Cement plant operation
#1
Hi,

I'm actually in the process of revisiting my plans for a large cement plant.

I've been happy enough to talk with a fellow modeller whom is uncle worked at the plant. He's getting old and his memory don't serve him as it was in the past, but he said interesting stuff.

According to him, CN hauled gypsum in "Brown car" which were unloaded with a shaker. Historic photos show us brown cars, in fact they are 3-bay uncovered standard CN hoppers. What is common to carry gypsum in such unprotected cars? Would they have put some weather protection over the hoppers? Sound strange to me!

He also told us "black cars" were used to haul coal. Once again, is memory is right, those were Pennsylvania 70-ton coal hopper in black paint scheme. There's photographic evidence of it.

Where things get messy is how they unloaded both commodities. Insurance maps do indicate the coal unloading device, but not the gypsum. But if you follow the conveyor, it indicates it is used as "Gypsum & Coal Discharging". Well, that means the SAME conveyor was used for the coal AND the gypsum!!!! Sounds crazy to me. You don't mix your fuel with a primary ingredient of your final product! My guess is the conveyor was in fact a double conveyor, one part for gypsum and one part for coal. But that would means gypsum and coal were discharged from the cars into the same pit. Could it be possible to have, located side to side, to bins with a parallel conveyor?

Hope my questions makes sense!

Matt
Proudly modelling Quebec Railway Light & Power Company since 1997.

Hedley-Junction Club Layout: http://www.hedley-junction.blogspot.com/

Erie 149th Street Harlem Station http://www.harlem-station.blogspot.com/
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#2
This is a puzzling question, since the cement plants I've been familiar with have the limestone input right there. This is borne out by a google search: the opinion seems to be that since the limestone raw material gets burned up a lot in processing, you don't want to spend a lot of money hauling it in. So normally there would be the limestone quarry handy, with other materials, like iron and coal, hauled in by rail. I'd certainly be asking that and other questions about this particular plant.
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#3
jwb Wrote:This is a puzzling question, since the cement plants I've been familiar with have the limestone input right there. This is borne out by a google search: the opinion seems to be that since the limestone raw material gets burned up a lot in processing, you don't want to spend a lot of money hauling it in. So normally there would be the limestone quarry handy, with other materials, like iron and coal, hauled in by rail. I'd certainly be asking that and other questions about this particular plant.

@jwb: I finally got my answer from a search. Found out it was carried and is still carried in open top hoppers, just like coal would be. Found many pictures of it. Also, a guy I know asked his uncle, a retired employee of my specfific prototype. From what he told me this afternoon, gypsum was really carried in standard hoppers. They had a shaker to make it flow into the conveyor pit. He also confirmed me there was only one track for cement unloading. Meaning I misunderstood for years the insurance maps. Going back in time with Google Earth, I was able to spot the gypsum pit and the coal pit. Both on their own tracks. Now that makes much more sense.

There was a HUGE limestone quarry beside the plant. But when making Portland Cement, you need gypsum into the mix. From what I read, without gypsum, the concrete would set extremely fast and would flow at all.

So you got a cement plant, be ready to have a track for coal (hoppers), a track for gypsum (hoppers) and a track for loading cement (covered hoppers, boxcars). Really a nice industry... I calculated this very industry would need 17 cars at full capacity, and 5 car spots (cement loading, coal pit, gypsum pit, and 2 loading bay at the bagging plant) and finally, you have to weight most cars at the scale! No wonder e-paw's doing one!

Matt
Matt
Proudly modelling Quebec Railway Light & Power Company since 1997.

Hedley-Junction Club Layout: http://www.hedley-junction.blogspot.com/

Erie 149th Street Harlem Station http://www.harlem-station.blogspot.com/
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#4
Yep I'm doing one of those little cement plants,, Big Grin

You got the quarry thing right also. The only difference is that in my neck of the woods both the limestone and gypsum are readily at hand, you just have to dig them up. At one time the Lehigh river flowed through the area where all the cement plants are over here, but when the dinosaurs were the having a good time the river shifted to it's present location. This left all the right minerals for cement right next to each other . Coal is really the only thing that is shipped in and that comes from the next county over. The end result is at least five major cement plants in the same neighborhood. Most of that cement went to New York City via the Lehigh and New England railroad, when you factor how much steel from Bethlehem was shipped there also, the New York Sky line is really just an extension of eastern Pennsylvania. Now that I have rambled way of topic I will go the bed.. :? :? :?
 My other car is a locomotive, ARHS restoration crew  
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#5
Is the gypsum that they get or mine like the plaster in wallboard? Do they take that and heat it to remove the water and make powder out of it?
David
Moderato ma non troppo
Perth & Exeter Railway Company
Esquesing & Chinguacousy Radial Railway
In model railroading, there are between six and two hundred ways of performing a given task.
Most modellers can get two of them to work.
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#6
BR60103 Wrote:Is the gypsum that they get or mine like the plaster in wallboard? Do they take that and heat it to remove the water and make powder out of it?

Ok, I got new information from the worker a few minutes ago. The gypsum was in raw state and they had to crush it at the plant to get the fine powder we know. Yes, it's the same thing as wallboard and joint coumpound. Makes it more workable, but a little bit less efficient as a fire barrier than pure plaster.

Also, they only had one conveyor for gypsum AND coal. He told me they would let it run a few minutes to get most of the dirt out and would start moving other material. It was relatively clean and anyway, there was a cleaning process when gypsum was treated.

@e-paw, those plant must have make a hefty profit with such excellent location! There's no gypsum in Quebec, I suppose they got it from the Maritimes or Ontario. The worker told me most of the profit they made back then was with hydroelectric dams being built in the 60s, 70s and 80s in Northern Quebec at James Bay. Coal was from Pennsylvania. Do you have an idea what type of coal would be used? Anthracite or something less efficient?

He said the switcher was extremely busy everyday, the production was at a peak and the small yard was overcrowded with slabside hoppers, cylindrical hoppers and Procor pressure cars.

Matt
Proudly modelling Quebec Railway Light & Power Company since 1997.

Hedley-Junction Club Layout: http://www.hedley-junction.blogspot.com/

Erie 149th Street Harlem Station http://www.harlem-station.blogspot.com/
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#7
If the coal was coming in via PRR hoppers, as you say, it would be bituminous from the western half of the state.
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#8
jwb Wrote:If the coal was coming in via PRR hoppers, as you say, it would be bituminous from the western half of the state.

Thanks. Here's the physical evidence of Pennsylvania hoppers at Villeneuve, QC in 1974.

http://www.hankstruckpictures.com/pix/tr...large.html

Matt
Proudly modelling Quebec Railway Light & Power Company since 1997.

Hedley-Junction Club Layout: http://www.hedley-junction.blogspot.com/

Erie 149th Street Harlem Station http://www.harlem-station.blogspot.com/
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#9
They seem to use both anthracite and coke. I know the used the hard coal for firing the furnaces and plant heat. I don't know about the coke, may be it is added to cement mix to make clinker. The current plant fires the kilns and furnaces with natural gas, I think, any coal shipments they get today is brought in by truck.
 My other car is a locomotive, ARHS restoration crew  
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#10
e-paw Wrote:They seem to use both anthracite and coke. I know the used the hard coal for firing the furnaces and plant heat. I don't know about the coke, may be it is added to cement mix to make clinker. The current plant fires the kilns and furnaces with natural gas, I think, any coal shipments they get today is brought in by truck.

I once remember talks, in the early 1990s, they wanted to convert the St. Lawrence Cement plant to coke. Which means it wasn't before. I personnally don't recall seeing coal hopper cars during the 80s and 90s, so no clue what fuel they used when they stopped using coal in the late 70s/early 80s.

Matt
Proudly modelling Quebec Railway Light & Power Company since 1997.

Hedley-Junction Club Layout: http://www.hedley-junction.blogspot.com/

Erie 149th Street Harlem Station http://www.harlem-station.blogspot.com/
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#11
Modern portland cement is made today from a mixture of limestone, sand, aluminum, iron,gypsum and "other ingredients". The limestone is crushed to a fine powder in ball mills and baked in rotating kilns at 2700 degrees F, which is where the coal came in.

Prior to the advent of plentiful electrical power from a grid and the availability of natural gas, coal fired the the boilers that ran the machinery and also provided the heat necessary to bake the limestone.

A hypothetical cement plant thus needs many different loads which are kept separate, since the actual mix depends on the specific customer order. Aggregate does not get added unless the mix is bagged for sale as ready-mix concrete.
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#12
I don't know what materials are used to fuel the kilns back east now, but in 2008 when I toured the CEMEX plant in Victorville as part of the NMRA National Convention in Anaheim, they had used coal exclusively in the past. Then the Kaiser steel mill closed in Fontana, and the oil refineries no longer had a market for their coke (what is left over after all of the oils and greases are refined out of crude oil). For a while Cemex was receiving coke for just the cost of shipping, but I think they pay for it now. It is probably still cheaper than coal, and burns hotter than coal as well. They also receive trailer loads of old tires. Up on Highway 99 in Cali's Central Valley, there are mountains of old tires. They were left in piles when no one knew what to do with them for disposal. Cemex runs the tires through the same crusher that crushes both coal and coke, and they burn a mixture of crushed coal, coke, and tires in the kiln.
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#13
I would have thought that with its plentiful and cheap hydro-electric capacity that they would be using electricity in Quebec.
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#14
@Russ: A big thanks, you put me back on rail with your suggestion! Thumbsup

Genetk44 Wrote:I would have thought that with its plentiful and cheap hydro-electric capacity that they would be using electricity in Quebec.

Gene, cement-making is one industrial process where using hydro-electricity does not good. I remember St. Lawrence Cement wanted to use coal again in the mid-90s but there was a lot of protest. Tires were also considered. Nothing happened because the plant shut down.

Seriously, I don't know what they used during the 80s and 90s. I never saw any coal hoppers in the yard. I suspect the fuel was trucked in, but that means they had a local source for fuel. It could have been petroleum coke from the nearby refinery in Levis (which opened in 1971). The date would somewhat match. The new announced cement plant project in Gaspésie will be fuel by coke too.

OK, just did some researches, inputting the cement plant name + petroleum coke. Villeneuve plant was effectively fuel by petroleum coke. The shift from US coal to local coke, as stated, probably occurred by the mid-70s went a cheaper local source was available. Was it trucked, I don't know. I only remember covered hoppers (cylindrical and procor).

That said, I'll continue to fuel the layout plant with COAL just for the sake of Pennsylvania's hoppers coolnest factor!

Matt
Proudly modelling Quebec Railway Light & Power Company since 1997.

Hedley-Junction Club Layout: http://www.hedley-junction.blogspot.com/

Erie 149th Street Harlem Station http://www.harlem-station.blogspot.com/
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#15
The plant here in Florance, Colorado uses natural gas.
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