What the uses of polyaluminum chloride

Poly aluminum chloride is a type of acidic solution, considered corrosive when at a higher concentration. It is generally yellow and miscible in water at any concentration, but dilute solutions hydrolyze to precipitate Al (OH) 3 (aluminum hydroxide). Polyaluminum chloride is composed of polymers classified according to their basicity and their resistance (generally in% of Al2O3).

Poly Aluminum Chloride or PAC is a coagulant used for water purification. When comparing PAC with other types of aluminum salts, it is more suitable for destabilizing and removing suspended matter, due to its higher load. PAC is commonly used in water purification systems to ensure that water is safer to drink. Similar to other coagulants, polyaluminum chloride extracts dissolved material present in water to suspend and aggregate material together. The material can then be filtered and removed.

How is polyaluminum chloride produced?

PAC is made up of these components: 30 to 40 parts of calcium carbonate. 70 to 90 parts of calcium aluminate. 160 to 190 parts of hydrochloric acid (2030%). 100 to 121 parts of bauxite. Here is a summary of the production process :

Bauxite is heated to a temperature of 12001500 ° C for 30 minutes to 2 hours. The bauxite is then crushed and combined with calcium aluminate inside a device called a reaction kettle. 25 to 30% hydrochloric acid are then added to the kettle. The mixture is then brought to a temperature of 95110 ° C. for 1 to 3 hours. The mixture is then left to stand for 15 to 24 hours to allow the reaction, which forms polyaluminum chloride. At a temperature of 105 ° C, the final solution is usually dehydrated and a sample is taken for analysis.

The advantages of using PAC 

About the advantages of using PAC. When using it, it produces much less sludge. Very efficient. Coagulant Requires smaller volumes than alum (in water treatment systems) Very versatile (has different fields of 'application). As it has lower corrosivity, it is easier to use, transport and store. The flakes that form are easier to filter It is a cheaper product to use than aluminum sulfate. This grade refers to the concentration of hydroxyl groups bonded to aluminum ions. In general, when it comes to using PAC when the basicity is higher, the efficiency, the polymer value and the cationic charge density are also higher. Polyaluminum coagulants are also increasingly used in portable wastewater treatment plants. In many situations during the post-treatment pH adjustment process, the use of alkali was found to be irrelevant or unnecessary. Not only does this have positive effects on water quality, but it also offers significant savings in terms of maintenance requirements and overall production costs.