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Reactivity Siries

The document outlines the extraction of metals, emphasizing that unreactive metals can occur freely while most require processing from ores. Key steps include ore concentration, reduction to crude metal, and refining to obtain pure metal, with methods varying based on the metal's reactivity. It details the extraction of iron, including the raw materials used and the stages involved in the process, such as the production of carbon dioxide and monoxide, reduction of haematite, and removal of impurities.

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Fady Gamal
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23 views17 pages

Reactivity Siries

The document outlines the extraction of metals, emphasizing that unreactive metals can occur freely while most require processing from ores. Key steps include ore concentration, reduction to crude metal, and refining to obtain pure metal, with methods varying based on the metal's reactivity. It details the extraction of iron, including the raw materials used and the stages involved in the process, such as the production of carbon dioxide and monoxide, reduction of haematite, and removal of impurities.

Uploaded by

Fady Gamal
Copyright
© © All Rights Reserved
We take content rights seriously. If you suspect this is your content, claim it here.
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Download as PDF, TXT or read online on Scribd
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Extraction of

metals
Only some unreactive metals such
as silver, gold and platinum can
occur freely in nature. Most metals
react with other elements to form
ores.
Major steps in extraction of metal
 Ore concentration
– Ore is purified and concentrated, unwanted
rocks removed
 Reduction to crude metal
– Metal oxides to be reduced to metals, resulting
in a mixture of metals collected
 Refining to obtain pure metal
– To obtain a specific metal, purify and remove
unwanted metal impurities
the extraction of metals
Method of extraction depends on the position of the metal in
the reactivity series.
 extraction of metal involves:
o getting rid of the unwanted rock to obtain concentrated
form of the mineral
o obtaining pure metal from the mineral by chemical
reactions
the extraction of metals
Metals at the top of the reactivity series are very reactive:
 bonds in their compounds are very strong
 must be extracted by decomposing their compounds with
electricity in an expensive process called electrolysis
 aluminium is extracted from aluminium oxide by passing an
electric current through it

2Al2O3
4Al + 3O2
Ways of Extraction
 Potassium K
Extracted by
 Sodium Na
electrolysis of
 Calcium Ca
molten chlorides
 Magnesium Mg
Extraction by  Aluminium Al
electrolysis of  Zinc Zn
molten Al2O3  Iron Fe Extraction by
dissolved in  Tin Sn reduction of
cryolite  Lead Pb oxides using
 Copper Cu carbon
 Mercury Hg
 Silver Ag
Roasting ore by
 Gold Au
heating alone
 Platinum Pt
Extraction of Iron
Raw materials of extraction of Iron
 Iron Ore
– eg haematite ore [iron(III) oxide,
Fe2O3]
 Coke
– carbon, C
 Hot air
– for the O2 in it
 Limestone
– calcium carbonate, CaCO3
Stage 1 – Production of carbon
dioxide
 Thecoke is ignited at the base and hot air
blown in to burn the coke (carbon) to form
carbon dioxide
– C(s) + O2(g)  CO2(g)
 Thelimestone is decomposed by heat to
produce carbon dioxide & quicklime
– CaCO3(s)  CaO(s) + CO2(g)
Stage 2 – Production of carbon
monoxide
 Athigh temperature, the carbon dioxide
formed reacts with more coke (carbon) to form
carbon monoxide
– CO2(g) + C(s)  2CO(g)
Stage 3 – Reduction of haematite
 The carbon monoxide removes the oxygen
from the iron oxide ore.
 This frees the iron, which is molten at the high
blast furnace temperature, and flows down to
the base of the blast furnace.
 Fe2O3(s) + 3CO(g)  2Fe(l) + 3CO2(g)
 Other possible ore reduction reactions are ...
– Fe2O3(s) + 3C(s)  2Fe(l) + 3CO(g)
– 2Fe2O3 (s) + 3C(s)  4Fe(l) + 3CO2 (g)
Stage 3 – Reduction of haematite
 Waste gases escape through the top of the
furnace
 Eg. Carbon monoxide, carbon dioxide,
nitrogen…
Stage 4 – Removal of Impurities
 The original ore contains silica (SiO2, silicon
dioxide). These react with limestone to form a molten
slag of e.g. calcium silicate in 2 stages
– CaCO3  CaO + CO2
– CaO + SiO2  CaSiO3
 The molten slag forms a layer above the more dense
molten iron and can be separately, and regularly,
drained away. The iron is cooled and cast into pig
iron ingots / transferred directly to a steel producing
furnace
 Slag can be used for road surfacing

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