Polyaluminium chloride (PAC) is increasingly used for water treatment. Against the conventional use of aluminium sulphate (alum) it is showing distinct advantages.
A polyaluminium chloride plant is an investment opportunity with attractive returns in a growing market.
The production process for polyaluminium chloride is including the following reaction steps:
Depending on reaction conditions products with different characteristics are obtained. For the production of polyaluminium chloride 9% special auxiliaries and catalysts are used.
The proposed improved PAC process is giving the following advantages against a conventional process:
- PAC with a concentration of 18% Al2O3 (1-2 % higher)
- PAC with a higher basicity
- Low production cost
- No by-products ( no acidic calcium sulphates)
PRODUCT CHARACTERISTICS AND APPLICATIONS
Polyaluminium chlorides are synthetic polymers dissolved in water. They react to form insoluble aluminium poly-hydroxides which precipitate in big volumetric flocs.The flocs absorb suspended pollutants in the water which are precipitated with the PAC and can together be easily removed.
PAC can be used as a flocculant for all types of water treatment treatment, drinking water, industrial waste water, urban waste water and in the paper industry.
The possible slightly higher unit price of PAC is compensated by a
- lower dosage requirement
- no requirement for any neutralising agent (soda, lime)
- shorter flocculation time
- smaller amount of sludge
- reduced number of back washing steps
- higher quality of the treated water.