What era?

Era drives what pieces you'll need.

And will this be an integrated mill?  Blast furnace(s) + steel furnaces + rolling mill(s) and/or casters.  All you mentioned was raw materials inbound, which implies a blast furnace.  And don't forget limestone for flux.  Steel mills used a bunch of that.

And most mills converted coal into coke first.  Now you need coke batteries.   Or you bring in coke from an off-layout site.

Lots of questions. 

I recommend you get Dean Freytags's book on the steel industry.  And if you can find one, a copy of US Steel's "The Making, Shaping, and Treating Of Steel".  Several editions, so get one closer to your era.

Scott Chatfield 

Can - O - Worms

Just a word of caution. 

You will get a ton of opinions on this lol. 

Scott nailed it. What era do you plan to model, and also do you have any prototypical company/or region you wish to model?

Mill layouts vary greatly by region due to the physical characteristics of the sites. 

Let us know where and when you would like the mill to be located.

Bob

Steel modeler in N

Scale

And what scale are you?

Replies to all

My apologizes. I should've left more for yall to chew on. I am doing it in HO scale more modern day. Its technically a freelanced layout. It will definitely be an integrated mill. I thought about making a coke plant elsewhere and ship it in. Is there any byproducts from the coking process? From what I read, it seems like there would be use for tank cars at a coking plant to take tar and acid away from the coking plant. Did the limestone come in from a covered hopper or a open hopper. I also have a slag dump area to the south which will send crush slag to cement plants and fertilizer companies. 

Study the 1:1

Since you are going freelance the options are endless, and it is easy to get bogged down by the actual workings of todays integrated mills. The mass and scale is very hard to replicate. 

Different mills will use different amounts of raw material due to the actual make up of the furnace, as well as the output steel they are trying to produce. 

Flux stone for the Basic Oxygen Furnace is moved in covered hoppers, and lime stone (not used as much these days) for the blast furnace is often moved in open top hopper. Modern flux or taconite pellets incorporate lime stone into the pellet so it helps cut down on needed flux. 

For your coke works, ammonia, tar, sulfur, benzol, and I am sure I forgot a couple are all produced at the byproducts plant. 

You will quickly find modeling a mill eats a ton of space. All of us steel modelers have to get creative and also have to omit certain parts of the process. Its fun to model and requires some head scratching for sure. 

Lastly, The Model Railroader's Guide to Steel Mills is a great book to pick up before you start to lay down track!

Subject Thread Reference

You might have a look thru this long subject thread on my venture to developing a steel mill scene and the different paths I chased. Also lots of help from other members, and lots of other links made thruout the subject thread,..plus some good video links.

Steel Mill Scene in a corner (now Coke Plant & Power Plant)
https://forum.mrhmag.com/post/steel-mill-scene-in-a-corner-now-coke-plant-power-plant-12209837

Aye, there's the rub....

Blast furnaces are definitely an endangered species in the modern day.  Most North American mills are now "mini mills" using electric melt furnaces fed solely a diet of scrap.  Many modern integrated mills have retired their blast furnaces in favor of Basic Oxygen Furnaces (BOF) that can make steel from raw materials.   I think the new-ish mill at Mobile, Alabama is one of these.  I gather it uses iron ore imported from South America.

On the bright side, BOFs and electric melts are a lot easier to model than blast furnaces.  They're just housed in big steel buildings.  And I do mean big.  The only steel mill I had any professional experience with was an electric melt that fed a continuous caster.  Together they were about a mile long.  Scrap in, pipe out.

Scott Chatfield 

Blast Furnace needed

To me the 'blast furnace' says STEEL. I'm not a sticker for modeling eras on my RR, and I just would not do a steel mill scene without a blast furnace structure. Just my opinion. (it would be like doing a model RR without any steam engines at all....ha...ha)

Not dead yet

Blast furnaces are not dead yet, and if you are modeling modern times as in 2021 and back a handful of years blast furnaces are still making millions of tons of Iron in the US. 

The industry is changing rapidly like much of the world, but that is side note in modeling a freelance steel mill in 2021. And yes technology is quickly making the blast furnace a thing of the past but for now they are still going. 

Research what aspects of the process you would like to model. Then start to mock them in the available space you have on your layout. 

If you want a blast furnace keep in mind it produces liquid iron, this will now need to be converted into steel. 

In modern times this is done in a Basic Oxygen Furnace (BOF) The BOF then can produce various products, steel slabs, billets, and blooms. These are then sent for finishing, steel coils, structural shapes, pipe etc. 

Here is where you can simulate various parts of the process. Offline coke works, off line rolling mill and you still have a lot of the process on your layout and a ton of interchange traffic.

Tons of ways to pull all of this off, I have been working around mills for almost two decades now all around the the eastern and midwestern states. I can say from experience each mill is different, the blast furnaces are unique, and even terms are more regional then an industry standard. So with al of that said do not get hung up on minor details. Make it work and make it fit. 

Don't write off blast furnaces just yet

Hi Joshua, all,

As a former metallurgist and production planner in the steel industry for a lot of years here's my take on modelling a steel industry -  See  https://forum.mrhmag.com/post/steel-mill-scene-in-a-corner-now-coke-plant-power-plant-12209837

Regardless of what you might read, if you want big steel tons, then you still need a blast furnace or the molten iron from one. In the US and in Germany some steelmake plants transported their molten iron in from blast furnaces on other sites in torpedo or hot-metal cars. Google up Pollock and Treadwell hot metal or torpedo cars for inspiration. These cars a HEAVY so they need many wheels under them to spread the load on the rails Check out this Krupp monster  With that number of wheels under it, that type of torpedo ladle may have been used on inter-site runs.  

The BOS process simply won't work without a blast furnace. That basic oxygen steelmaking process cannot work thermodynamically on a 100% scrap charge. So far various expensive  attempts have failed to come up with a successful low cost conversion process that will convert iron ore directly to liquid steel. I've been on the margins of 2 of those attempts. 

The older open hearth process could run with 100% scrap charge, but it was far more efficient in terms of steelmake tonnes out in a given time if you could feed it a drink of molten iron from a blast furnace. But the Basic Oxygen process could give you the same amount of steel in far less than 1/3 the time - that's why there are no open hearth steelmaking shops left anywhere. They were heading toward extinction from the late-1950's once the Basic Oxygen process had been around long enough to prove itself. I wrote the steelmake schedule for the last open hearth operating in the southern hemisphere. 

As for electric furnaces, someone has to generate the big amount of volts and amps to melt the scrap. and buying in bulk power is expensive. Without a blast furnace the scrap has to be heated from room temperature. With a blast furnace, the molten iron in a charge helps to lift the temperature of the melt rapidly. This both reduces the power consumed by the electric furnace and shortens your tap to tap time - enabling you to get more tons of steel quicker and cheaper from your electric arc furnace - but you need a high cost blast furnace. 

The most significant cost for a blast furnace is the reline cost. With current technology and refractories the intervals between relines has been gradually being extended from 5 to 10 to 15 and now to almost to 20 years between relines. The reline cost is not just the brick lining inside the furnace shell. Other costs involve having enough inventory on the ground to cover for when your blast furnace isn't making iron. And your major steelmake and caster units might also be sidelined or drastically reduced until you get your blast furnace back up and running well. For a big blast furnace a reline might take up to 3 months. For a big furnace like the one I have near me  that's rated at more than 5000tpd (tonne/per day) of iron, that's almost an equivalent amount of steel that's not being made while your furnace is down for reline. At current US finished steel prices of about $2000/ton that's a lost production cost of $10 million/day - now multiply that by the time you are down for the reline.   

Environmentally, the real problem with the blast furnace and the whole of the steel industry is that it is heavily carbon dependent both in the process itself and in the amount of heating and re-heating that has to be done in the initial blast furnace process and the subsequent steelmake and rolling processes. With carbon being a big "no-no" word at present.   In simple terms: 

1. at the blast furnace - coke burns inside the furnace with the hot blast coming in from the stoves providing the oxygen to make CO - (carbon monoxide)  => CO strips an oxygen from the iron ore (Fe₂O₃ or Fe₃O₄)  to form CO₂ (carbon dioxide) and a lump of oxygen-depleted ore => CO2 is unstable at that temperature, so it grabs a carbon atom from the coke as it burns to give 2 CO molecules => and the process repeats many times as the gasses inside the furnace travel upward to the big offtake pipes at the top of the furnace. Eventually all the oxygen is stripped off the iron ore and liquid iron trickles down inside the furnace to pool at the bottom inside of the furnace. Big furnaces are making iron that quickly that you will have multiple cast houses with one taphole always open and running iron. Limestone is added in the charge mix to form slag that will float on the molten iron as it leaves the furnace. This slag traps mainly sulphur and phosphorus impurities that were contained in the iron ore. if slag is transported away from the furnace by rail, it is usually moved in smaller thimble shaped "slag pots". The thimble shape makes it easier for the partially solidified slag in the slag pot to slide out at the dump. Molten iron is transported to the steelmake shop. When it leaves the blast furnace it contains about 4% carbon. The CO in the gas at the top of the furnace is used to burnt in the stoves to heat the brickwork inside the stoves. The hot bricks inside the stove convert high pressure cold air from the blower station (cold blast) to high temperature high pressure air (hot blast) that is fed into the lower part of the blast furnace. 
2. At the steelmake shop - The amount of carbon is reduced to less than 1% and various other alloys like manganese are added to get the required chemical specification for the steel. If oxygen is being injected the will be CO or CO₂ going up the stack.
3. At the caster - liquid steel is solidified and cut to length (kind of like a very big, very hot sausage machine) These days some casters can produce steel coils directly. But if you want big tonnes out of a caster you produce slabs at about 8" thick. These can be processed in downstream rolling mills or sent as slabs to other rolling mills elsewhere. 
4. Rolling mills - are LOOONG and are usually hidden under long roofs. For example the local Hot Strip Mill that converts 8" thick slabs to about 1/8" thick coils is just over a mile long and the 3' wide strip is doing +30mph when it hits the coiler unit at the end of the mill. Some of the blast furnace and coke ovens gas is used to reheat the slabs to rolling temperature = CO₂ up the stack 

There are also a whole flock of subsidiary processing sites like

• coke ovens
• coke oven by products
• raw material stockpiles and related machinery
• sinter plant
• desiliconiser (treats molten iron before it gets to the steelmake shop)
• lime kiln (for BOS fluxes)
• roll shops (usually adjacent to a rolling mill for refurbishing the rolls used in rolling mills)
• blower station (provides large volume of pressurised air for the blast furnaces and around the plant)
• scarfing areas (where surface defects are removed from slabs etc) 
• testing labs 
• electrical distribution (and possibly generation)
• gas distribution pipework (coke ovens gas, blast furnace gas, compressed air, oxygen, argon)
• water pipework (fresh water, fire fighting mains, recycled water for cooling, waste water)

I hope that this helps make some sense of some of the stuff you might find on an integrated steel mill site.  

WOW, John G

Great posting. I think I will likely have to make a link to it over on my subject thread.

Your help with my steel mill scene & coke plant development was great.

layout

Your space looks like mine and I have a full operating steel mill in that area. My layout plan is in Bernie Kempinski steel mill book by Kalmbach. These are birds eye view of the Steel Mill. The coke batteries running down the middle are a view block. The pusher on one side and coke side with quenching car and coke wharf on other. The Blast Furnace and Ore Bridge on second picture The steel end with Open Hearth and rolling mills are on the back wall. My Union RR main line comes behind the buildings. The main yard for the mill is in the far wall.  The steel mill si at 62" so I kept the track toward the edge so operators can easily do there switching. If you have any question contact me. Hope this gives you some ideas in your space.