Metallurgy

class 10 icse

Liquid Metal

Mercury

Liquid Non Meal

Bromine

Constituent of blood pigment

Iron

Metal present in insulin

zinc

Metal present in vitamin B-12

Cobalt

Metal present in chlorophyll

Magnesium

Name some metalloids

Boron, Silicon and Germanium

It is a constituent of blood pigment

Iron

Define minerals

Naturally occuring compounds of metals which are generally mixed with other substances like soil, mud, sand, silico(SiO₂), etc.

Name some gangue(earthly impurities)

Soil, mud, sand, Silicon(SiO₂)

What are ores

Ores are those minerals from which metals are extracted commercially at a comparatively lower cost and with minimum effort

Name the main ore of Aluminum with Formula

• Bauxite: Al₂O₃.2H₂0

• Cryolite(Na₃AlF₆)

• Corundum(Al₂O₃)

Name the main ores of Zinc with their formula

• Zinc Blende: ZnS

• Zincite: ZNO

• Calamine: ZnCO₃

Principle of Froth Floatation process

This process depends on the potential wettaility of the ore with oil(pine oil) and gangue particles by water

Ores concentrated by Froth Floatation process

Sulphide ores

What is roasting

It is a process of heating the concentrated air to a high temperature in the present of air

What is Calcination

If an ore is a carbonate or a hydrated oxide, it is heated in the a bsence of air to a temperature that is high enough but insufficient to melt the ore.

Zinc Oxided cannot be reduced by Carbon Monoxide or Hydrogen(Reason)

This is because they are unable to overcome the affinity of zinc towards oxygen. Therefore, zinc oxide is reduced only by heating with carbon which is a stronger reducing agent as compared to carbon monoxide and hydrogen

Powerful reducing agent

Aluminum

Aluminothermy

When a mixture of aluminium powder and iron oxide is ignited, the latter is reduced to metal.

What is Purification of Bauxite Ore

Conversion of bauxite into alumina

Bayer’s process(reaction)

• Al₂O₃ . 2H₂O + 2NaOH → 2NaAlO₂ + 3H₂O

• NaAlO₂ + H₂O → NaOH + Al(OH)₃

• 2Al(OH)3 (heat, 200^D C) → Al₂O₃ + 3H₂O

What is the role of Sodium Hydroxide in bayer’s process

Bauxite dissolves and form sodium meta aluminate because of the amphoteric nature of aluminum, leaving behind insoluble impurities called Red mud

Give reaction for:

• Sodium Meta aluminate with water

• Drying of the precipate formed.

• NaAlO₂ + H₂O → NaOH + Al(OH)₃

• 2Al(OH)3 (heat, 200^D C) → Al₂O₃ + 3H₂O

Give the reaction for cathode and Anode for bayer’s process

Why does anode needs to be replaced from time to time

It gets oxidised by the oxygen evolved at the anode

Cryolite(function)

• Lowers the fusion temperature from 2050 d C to 950 dC

• Enhances Conductivity

Fluorspar and cryolite (function)

• Acts as a solvent for electrolytic mixture

• increases its conductivity

Powdered Coke(Function)

• Reduces Heat Loss by Radiation

• Prevents the burning of Anode

Define Allow

An alloy is a homogenous mixture of two or metals or one more metals with certain non metallic elements

Composition of Duralumin

Al, Cu, Mg, Mn

Composition of Stainless Steel

Fe, Cr, Ni, C

Composition of Brass

Cu, Zn

Composition of Bronze

Cu, Sn, Zn(Optional)

Composition of Solder

Pb, Sn

Composition of Type Metal

Pb, Sn, Sb

It is used for making aircraft parts

Magnalium

it is used for making utensils, Cutlery, Surgical Instruments

Stainless steel

It is used for making electrical goods

brass

It is used for soldering purposes & printing blocks

Lead

Metal present in chlorophyll

Magnesium

Main ore of iron

Ferris

Define Amalgam

A mixture of an alloy of mercury with a number of metals or allows such as sodium, zinc, gold, or silver as well as with some non metals is known as amalgam

Name a metal present in cryolite other then Na

Aluminium

Impurities present in minerals

Gangue or matrix

Name a divalent metal present in Fluorspar

Ca

Name a divalent metal present in fluorspar

Calcium