the steel industry

An integrated steel mill is composed of several units:

• agglomeration: preparing ore and blast furnace loads that will be used to produce cast iron (virtually no wastewater);
• coke plant: producing steel mill coke used to reduce the ore;
• blast furnaces: producing cast iron;
• steel mill: producing various types of steel (depending on added loads);
• electric steel mill: producing special steels and recycling scrap metal;
• continuous casting: forming slabs, blooms, billets used to produce finished products;
• hot rolling: forming sheets, beams, wires…
• cold rolling: producing finished products (different grades of thin sheets, merchant bars…).

In all these units, it is important to distinguish between:

• the layout of large open recirculating systems used for gas scrubbing or for watering hot rolling mills, and how the blowdown is processed before being discharged (this effluent is not very polluted);
• and the treatment of specific effluent produced by the coking plant (ammonia water) and from the cold rolling unit (pickling, rolling and finishing); this effluent is very heavily polluted.