关键词: 高硫磁铁矿　, 工艺矿物学　, 磁-浮联合工艺　, 浮选脱硫

Abstract: The iron and sulfur grades of a high-sulfur magnetite ore from a mining area in Southwest China are 38.18% and 3.34%.In order to identify the ore characteristics and develop an appropriate beneficiation process to address the issue of high sulfur content in the iron concentrate,detailed mineralogical studies and process testing were carried out.The results show that magnetite is the primary iron-bearing mineral,accounting for 75.25% of the total iron,followed by hematite and goethite with a combined distribution rate of 14.85%.Pyrrhotite is the main sulfide mineral,contributing 5.45% of the total iron.Cas siterite is present at approximately 0.10% and occurs as finely disseminated particles,making recovery difficult.The majority of magnetite is distributed in the -0.074 mm size fraction (about 60%),while gangue minerals such as mica and feldspar are mainly concentrated in the +0.074 mm fraction,the difference of embedded particle size is conducive to the realization of tail throwing through preprocessing.However,the close association between magnetite and gangue minerals increases the grinding and separation difficulty.Based on test results,a process flowsheet of "coarse wet magnetic separation for pre-discarding tail ings-staged grinding and magnetic separation-flotation desulfurization" was established.The final iron concentrate achieved a yield of 37.37%,iron grade of 68.24%,sulfur grade of 0.13%,and iron recovery of 66.74%.The sulfur content met the standard requirement (below 0.40%),achieving effective desulfurization and iron recovery.Additionally,preliminary tin recov ery tests produced a tin concentrate with a tin grade of 16.85%,indicating potential for the comprehensive recovery of associat ed tin resources.

Key words: high-sulfur magnetite ore,process mineralogy,combined magnetic-flotation process,flotation desulfurization