Steel Mill Consumption Rates

Everything in the steel industry is based on finished tons. Then, using yield, you can work back to liquid tons, and from there, the raw materials to create the liquid tons.

I am a rolling mill guy, so I do not have good information on blast furnace operation. However, you can scale your operation by deciding how big your blast furnace is (Tons), which will help determine the amount of raw materials you will need each day.

If you are modeling a steel, mill, I suggest you do not use a fast clock.   Instead set up a sequence of moves to support process.     For example, you pickup 2 empty bottle cars at the open hearth and move them to the Blast fce.   you take the two loads from the blast fce to the Open Hearth.     Then  you put a string of coke cars on the high line and a string with limestone etc.     Just list the moves in sequence that makes sense.

I didn't even think of that! Guess I got too focused on finding the info. So if I have 3 BFs putting out 400 tons a day, then I can assume 1200 tons of capacity is needed at the open hearth. Finding the average size of an open hearth shouldn't be hard. I suppose I could estimate limestone, fuel, and scrap consumption for the OHs based on congestion in the yard.

@prrjim posted:

If you are modeling a steel, mill, I suggest you do not use a fast clock.   Instead set up a sequence of moves to support process.     For example, you pickup 2 empty bottle cars at the open hearth and move them to the Blast fce.   you take the two loads from the blast fce to the Open Hearth.     Then  you put a string of coke cars on the high line and a string with limestone etc.     Just list the moves in sequence that makes sense.

I think that might be easier. I like the idea of the clock because then you got something to compete against. Especially in the case of the coal/iron ore/limestone coming from the mine. Maybe I can run that on more of a schedule and have each mill engine tackle a list of moves.

I have a book published in 1950 by the American Iron and Steel Institute.   It describes a heat of steel being made in an Open Hearth.    This one is a 12 hour give or take tap to tap time.    I have heard others as long as 16 hours.    The long process times is why Open Hearths were built in banks of multiple furnaces to support the production level desired - such as 12-16 or more furnaces.

This heat used a rather large charge of scrap in addition to molten Iron to make a heat .08 % carbon, .2-,3 % Manganese, .02  phosphorous and .035% sulfur (note all less than 1%). 

14,400 lbs of limestone (7.2 tons)

186,900 Lbs of scrap steel (93.5 tons)

Later 13,500 lbs of scrap iron (6.75 tons)

67,600 lbs of molten pig iron (33.8 tons)

total charge 268000 lbs of iron and steel (134 tons) and 14,400 lbs of limestone

This was used to make a heat that tapped at about 125 tons.

Some melt shops I think used a lot more molten iron and less scrap especially if wanting tighter quality control on the metallurgy of the steel for more high end applications.   It is very hard to control the metallurgical properties of the steel when more scrap is  used because of the trace elements of all sorts in the scrap which may be very undesirable for such applications as cold rolled for the auto industry where deep drawing and very smooth finishes are required.

So it looks like the materials input are primarily Iron and maybe scrap steel and a little limestone.   

You can size  your open hearth shop to match the output of your blast fces more or less.     for example if you get 4  250 ton bottle cars of iron per shift, and you want to charge as above, You would be able to support 15 open hearths.    If you want to use a higher iron charge, then you need more blast fce production etc

Thanks @prrjim! That was really helpful. Would you happen to have the name of that book? I would love to read it for myself. Our local university library might have it.

I see why open hearth departments are so big now. My three BFs putting out 400 tons a day means I would need roughly 12 OH minimum. Now I'll see if I can find some dimensions on OH furnaces. It sounds like I'll be taking some of that iron to a backdrop or else these will be magical OHs that have astounding capacity haha

I thought I read that BFs tapped out about ever 8 hours. Does anybody know if that's true? I assume it probably depends on the size of the furnace. In which case I might just pick my tap times.

Edit: eh, maybe not. I'm seeing more like somewhere between 30 minutes and 3 hours.

I worked for  years at Armco in Middletown Oh, and by then the Open Hearth was used only for backup mostly.    At one time they had two shops.    But I remember being told that the tap to tap time was about 16 hours on the Open Hearth fces vs 44 minutes on the BOF. 

The book mentions that most fces were tapped every 4-5 hours for 100 to 300 tons of iron.

The name of the book is

"The Making of Steel" published by the American Iron and Steel Institute.  

there is no specific author listed, it appears to be a document put together by a technical committee of the Institute.     The copyright date is 1950.   It has most or all steel making processes from mining to finished product such as wire and tin plate described.

Middletown #3 the only one actually in the plant there was a "large" BF and was run with a "sweetheart" burden to get a higher production rate because the rest the plant had more capacity so it was pushed hard.   The plant was always considered short of Molten Iron.

Thank you for the details! I will look up the book.

I know the BOF is darn quick. The steel companies around here didn't upgrade to a BOF and the only one that did, was simply too late.

I appreciate the information too. Definitely helped me get some basic operation planned. Thank you guys!

Edit: Found a copy online linked here. Super interesting read! It's got a lot of good enough for details I was missing to the process flow. I know the basics but this book has a lot of extra info.

Bill,

There are some great Facebook steel mill groups.  You might also try looking there.

I'm interested in what you have going on with your layout and how you plan to operate.

I've been away from Facebook for a few years now but it keeps coming up lately so maybe I'll have to get back to it. Especially with the Museum in Youngstown being limited. @prrjim's book has been phenomenal.

Thanks @David Minarik. I'm excited to get started. Hopefully benchwork starts going up this weekend pending the work schedule. I'm very much ready to graduate from the 4x8 test loop.