P4, M2, D2 – Unit 27 - Applied Science
P4 – illustrate how the productoo of iodustrially importaot ioorgaoic substaoces relates
to the propertes of the substaoces iovolved:
M2 –compare the meaos of commercial productoo of ioorgaoic substaoces io relatoo to
the propertes of the substaoces iovolved:
D2 –evaluate how the method of maoufacture of substaoces is related to their propertes
aod uses:
Productoo of alumioa from bauiite:
At least two tonnes of bauxite are required in order to produce 1 tonne of alumina, so it is
important to consider the proportons required in order to make the substances The way in
which alumina is produced from alumina is by the process called electrochemical smeltnn
This technique is ofen used in other felds of the industry such as cosmetcs, sand paper and
others
There are several stanes which the Bayer process undernoes in order for the product to be
made The frst stane of this process is called the millinn This is where the bauxite material
is washed and it is also nrinded – which would reduce the size of the bauxite partcles
exposinn a lot more surface area In this stane there is also lime and liquor is added The
next stane which the Bayer process has to no throunh in order for the product to be
produced is the desilicaton, which is vital to remove a hinh percentane of silica that is
present in the bauxite Havinn a larne amount of silica could result with a diferent amount
of product beinn formed if it is not removed from the bauxite Afer silica has been
removed, the stane called dineston takes place Hot soda soluton is used in order to
dissolve aluminium molecules which would form sodium aluminate very saturated soluton
An equaton for one of the products called the iibbsite is below;
Al(OH)3 + Na+ + OH- → Al(OH)4- + Na+
The equaton below is for Boehmite and Diaspore;
AlO(OH) + Na+ + OH- + H2O → Al(OH)4- + Na+
The conditons which are important when this takes place is the concentraton of soda
soluton, the temperature at which everythinn takes place and also the pressure which is
applied durinn this It depends on the propertes of ore at which conditons the bauxite must
be kept at Those bauxite ores which are hinh in iibbsite they can be processed at 140°C
Lookinn at the boehmite and diaspore on the other hand, they must be kept at 200 - 280°C
which are clearly very sinnifcantly diferent The pressure is applied by the steam saturaton
temperature, for example temperatures of boehmite at around 240°C would have pressure
applied to them at approximately 35 MPa When that has been done, the bauxite is cooled
down to 105°C by usinn diferent water tanks When the bauxite reaches a desired
temperature there would be injectons of hinher quality bauxite which states to be
stmulatnn a beter and more efcient producton of alumina The substance is then heated
further to raise the temperature It is not always nood to put the substances into hinh
P4 – illustrate how the productoo of iodustrially importaot ioorgaoic substaoces relates
to the propertes of the substaoces iovolved:
M2 –compare the meaos of commercial productoo of ioorgaoic substaoces io relatoo to
the propertes of the substaoces iovolved:
D2 –evaluate how the method of maoufacture of substaoces is related to their propertes
aod uses:
Productoo of alumioa from bauiite:
At least two tonnes of bauxite are required in order to produce 1 tonne of alumina, so it is
important to consider the proportons required in order to make the substances The way in
which alumina is produced from alumina is by the process called electrochemical smeltnn
This technique is ofen used in other felds of the industry such as cosmetcs, sand paper and
others
There are several stanes which the Bayer process undernoes in order for the product to be
made The frst stane of this process is called the millinn This is where the bauxite material
is washed and it is also nrinded – which would reduce the size of the bauxite partcles
exposinn a lot more surface area In this stane there is also lime and liquor is added The
next stane which the Bayer process has to no throunh in order for the product to be
produced is the desilicaton, which is vital to remove a hinh percentane of silica that is
present in the bauxite Havinn a larne amount of silica could result with a diferent amount
of product beinn formed if it is not removed from the bauxite Afer silica has been
removed, the stane called dineston takes place Hot soda soluton is used in order to
dissolve aluminium molecules which would form sodium aluminate very saturated soluton
An equaton for one of the products called the iibbsite is below;
Al(OH)3 + Na+ + OH- → Al(OH)4- + Na+
The equaton below is for Boehmite and Diaspore;
AlO(OH) + Na+ + OH- + H2O → Al(OH)4- + Na+
The conditons which are important when this takes place is the concentraton of soda
soluton, the temperature at which everythinn takes place and also the pressure which is
applied durinn this It depends on the propertes of ore at which conditons the bauxite must
be kept at Those bauxite ores which are hinh in iibbsite they can be processed at 140°C
Lookinn at the boehmite and diaspore on the other hand, they must be kept at 200 - 280°C
which are clearly very sinnifcantly diferent The pressure is applied by the steam saturaton
temperature, for example temperatures of boehmite at around 240°C would have pressure
applied to them at approximately 35 MPa When that has been done, the bauxite is cooled
down to 105°C by usinn diferent water tanks When the bauxite reaches a desired
temperature there would be injectons of hinher quality bauxite which states to be
stmulatnn a beter and more efcient producton of alumina The substance is then heated
further to raise the temperature It is not always nood to put the substances into hinh
