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This document has not been fully peer reviewed and <strong>the</strong> <strong>information</strong> within is not validated nor endorsed by <strong>the</strong> TWG
on LVIC-S or by <strong>the</strong> European Commission, it is meant for <strong>information</strong>, only
Due to different types of polyaluminium chloride (PAC) with different aluminium contents, all
tonnage related data are normalised to one common PAC with a content of 9 % aluminium and
are calculated on this basis. About 520000 tonnes of PAC were produced in Europe in 2002 at
about 17 locations [89, CEFIC-INCOPA, 2004].
1.1.1.2 Process description
1.1.1.2.1 Aluminium hydroxy chloride
Aluminium hydroxy chloride is formed directly by <strong>the</strong> digestion of aluminium hydroxide and
hydrochloric acid in an under-stoichiometric reaction. The reaction is carried out at a
temperature between 140 and 160 °C and pressure between 3 and 5 bars. After <strong>the</strong> reaction,
insoluble aluminium hydroxide is removed by filtration and is used again at <strong>the</strong> beginning of <strong>the</strong>
process. The clear liquid is conditioned with water to become <strong>the</strong> finished product of a well
defined quality.
2
Al(OH)3 + HCl F Alx(OH)yClz + H2O
The process diagram of <strong>the</strong> manufacture of aluminium hydroxy chloride is given in Figure 1.1.
Al(OH) 3
HCl
Reaction Filtration
Unreacted Al(OH) 3
PAC
Figure 1.1: Process flow diagram – manufacture of aluminium hydroxy chloride
[89, CEFIC-INCOPA, 2004]
1.1.1.2.2 Aluminium hydroxy chloride sulphate
Aluminium hydroxy chloride sulphate is formed by <strong>the</strong> digestion of aluminium hydroxide with
hydrochloric acid and sulphuric acid. The reaction is carried out at a temperature between
105 and 115 °C. The reaction solution is partially neutralised by CaCO3 slurry to remove
excessive sulphate by forming gypsum (CaSO4 . 2 H2O). The mo<strong>the</strong>r liquor is separated from <strong>the</strong>
gypsum by filtration. The gypsum is washed and <strong>the</strong> washing water is used to condition <strong>the</strong>
product.
Al(OH)3 + HCl + H2SO4 + CaCO3 F Alp(OH)qClr(SO4)s + H2O + CaSO4 + CO2
The process diagram of <strong>the</strong> manufacture of aluminium hydroxy chloride sulphate is given in
Figure 1.2.