Abstract: Aiming at the problems of flotation process indicators deterioration generating beneficiation recovery rate slumped because deep ores properties changed,direct flotation and middlings flotation after regrinding tests were conducted.The tests determined the best technological parameters,optimized the beneficiation process,solved the problems of flotation indicators deterioration because of ores properties changing.The process indicators of gold concentrate with yield rate of 3.0%,gold grade of 87.91 g/t,gold recovery rate of 95.06% was obtained via the tests,which could lay a massy foundation for improving the enterprise economic benefits.

Key words: Flotation, Regulators, Middlings regrinding