In-depth survey report: Cominco American, Inc., Bixby, Missouri, report no. CT-111-12b.
Health hazard controls used in lead (7439921) ore beneficiation operations were surveyed at Cominco American, Incorporated (SIC- 1031), Bixby, Missouri in February, 1982. The company used a lead flotation process, and employed 26 workers in the mill. An average of 4,600 tons of ore containing about 7 percent lead were processed each day. Work processes and controls were evaluated, and personal and area air samples were collected for lead, carbon-disulfide (75150), and cyanide (57125). Average personal exposures were 0.158 milligram per cubic meter (mg/m3) for lead, 1.31mg/m3 for carbon- disulfide, and 0.007mg/m3 for cyanide. Average area concentrations of lead ranged from 0.014 to 1.950mg/m3, and were 0.006mg/m3 for cyanide and 1.14mg/m3 for carbon-disulfide. Dust concentrations were effectively controlled by the use of a ventilated starch mixing tank equipped with a polypropylene lined dump chute, but the cleaner and recleaner flotation cell covers were not effective in reducing mist generation. The use of water spikes did reduce cyanide and carbon-disulfide exposures, and lead exposures for the mill operation were controlled with the use of an isolated, enclosed, air conditioned flotation cell control room.