Metallurgy — Part 1: From ore to metal: visual lesson, ICSE Class 10 Chemistry (Science Paper 2)

Lesson

From rock to metal

Part 1 — Most metals are found in the earth as compounds mixed with rock. Metallurgy is the set of steps that turns such a rock into a pure metal.

In this lesson you will

Distinguish between a mineral and an ore and name the ores of iron, aluminium and zinc
Choose a concentration method for a given ore and justify it
Distinguish roasting from calcination with an equation for each
Write equations for reducing metal oxides and link the method to the activity series

Concept

Minerals and ores

A mineral is a naturally occurring compound of a metal in the earth’s crust. An ore is a mineral from which the metal can be extracted conveniently and profitably. So every ore is a mineral, but every mineral is not an ore. The earthy impurities (sand, clay, rock) in an ore are called gangue or matrix.

Table comparing a mineral, an ore and gangue with aluminium examples
Term	Meaning	Aluminium example
Mineral	Natural compound of a metal	Clay and bauxite
Ore	Mineral that gives the metal at a profit	Bauxite only
Gangue	Unwanted rock mixed with the ore	Sand, silica, iron(III) oxide

Concept

Ores of iron, aluminium and zinc

Learn the name and the formula of each ore. Notice the type of compound — it decides how the ore is treated later.

Table of the ores of iron, aluminium and zinc with formulae and type of compound
Metal	Ore	Formula	Type
Iron	Haematite	Fe₂O₃	Oxide
Iron	Magnetite	Fe₃O₄	Oxide (magnetic)
Aluminium	Bauxite	Al₂O₃·2H₂O	Hydrated oxide
Aluminium	Cryolite	Na₃AlF₆	Fluoride
Zinc	Zinc blende	ZnS	Sulphide
Zinc	Calamine	ZnCO₃	Carbonate

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