Abstract: A certain tin tailings in Inner Mongolia contains Sn of 0.10% and Fe of 13.83%.Cassiterite and iron minerals are densely intergrown,with high weathering and severe argillitization.The proportion of -0.005 mm particles is 69.77%,mak ing it a refractory lean tin ore with high mud and iron content.To reduce the impact of slime and iron-bearing minerals on the separation of cassiterite,based on the study of ore properties,the experiment focused on comparing the desliming effects of cen trifuges and cyclones.The deslimed material was then subjected to high-intensity magnetic separation to remove iron,and the high-intensity magnetic concentrate were further processed by gravity separation to recover cassiterite.Ultimately,a process flow consisting of agitation scrubbing,centrifuge desliming,high-intensity magnetic separation for iron removal,centrifuge cleaning was developed,resulting in a centrifuge concentrate with a tin grade of 4.25% and a comprehensive tin recovery rate of 45.50%.Through table shaking,high-grade tin concentrate with a Sn grade of 22.58% and a recovery rate of 13.30% can be obtained,as well as tin-rich middlings with a Sn grade of 3.23% and a recovery rate of 34.28%.The efficient recovery of tin in high-mud and low-grade iron-containing intractable tin tailings is achieved,laying a basis for the development and utilization of similar tin tailings resources.

Key words: tin tailings,high mud content,low tin grade,desliming,centrifuge cleaning