Bethlehem Steel Corporation

Robert L Greenawalt

Stewart T Herman

Richard W Faupel

Electro-magnetic filter apparatus and method of operating to separate and remove oily magnetic solids from wastewaters. The filter apparatus includes a filter assembly having an electro-magnetic coil that encircles a canister. The canister has an interior space defined by a wall surface and a first perforated baffle spaced apart from a second perforated baffle. The interior space contains a ferromagnetic matrix comprising split ring lock washers. The feed side end portion of the canister communicates with the wastewater source that contains the oily magnetic solids, a wash-water supply, a pressurized air supply and a disposal stream. The discharge side end portion of the canister communicates with a recycling stream, the disposal stream and the wash-water supply. A feed side valve arrangement selectively introduces the wastewater into the feed side end portion of the canister during filtering operations, and selectively injects a pressurized air/wash-water mixture from the wash-water and pressurized air supply into the feed side end portion of the matrix canister during up-flow backwashing operations. The ferromagnetic matrix is fluidized by the pressurized air/wash-water mixture the during the up-flow backwashing. A discharge side valve arrangement selectively discharges clean effluent through the recycling stream during filtering or introduces water, from the wash-water supply, into the discharge end portion of the matrix canister during down-flow backwashing.

Method for magnetically filtering wastewaters containing oil-coated mill

A system and method for disposing of vacuum degasser contaminants which includes adjusting the pH, in a reactor vessel, of a vacuum degasser underflow stream to precipitate lead and zinc into particulate matter. The solids are then concentrated in a thickener to produce an underflow stream that is communicated to a holding vessel to settle. The overflow from the thickener is filtered through a sand filter and discharged to meet applicable NPDES permit limits. Lime is added to the slurry in the holding vessel to further settle the solids, to aid in filtration, and to prevent leaching of lead from the filter cake during TCLP testing. An overlaying supernatant is decanted from the holding vessel and returned to the reactor vessel for further treatment. Limestone is added to the underflow stream. The resulting slurry is dewatered to produce a friable, non-hazardous filtrate cake and a filtrate. The filtrate is directed back to reactor vessel prior to discharge for further treatment.

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Ottsville, PA, United States of America

Robert L Greenawalt