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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
According to most sources, <strong>the</strong> total sodium sulphate consumption in Europe is estimated at
1.6 million tonnes. Industry experts feel that overall consumption will remain stable or will
slightly decline over <strong>the</strong> next five years, with detergents remaining <strong>the</strong> dominant market.
In recent years, <strong>the</strong> capital investment in sodium sulphate production in Europe has decreased.
Some productions have been stopped among o<strong>the</strong>rs in Italy, some plants have been
debottlenecked, but no new plants have been built.
1.6.2 Industrial processes used
Sodium sulphate is produced ei<strong>the</strong>r from <strong>the</strong> mining of natural sodium sulphate or as a byproduct
from various kinds of processes. As previously mentioned, mining process is not
included in this section.
The six major production processes covered are sodium sulphate as a by-product from:
fibres (rayon/viscose)
Messo process (from ‘Glauber’s salt’, <strong>the</strong> same as fibres)
chromium
Mannheim furnaces (HCl is considered <strong>the</strong> main product) [64, CEFIC-SSPA, 2004]
methionine
formic acid.
Of <strong>the</strong> above processes, <strong>the</strong> production of fibres is <strong>the</strong> dominating route for <strong>the</strong> production of
sodium sulphate as by-product in <strong>the</strong> EU.
Example plants most characteristic to <strong>the</strong> sodium sulphate recovery and production are:
viscose process – sodium sulphate plant in Lenzing, Austria
Mannheim furnace process – sodium sulphate plant of <strong>the</strong> Tessenderlo Group, Belgium
chromium process – sodium sulphate plant Elementis Chromium, Eaglescliffe, UK.
There is much less <strong>information</strong> available on <strong>the</strong> o<strong>the</strong>r process routes (ascorbic acid,
desulphurisation, battery recycling).
The starting materials for sodium sulphate depend on <strong>the</strong> main process, but in common to all
processes <strong>the</strong> production of sodium sulphate starts with Glauber’s salt (sodium sulphate
decahydrate Na2SO4 . 10H2O) or sodium sulphate in solution, which has to be separated from <strong>the</strong>
main product by, or followed by, crystallisation and drying. The different process steps can be
applied in a numerous of ways and with a large variety of equipment, which depend mainly on
<strong>the</strong> main production process used.
The different processes for producing sodium sulphate as a by-product, <strong>the</strong> variations within
each process and <strong>the</strong> varying raw materials, yield sodium sulphate with different purity, particle
size and contents of impurities.
1.6.2.1 Fibres process (Na2SO4 production from <strong>the</strong> viscose-fibre process)
Fibres are produced by spinning viscose in a sulphuric acid precipitation bath in which <strong>the</strong>
following reaction takes place – refer to <strong>the</strong> BREF for <strong>the</strong> Manufacture of Polymers (POL):
2 Cell–OCS2Na + H2SO4 2 Cell–OH + 2CS2 + Na2SO4 (Cell = cellulose)
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