(BAT) Reference Document for the Production of Chlor-alkali ...

3.3.3 Ancillary materials
Ancillary materials are used in various steps of the processes:
Chapter 3
the main products used to remove impurities from the brine are sodium carbonate, barium
salts, calcium chloride and sodium hydroxide
hydrochloric acid is used to adjust the pH of cells and reduce undesirable products in
chlorine
sulphuric acid is used for chlorine drying
{The information of the first three bullets is included in the table below.}
inhibitors can be added to cooling water systems
{This is covered by the BREF on Industrial Cooling Systems.}
sodium carbonate can be used in mercury retorting to react with sulphur compounds as
well as sodium hydrosulphide
reducing agents (hydrazine or sulphides) are used to remove mercury in waste water,
flocculants such as ferric chloride and polyaluminium chloride are used for water
purification in the waste water treatment process
{This information was moved below the table.}
The use and consumption levels of the main ancillary materials are listed in Table 3.4. In
general, the consumption of ancillary materials depends on the purity of the salt, with vacuum
salt requiring only limited quantities [ 3, Euro Chlor 2011 ].
WORKING DRAFT IN PROGRESS
TB/EIPPCB/CAK_Draft_1 December 2011 69