Abstract: In view of characteristics of low grade ascharite ore in Dandong, the study on flotation is carried out using sodium hydroxide as pH adjustment agent, sodium oleate as collector and compound agent FLM3 as inhibitor. In the crude ore B₂O₃ grade of 6.72%, the final concentrate grade of closed product is 12.65%, concentrate yields is 37.66%, and concentrate recovery is 70.88% by adopting a circuit of one roughing, two concentrating and one scavenging. The test index provides a basis for reasonably recovering these mineral resources.

Key words: Low grade ascharite ore, Flotation, Compound inhibitor FLM3