Learn more about Praxair’s Argon Oxygen Decarburization process that is used to make over 75% of the world’s stainless steel. Argon oxygen decarburization (AOD) converter is popularly used in the stainless steel making process. AOD has a top lance for oxygen injection and several.

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Praxair can quote a server-only option for these systems. The process is so popular because it combines higher metallic yields with lower material costs. This accretion protects the tuyere and surrounding refractory. After a desired carbon and temperature level have been reached the process moves to reduction. These tuyeres typically consist of provess copper tube with a stainless steel outer tube.

The installation of a lance and introduction of oxygen in the early stages of decarburization can reduce the time for a heat. The next step is the reduction step, in which the reduction additions are charged and stirred with an inert oxygdn for a desired time.

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Posted by Satyendra on Apr 28, in Technical 1 comment. As molten stainless steels do not generate foam, and most stainless steel refining processes are side or bottom-blown, the dimensions of a stainless refining converter are smaller than a comparable BOF basic oxygen furnace converter.

Refractory costs are a significant fraction of total operating costs. Reduction recovers the oxidized elements such as chromium from the slag. Sidewall mounted tuyeres are submerged while processing. If the grade to be produced requires an extra low sulphur level, the bath is deslagged after the reduction step and another basic slag is added. A major modification of the AOD process involves the use of top blowing lance in addition to the side ozygen tuyeres.


Argon Oxygen Decarburization for Metal Production | Praxair, Inc.

After sulphur levels have been achieved the slag is removed from the AOD vessel and the metal bath is ready for tapping. Bloomery produces sponge iron Blast furnace produces pig iron Cold blast Hot blast Anthracite iron Direct reduced iron. Careful manipulation of slag, as it precipitates in the reaction, is important. By using this site, you agree to the Terms of Use and Privacy Policy. The amount of stirring energy from the gas blown through the subsurface tuyeres and the formation of the carbon monoxide deep within the metal bath results in the converter processes being among the most intensely stirred metallurgical reactors.

Volatile elements with high vapour pressures, such as lead, zinc, and bismuth, are removed during the decarburization period. While typical BOF refractory campaigns are months or years long, stainless converter campaigns are several days or weeks long.

Magnesite chromite refractories have high wear resistance but have a higher unit cost than dolomitic refractories. Decarbueization burning of carbon increases the bath temperature.

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At this point, the decqrburization gases can be shut off and a small cooling flow protects the tuyeres. The intimate gas — metal contact and excellent slag — metal mixing facilitate decabrurization reactions.

An annulus is formed between the copper and stainless tubes. Such an approach is usually practiced by steelmakers to reduce argon usage and costs and still achieve a desired nitrogen specification.

Would like to more details of how to increase vessel life and to reduce refractory wear near tuyers.

After initial melting the metal is then transferred to an AOD vessel where it will be subjected to three steps of refining; decarburizationreductionand desulphurization. The top lance can also be designed for blowing aargon gases such as inert gas — oxygen mixtures. After tapping, the ladle is often stirred for composition homogenization and temperature uniformity along with flotation of inclusions.

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Argon oxygen decarburization for metal production

During the final stage of blowing, the ratio of oxygen to argon is changed to 1: Bessemer process Open hearth furnace Electric arc furnace Basic oxygen oxyben. Argon oxygen decarburization for metal production Share Print. The AOD converter can be rotated downwards so that the side mounted tuyeres pprocess above the bath level during charging of the liquid steel.

These additions also serve to reduce the bath temperature as carbon and chromium oxidations are exothermic.

Argon-oxygen decarburization | metallurgy |

After the ladle treatment, the steel is ready to be cast. In case of those steel grades which can tolerate nitrogen, a mixture of oxygen and nitrogen can also oxggen blown. Decarburization occurs when dissolved carbon reduces the chromium and iron oxides that form. The formation of a high basicity slag and the reduction of oxygen potential in the metal bath are good conditions for sulfur removal.

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The ratios can be done in any number of phases to facilitate the reaction. Ideally at this stage of the process, the chemistry of the liquid steel should meet the final specifications so that the heat can be tapped.

Designed by Elegant Themes Powered by WordPress. Dolomitic refractories are usually less costly than magnesite chromite refractories and chromium pickup is not a factor.

It provides an economical way to produce stainless steel with a minimum loss of precious elements.