To show two crystallisation processes: one in the laboratory and
one in industry.
On the left-hand
side of illustration ST 09 the crystallization of a solution of aqueous
copper sulphate can be seen.
the water evaporates slowly beautiful blue crystals of copper sulphate
are formed. Copper sulphate is thus separated from the solvent in a homogeneous
On the right of the illustration the extraction of salt from seawater
is shown. This is a technique that is used frequently in many Southern
European countries. The seawater is transferred via sluice gates into
the first settlement basin (A). Here the sand and mud sink to the bottom.
The clarified seawater then passes through sluice gates into the first
crystallisation basin (B). Here, the less soluble calcium salts precipitate
out (among others, the calcium halides).
Some evaporation takes place in this basin and so the concentration of
the sodium chloride increases. When the original volume has been reduced
by a factor of 10, the almost saturated salt solution is transferred via
sluice gates into the shallow salt basins (C). Common salt (NaCl) crystallises
out as the water evaporates. The crystallised salt is gatheredinto heaps