Sam+Abbey+Liam

__ Our Group: Sam: sam_martin94 Liam: liammarshall Abbey: abbeylucysimpson

Chapter 1:__ The three main raw materials that are used to make iron are, iron ore, limestone and coke. The raw materials that make iron come from China, Brazil and Australia they are transported by ship to other countries. The raw materials are processed before they are used in the blast furnace to rid the materials of oxygen. Large amounts of air are blast into the bottom of the furnace where the limestone reacts with the silicates to form slag. Oxygen reacts with coke to produce carbon monoxide. Impurities in the iron ore are removed using limestone, this stops the furnace being filled with solid material. Much is said nowadays about the consequences of human activity for the environment. It is drilled from underground, which means that a lot of electricity is being used, also harmful gases such as carbon monoxide are being produced when it is being purified. It is transported by ships to other countries which means using fuels which release gases into the atmosphere. The side effects can be reduced by
 * What are the main three raw materials used to make iron?
 * Where do the raw materials come from and how are they transported to the plant?
 * How and why are the raw materials processed before they are used in the blast furnace?
 * What role does each of these three raw materials play in the iron-making process?
 * What can you say about the ecological effects of using these raw materials (for the country where they come from and for the means of transportation)?
 * How can the bad side effects be reduced?

Scrap is used to reduce the cost of prodution and to save iron being extracted from the earth. Advantages: Disadvantages:
 * Why is scrap used?
 * an advantage of this is saving money.
 * a disadvantage of this is that scrap iron must be located and transported.

__Chapter 2:__ __Part 1:__ Fe = 94.9kg C = 4.55KG Si = 0.25kg Mn = 0.3kg

__ How Many Kg Are Oxidised: __ 94.9% Fe x 0.02 (amount oxidised) = 1.898 4.5% of C (oxidised) 4.5% of C (4.55) = 2.0475 0.2% of Mn (oxidised) 0.2% of Mn (0.3) = 0.006 All Si oxidised

__ How many Kg of steel are produced from the 100 Kg mixture: __ 100Kg - 1.898Kg (Fe) - 4.5Kg (C) - 0.25Kg (Si) - 0.2Kg (Mn) = 93Kg (Steel)

__How much energy is produced from oxididation:__ Fe = 4.3 x 1.898 = 8.1614 Mj C = 11.7 x 4.5 = 52.65 Mj Si = 33.9 x 0.25 = 8.475 Mj Mn = 7.4 x 0.2 = 1.48 Mj

Total = 70.6 Mj

__How much energy is used in natural gas a year per household:__ 2000 x 32 Mj = 64000 Mj (per household, per year)

__Compare the rusult from the last question to how much energy is given out from the oxididation of the hot steel mix:__ 100Kg of mixture = 70.6 Mj of energy. 64000/70.6 = 906Kg of mixture to make 64000 Mj of energy.

__Part 2:__

If 45% of the heat generated by the reaction is lost by the waste products, when the waste gases leave... What will the remaining temperate of the hot metal mixture be? 1 kg of Carbon, when oxidised makes 11.7Mj of energy. 0.05Kg of the 4.55Kg of carbon becomes part of the steel, this means that 4.5Kg is oxidised.

This means 4.5kg x 11.7Mj = 52.65Mj 45% leaves as waste energy leaving 55% of that energy in the reaction 55% = 0.055 as a decimal, 0.55x 52.65Mj = 28.96 Mj left by carbon. When everything was oxidised there was 70.76 Mj energy released. Energy from oxidation of Fe (8.16), Si (8.47) and Mn (1.48) makes 18.11MJ of energy.

When you add this to the heat from the carbon that is not lost: 18.11 + 28.96 = 47.07Mj So we calculated heat generated from the reaction once we lost heat by losing hot gases like carbon dioxide. We have left 47.07Mj.

__Now we need to work out what temperature this EXTRA heat would cause our metal mixture to increase to.__ The starting temperature of the mixture is 1350 degrees C. 47.07Mj of extra heat is released in jewels it equals 47070000j of energy. 47070000j / 690 = 68217.4 The energy needed to heat 1kg of steel by 1 degree is 47070000j.

93Kg of steel is produced so : 68217.4 / 93 = 733.5 degrees __increased.__ The final temperature is 1350 (the starting temperature) + 733.5 = 2083.5 degrees C.

__How much energy is needed to melt 1kg of scrap and then heat it to 1650 degrees?__ The starting temperature of scrap metal is 20 degrees; so we need to heat it by 1650 - 20 = 1630 degrees. The energy needed to heat 1Kg of steel by 1 degree is 690j of energy. So 1124700 joules of energy is required to heat the scrap metal.
 * 1630 x 690= 1124700 joules of energy.

More energy is needed as when we heat the scrap metal as it needs to be taken past its melting point in order to turn it into a liquid. Latent heat (energy needed to melt 1 Kg) is 271Kj this is converted to 271000J/Kg. The energy needed to heat it is then added. The energy needed to melt it : 1124700 + 271000 = 1395700J of energy is needed to melt and heat 1Kg of scrap. __ —1395700 / 1000 = 1395.7Kj __