Environmental Code of Practice for Non-Integrated Steel Mills: glossary

Glossary of Terms

Acid Neutralization
Chemical treatment of water to eliminate acidity and remove iron compounds from solution.

Controlled heating of steel to relieve cooling stresses induced by cold or hot working and to soften the steel to improve its machinability or formability.

An air pollution control device used to trap particulates by filtering gas streams through large fabric bags, usually made of glass fibres.

Refers to the controlled discharge of spent waters to limit the build-up of dissolved solids and other pollutants.

Carbon Steel
A kind of steel with various percentages of carbon and little or no other alloying elements; also known as straight carbon steel or plain carbon steel.

Clarifier Thickener
A settling tank that is used to remove settleable solids by plain gravity or colloidal solids by coagulation following chemical flocculation; will also remove floating oil and scum through skimming.

Carbon monoxide is a normal product of incomplete fossil fuel combustion. CO is itself a fuel as it can be oxidized to form CO 2.

Carbon dioxide is a product of fossil fuel combustion. Globally it is the dominant greenhouse gas.

Chemical oxygen demand is the amount of oxygen required for the chemical oxidation of organic matter in a wastewater sample.

Cooling Tower
A device that reduces the temperature of the water through contact with air.

A mineral (CaMg(CO 3) 2) consisting of a calcium magnesium carbonate found in crystals and in extensive beds as a compact limestone.

Dry Dust Catcher
A device to remove solid particles from a gas stream.

Electrostatic Precipitator
An air pollution control device that removes particulate matter by imparting an electrical charge to particles in a gas stream for mechanical collection on an electrode.

A release of pollutants into waters.

A release of pollutants into the air.

Emission Factor
The average amount of a pollutant emitted from each type of polluting source in relation to a specific amount of material processed.

Fabric Filters
A device for removing dust and particulate matter from industrial emissions, much like a home vacuum cleaner bag. Fabric filters are generally located in a baghouse.

In wastewater treatment, the process of separating suspended solids by chemical creation of clumps or flocs.

Fluorspar is the commercial term for fluorite, a calcium fluoride mineral (CaF 2) that is used as a flux material in electric arc furnace operations to achieve the desired slag fluidity.

Fugitive Emissions
These emissions usually result from process leakage and spills of short duration that are associated with storage, material handling, charging, and other secondary process operations. Fugitive emissions are usually uncontrolled.

Steel sheet with a unique coating of 55% aluminium and 45% zinc that resists corrosion. The coating is applied in a continuous hot-dipped process, which improves the steel’s weather resistance. Galvalume is a trademark of BHP Steel, and the product is popular in the metal building market.

The process of applying a coating of zinc to the finished cold-rolled steel; the coating is applied by dipping in molten zinc (hot dip) or by the electrolytic method.

Hexavalent Chromium (Cr+6)
Chromium in its hexavalent state.

ISO 14000
The International Organization for Standardization ( ISO) is an international federation of over 100 national standards bodies that since 1993 has been developing a series of integrated environmental management systems ( EMS) standards, known as the ISO 14000 series.

Life Cycle Management
An integrated approach to minimizing the environmental impacts associated with a product or service through all stages of the life cycle.

Refers to that portion of the total iron present as metallic iron.

Multiple-Cyclone Separator
An air pollution control device that separates particulate matter from a gas by spinning the gas in a vortex fashion. It consists of a number of small-diameter cyclones operating in parallel with a common gas inlet and outlet. The gas enters the collecting tube and has a swirling action imparted to it by a stationary vane.

New Facility
Any facility whose construction or reconstruction was not approved by the appropriate regulatory authority(ies) prior to the date of publication of this Code of Practice. Reconstruction means the replacement of components of an existing facility to such an extent that the fixed capital cost of the new components is a significant proportion (in excess of 50%) of the fixed capital cost of the facility.

Refers to volume of gas at Normal conditions of 101.325 kPa and 25 °C.

Refers collectively to nitric oxide ( NO) and nitrogen dioxide ( NO2) expressed as nitrogen dioxide equivalent.

Particulates are any finely divided solid or liquid particles in the air or in an emission. Particulates include dust, smoke, fumes, and mist.

An iron oxide that forms on the surface of the hot steel.

Scale Pit
A settling basin for removing solid materials from water used on rolling mills. These solids are mostly mill scale, the flakes and particles of iron oxide that form on steel during heating. The solids sink to the bottom of the basin, from which they can be dredged for recycling. Oil rising to the surface of the basin can be skimmed off and reprocessed.

An air pollution control device that uses a liquid spray to remove pollutants from a gas stream by absorption or chemical reaction. Scrubbers also reduce the temperature of the gas stream.

In wastewater treatment the settling out of solids by gravity.

Shaft Furnace
A refractory-lined vertical cylinder where iron pellets are fed into the top of the shaft furnace through a large number of distributor pipes, which reduce the possibility of size separation and gas channelling.

Sulphur dioxide, formed primarily by the combustion of sulphur-containing fuels.

Any water from a precipitation event that is not considered to have been contaminated as defined by the appropriate regulatory authority.

Sustainable Development
Development that meets the needs of the present without compromising the ability of future generations to meet their own needs.

A special rolling procedure that adds hardness to the steel, usually applied after annealing.

Vacuum Degassing
Vacuum degassing is used as a refining operation to reduce the hydrogen content in the molten steel for rolling operations in order to prevent the formation of flakes or internal cracks.

Venturi Scrubber
An air pollution control device in which the liquid injected at the throat of a venturi is used to scrub particulate matter from the gas flowing through the venturi.

The environmental protection agency in the United States that is the U.S. equivalent to Environment Canada.

Volatile organic compounds are also known as reactive organic gases ( ROG) or non-methane volatile organic compounds ( N-MVOC). Volatile organic compounds refer only to photochemically reactive hydrocarbons and therefore exclude compounds such as methane, ethane, and several chlorinated organics.

Solid or liquid materials that are generated by production processes, maintenance, and demolition activities that have no further use and have to be disposed to appropriate disposal sites. Some wastes are classified as hazardous wastes. Recycled materials, by-products, and co-products that are sold or reused are not considered to be wastes.

Any water that is known to contain a deleterious substance that originates in and is discharged from the plant. This includes the discharge of water used for direct cooling or cleaning, blowdown from water treatment systems, and water that has been contaminated by process leaks. This does not include water used for indirect cooling or stormwater.

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