Laboratory concentration of a lead-zinc-fluorspar ore from southern Illinois

The purpose of this investigation was to ascertain the feasibility of preparing marketable products from a rather complex sulphide-fluorspar ore --Object, page 2. The ore was examined exhaustively by chemical, microscopic, and mineralogical methods of analysis. After a thorough knowledge of the physical characteristics of the ore had been obtained, flotation concentration tests were made to separate the sulfide minerals from the fluorspar and to attempt to prepare lead-zinc and fluorspar concentrates of marketable grade --Scope of Work Done, page 2