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Chemistry.

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Presentation on theme: "Chemistry."— Presentation transcript:

1 Chemistry

2 Metallurgy - 1

3 Session opener What is lye? KOH-Aqueous

4 Session objectives 1. To know about origin and distribution of elements 2. Different modes of occurrence of metals 3. Minerals of India 4. Metallurgy 5. Different methods of concentration of ores 6. Different methods to convert concentrated ore into oxides 7. Methods to convert oxide ore into metal – Smelting, Aluminothermy, Hydrometallurgy, Electrolytic reduction.

5 Origin Of Element Universe 89%H and 11% He
After its formation great decrease in temperature In two hours Formation of stars (made of clouds of H and He) Rise in temperature of stars due to gravity Nuclear fusion reaction started in formation of elements upto iron (atomic number 26)

6 Origin Of Element

7 The Zones in Earth’s Interior
Give circles different colours Mantle (Fe and Mg silicates) Crust(rocks) Outer core (liquid Fe–Ni only) Inner core solid (Fe–Ni)

8 Modes of Occurrence of Elements
Native state Insert pic Combined state

9 Ask yourself Name the element which is extracted from sea water.?
Magnesium Name the element which is extracted from sea weeds.? Iodine

10 Terms Used in Metallurgy
mineral Ore Ganuge or matrix

11 Ask yourself Clay Al2O3.2SiO2.2H2O and bauxite Al2O3.2H2O are two sources of Al. Are they ores or minerals? Al can be obtained profitably only from bauxite.

12 Flux Acidic Flux Removes basic impulses Basic Flux
Flux + gangue Slag (fusible mass) e.g. CaO + SiO CaSiO 2 3 Acidic Flux (slag) Removes basic impulses Basic Flux Removes acidic impurities

13 Refractory materials

14 Furnaces A place where metallurgical processes take place
Cup and cone arrangement for finding Lining of heat resistant bricks Slag hole Hole for molten metal Hot air blast

15 Reverberatory furnace

16 Open Health Furnace Slag steel Hot gases Air Producer gases

17 Bessemer converter Magnesia lining Sand+air

18 Ask yourself Can you name lustrous non-metals? Iodine and graphite

19 Flow sheet for general metallurgical operations
Ore Concentration of ore Conversion of ore into oxides Conversion of ore into free metals Purification of metal

20 Concentration of ore 1. Hand picking : to show by picture
2. Levigation or Hydraulic washing or gravity separation.

21 3. Magnetic Concentration
Concentration of ore 3. Magnetic Concentration animation Wolfarite FeWO4 and Cassiterite SnO2

22 4. Froth Flotation Process
Concentration of ore 4. Froth Flotation Process Froth Ore + pine oil

23 Concentration of ore 5. Leaching Leaching of bauxite Al2O3 2H2O+2NaOH
Bauxite ore 2NaAlO H2O Sodium aluminate Al(OH)3 + NaOH NaAlO2+2H2O Aluminum hydroxide Some chemical properties of ores and Gangue particles are different. Al(OH) Al2O H2O

24 Concentration Leaching of Argentite Ag2S + 4NaCN 2Na[Ag(CN)2] + Na2S
2Na[Ag(CN)2] + Zn Na2 [Zn(CN)4] + 2Ag 4Au + 8KCN+ 2H2O + O2 4K[Au(CN)2] + 4KOH 2K[Au(CN)2] + Zn K2 [Au(CN)4] + 2Au

25 Electrostatic concentration
Principle The good conductors of electricity become electrically charged under the influence of an electrostatic field and therefore they are repelled by electrode carrying the like charge. Example Lead sulphide (good conductor) is separated from zinc sulphide (poor conductor) by this method.

26 Oxidation of ore or conversion of ore into oxide
Concentrated ore Calcination or Roasting Oxide of ore Calcinations Ore is heated in absence of air. Carbonate ores are converted to oxide

27 Ask yourself Name calcination originated from ore calcite which on thermal decomposition gives quick lime.

28 Oxidation of ore or conversion of ore into oxide
Roasting Ore is heated in presence of air. Sulphide ores converted into oxide.

29 Reduction of oxide to free metal
1. Smelting( Reduction by carbon) Oxide Ore + C + flux Metal

30 Reduction of oxide to free metal
2. Auto Reduction or Self Reduction

31 Reduction of oxide to free metal
3. Goldschmidt alumino thermite Process Thermite = 3 parts Fe2O3 + 1 part Al Cr2O Al 2Cr + Al2O3 3Mn3O Al Mn + 4Al2O3 3MnO Al Mn + 4Al2O3   Fe2O Al Fe Al2O3

32 Do you know Silver paint contains Al Gold paint contains Cu

33 Reduction of oxide to free metal
4. Amalgamation Method 5. Hydrometallurgy more reactive metal displaces the less reactive metal from its salts.

34 Electrolytic reduction (electrometallurgy)
Metals of group I and II cannot be obtained by chemical methods due to their highly reactive nature. They are obtained by electrolysis of their chlorides or by hydrolysis in fused state.

35 Do you know Alkali and alkaline earth metals are obtained by electrolysis of their chlorides, oxides and hydroxides.


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