Physical-chemical and toxicological properties of liquid hexyl xanthate, synthesized on commercial scale for the first time, were considered. Its stability in storage was monitored. Flotation properties of the reagent were studied under laboratory conditions. Effect of hexyl xanthate aggregation state on increase of copper recovery into concentrate was established. As a result of the reagent commercial testing at NPO «Zhezkazgantsvetmet» concentrating plants, copper recovery increase was obtained without decrease in concentrate grade.