Sacré-Davey was contracted to provide services for two existing banks of Denver flotation #100 (eight cells each) which had reached the end of their useful life and required replacement. Our design approach was to make the changeover with minimal disruption to production. The existing structural support steel was used and reinforced. The tank cells were covered with lids to contain the H2S gas, and a manifold connected with duct work to a new scrubber. The two conditioning tanks were raised and pump boxes and pumps were added to the floor level below the cells to pump concentrates to the thickeners.