Abstract: The dissemination granularity of tin polymetallic ore treated by Chehe Dressing Plant of Dachang Tin polymetallic Mine is getting finer，thus the metal amount of fine fraction in the process in⁃ creases. Therefore，strengthening the flotation recovery of tin minerals with fine particle is of great signifi⁃ cance. Firstly，comparative test on two kinds of new and old collectors were carried out. Based on it，indus⁃ trial application test was proceed. The results showed that the laboratory test with CS-6 as the collector，tin concentrate with grade of 18.43% and recovery rate of 88.58% was obtained. When the concentrate grade is the same，the recovery rate is significantly higher than 80.94% with BY-9 used as collector. The dosage of CS-6 in industrial production test was 171 g/t，which was lower than that of BY-9 (185 g/t). The grade of total zinc concentrate with CS-6 was 45.90%，which was higher than that with BY-9 (45.35%)，and the re⁃ covery rate was increased by 0.17 percentage points. The usage of new collector CS-6 for fine particle cas⁃ siterite flotation has achieved an annual economic benefit of 1.794 9 million yuan per year. Therefore，CS- 6 is significantly better than BY-9 in the flotation of fine particle cassiterite.

Key words: novel collector CS-6, cassiterite with fine particle, flotation recovery