hematite. However, the qualified hematite concentrate can only be obtained after many times of cleaning, and the foam is easy to be sticky, so the product is not easy to be concentrated and filtered.
2. Reverse flotation process
Hematite reverse flotation process is a method of using an ionic or cationic collectors to float gangue minerals from raw ore.
Anionic collector reverse flotation process is mostly used when the pH value is 8-9. It is used to treat quartz-containing gangue minerals. After activated by calcium ions, collector of fatty acid is used to reverse flotation for obtaining hematite concentrate.
Cationic collector reverse flotation process usually adopts a mine collector as the flotation reagent, which is suitable for the flotation of quartz gangue. Ether amine is the first choice as the amine collector, followed by the fatty amine. The inhibitor of iron ore uses the sodium silicate, tannin and sodium lignosulfonate, and their inhibitory effect is the best when the pH value is 8-9.
In terms of the ore properties of hematite ore, reverse flotation process is more advantageous than the positive flotation process. Because the collecting object of the reverse flotation process is gangue, while the collecting object of the positive flotation process is iron ore. Therefore, it is difficult to obtain high-quality hematite concentrate for gangue minerals with serious inclusions.