Extraction of Crude Metal from Concentrated Ore Video Lecture - NEET

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as I told once we have got the
concentrated code we have to extract the
crude metal from the concentrated oh so
this is what my raw / this became my
concentrated oh and from this record
this you get impure metal first oh
really
we'll call it cruel winter yeah so when
we now discuss about this process this
is already we have discussed a lot of
methods to get concentrated over from
the raw or normal try to extract the
crude metal from this concentrated Hood
correct so as I told these metals are
generally reactive and they are found
either in oxides or sulphides form it is
metals these concentrate over is really
in the oxide or sulfide or sometimes in
the carburetor
during this form so we have to reduce
this because if you see metal oxide for
example I have or sulfide PBS here this
is plus 2 state and the P or P P will be
plus I mean zero state so we have to
actually reduce these sulfides to metal
or to talk about oxides also the
oxidation number of the metal immiscible
is high so we have to actually reduce
them okay pure metal hope you understood
why we are telling you reduce by way of
saying V naught we don't have oxidized
see all the typically in case of metals
to talk about the oxide carbonates or
sulfides
the oxidation number of metal is high
and in the pure metal form the oxidation
number of
zero so you are talking about the
reduction in the oxidation of iron we
are talking what production process
right so we have to reduce these oxides
or sulphides or carbonate pores to the
metal and also we have noted that it is
easier to reduce oxide oxide easy to
reduce correct so what we do is
sometimes we convert sulphide to oxide
and then reuse it is a sulfide all right
so there are two steps actually they are
calcination and roast so in all these
steps calcination endorsing any heat so
calcination and roasting what we do we
convert to oxide you see we're talking
about conversion to oxide as I told
sometimes the sulfides in the carbonates
we convert to oxide first and then we
reduce oxides to metal so in the first
part calcination are roasting in both
these case the first convert the
sulfites or carbonates to oxide okay so
let us talk about the calcination see
calcination is nothing but again you
need heat removal of volatile fraction
so we try to remove the volatile
fraction on the pole so it implies
simple heating simple heating in
presence of limited air or no air
limited air or almost noise where it
listeth actually air is not required
right so in this case we see the
volatile
material escapes out for example I have
fe2o3
it doesn't water comprehend also from
the social but it is good to have every
two or three so what we do is really
heated and you get Fe 2 O 3 and the
volatile component that is water escaped
out if I have zinc carbonate you heat
this you get zinc oxide and carbon
dioxide if you have calcium carbonate
dot mg Co 3 in this also you heat it it
becomes calcium oxide magnesium oxide in
complex C carburettor also we are
converting into oxide and we are also
removing the volatile component so this
is derived from the Latin word actually
calcination derived from the Latin word
called calcium there and Kelsey near
means one to burn line this process was
actually used to burn line line is what
caco3 CSU three when you heat an absence
of here become CEO and see over so this
same method to Rita or in absence of air
is used here right and it removed the
volatile fashion and also it converts a
carbonates to oxide this is what
calcination please note in the AB cells
or almost limited supply of it the next
is roasting roasting is also same thing
you have to heat this but you heat this
in the presence of air and if you heat
this at a temperature below melting mine
in fact this temperature below melting
point is to even for calculation even
for cancellation we generally heat below
melting point a good example can be if
you see have a jing sulphide you heat
the
the presence of air you get zinc oxide
and so2 gas so in this if you see
sulphide is converted to oxide or you
can balance this same thing I have lead
sulphide like the balanced reaction for
you so you get lead oxide and sulfur
dyes it same thing I have C 2's personal
file not you read this you get cu2o and
so2 right so in all these whatever's so2
gas which you get this is used to
prepare sulfuric acid because see these
reaction happens in a large scale and we
cannot waste so much of sulphur dioxide
this is all industrial process these are
used again to prepared sulfuric acid
okay now one point to note that if
example if copper over has only here
copper sulphide use this method but
let's suppose it has iron also has
impurity so if it has iron also is
impurity what we do is mixed silica also
so whatever happen is example this iron
is my impurity in this case so talking
about this case now let's suppose there
was an impurity with copper sulfide that
means I had or which has Cu 2 s and Fe o
where this is Fe o is my impurity and
this is the copper origin so what we do
is we also mix SiO 2 in the hole or can
you do the same process when you heated
this home slide and this slide can
easily be to move correct why I'm
telling you is this see in this roasting
process of all calcination process it
involves huge amount of heat
in here right so we take advantage of
this heat even if it contains other
impurities we add something to form
slide so the same heat will be used to
forms like you don't need to repeat the
process again and again right so in this
case I had a copper ore which had iron
oxide as impurities we added sio2 there
is silica before this process so that
when this or is being heated my impurity
is converted to slack so they've told
the first step was to convert the
sulfates carbonates to oxides right now
I have bought the oxide or I have got
the oxide or now I have to get the crude
metal from the oxide or by reduction so
it also involves heating but it needs
some reducing agent and you're using it
it is normally carbon why because it is
cheap and it has a good reducing
capability it is available right so if
you talk a few typical reaction an
example metal is my metal n MX co I is a
typical metal oxide you react with some
carbon you get XM and y co carbon
becomes columns on oxide and you get the
metal
this is a typical reaction a good
example is Fe o let's suppose this is my
oxide react with carbon I get Fe plus CO
right now the good part
or the the creek the trick here is some
metals oxide submit lock sides can
easily be reduced by carbon but some are
difficult to reduce right true to
understand why some metal oxides reduce
easily and why some metal oxides are
hard to reduce we need to understand the
concepts of thermals and here is the
application of thermodynamics to make
this process better because I can't say
that carbon is a universal reducing
agent the carbon works in some case it
doesn't work in some case some metals
are easy to reduce so you need some
temperature some metals are hard to
reduce we need baking you may have to
increase the temperature but try to
understand that this reaction happens on
a large scale so this temperature and
this reducing agent both involves cost
both involves money right so we want to
make this better so that the total cost
of the losing agent and the heat is less
and this is where thermodynamics comes
into picture it helps us to identify
that for a given metal oxide which is
the best reducing agent you can use and
what is the optimum temperature you can
use so that the total cost involved is
less correct see there can be a scenario
where if you use a particular reducing
agent you don't even need temperature
but actually what matter is what is the
cost of the to distinguish it is that
available for cheap because it's all at
industrial scale right you want to
minimize the cost the cost is a critical
factor here so we are looking for the
reducing agent which can do it work in a
decent way that should be cheap and also
the temperature required should be in a
decent scale it should not be very high
it should not we have the range 5,000
degree Celsius of right
in Kelvin it should be on the range of
500 600 at the max 100 on 1000 or 1500
Kelvin height of rain
so here thermodynamics helps us thank
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