Concentration of an oxidized lead ore from Southeast Missouri

In the main ore bodies of the Southeast Missouri Lead Belt the lead occurs as galena disseminated in dolomite. The concentration in the mills is by tabling and flotation. The grade of the concentrates and the recovery of the galena are excellent. However, in certain areas of some of the mines ore has been developed that does not concentrate so readily. Because of its reddish brown color this ore is known locally as red ore , and the presence of oxidized lead has been suspected. The purpose of this investigation was to determine the extent to which oxidized lead minerals were present in the ore, to ascertain the manner in which they interfered with normal flotation practice, and to devise, if possible, a satisfactory method of concentration --Introduction, page 1