Stone Crusher Spare Parts Manufacturer and Supplier - VK Metal Cast & Engineering Brochure
From Stone to Mystic Metal
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Transcript of From Stone to Mystic Metal
From Stone to Mystic Metal
A journey of discovery
Before metals
• Pre 9000 BCE - Stone Age
• Malachite (a green copper ore) and Hematite (a red iron ore) ground to powder and used for art work
• Coloured ores used as jewellery
• All tools made from stone and wood
Discovery of metals
• Earliest known metals were “native”metals
• Found as nuggets
• Copper, silver, gold
Ores
• Compared to pure metals, ores were just rocks
• No ‘metallic splendour’
Native Metals vs OresNative metal Ore
Lustre (Shiny) Some are glittery
Malleable (can be hammered into sheets) Shatter when hit by a
hammerDuctile (can be drawn into wires)
Conduct electricity and heat Don’t conduct electricity and heat
Insoluble Insoluble
Don’t burn Don’t burn
Native metals could be....
• Converted to a state similar to ores by heating with sulphur
• Earliest forms of ores (metal sulphides)
• Formed naturally by heat and sulphur from volcanic activity
• This can also be done by heating in air (oxygen)
• This form of ore (metal oxides) developed naturally after plant life formed on Earth.
Timeline
Major Discovery!
• Ores can be converted to metal by heating with charcoal
• Discovered by accident?
• Copper bearing rocks around a camp fire
• Inefficient method but...
•
Copper Smelting• Development of a simple clay kiln plus use of
bellows - much more efficient due to increased temperature
Copper smelting
Progress
• Without the discovery of the smelting process...
• No extraction of other “non-native” metals such as tin or iron
• No Bronze or Iron Ages (and no further progress!)
The Thermite reaction
Alloys
• A mixture of metals
• Have different properties to the metals that make them up
• Bronze - a mixture of copper and tin
• Brass - a mixture of copper and zinc
Reactivity seriesA list showing metals in order of their reactivity
(from most to least)
• Magnesium
• Aluminium
• Zinc
• Iron
• Lead
• Copper
Note: This list is a partial list
Going from bottom to top, the metals:
• increase in reactivity;
• lose electrons more readily to
form positive ions;
• corrode or tarnish more
readily;
• require more energy (and
different methods) to be
separated from their ores
Metal Reactivity ExtractionPotassium K
React with waterElectrolysis
Sodium Na
Lithium Li
Strontium Sr
Calcium Ca
Magnesium Mg
React with acids
Aluminium Al
Zinc Zn
Smelting with coke
Chromium Cr
Iron Fe
Cadmium Cd
Cobalt Co
Nickel Ni
Tin Sn
Lead Pb
Copper Cu
Highly unreactiveHeat or physical
extraction
Silver Ag
Mercury Hg
Gold Au
Platinum Pt
Transition Metals
Transition Metals•Cobalt - Pink
•Manganese - Orange
•Copper/Nickel - Blue or Greenish Blue
•Iron - pale Green or Red
•Titanium/Zinc- White
•Vanadium - Yellow
•Chromium - Yellow/Red
•Note all bunched together in terms of weight
•All the coloured salts are multi-valency
•Valency = the number of bonds an atom will form with another element