You are confusing two different stages in steel making. The blast furnace reduces iron ore to iron metal. It uses limestone as a flux and coke (made from coal) as the heat source. Air (not pure oxygen) is blown into the furnace as part of the chemical process to reduce the ore to iron metal.

There are several methods to produce steel, which is a special alloy of iron, carbon and some other elements. One method of making steel from the iron is the basic oxygen furnace (BOF), which is mostly used these days in place of the older technology open hearth furnace. The BOF does use pure oxygen to lower the carbon content of the iron in order to make steel.

There is a new Kalmbach book on making steel by Bernard Kempinski (I think I have his name correct) which explains all of this, including using the Walthers structures. It is worth buying--well written and informative with lots of good pictures and diagrams on the steel making process and the structures associated with it.

Walthers makes a kit for a blower house which supplies high pressure air to the blast furnace. Oxygen I believe comes in daily for the BOF in railroad tank cars or other means like pipelines.

John

I know virtually nothing about making steel, and don't model an area where steel mills exist, but if oxygen is needed for a steel mill, or any other gas for that matter, how it would get to the steel mill would depend on where the mill was located in relation to a cryogenics plant.  Here in So Cal we have a number of refineries in the harbor area in Wilmington.  We also have a Linde plant in the same vacinity, as well as off loading facilities for tankers bringing in crude oil and a CNG and LNG unloading terminal.  There is an underground maze of pipelines from Linde to carry nitrogen for fire supression to all of those facilities so that nitrogen is available with the activation of a valve anywhere it might be needed to put out a fire.  If there was a steel mill that needed oxygen in the area, they would run an oxygen pipeline to the steel mill from Linde as well.  On the other hand, when the distance from the cryogenics plant is far enough from the steel mill to make the cost of constructing a pipeline greater than the cost to transport the gas in tank cars, then they would bring the oxigen in by railroad.

John is correct in that pure oxygen is used at the Basic Oxygen Furnace (BOF) to convert pig iron to steel.

Blast furnaces use pressurized  atmospheric air to provide the oxygen to reduce the iron ore to make pig iron, the step that precedes the BOF. The actual pressure is quite modest, but the air gets preheated to about 1500 degrees before entering the blast furnace. There are exceptions to most rules and I have read about some blast furnaces that also inject oxygen, but that is not typical. It may become more popular as steel makers strive to improve blast furnace efficiency. See here  for a proposed example of oxygen used in a blast furnace,

BOFs consume a lot of oxygen. A 250-ton basic oxygen furnace needs about 20 tons of pure oxygen every 40 minutes. Generally the oxygen is piped in from a oxygen plant near the furnace, though frequently the oxygen plant is run by an outside company such as Linde, Praxis or Air Products. I have seen white used frequently for oxygen piping at a steel mill.

In 1952 BOFs were just coming on line, but open hearths and to a lesser extent Besemers furnaces dominate. It would be very possible to model a steel mill without a BOF in the 1952 era. In that case you would not have oxygen coming in to your mill.

The history and operation of open hearth furnaces and BOFs is covered in more detail in my book, along with modeling suggestions. I didn't cover the oxygen plant in any detail this volume, but it may end iup in a follow-on volume. You can order a signed copy  of my book from www.alkemscalemodels.com or get it through Amazon or many hobby shops.

Bernard Kempinski

 www.alkemscalemodels.com

 

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