Iron & Steel

Steel production requires 2.8 tonnes raw materials, 2.5 tonnes water and 5 tonnes air per ton liquid steel, with gross water use ranging from 11,200 to 110,000 gallons per ton of steel ingots depending on plant age, process efficiency, and water availability.

Each ton of liquid steel generates 8 tons moist dust-laden gases, 0.5 ton effluent water, 0.4-0.8 ton solid waste, with wastewater containing iron levels up to 52,633 mg/L, suspended solids 1000-5000 mg/L.

Coke oven byproduct wastewater requiring phenol < 1 mg/L, cyanide < 0.2 mg/L, BOD < 30 mg/L, ammonia nitrogen < 50 mg/L for most polluting steel plant stream.

Generation of 450-550 kg solid waste per tonne crude steel including slag, dust, GCP sludge, mill scale, refractories requiring simultaneous water and waste treatment.

pH conditions ranging from < 2 in pickling operations to 10+ in pig casting, temperature variations, and toxic substances including PAH, cyanides, phenols across different unit operations.

Meeting discharge limits for heavy metals, BOD, COD, pH with specialized treatment for blast furnace (20,500 gal/ton pig iron), open-hearth (5,130 gal/ton steel), and rolling mill operations.