Abstract: There is 1.5% lead in a high mud and low grade lead-zinc ore in Guangxi，and main lead mineral is galena，about 15% of lead being oxidized.The process of lead flotation first and then zinc flotation is brought for production of lead concentrate and zinc concentrate，but the flotation index is not well due to the interference of slime.The grade and recovery rate of lead concentrate are only about 45% and 65% respectively.Beneficiation experiments on lead concentrate index improving are carried out based on the characteristics of the ore.Spiral washing machine and spiral chute are firstly used to discard the 12.11% slime and then endure lead flotation，during which self made non-toxic organic depressor YJ is used to replace the original zinc sulfate and sodium sulfite，and combination collector GD-1 is brought to replace the original sulfur nitrogen.Lead concentrate with lead grade of 54.65% and recovery of 79.78% is obtained.Compared with the on-site process，lead grade is increased by 10 percentage points and lead recovery is increased by about 15 percentage points，providing a persuasive technical support for copper flotation process optimization.

Key words: High mud and low grade lead-zinc ore, Pre-desliming, New inhibitors YJ, Combination collector GD-1