Coke and Steel Production Question

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AARR
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Coke and Steel Production Question

Unread post by AARR »

This is an excellent question for Rail Dude's Dad (or anyone else for that matter).

I am trying to calculate how much coke a steel company will use based on the tons of steel they produce. From what I have read on the internet it seems that for every 100 tons of steel made, about 40-60 tons of coke is needed.

So take the foundry in Cadillac, Cadillac Casting. Their website says they can produce up to 80,000 tons per year of steel. So based on what I have read they would need about 32,000 to 48,000 tons of coke. Predicated on what I see delivered to Cadillac they are not getting half that, maybe three cars a week (300 tons or 15,000 per year).

I have done this same math equation for several other smaller Michigan foundries (100,000 tons a year or less) and am finding the same results, less carloads of coke delivered than what the formula I have read calls for.

So my question is how many tons of coke are needed to produce, say, a 100 tons of steel?

Rail Dude's Dad is been very helpful in finding answers to similar questions (the last one was how much resin is used to make plywood and other particle boards) so perhaps you can assist me again or anyone else would be appreciated.
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Standard Railfan
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Re: Coke and Steel Production Question

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The US EPA has a series of reports colloquially named AP-42 which discusses the inputs and outputs to various industrial processes. Chapter 12.5 covers Iron and Steel production. From that document:

“The production of 1 ton of iron requires 1.4 tons of ore or other iron bearing material; 0.5 to 0.65 tons of coke; 0.25 tons of limestone or dolomite; and 1.8 to 2 tons of air. Byproducts consist of 0.2 to 0.4 tons of slag, and 2.5 to 3.5 tons of blast furnace gas containing up to 100 pounds (lb) of dust.”

https://www3.epa.gov/ttnchie1/ap42/ch1 ... c12s05.pdf

The above is for reducing iron ore to iron. Casting of iron requires a much lower energy input. Another EPA document from 1971 entitled “Air Pollution Aspects of the Iron Foundry Industry” provides some information on foundries using cupolas. This document indicates that a ratio of 7/1 iron to coke was the average. The data for the type of cupola at Cadillac Castings indicates a coke charge of 250 pounds per ton of metal.

The link below should take you to the page showing the data.
https://nepis.epa.gov/Exe/ZyNET.exe/P1 ... yEntry=151

On that basis, Cadillac Castings would use about 10,000 tons of coke per year based on 80,000 tons of melt.

Edited for additional content and to correct calculations for cupola type.
Last edited by Standard Railfan on Thu Mar 10, 2022 5:34 pm, edited 5 times in total.

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AARR
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Re: Coke and Steel Production Question

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Thank you Standard Railfan. This is exactly what I was seeking. 8)
PatC created a monster, 'cause nobody wants to see Don Simon no more they want AARR I'm chopped liver, well if you want AARR this is what I'll give ya, bad humor mixed with irrelevant info that'll make you roll your eyes quicker than a ~Z~ banhammer...

Raildudes dad
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Re: Coke and Steel Production Question

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I wasn't ignoring you AARR, just real busy this week.

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AARR
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Re: Coke and Steel Production Question

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Thank you Rail Dude’s Dad. I appreciate all the times you respond to my questions. :)
PatC created a monster, 'cause nobody wants to see Don Simon no more they want AARR I'm chopped liver, well if you want AARR this is what I'll give ya, bad humor mixed with irrelevant info that'll make you roll your eyes quicker than a ~Z~ banhammer...

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Standard Railfan
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Re: Coke and Steel Production Question

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AARR wrote:
Thu Mar 10, 2022 4:14 pm
Thank you Standard Railfan. This is exactly what I was seeking. 8)
No problem. I hadn’t looked at any of those EPA documents in years. There is some interesting information therin.

I tried to back calculate Cadillac Castings production based on their annual emissions reports. The plant runs too cleanly to do so. 8)

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AARR
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Re: Coke and Steel Production Question

Unread post by AARR »

My observation of the number of coke cars being delivered to Cadillac (seems like around 3 a week) vs. what a plant like CC should receive (seems like it should be in the 6-10 range per week) is what led to my original question and your research supports my calculation.
Standard Railfan wrote:
Fri Mar 11, 2022 5:58 pm
I tried to back calculate Cadillac Castings production based on their annual emissions reports. The plant runs too cleanly to do so. 8)
PatC created a monster, 'cause nobody wants to see Don Simon no more they want AARR I'm chopped liver, well if you want AARR this is what I'll give ya, bad humor mixed with irrelevant info that'll make you roll your eyes quicker than a ~Z~ banhammer...

PatAzo
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Re: Coke and Steel Production Question

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Foundry melt also differs from pig iron production in yield. An iron foundry yield is typically 60-80%. The gating and risers needed to deliver metal into the cavity are removed prior to shipping the casting and re-melted. To produce 80,000 tons of castings per year they will be melting 100,000+ tons per year at the cupola.

10:1 iron to coke is an often cited charge ratio for a foundry cupola. This paper on page 29 shows typical energy input per ton and heat losses. They cite the data coming from Kuttner who are a cupola supplier. https://www.energy.gov/sites/prod/files ... 052804.pdf These fall right in the range of what you observe at Cadillac Casting.

If you work Waupaca's 2.5% (656 TPY) saving backward it would give a charge ratio of 15:1. https://betterbuildingssolutioncenter.e ... mprovement

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AARR
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Re: Coke and Steel Production Question

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Thank you PatAzo. It looks like you’re on to something.
PatAzo wrote:
Sat Mar 12, 2022 11:09 am
Foundry melt also differs from pig iron production in yield…..
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Standard Railfan
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Re: Coke and Steel Production Question

Unread post by Standard Railfan »

AARR wrote:
Sat Mar 12, 2022 11:44 am
Thank you PatAzo. It looks like you’re on to something.
PatAzo wrote:
Sat Mar 12, 2022 11:09 am
Foundry melt also differs from pig iron production in yield…..
Very interesting. Thank you for posting.

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