Common pyrite mainly includes pyrite, white iron ore and pyrrhotite, and is often associated with copper, lead, zinc and other metal sulfides. The sulfur content is an important indicator of iron concentrate, and the sulfur content affects the quality of iron concentrate. Therefore, it is important to fully combine magnetic separation and flotation to reduce the sulfur content in iron concentrate and select high-grade iron ores.
Through the analysis of raw ore properties, we know that there are many kinds of minerals embedded in high pyrite, and the properties are complex, especially the particle size is particularly small, which leads to poor monomer dissociation of useful minerals, which has great consequences for the desulfurization effect of minerals. Therefore, we need to achieve desulfurization and recovery of iron minerals under finer grinding conditions. Therefore, we have carried out many experiments for sulfur removal from high-sulfur magnetite, and the test process is as follows:
Magnetic separation fineness test: with the increase of grinding fineness, the grade of iron concentrate gradually increases, and the sulfur content in iron concentrate also gradually increases. When the grinding fineness reaches 95%, the grade of iron concentrate is 62.01%. Its sulfur content is 3.42%. Therefore, it is difficult to obtain qualified iron concentrate by using a single magnetic separation process.
Flotation fineness test: we found that with the increase of grinding fineness, the grade of sulfur concentrate gradually increased. When the grinding fineness is more than 75%, too many fine particles affect the flotation of sulfur, resulting in a decline in sulfur recovery. When the grinding fineness is 60%, the grade of sulfur concentrate is 29.88%, and the recovery rate is 83.18%; The iron grade of flotation tailings is 29.18%, and the sulfur content is 1.18%, which is more suitable.
Flotation-magnetic separation process test: under this process, the grade of sulfur concentrate can reach 29.12%, the grade of iron concentrate can be increased to 62.05%, and the sulfur content can be reduced to 0.83%, but qualified iron concentrate has not been obtained.
Flotation-grinding-magnetic separation test: in order to reduce the sulfur content of the concentrate, the flotation is strengthened under the condition that the primary grinding accuracy is 60%, sodium carbonate is added, and the ph value is increased. Use a 1mm fine screen to screen the flotation tailings, regrind the materials on the screen, and conduct magnetic separation of the materials under the screen. In this case, adding sodium carbonate can improve the ability of xanthate to collect sulfide ores. After flotation desulfurization, the tailings are finely screened and reground. After a period of magnetic separation, a qualified iron concentrate with a grade of 65.42%, a sulfur content of 0.285 and a recovery rate of 68.31% can be obtained.
After many tests, we found that the combined magnetic flotation process with floatation-flotation tail grinding-magnetic separation process may be more suitable for the treatment of high-sulfur iron ore, thus greatly improving the flotation index. If you have requirements for beneficiation equipment, please consult Shandong Xinhai Mineral Equipment.
