Metals are commonly found within ores, which are rocks containing minerals. Ores form over long periods of time through intense heat and pressure. While ores are not a renewable resource on a human timescale, they can be extracted through mining. Common extraction methods include smelting, which uses high temperatures to separate metals from ores, and electrolysis to extract pure metals like copper. Recycling metals provides environmental and economic benefits compared to extracting virgin materials, as it requires far less energy. Aluminum in particular is widely recycled as it only uses 5% of the energy needed for primary aluminum production.

2. In terms of chemistry, metals are vastly the majority of the natural elements. Metals
are typically characterised by:
• High melting points
• High density
• High conductivity (free flowing electrons)
• Usually have high or easy malleability
Metals in mining terms are usually derived from ‘ores’.
An ore is a type of rock containing minerals such as:
• Gemstones
• Metals
Ores are usually the formations of two or more
Elements, e.g. Acanthite Ag₂S (Silver Sulfate)
(to the right: a piece of platinum surrounded by its ores)

3. • As stated in the previous slide, Ores are what we use to obtain our natural
metals.
• Some of the processes in which we obtain the metals from these ores can vary
from physical/mechanical means or chemical means, e.g. Reaching a point to
which one element changes physically and hence extracting the other
element(s).
• Are ores a renewable resource?
In terms of human lifetimes, no. Ores are not
a renewable source, because it takes much
Longer than human lifetime for ores to form, as
They need intense pressure and heat to be
Formed. Much like any other rock.
(to the right: a conveyor belt carrying ore across a mine)

4.  Ore is traditionally extracted by mining for it as shown in the picture below
and on the previous slide.
 Ore usually is looked at with an economical view at first, as if extracting these
ores costs more than what it will make by being sold, then there is absolutely
no point in attempting to extract it in the first place in the eyes of the sellers
like ‘RioTinto’.
 Yielding in the mining industry usually is not considered, the only real goal any
big mining company has in mind is to take money. So with this, often all the
ore that can possibly be found is usually harvested and sold.
However if the companies do not intend to leave a bit
for the natural environment, our supply of ore could
quickly run out, increasing the cost of naturally pure
metals around the globe.
And in more recent times with the environment
becoming a hot topic in the business, many companies
are looking for more sustainable options with less
impact.

5.  The most common process for the separation of metals from their ore is smelting
(pyrometallurgy).
Smelting is the process by which the ore is brought to a certain heat where the metal
remains as a liquid while the other substances contained within the ore are either
evaporated away as gas or remain there as solids(very rare).
Smelting is most often used in copper extraction from many of its ores
(Azurite, Malachite and Cuprite.)
Another process by which we can extract copper is by mixing chalcopyrite
(CuFeS₂) by heating this chalcopyrite(roasting), it is
Reacting with oxygen to form iron oxide, copper sulfate
And finally sulfur dioxide. The final process to get near
Pure copper is electrolysis of copper sulfate
2CuFeS2(s) + 3O2(g) → 2FeO(s) + 2CuS(s) + 2SO2(g)
(the above process involved both electrometallurgy with
Electrons and hydrometallurgy with aqueous solutions)
(to the right: copper ore)

6.  Often with copper, it is combined to form certain alloys, for example brass
which is used to make instruments and has a shiny gold appearance.
 Because of this, copper can be extracted through separation by smelting, this
involves the metal being heated to very high temperatures and the separated by
the temperature difference (as zinc and copper have different melting points).
 Primarily copper is one of the three metals primarily used in industry and
housing because of its high conductivity and malleability. This is why it is in
such high demand, as the metal has a huge value in everyday lives and jobs.
The general ways of extracting copper from their ores are big consumers of
energy, as most require both heating up and
electrolysis to get a decent purity percentage
of copper.
 (to the right: the liquid metal after smelting)

7.  Aluminium like every other metal is much easier to recycle compared to
mining it and electrolysing the Iron oxide.
 This is because scrap aluminium (like drink cans) is easily obtained from
recycling factories and simply just re-melted and formed into whatever object
it needs to be made into.
 Whereas with the natural resource, the first step is mining the bauxite ore and
then converting it to Iron oxide through pyrometallurgy and finally
electrolysing the final product to create aluminium in the purest form for use.
Because recycling aluminium only uses 5% of the
energy that creating new aluminium does, it is
being used much more widely as an environmental
incentive and a more cost effective system.
(to the left: crushed aluminium cans ready to be
melted and re-used)

8.  The steps in recycling aluminium are as follows:
 Collecting all used materials from either cans, wire, bikes and many more
things
 Processing it through a recycling plant by separating it into categories and
crushing it into cubes
 Sending off to the mills to be processed, melted and reformed into useful
things like cans, aeroplane parts and computer parts etc...
Aluminium is often used in cookware too as it has a high thermal
conductivity, meaning it can retain and gain heat much easier than other
objects with lower thermal conductivity.
Aluminium is a valuable
resource in our society, and we
need to make sure we retain it
for future use.

9.  Pictures from www.google.com last accessed 18th march
 http://en.wikipedia.org/wiki/Ore last accessed 18th march
 www.riotinto.com last accessed 18th march
 http://www.nickelinstitute.org/index.cfm/ci_id/263.htm#Metals%20and%20S
ustainable%20Development last accessed 18th march
 http://www.unr.edu/sb204/geology/smelt.html last accessed 18th march
 http://resources.schoolscience.co.uk/CDA/14-16/cumining/copch2pg3.html
last accessed 18th march
 http://en.wikipedia.org/wiki/Aluminium_recycling last accessed 22nd march
 http://www.azom.com/details.asp?articleID=1388 last accessed 22nd march
 Books: Chemistry by Silberberg and Chemistry by Olmsted & Williams last
used 22nd march

10. Thank You