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[Saurabh Jain]

Gas Applications
The iron and steel industry and metal processing companies are among the largest users of industrial gases and consume significant quantities of oxygen, nitrogen, argon and hydrogen. In addition, a small but growing amount of carbon dioxide is also consumed.

[Saurabh Jain]

Argon for the Steel Industry
Argon is used whenever a totally inert gas that does not affect metal chemistry is required.

Argon is used for inerting vessels, equipment, and metal transfer streams in tapping and casting operations; to provide stirring and promote slag/metal refining reactions; to flush out carbon monoxide and reduce chromium loses in the Argon Oxygen Decarburization (AOD) process for producing stainless and high alloy steels; and as a coolant to protect oxygen injection tuyeres in various oxygen converters.

Argon in Integrated Steel Mills
Traditional uses for argon in integrated mills include: injection through bottom tuyeres to provide stirring and slag/metal mixing during the final stages of refining in the BOF which improves yield, reduces slag FeO content, and lowers metal oxygen content; injection through porous plugs to provide stirring for improved temperature and chemistry control and to promote desulfurization in ladles and ladle furnaces; injection of various powdered reagents in ladles and ladle furnaces for desulfurization; injection in vacuum degassers to facilitate carbon, hydrogen, and nitrogen removal and to provide circulating metal flow in RH type degassers; and inerting submerged entry nozzles to prevent clogging and re-oxidation or nitrogen pick-up by the steel during lade to tundish and tundish to mold transfers in continuous casters. Recently, argon has also been used to inert the tundish headspace during transient periods of operation to improve slab surface quality.

Argon in Electric Arc Furnace (EAF) Steel Mills
Argon is primarily used in plants that produce stainless and high alloy grades, flat carbon steel products, and high quality long products. Traditional uses include many of those described above for the integrated plants such as ladle, ladle furnace, and vacuum degasser stirring, powder injection, and inerting of submerged entry nozzles and tundishes in continuous casters. In addition, argon is also used extensively to facilitate carbon, nitrogen, and hydrogen removal in the AOD process for producing a wide variety of stainless, tool, heat resisting, and other high alloy content grades.

[Saurabh Jain]

Carbon Dioxide for the Steel Industry
Carbon dioxide can be used as a stirring gas in BOFs, ladles, and furnaces in place of nitrogen and argon. It also can be used as a protective atmosphere in casting and to suppress fume emissions.

Carbon Dioxide for Stirring Ladles and Vessels
The use of cabon dioxide in these applications provides the ability to achieve lower steel nitrogen contents and lowers stirring gas costs by reducing or eliminating the use of argon which is more expensive per unit volume. However, since carbon dioxide is a reactive gas when exposed to molten steel under the conditions associated with submerged injection, increased wear of the bottom injection tuyeres and surrounding refractory materials and an inability to achieve low aim carbon contents may result.

Carbon Dioxide for Other Metal Applications
Carbon dioxide has been used as a protective atmosphere in continuous billet casters for protecting the tundish to mold stream from contact with the surrounding atmosphere. It also has been used to suppress fugitive fume emissions during electric arc furnace (EAF) charging and tapping operations and to lower nitrogen pick-up during EAF or BOF tapping operations. Typically, carbon dioxide is injected in "snow" form to eliminate air from the furnace during charging and from around the tap stream and its impact zone in the ladle.

[Saurabh Jain]

Helium
Helium is used in heat-treating applications and metal finishing to create an inert gas shield and prevent oxidation during joining/welding of light metals such as aluminum, copper, stainless steel and magnesium alloys.

[Saurabh Jain]

Hydrogen
Hydrogen is used as a protective atmosphere in high-temperature metal finishing and coating operations such as annealing and hot dip galvanizing. It is also used in significant quantities for natural gas based production of direct reduced iron.

Hydrogen for Annealing
Hydrogen is used for annealing atmospheres. For carbon steel annealing, atmosphere compositions of 5 to 10 percent hydrogen with the balance nitrogen are commonly used in both continuous and batch furnace types. For stainless and other high alloy products, the hydrogen content is typically in the range of 75 to 100 percent. Typical hydrogen purity is 99.995 percent. These atmospheres serve to transfer heat, remove residual rolling oils, prevent surface oxidation, and reduce any surface oxides that may be present resulting in a bright annealed surface free from oxides, deposits, and discoloration.

A recent trend is to anneal coils in batch bell-type furnaces that have been designed to use a 100 percent hydrogen atmosphere. The main benefit is a shorter cycle time and increased productivity due to the higher diffusivity and thermal conductivity of pure hydrogen and improved uniformity of mechanical properties as a result of more uniform temperature distribution throughout the coil.

Hydrogen for Direct Reduced Iron
Hydrogen is used to convert iron ore lumps or pellets in a moving bed shaft furnace to direct reduced iron or "sponge iron" by high temperature reduction. In the Midrex process, the carbon dioxide and water which are present in the off-gas from the direct reduction shaft reactor are used to reform natural gas and produce the high temperature hydrogen- and carbon monoxide- containing reducing gas required to achieve the desired level of iron ore conversion to iron. In Hylsa's HYL III process, a conventional steam reformer is used to produce the reducing gas, and the carbon dioxide and water in the reactor off-gas is removed to allow recycle of unreacted hydrogen and carbon monoxide back into the reactor. The natural gas consumption is approximately 11,000 scf per ton of direct reduced iron (DRI), and the reducing gas generators are part of the overall plant installation.

[Saurabh Jain]

Nitrogen
Nitrogen atmospheres are used for cooling, stirring, and protecting metal from oxidation during production. Nitrogen is used for inerting vessels, equipment, and metal transfer streams in tapping and casting operations; to eliminate the formation of explosive mixtures in enclosed spaces; and to prevent undesirable reactions between iron and steel with oxygen and hydrogen in the surrounding atmosphere. Nitrogen is also injected into molten iron and steel to provide metal stirring and slag/metal mixing, and as a carrier gas for powder injection. High purity nitrogen containing 5 to 10 percent hydrogen is used to provide a protective reducing atmosphere in batch- and continuous-type bright annealing furnaces for carbon steel grades. Nitrogen purity for most applications is typically 99.999 percent.

Nitrogen in Integrated Steel Mills
Traditional uses of nitrogen in integrated steel mills include: purging and inerting of blast furnace raw material charging equipment to prevent reactions of air with furnace off-gas; injecting lime, lime-magnesium mixtures, or other reagents in powder form through refractory coated lances to desulfurize hot metal in torpedo cars and ladles; injection through bottom tuyeres to provide stirring and slag/metal mixing during the initial period of refining in the BOF which improves yield, reduces slag iron oxide (FeO) content, and lowers metal oxygen content; as the inert component with 5 to 15 percent hydrogen for bright annealing in continuous or batch furnaces; and as a clean and dry gas for various types of pneumatic instrumentation and process control equipment.

The adoption of powdered coal injection (PCI) in blast furnaces usually creates a new requirement for nitrogen to inert and prevent explosions in coal grinding, storage, and handling equipment. A process called slag splashing uses high pressure and flows of nitrogen through the top lance to coat the steel making vessel with slag and extend the refractory life. Finally, nitrogen can be used instead of air in the pneumatic knives used to control coating thickness in hot dip galvanizing lines. The benefits of such nitrogen wiping include less dross formation, improved coating thickness control, and fewer coating defects such as edge build-up or entrapped oxides.

Nitrogen in Electric Arc Furnace (EAF) Steel Mills
Traditional uses for nitrogen in EAF plants include: injection through top lances or porous plugs in ladles to provide stirring for steel temperature and composition control and to remove oxide inclusions; injecting powdered reagents containing one or more constituents such as calcium, silicon, and aluminum to desulfurize steel in ladles and ladle furnaces; preventing reaction with surrounding air of open teem streams between the tundish and molds in continuous casters; and as a clean and dry gas for pneumatic instrumentation and process control equipment.

Uses that are more site specific include: injection through multi-hole elements to provide stirring in the EAF for faster melting, power savings, and improved temperature and composition control; injection through porous elements of various designs to modify flow patterns and remove inclusions in tundishes; to protect the tuyeres and promote carbon removal with minimum oxidation of chromium in the AOD process for producing stainless and other high alloy grades; and as the inert component with hydrogen for bright annealing in continuous or batch furnaces.

[Saurabh Jain]

OxygenOxygen is used in heating and melting metals. It is the most widely used industrial gas in steel making due to its continued use in the basic oxygen furnace (BOF), its growing use for air enrichment in the blast furnace, and its ability to provide supplemental chemical heat in the electric arc furnace (EAF). Also, injected oxygen is used for converting potential carbon monoxide into extra energy in the EAF; for heating and generating carbon monoxide to reduce iron ore in the blast furnace; and for producing alternate iron.

Oxygen in Blast Furnaces
The blast furnace uses significant amounts of oxygen -- up to 40 percent of the total oxygen requirement of a typical integrated steel mill is consumed in the blast furnace. In the blast furnace, oxygen is injected through spargers to enrich the air which increases furnace productivity, lowerscoke consumption by allowing injection of large amounts of powdered coal or natural gas, and lowers overall production costs.

Oxygen in the Basic Oxygen Furnace (BOF)
Oxygen is used primarily for decarburization and conversion of blast furnace hot metal to liquid steel in the BOF. This accounts for about 50 percent of the total oxygen consumption in integrated steel mills. The heat which results from the exothermic reactions of oxygen with silicon and carbon in the hot metal and the post combustion of a portion (about 10-15 percent) of the carbon monoxide (CO) which is generated in the converter is sufficient to melt scrap in quantities that amount to about 25% of the total vessel charge weight.

Oxygen in the Electric Arc Furnace (EAF)
The total consumption of oxygen used in EAFs has also more than doubled in the last five years, and much of this increase is due to a 75 percent increase in specific oxygen consumption. Typical uses for oxygen in the EAF include: oxy-fuel burners for scrap heating and melting; high velocity lancing for localized scrap melting, steel decarburization, and slag foaming; and sub-sonic injection for post combustion of carbon monoxide. Recent trends to use more supplemental chemical energy to increase furnace productivity and reduce melting time and electric power consumption, scrap pre-heating, and the growing use of high carbon content materials such as direct reduced iron (DRI), pig iron, iron carbide, and hot metal have all contributed to this significant increase in specific oxygen consumption. Oxygen-derived chemical energy can provide 30 percent or more of the total energy required to make steel in a modern, high-productivity EAF.

Oxygen in Cutting and Burning
High-purity oxygen (above 98 percent) is also used extensively in steel mills for steel cutting and burning as well as general lancing requirements. Significant uses in this category include automatic cut-off torches on continuous casters, periodic lancing to remove skulls from the mouths of vessels and ladles, and cutting of crops, skulls, and other forms of mill scrap into pieces that can be readily fed to the BOF or EAF.

Oxygen for Rotary Furnaces
oxygen-gas burners on rotary furnaces offer an alternative to traditional smelting. Working with European rotary furnace manufacturer SIDERPROGETTI, sulphur oxides (SOx) are eliminated and nitrogen oxides (NOx) are minimized, thus reducing dust emissions into the atmosphere. The use of pure oxygen avoids heat losses with no unburned gases in the discharge chimney. The final result is a high-temperature and radiant flame that transmits its heat intensely, leading to a substantial improvement in smelting output, and drastically reducing both the time needed to smelt the iron and the volume of combustion fumes.

Oxygen in Steel Reheating
Oxygen is also used for enrichment or with oxy-fuel burners in steel re-heat furnaces. Benefits associated with the use of oxy-fuel burners include a 25 to 60 percent reduction in fuel consumption and associated sulfur dioxide (SO2 ) and CO2 emissions, increased furnace productivity, up to 90 percent reduction in nitrous oxide (NOx) emissions, and elimination of recuperators.

[ivandavis99]

Argon gas:
Industrial Gas Co engaged in supplying pure Argon Gases, which are procured from reliable vendors of the industry.These gases are widely used in
engineering,pharmaceutical, chemical, and offshore Contractor industries.

Ammonia gas:
Industrial Gas Co offer Ammonia gas,Which is used in heat treatment furnaces for reducing its temperature. Further, it finds vast application in agro,chemical and
other allied industries.

Oxygen gas:
Industrial Gas Co provides oxygen gas,which comprises of 21 percent of earth's atmosphere and supports life as well as make combustion possible. It reacts with all the elements except inert gases and finds usage in different areas.