[speaker001:] with Mr but what I thought I'd do today is see how much you've remembered of one or two of the basic topics. So... topic I want to start off today with is iron and steel.... Who can remember what four things which four things go into a blast furnace?... Let's have one of them from somebody.... Copper.
[Tony:] Copper. We're trying to make iron and steel Edwin. [LAUGHTER]
[speaker001:] Oh. Oh right yes, I knew that.
[Tony:] You knew that. Good.... Okay. So what four things? There's four things that go into a blast furnace. Come on you've done this....
[speaker001:] Zinc.... [LAUGHTER]
[Tony:] N not zinc if we're trying to make iron.
[speaker001:] Iron. Should be iron or steel.
[Tony:] Iron what?
[speaker001:] Ore. Iron ore.
[Tony:] Right.... Ha hallelujah, we're getting somewhere. Right iron ore. most of the iron ore is used ir in the form of iron what? Somebody said it actually....
[speaker001:] Oxide.
[Tony:] Oxide, right. And they're iron oxides.... Right there are two iron oxides commonly used in the blast furnace, one of which is named because of its colour [phone rings] Excuse me a moment. [talking into telephone] Er... right as I was saying there's two iron oxides one named because of its colour and the other one named because of its properties.... Anybody remember what they are?... Simon.
[speaker001:] .
[Tony:] No I think invoking the deity is not going to help you here.... I'll give you a further clue. One of them is because of its blood red colour.
[speaker001:] .
[Tony:] What's Yes. What's the name of the department in a hospital that deals with blood?
[speaker001:] The blood bank.
[Tony:] The blood bank. No. No.
[speaker001:] [LAUGHTER]. .
[Tony:] That's where they store it not where they er play about with it.
[speaker001:] Transfusions
[Tony:] Begins with H.
[speaker001:] H. Hospital. Hospital blood [LAUGHTER] bank []. [LAUGHTER].
[Tony:] H A E.
[speaker001:] Hae...
[Tony:] Mm.
[speaker001:] A E A [LAUGHTER] A E [] [LAUGHTER]. A E . Haematology.
[Tony:] Haematite.
[speaker001:] Haematite.
[Tony:] Haematology is the department that deals with blood and the red colouring in the blood is haemoglobin. Edwin.
[speaker001:] Sir is it erm are they the people who tell you what erm group your blood is?
[Tony:] Yes, basically. And the way they do that is they take a sample of your blood and mix it with er... agents taking taken from the blood of other people.
[speaker001:] Ugh.
[Tony:] So for example when I've given a pint of blood instead of giving it into a plastic bag with sodium citrate to stop it clotting I've actually given into a plain glass bottle and when I asked what this for the erm transfusion nurse said that they're going to let the red cells all clot together at the bottom and use the... serum that was left for blood grouping purposes... which of course is very important. So when they're actually blood grouping they're using human blood serum to er test which group you belong to. So... haematology because of haemoglobin the red... colouring of the erm red cells that carry the oxygen around the body and haemoglobin contains iron which is why when people are short of iron they suffer from anaemia because they've got en not enough of this red colouring in their... blood cells to carry the oxygen around the body. Haematite is F E... 2 0 3.... Iron three oxide....
[speaker001:] iron three oxide....
[Tony:] The other one... I n said named because of its property is called magnetite.... Okay? So what's the property of magnetite that makes it interesting?... It's magnetic. Right.
[speaker001:] ....
[Tony:] And it's believed that magnetite in its er one of its forms lodestone was er the earliest form of compass. You had this lump of rock that you dangled from a thread and people discovered that it always pointed in the same direction, so if you were on board, a ship for the first time people were able to travel in a ship without having to hug a coast all the way across or navigate to where they could see. Er the... I know this is basically not iron and steel but if you take the Mediterranean... er very loosely...
[speaker001:] .
[Tony:] That's Italy and er the home of the Mafia, there's Greece and Turkey and so on and you come back round again, there's the Straits of Gibraltar. In the early days of er navigation within the Mediterranean people used to actually have to navigate by going all the way round the coast.
[speaker001:] [LAUGHTER].
[Tony:] So if you wanted to go from there to there you went all round that way. The reason being that you had to navigate where you could see. And in the Bible it's recorded that for example there are some cases where there was a big storm and they lost sight of land and all the sailors er promptly panicked because once they'd lost sight of land they hadn't got a clue where they were.... But with a lodestone compass which was er magnetic iron oxide hung up on the ship, you could actually then work out that you go straight across from there to there... no problems.... And it then made possible going by the shortest route. So magnetite is a very important iron oxide.... Where do we get our iron ore from these days?...
[speaker001:] ....
[Tony:] Well you're telling me other countries. In other words we import it. Why do we import it?
[speaker001:] Cheaper.
[Tony:] It's cheaper, yes. And why is it cheaper? What's happened to the iron ore in Britain?
[speaker001:] . [LAUGHTER] It's gone [LAUGHTER] rusty []. Finished.
[Tony:] It's gone rusty. No.
[speaker001:] [LAUGHTER] Er it's Yeah. finished.
[Tony:] It's finished. Yes
[speaker001:] .
[Tony:] It's run out. Right.... The two main... areas that I'm thinking of are in Northamptonshire... where the iron ore works there have been completely exhausted and the other is Consett in County Durham. And if you go to Consett from Nottingham,... you
[speaker001:] ?
[Tony:] Consett. C erm... C O N S E... double T I think it is.
[speaker001:] .
[Tony:] If you go to Consett in County Durham you come along the road and there's the town and... what was left of the old steel works... because the steel works was built there because of its easy access to the iron ore deposits. And you come over this hill... and suddenly there's nothing on the other side... except a huge hole in the ground, and the road goes along almost a cliff edge the side of this... erm hole which is this worked out iron ore quarry. It completely all the iron ore deposits there er have gone.... So we import our iron ore from other countries. For example Australia produces quite a lot, Sweden produces a lot, and it's imported into this country in bulk ore carriers. So... we've got iron ore... obviously from which we get the iron.... Three other things to go into the blast furnace?...
[speaker001:] Me?
[Tony:] Anybody.... Iron ore is one.... What's the fuel?
[speaker001:] Erm....
[Tony:] Right, begins with that letter, yes.
[speaker001:] . coal? coke.
[Tony:] No it's con
[speaker001:] Coke?
[Tony:] Coke. Right. Obviously
[speaker001:] .
[Tony:] ... coal is converted into coke.
[speaker001:] . .... No it's not cocaine. Oh. All right then.
[Tony:] You're confusing the slang for cocaine with... coke. Coke... in the terms in which we're talking about it is Er it's not that soft drink either. It's actually a black porous substance made by heating coal in the absence of air, and consists of virtually pure carbon.... The er... coke is produced from the coal and the coal gas that's driven off is then used for heating and powering things elsewhere in the steel works. So we have two things, we've got iron ore, coke. Now for that coke to burn in this furnace what must we add?...
[speaker001:] Heat? .
[Tony:] Heat, yes. I'll give you a clue. It's the sort of thing you might collect from the House of Commons particularly during a... er big debate.... Producing lots of...
[speaker001:] . [LAUGHTER]....
[Tony:] Possibly but er that's
[speaker001:] [LAUGHTER].
[Tony:] not quite what I'm thinking of.... Politicians are renowned for producing?
[speaker001:] Hot air.
[Tony:] Hot air, right.
[speaker001:] [LAUGHTER]. ....
[Tony:] Hot air.... Air obviously makes it burn. Hot air means that it's burned better. And the hot air is injected near the bottom of the furnace where the temperature is about fifteen hundred degrees celsius,
[speaker001:] Whoa!
[Tony:] which is just a little bit warm. If you injected cold air you'd actually chill the furnace down a bit. The reason that you use hot air is to keep that combustion going at a good temperature. And finally coming from Derbyshire... from up the road in Buxton, the biggest quarry and the purest in Europe.
[speaker001:] Spring water.
[Tony:] No.
[speaker001:] . [LAUGHTER] Yeah but there is
[Tony:] There is Derbyshire spring water from Buxton yes.
[speaker001:] . [cough].
[Tony:] O
[speaker001:] Er excuse me, we got the answer right? Spring water in a blast furnace?... Anyway carry on. [LAUGHTER].
[Tony:] [LAUGHTER] Yes, right. []... So... what is mined in large quantities in Derbyshire? You saw a video about it.
[speaker001:] Limestone.
[Tony:] Limestone, thank you.... Now limestone has a very important function in the blast furnace.... What is that?... What does it make?...
[speaker001:] Erm... lime water? [LAUGHTER].... . [LAUGHTER]....
[Tony:] Four-letter word,...
[speaker001:] .
[Tony:] used in a er derogatory sense of certain people.... Limestone is used to make? Come on, think.
[speaker001:] Burn. Burn. Burn. Make it burn? Slag! Slag! [LAUGHTER].
[Tony:] Thank you. Anybody would think you haven't done this. Come on.
[speaker001:] .
[Tony:] Right.
[speaker001:] .
[Tony:] So...
[speaker001:] . [LAUGHTER].
[Tony:] The... impurity in iron ore is about one third... sand,... which is silicon oxide. Now if you have... silicon in your steel it becomes very brittle and useless. For example if you think of the Vauxhall Cavalier advert where they're crashing these Cavaliers all over the place, if you had a silicone er a silicon-based steel... instead of crumpling nicely the steel would actually crack and break. So basically you have to remove this silicon which was in this impurity. To do that you need to add... limestone which then converts into er calcium oxide in the heat of the blast furnace and then reacts with the sand to form slag. The equations are as follows.... What's the formula for er limestone?... Simon. Come on.
[speaker001:] . I don't feel special no more. .
[Tony:] don't feel special any more Edwin, let's at least
[speaker001:] Oh.
[Tony:] get English right. Even if chewing in class is not allowed in a science lab. Calcium oxide heated in the blast furnace turns very rapidly to calcium... oxide plus carbon dioxide.
[speaker001:] . Which makes erm
[Tony:] Now
[speaker001:] C O three. It's easy.... .
[Tony:] Calcium silicate. Now calcium silicate is the... slag.... What happens in the blast furnace is that the slag is lighter than the molten iron... and it collects on top of the molten iron and by some means that I s
[speaker001:] scoop off....
[Tony:] But they don't actually scoop it out off from the blast furnace, they drill a hole in the side where they've plugged it with a lump of clay.
[speaker001:] Cos they have to keep the blast furnace going don't they.
[Tony:] That's right. Yeah. I'm coming to that, good, but that is a very important point.... The tapping from the furnace is done by means of tap holes in the side of the furnace and these are plugged with clay... and what happens is one of the... workers has a lump of... clay on the end of a long metal rod. He then... pushes this clay into the hole and the heat of the furnace means that the clay bakes almost instantaneously blocks the hole and then the furnace can go o carry on working. And the slag is normally tapped off first.... They then run it into pits, break it up, and use it for road stone or alternatively, the molten slag is run over water-cooled rollers where it forms little tiny pellets... with a high air content which are used for making insulation blocks.... But the... slag making is an important part of the process. By the way interestingly enough this is a sort of acid plus base type reaction, where you've got calcium oxide which is a basic oxide,... silicon dioxide which is an acidic oxide, and the salt that it makes is calcium silicate.... Let's have a look at the reactions.... The most common ore used in the blast furnace is haematite,... so I'm going to restrict my... equations to dealing with haematite. Because that's the one you may be asked in your exam.... F E two O three.
[speaker001:] Haematite.
[Tony:] Haem Haematite.... Blood-red colour. If you rub it in your fingers, you'll find that your fingers are actually stained red by the haematite dust, and it looks just as if you've cut yourself. Now there are two ways in which iron oxide can be reduced to iron and they depend exactly where you are in the blast furnace.... The first one is by reacting directly with carbon.... When you get iron... and carbon monoxide.... That is a high-temperature reaction and tends to happen near the bottom of the furnace.... Nearer the t higher up our reducing agent... is carbon monoxide which is formed by partial burning of the coke, and that forms... iron again... and carbon dioxide.... Now... the carbon dioxide formed can react with more carbon to form... car more carbon monoxide. So there's a whole a series of complicated equations that take place at different layers... in the furnace and different temperatures, but the end product of of all of these is basically to produce... the iron, slag... and carbon dioxide, carbon monoxide... and nitrogen. So coming off the top of the furnace we have a mixture of nitrogen, quite a lot of that, carbon monoxide and a bit of carbon dioxide.... Now what do you know about carbon monoxide?... What happens if you react carbon monoxide with oxygen and ignite it?
[speaker001:] .
[Tony:] It burns. Yes.... Have you ever looked at a coke fire?... the coke fire has been banked up with only a limited supply of air. What colour are the flames?......
[speaker001:] .
[Tony:] Blue. Yes. You've seen it, good. They're blue flames. Now the blue flames are What's happening is this, there's two reactions taking place in that coke fire.... Down in the heart of the coke the limited supply of air is reacting with the carbon to form carbon monoxide. You shut the... damper doors on the bottom of fire. This carbon monoxide comes up through the coke and then comes in contact with air at the top of the fire and then burns to give you carbon... dioxide. The carbon monoxide burns with a blue flame. So there is a fuel.... It's called blast furnace gas. Blast furnace gas.
[speaker001:] Which is harmful.
[Tony:] It is. Would be if you discharged it into the environment, because of course, carbon monoxide is what?
[speaker001:] [sneeze]
[Tony:] Poisonous. Yeah.... Come on to the poisonous nature of carbon monoxide in a minute. So carbon monoxide is poisonous.... So they don't discharge it, and since it's a fuel anyway they don't want to waste fuel, they use the heat generated from burning this fuel... to heat the incoming blast of air. They do that in brick s stoves called er Cooper stoves. They've got effectively three of those. Two of those are being heated by burning blast furnace gas and the third one has the cold air blown through it and the brickwork inside gives up the heat to the er... cold air, warms the air and then that's blown into the blast furnace. Blast furnace gas is what is called a low-grade fuel. Why is it a low-grade fuel?... Compared with so many things. Simon?...
[speaker001:] Er
[Tony:] You looked like you were going to try and answer.
[speaker001:] I w Well actually I wasn't but I'll have a go. Cos it cos it's cheap to make?
[Tony:] No. No. Low-grade fuel.
[speaker001:] use it?
[Tony:] No.... What are we after when we burn a fuel? Lots and lots of?
[speaker001:] Heat.
[Tony:] Heat. So a high-grade fuel will give us...
[speaker001:] Er plenty of... heat.
[Tony:] Right. And a low-grade fuel?
[speaker001:] .
[Tony:] Why doesn't that give us a lot of heat?
[speaker001:] It doesn't react very well.
[Tony:] Right. What doesn't react very well out of that lot?
[speaker001:] Er... carbon. Carbon....
[Tony:] Well look.
[speaker001:] Oxygen.
[Tony:] You've got three things in blast furnace gas.... Nitrogen, carbon monoxide and carbon dioxide. Which one burns?
[speaker001:] Nitrogen. Carbon monoxide.
[Tony:] The carbon monoxide. What about the nitrogen and the carbon dioxide? Do they burn?
[speaker001:] No.
[Tony:] No. So th most of that doesn't burn.... So... out of a large quantity of fuel... this blast furnace gas, only a little bit will actually burn to give you heat. But there's still enough to make it worth their while doing it. Talking about carbon monoxide. Carbon monoxide poisoning. How can you deliberately give yourself carbon monoxide poisoning to a mild degree?
[speaker001:] Get in a car and put. .
[Tony:] That that tends to be a little bit permanent. I was thinking of a slightly less permanent way and one which the Chancellor's made slightly more expensive....
[speaker001:] Erm... [whispering] Cigarettes. [] Cigarettes.
[Tony:] Cigarettes. That's right.
[speaker001:] Oh yes of course.
[Tony:] Okay Ashley. Cigarettes. The average smoker at any one time has approximately ten percent of their blood out of action with carbon monoxide poisoning....
[speaker001:] .
[Tony:] That's why a blood donor if they've given a pint of blood... they're told not to smoke afterwards if they're a smoker. The reason being that having given up ten percent of their blood... roughly, er in the blood donation... if they then continue to erm... smoke afterwards, they they'll knock another ten percent of what's left out. They may be dropping their... oxygen carrying capacity of their blood to a level at which they pass out.... So er... that's... how people deliberately give themselves carbon monoxide poisoning although perhaps without realizing it. Simon.
[speaker001:] Sir right, you know if you... go for a blood transfusion and you're a smoker, how do you know that when you have the transfusion you won't get the ten percent of the blood that's not working properly?
[Tony:] What it is, is that it would be averaged out over the blood as a whole. And just bear in mind that if you're having a blood transfusion, you could actually be having having the blood of a smoker. Other things are if the erm person giving
[speaker001:] Yeah but wouldn't that get you hooked on smoking?
[Tony:] It wouldn't be enough to get you hooked, no. But bear in mind that if the person
[speaker001:] What if there were plenty of smokers?
[Tony:] ... If there were?
[speaker001:] Plenty of smokers.
[Tony:] ... It still wouldn't be enough er nicotine to get you addicted to cigarettes. The addiction takes quite a time to develop.... The erm... other side of the coin is if the blood donor has had a liquid lunch... And what do I mean by liquid
[speaker001:] Boozing.
[Tony:] lunch Fiona?
[speaker001:] .
[Tony:] Boozing. Right. If they've been boozing, you could end up with erm enough blood... to
[speaker001:] .
[Tony:] make you quite er high.
[speaker001:] Ooh. Yeah you you. . If you go for a pint at dinnertime you'd... Yeah you're driving and you Can't you get done for drink driving? Yeah. [LAUGHTER].
[Tony:] If you needed a blood transfusion er you're not likely to be driving a car straight afterwards.
[speaker001:] .
[Tony:] You tend to be rather poorly which is why they've given you the blood transfusion. But they are extremely careful. The only things that they don't seem to worry too much about your having taken beforehand are alcohol and smoking, cigarettes. If you've got carbon monoxide poisoning... one of the problems is that your blood can't carry the oxygen because the... red blood cells are being put out of action by the carbon monoxide. You form carbonyl haemoglobin which er doesn't carry oxygen. How do you treat somebody... who's er... had carbon monoxide poisoning?
[speaker001:] Give them plenty of oxygen.
[Tony:] Right. Now the problem is with this that the blood as is it won't normally take it up. So what can be done if you live near... er a naval town or North sea support town to actually get that oxygen into the bloodstream?...
[speaker001:] Oh erm... ask them if you can sit in one of those er machines that erm get you out of the bends.
[Tony:] Right. Absolutely right. Yes. Er the h it's called hyperbaric oxygen. Basically what they do is they stick you in one of these divers' decompression chambers,
[speaker001:] Oh yeah.
[Tony:] flood it with oxygen, and you're putting so much oxygen in... that the normal mechanism of the oxygen combining with the haemoglobin in the red blood cells is bypassed and the oxygen under high pressure will actually dissolve straight into the bloodstream. That's how you get the bends because the oxygen nitrogen have dissolved directly into the blood.... So that it's actually the blood itself carrying the oxygen round in solution. And you keep the person in that condition long enough for the damaged red cells to be replaced. The only problem is if you don't happen to live near a port... which has one of these hyperbaric er diving chambers then you've problems that erm... just putting a mask over the person and giving them oxygen that way is normally isn't enough. It may actually paralyse the person and put them on erm a life-support machine.
[speaker001:] footballers sort of when footballers get injuries they go in them to get fit quicker..
[Tony:] You're right Duncan. Do you know why?
[speaker001:] ... No.
[Tony:] Well,... instead of just saying no, how about taking it through and working it out?... When you're growing new muscle... or replacing tissue... what is needed? Apart from the food to supply the proteins to make that muscle, what else?... What do you need all the time?
[speaker001:] Oxygen.
[Tony:] Oxygen, right. Some of that oxygen's used in the processes, together with the proteins to repair damages tissue. So if you increase the amount of oxygen present, what happens then?...
[speaker001:] The tissue will heal quicker.
[Tony:] The tissue will heal up quicker. And that's the way it works. Another advantage is, and this is another case for being put in one of these hyperbaric oxygen chambers, if you've got... erm... an anaerobic infection. Now, anaerobic... [phone rings] Excuse me.
[speaker001:] ....
[Tony:] [phone rings] Think of Jane Fonda and aerobics and I'll come back to you. [talking into telephone] [shouting] Can you be quiet please? [] I can't hear on the phone. Thank you. [talking into telephone]. [shouting] Right folks. Sorry about that. Happened yet again. Erm []... that was er Steve from the Youth Centre because we've just er told him how much it's going to cost him to use the school premises next year, and he's thrown a dickey fit.
[speaker001:] Who? Good.
[Tony:] The youth leader.
[speaker001:] Oh.
[Tony:] Erm... because the problem is the school's s now supposed to be making economic charges... er which involves caretaker's fees plus heating costs and everything. Erm and it comes to quite a high figure and he's not happy.
[speaker001:] . Sir school trips? . Yeah.
[Tony:] At the moment at the moment I don't know because er I had er one or two problems with organizing that. But I will leave that with me and I'll come back to you.
[speaker001:] Sir could you do something because ages ago you promised to do a chip-pan fire for us. Yeah! Yeah Sir I And you still haven't done one. Every time you've done
[Tony:] I haven't forgotten the chip-pan fire.
[speaker001:] Every time you've done the chip-pan fire I've always missed out. . Yeah.
[Tony:] Yes. I will er demonstrate it again. That is the... the effects on the ceiling are the effects of the last one. I'm going to be doing one or two more... over the next erm... few weeks or so. I will do it for you. Because then when it's been er finished I'm going to repaint the ceiling to cover up the
[speaker001:] .
[Tony:] Well, I'm s sure if you wanted to I could give you the paint and you can do it for me.
[speaker001:] .
[Tony:] You'll notice it doesn't. It doesn't.
[speaker001:] .
[Tony:] If you notice the smoke and flames reached somewhere nearly to Duncan's head. Last time.
[speaker001:] .
[Tony:] Which was quite effective. Back to the blast furnace.
[speaker001:] .
[Tony:] We've got our four elements going in, four main components. We've got coke, iron ore, limestone and hot air. Hot air is blown in to the furnace. We've got the blast furnace gas and dust coming off the top, and the dust's removed and the blast furnace gas is used as a fuel. Coming out at the bottom, comes out what?...
[speaker001:] At the bottom? Ash, Sir.
[Tony:] No.
[speaker001:] Iron?
[Tony:] Iron. Right. Molten iron....
[speaker001:] Which is very hot indeed.
[Tony:] Yeah. Which is why in the iron and steelmaking trade they refer to the molten iron as hot metal.... If you were to let that iron cool, what form of iron would you actually have?
[speaker001:] Is it steel?
[Tony:] No.... It's not steel yet, we've got to convert it into steel.... What's that iron
[speaker001:] .
[Tony:] Solid iron. Begins with C....
[speaker001:] .
[Tony:] Four-letter word.
[speaker001:] Cast iron.
[Tony:] Cast iron.
[speaker001:] .
[Tony:] Good, right. Okay. says it's cast iron. Now cast iron, if you are in the metal workshops... and you are hitting something with a hammer and you hit the vice instead, Mr will throw a scranny at you. Why?
[speaker001:] snap and break.
[Tony:] Because it will snap and break, yes. Cast iron is very brittle.... Which is one of the reasons, by the way, why another thing you will get murdered for in the er workshops is taking two hammers and hitting the heads against each other, because they're hardened and y they may well shatter quite explosively if you do that.
[speaker001:] Why would you wanna do that?
[Tony:] Pupils do all sorts of peculiar things.
[speaker001:] ....
[Tony:] So cast iron is brittle.... So what is cast iron used for?...
[speaker001:] Making vices?
[Tony:] Yes. Because
[speaker001:] .
[Tony:] Well not d er it's a special form of steel for hammers. But in a vice, what are you putting that cast iron under? Are you stretching it or squashing it?
[speaker001:] Squashing.
[Tony:] Squashing. So cast iron is extremely good under compression. If you stretch it it cracks very easily. So cast iron res resists crushing better than steel does.... Cast iron is an alloy. That's a mixture of... two elements. Normally alloys are mixtures of two metals. But in this case, for cast iron, it's a metal and a non-metal. Which is the metal, first of all?... For cast iron, pretty obvious....
[speaker001:] .
[Tony:] Iron. Right. And what have we put lots of in the blast furnace, all that black stuff?...
[speaker001:] Slag. Coke. Coke. The
[Tony:] Coke. Right. Which is carbon. So cast iron is approximately... four percent carbon. It's an alloy of iron and carbon.... That makes It's the carbon that makes it brittle. And during the steelmaking process the excess carbon is burnt off by injecting what gas into the molten iron?
[speaker001:] Carbon monoxide....
[Tony:] Much more reactive than carbon monoxide. Carbon... er er er. Not carbon anything. Take the last bit.
[speaker001:] Oxide. .
[Tony:] Oxygen. Yes. So beside a steel works you will have an oxygen-making plant because they actually use oxygen by the ton.... Simon said something interesting earlier about the s the iron works. You said it runs... all the time. Yes.
[speaker001:] Yeah. .
[Tony:] David said then. Iron runs a... iron works run all the time. It's a continuous process.... How does that compare with steelmaking?...
[speaker001:] .
[Tony:] Yeah. Steelmaking is a batch process... a bit like making a cake, where you put all the ingredients in together bake the cake, then put another batch of ingredients, bake another cake. With steelmaking they work in er two hundred and fifty tonnes roughly at a time, pour it in the basic oxygen steelmaking furnace, blow oxygen into the steel which takes about twenty minutes, then the steel... with one or two other processes is basically ready to be used. But it's a batch process, whereas ironmaking's continuous.... Now, cast iron contains four percent carbon. When I had a lock that was sticking what did I blow What powder I did I blow into the lock to make it work better?
[speaker001:] Baking powder.
[Tony:] No.
[speaker001:] Yeast?
[Tony:] Got to tie up with the cast iron.... It's black powder...
[speaker001:] Coke.
[Tony:] Also Well, coke is
[speaker001:] Carbon.
[Tony:] Carbon. In what form? Beginning with G....
[speaker001:] Yeah. Yeah.
[Tony:] Er diamond is one form. What's the other form?...
[speaker001:] . Oh, gold? Graphite. .
[Tony:] Used in pencils.
[speaker001:] Graphite.
[Tony:] Graphite. Good. So graphite... is the black form of carbon. Diamond is the other form. And graphite, cos I blew this graphite powder into the lock it acts as a what?...
[speaker001:] Oh a lubricant. Lubricant. Lubricant.
[Tony:] Lubricant. So graphite is a dry lubricant. Now why don't you put oil in a conventional lock?
[speaker001:] It would clog it up.
[Tony:] Right. Because the oil would attract dust and the d oil dries up and the leaves the dust deposits sort of caked inside the lock, and it will... clog it up.... Graphite is a dry lubricant. Cast iron contains a lot of graphite, proportionately.... Right? So can you give me a use of cast iron which ha one of the effects of it is that it relies on the... occasional lubricating properties of the... graphite in the iron?...
[speaker001:] [LAUGHTER] Er... ice? [LAUGHTER]....
[Tony:] Er clue, it helped me to come to school this morning.
[speaker001:] Car.
[Tony:] Right.
[speaker001:] Moped. [LAUGHTER]
[Tony:] So... so what do you make the cylinder block out of?...
[speaker001:] .
[Tony:] Cast iron. Why cast iron? Because... cast iron's hard. What do you make the piston out of?
[speaker001:] Cast iron. Oh steel. Steel.
[Tony:] No.... You want to be light and a good conductor of heat.
[speaker001:] .
[Tony:] A light metal.
[speaker001:] Aluminium.
[Tony:] Aluminium. Right. Your pistons are aluminium... because you want a light weight because it going up and down, and if it's very heavy... when th the connecting rod wants to pull it back down again it will want to carry on straight out through the top of the cylinder head. So you want a light weight and a good conductor of heat.... And you have a... hard metal sliding against a soft metal, because that actually produces less wear than two hard metals rubbing together.
[speaker001:] .
[Tony:] Now normally your cylinder is lubricated by what?
[speaker001:] Oil.
[Tony:] Oil. If the oil film breaks down momentarily... for a very short period of time that little bit of carbon that four percent carbon in the cast iron will actually stop the aluminium sticking... to the cylinder. So the graphite it actually helps to make it self-lubricating. To a certain extent. Now obviously nobody would be daft enough to try running a car without oil,... although some of the garages doing their P D I 's, pre-delivery inspections, can cause that sort of problem. The one I was thinking of in fact was a poor lady who bought a Ford Escort from er what was then Garage, it's now in Daybrook.
[speaker001:] Oh yeah. Oh yeah yeah, I know.
[Tony:] Right. Opposite builders merchant.
[speaker001:] Near the train station.
[Tony:] Yeah.
[speaker001:] [LAUGHTER].
[Tony:] Near the what?
[speaker001:] Well... er you can see the train station [school bell rings] from there. Think you mean railway station. Where?
[Tony:] [sounds of chairs scraping] [shouting] Hang on a second. Wait. Let me just finish this off. [] It was delivered from Ford on a transporter to in Daybrook,... run off the transporter, they did the P D I, she went to collect her brand new car and got as far as Kwik-Save in Sherwood.
[speaker001:] [LAUGHTER].
[Tony:] That's when the engine seized solid because there was no oil in the engine. They forgot to check the oil.
[speaker001:] . Right, see you sir.