Ear on Chicago; Running a Mountain Through a Sieve: Universal Atlas Cement Company

That was the sound of a cement packing machine. Among the first large industries in the northwest corner of Indiana is the Buffington plant of the Universal Atlas cement company. The site chosen was a sandy stretch of land on the western shore of Lake Michigan, about 35 miles southeast of Chicago. Construction of the first unit of this cement plant was begun in 1903, and today the plant covers over 600 acres and employs about 1 ,200 persons. Today we're reporting on the manufacture of cement, and we will begin our story at the unloading dock. Our guide is Mr. Arch Adams, plant manager at Buffington. Well, Arch, we're standing now on the loading dock for your company. Right in front of us is the huge ship, the lake steamer, which is named the urban climber, right behind us, is a huge stock pile of material that you use. So I better start by

asking you the first obvious question, what did this boat come from, and what is it loaded with? This boat is one of the Bradley Transportation steamers. Bradley Transportation is a division of the subsidiary United States Steel Corporation that brings down limestone from Roger City, Michigan to the various U .S. steel and loading docks in the Gary area. This boat has approximately 11 ,000 tons, gross tons of limestone, which isn't being stocked by on our dock here. Now we're not very close to this arch, but down about maybe 150 or 200 yards is a large crane, an arm that sticks out from the boat, and a long conveyor belt running along the arm and the length of that crane, running limestone out and dumping it on top of a huge pile. Now is that all part of the equipment of the boat arch? Yes, the boom

sticking out from the clamor is part of the equipment on the clamor for unloading the limestone. The limestone is stored in hoppers, aboard the ship, and through various conveyors, elevators, it brings this limestone up to this boom, which extends out over our dock onto the storage pile. I might describe briefly the physical surroundings that we're standing there. This limestone is stacked in tremendous piles, and you may not know the physical characteristics of limestone, but you'll probably hear those crocks crumbling in my hand. They come in all marble size, regular size gravel type rocks. What happens now, Arch, you've got tremendous piles of limestone here. Now how do you get it from here to where you want to work with it? First, I say that we store the enormous amount of limestone on the dock here during the lake shipping season, that's during the summer, from April to first,

until November sometime. So these boats come in all summer and stockpile enough stone here to carry during the winter months. We'll have here come the December first over a half a million tons of limestone, which have to carry during the winter months. Now, underneath the limestone pile here is a concrete tunnel through which a balcony there runs the entire length of this tunnel. The limestone is drawn off from the pile through openings in the tunnel onto the belt, and the belt runs or must there's a good mile into the main plant where it's conveyed by the bell conveyor. Now that's our next step, is that right? That's correct. The highline building where the limestone is stored in bands and the various other raw materials used and producing cement. Right, let's go down there, Arch. We've

come now to what they call the Highline Building. We walked up several flights of stairs and we're standing now in a building which has a magnificent view of Lake Michigan, the harbor, and the long mile long conveyor belt that Arch just mentioned. Now this conveyor belt brings the limestone up into a smaller building and then transfers it on to another conveyor belt. Now Arch, what's the operation here? How does it work in through this building here? You, I'd like to turn you over to Mr. Sid England. England, assistant plant manager who can explain this this operation to you. Sid, I just mentioned that the limestone came through that long conveyor belt which is on somewhat of an angle going up into the Highline Building and then drops off onto this horizontal conveyor belt here running into the Highline Building itself. Now what happens is it moves along this flat conveyor belt here. As it moves along the conveyor belt onto the Highline, the tripper discharges the stone into the different stone bins. Now that occurs right down the line here, doesn't it? That is right. Let's walk down here, Sid.

As we walk down I might explain briefly that to our right here are a large number of bins. Railroad cars are also located up here and as we walk along to our right also you can see that flat conveyor belt which at the moment is not operating but when it is carries a large amount of that limestone. Now the tripper is just a few feet in front of us so we'll stop right about here, Sid. Sid, that tripper isn't working right now but suppose you tell us how it would work if it were working. The tripper spotted over the first stone bin and the stone is diverted by the tripper into this bin. Well not bin is fully smoothed down to the next one and so on until all six stone bins are filled. Now also along the railroad tracks here are a number of bins and I wanted to ask you about that. Now what about this railroad car right here in front of us? That is filled with blast furnace slag and the engine brings that up. We're served by the E .J. knee railroad on this high line and we handle about 40 cars of similar 24 hours.

Now Sid, that noise interrupted you far down the line down there. What's happening with that noise? That is the car shake up. We used one load the cars with. The car doors are open at the bottom and the car shaper shaker put into operation and it shakes the material out of the car. That's merely shaking that big railroad car, is that right? That is right. I wonder if it's a a little bit noisy from here. You can see that it's shaking the car pretty rapidly. Now how many bins along here do you have? We have a large number of them but what are they filled with? We have just been five coal bins. I wanted to wait just a minute Sid while the noise died down somewhat so we can talk a little bit better. Now I'll go back over that. What are these bins contain here? Blush furnace slag from the steel mills and we have nine of those, nine of those bins and we have one two iron dust bins and five coal

bins. Now this is called a high line building. Why why do they call it the high line building? Because it's built up in the air so the cars can be run up on the high line and unloaded and then gravity fed into the mill. Now we have all the raw materials here, the limestone and the iron and all this that you just got through mentioning. What happens after they fill the bins here? Where does it go from here? It goes down into the raw material building where it's processed and that's probably going to be our next stop. We'll go over here and talk to Arch just a minute. Arch we just mentioned to Sid that the raw materials building is where we should probably go next, is that right? That's correct, that's where the various raw materials you see here are dried and ground before they go to the rotary kills. Right, let's go down there. We have come now to the raw materials building and that noise you hear is that of the dryers which are working. We're standing only a couple of feet away from one of the dryers and we go look inside a small window and see the fire

inside. Now in order to explain that we're going to call upon Arch tell us just exactly what's going on inside that dryer. Here I'd like to introduce now Mr. Pete Ring, General Operating Forman who will explain this part of the operation to you. Pete this is a mighty big operation here and inside there we can see the flames shooting in. We might as well start at the beginning. First of all the last step we saw was where the limestone and your slag was dropped down the bins. Now as I can see away back in the corner the bottom of those big bins that comes a hopper out of there and onto the belt which brings it into the dryer. This dryer here as I understand it is only slag, is that right? That's right, this is only the slag dryer. All right now how does this work? First of all what about the fuel? How do you get the fuel in there? The fuel is a pulverized coal blown in with an air blast. That's through this pipe right here to our left? Through that pipe. That's an awful long

dryer keeps rotating. Now what goes on inside of there Pete? There are lifters inside the dryer which agitate the feed by lifting it up and dropping it through the hot gases of the dryer. So it keeps rotating that slag inside of there, is that it? That is right. The dryer sets on a slight pitch about three quarters of an inch to the foot and which will work. On down door dams and be discharged. What about the heat? How much heat do you have in there? The flame is approximately 1 ,000 degrees Fahrenheit. Well now what about the limestone? Where do you drive the limestone Pete? The limestone is right at the other end of the mill, in six dryers, the same design of this dryer. Way down there at the other end. That is right. Well now why do you do it? Why do you drive the limestone and the slag? It must be dried to remove the moisture that is present in the slag and the limestone on arrival in the plant. How much moisture do you have in there? The slag will run approximately 17 percent moisture

in the limestone and approximately 5 percent. Well now once you get this slag dried out to the point where you think it's just proper and also the limestone, what happens to it then? It is elevated down and then to hoppers over our ball mills which are preliminary mills that's ready for the preliminary grind. Where are the ball mills? They are just back of us. There's another room back here. That is right. Well I think perhaps that's the next place we're going to go. Arch we were just mentioning that the limestone and the slag after it's dried goes into the ball mills. Is that where we go next? Yeah we're going to the grinding department of this same building right here where the raw materials are pre ground and then finish ground into a real fine powder before it goes to the kilns for burning to cement clinker. All right so let's go in there. Now

that sound that you heard just a moment ago is the sound of the ball mill room which is just fixed to this drying room where we stood just a moment ago. Now at the cement plant they hand out a little folder here and I'd like to read just briefly from this folder I think it describes very picturesquely arch what happens in this room. This ball mill room is contains the ball mills. They are lined with armor plate and partly filled with steel balls. Now as the southerners revolve the balls are carried upward by centrifugal force which holds them in place on steel plates or ribs set inside into the sides of the cylinders. When the balls near the top of the mill they cascade forward and down onto the charge of raw material which is ultimately ground to small particles. Now these ball mails are up to 12 feet in diameter and 10 feet in length. Now arch I have a ball right here in my hand and we might better explain that a little bit better by looking at this ball and thinking of it in terms

of crushing that slag as it comes in there. First of all the last step we saw was the slag being dried and then it comes into those big hoppers up there. Now what happens after that? The slag is fed into the ball mill. There's a battery of 8 ball mails you can see there here that each of these ball mails is fed with what we call cradle feeder that feeds a material in certain amount per unit of time. You see what I mean? The ball mails charge with about five tons of two and a half inch balls as you read from the literature there as the cylinder turns and picks the balls up with the lifters and cascades them down and crushes the material in the mill by cascading effect and also from a trition grinding the rolling around of the balls and the ball mill. What kind of a fine grilling do you get out of this from

the ball? I mean is it like sand when it comes out of there? Yes that's about a sand sizing it comes out of the ball mill. I found this I supposed to be the best way to crush this slag and let's hold it with these steel balls. That's correct in the cement industry I think that the ball mails and tube mails or compound mails, mails of that sort are used throughout the cement industry. But now right here to the right of us not far away from the ball mails is a large cylinder rotating. Now what operation is this? That's a tube mill. Is that operated about the same theory? You said all the difference it has it's a little longer in length and it's loaded with smaller balls for the finer grinding those balls are three quarter inch in diameter instead of two and a half on the coarse grinding ball mails. In other words when you bring it out of these mails over here you go into the two mails for finer grinding. Well we might step back just a little bit before the two mails and say that the slag after its pre ground in the ball mill and the limestone which is pre ground at the other end of the building in a hammer mill those two materials go to

separate hoppers over the proportioning scales where the two materials are properly blended as set by the laboratory. Then the combine material goes to the two mails where it's grind to a real fine powder. Now once you bring this powder out of the two mails what happens to it then? It's conveyed to us a battery of blending tanks where the we have there are storage silos ahead of the rotary kills. Let's go there then. Okay. We're standing now right next to two operations. To our left here are two huge silos actually there are more than two but from where I'm standing I can only see two. Now I call them silos although maybe they have a different terminology for them but they are certainly tremendous buildings. Now to our right are huge kilns which are rotating and they're not a gentle incline. Now we're going to

describe and talk about those two operations. First of all arch what about these big silos? I think I'll let sitting and explain these operations to you. All right sit I mentioned that they are silos perhaps you call them something else. We call them blending tanks. Why do you call them blending tanks? The material the raw mix from the raw material building is blown into these blending tanks where the material is blended and from the blending that is blown by compressed air to the burner building. Now those are awfully big tanks. How much what you say said are contained in each tank? About two thousand tons in each tank. Two thousand tons. What do you mean tons tons of your basic mixture? A raw mix yes. Now I guess that from the bottom of the tanks you blow it through those tubes that we can see way down at the end of the building. Is that right? We blow it through the ten inch pipe up to the receiving hopper above the raw feed hopper in the kiln row. Now we won't go

down that far said we can probably describe it from here but you we can see those ten inch tubes going up into the building and then into the hopper. Now there's huge hoppers down there start at one end of that kiln that we mentioned. That kiln said is on an incline. I suppose that's to keep the material inside moving towards one end. Is that right? That is right and the rotation of the kiln, the rotating of the kiln helps to bring it down to the front of the discharge end. Why do you what what is the operation in there? There's a tremendous amount of heat coming out of one end of it. What what happens inside of there? The raw mix is fed in one end of the kiln and of course the hot gases are in the other end. The fire is putting the kiln from the other end where we have a temperature about 2700 degrees. The material is in the kiln for about all 45 minutes to one hour. Now said what's the purpose of the heat? Why do you why do you heat it at such a tremendous amount of heat? We burn the raw material as we say here we burn the raw material and make it clinker.

The clinker is what we've been hearing about but haven't mentioned up to this very point. The clinker actually is the cement, is it not? That is the material before it's made into cement. It travels for the finish mails from here. Now we talked about the heat inside of there. I'm not sure that we mentioned the temperature. How much is the temperature down at this one end? About 2700 degrees. And at the other end? About 1500 degrees. So as the material comes through the kiln it goes through a varying amount of temperatures. All right now Arch we've got the thing inside those kilns. We've got the raw material in there and it's finally been heated and as said just told that makes the clinker. What about the clinker? What happens to that? Well the clinker as it comes out of the kilns we spray it with water where it goes into the elevators that elevate it up and drop it out into an open clinker storage where the large amounts of clinker are stored ahead of the finished grinding operation where the clinker is ground

into finished cement and at that point during the grinding operation and the finishing mill a small amount of gypsum is added to it. Now that's the next operation that we should go to. That is correct. Now the storage you're hearing in the background comes from a number of large machines and hoppers. Now Arch we're talking about clinker storage and I understand that's right behind our wall here. Is that where the clinker is on? Yes as I told you the clinker is coming out of the kiln I elevated through an elevator and dumped into an open clinker pit. Clinker storage building we call it where there are three overhead cranes that handle the clinkers as they drop out from the elevators from the kilns and the cranes distribute the clinker throughout the whole storage building so that we get a proper blending of the clinker. It has to be cooled by handling with the crane and also we get a certain amount of blending by using the crane bucket. Now at least the machines that we're standing around

especially these hoppers above us Arch what happens in these hoppers right here? The clinker crane that I told you not in the clinker pit pick the clinker up out of the storage and dump it into these various hoppers over the percolise mills. I'd like for a feed ring take over part of the discussion here you. All right Pete now we've got the raw material into the hopper being dropped down into this whirling machine now what is that machine and this is what is called the Hercules mill it's it's on preliminary mill in the finish department. There the clinker is reduced to small size which will go through a 20 my screen before being conveyed through two melts and it's happening in there in that whirling activity and the clinker is being reduced inside that's right it's a big crush between three rolls and a die ring or a

circular steel ring and coming in contact with the clinker reduces it in size. Now it reduces it to what a powder for it, no to a form of a to find us the opacity of about a 20 my screen, another 20 my screen that's right. Now what happens then to the material pit after passing out through the mill with the bottom where it's discharged it goes by means of screw conveyors to a bucket elevator or there it's elevated and to screw conveyors over hoppers and it is distributed them among the 22 two mill hoppers we have in this mill. We finally reached to the reach the point when we have some finished cement we are getting close to it. Now let's get back over here to arch arch uh they just said we're getting ready close to the point where we have some finished cement. Now where is that uh taking place? Well the finished cement is being ground in these battery at two mills we have 22 two

mills in here the same as we're in the raw mill there those the two mills are loaded with three quarry steel balls the same as was in the raw mill and the material after it comes out of hercules mill as the feet said it's 20 mesh now a 20 mesh screen I'd say it's about the size of a screen you have on your screen door at home I give you an idea of what the size material that's being fed into these two mills let's describe briefly the two mills from here do they have the steel balls in them that we saw in the other two mills? Yes three quarrys balls is roughly 20 tons of these three quarry steel balls in each of the 22 two mills 22 two mills and believe me they're really big a huge rotating circular drum and uh out of this comes the finished product that's correct the feet going into the into the mill is regulated by a variable screw feeder screw conveyor feeder that regulates the what we call barrel's power going into the mill and we regulate the fineness

at the discharge in the mill by changing the revolutions on the screw conveyer feeding the mill when you have water pouring over that big cylinder that's the cool the cool outside shell because it's there's a great heat given off by the steel balls grinding with the material against the inside lining of the mill tremendous amount of heat so we use the water on the outside shell to cool the mill down at the same time uh cool the cement discharge temperature down to a reasonable so it's not too hot well now arch uh I suppose at the next obvious step is to put the finished product into some packages right yes uh but the finished cement leaving these 22 two mills is collected in uh screw conveyor and elevated to a large balcony there which takes the cement over to one of our three stock houses we have three storage stock houses in the plant here where we can store our large amount of cement all right let's go over there okay here

this is one of our seven uh packing and loading rooms that we have in the three stock houses and to explain this part of the operation I'd like to introduce to you mr. Roy Martin general packing and loading form them for your information Roy will have 50 years service come next February and I think he should know what he's talking about when he comes to packing and loading well I would think so Roy suppose you tell us a little bit about the operation of the packing and loading department here now first of all let me ask you about that boy I saw working up there a moment ago with a bunch of levers and sacks and all of a sudden the sack was filled with cement now how does all that happen well there are the bags placed alongside this man uh that are made up with a valve in one end that he inserts on a tube and these machines are automatically set to weigh 94 pounds net of cement and that

only weigh 94 pounds so that's means each sack will weigh 94 pounds is that right that's right when the sack is filled to 94 pounds it automatically goes out of registration and he removes it from that position and puts a new bag on the spot well where does the cement come from the cement comes from bins in this building 50 ,000 -barrow capacity bins here and they goes right above it there yeah the cement is withdrawn from the bins by it means a screw conveyors to an elevator and elevated to hoppers above these packing machines I see now we saw that the boy up there working with the empty bags and the bag being filled by that automatic system and then what happens to the bag it looks like it's coming down over a conveyor belt is that it drops down onto a conveyor belt that brings the packages out to the end or an apron from which the bags are taken and put on stevedore trucks and then uh we'll either

into uh box cars or onto one of the old trucks and they're distributed to whoever wants to buy some cement that's right the customers get it from there well Ryan it's been a pleasure talking to you thank you very much and congratulations on uh spending 50 years with the that's been my pleasure arch before we leave I want to ask you something about the packaging now we only see small packages what else do you have well we we ship not only by a package here we ship uh box them in also by rail it is hopper cars by rail road and also these uh block truck block uh automobile trucks too in addition to the what you've seen here this part of our packing and loading operation okay arch thank you very much and thank you very much for showing us through your operation we certainly enjoyed but here we've been it's been very nice to have you out here and it's been a real pleasure to meet uh to make this trip around through the plan with you