Difference between polyaluminum chloride and polyaluminum ferric chloride

Aluminum chloride (Pac) and polyaluminum ferric chloride (PAFC) are two commonly used inorganic polymer flocculants, the main differences are as follows:

1. Differences in composition and appearance

● Polyaluminium chloride (PAC)
● It is mainly composed of aluminum, and its color is mostly yellow, beige or white (high purity drinking water grade).
● Polyaluminium ferric chloride (PAFC)
● Aluminum and iron (iron content about 2-10%) are present and appear reddish brown or brownish brown.

2. Raw materials and production process

● PAC raw material
● Drinking water grade requires aluminum hydroxide powder, industrial grade can use aluminum ash, aluminum slag and other waste materials.
● PAFC raw material
● It is prepared by using aluminum calcium powder or iron-containing raw materials (such as ferric chloride) in combination.
● production engineering
● PAC is commonly used spray drying method (higher purity), PAFC is mostly used drum drying method.

3. Scope of application and treatment effect

● PAC application scenarios
● Drinking Water Purification: the treated water is soft and there is no residual aluminum ion harm.
● Low turbidity Water Treatment: such as river water purification, prevent fabric hardening.
● PAFC application scenarios
● High turbidity industrial wastewater: steel mills, paper mills, sewage plants, etc., flocculation speed is fast, sedimentation effect is significant.
● Low temperature turbid water: iron element enhances the adaptability to low temperature.

4. Performance and cost

● PAC merit
● High safety, suitable for drinking water treatment;
● The removal effect of organic matter and chromaticity is better.
● PAFC merit
● The dense and fast settling of the flower is suitable for high difficulty wastewater;
● The cost is lower, saving 10-20% of the agent cost compared to PAC.

5. Precautions

● PAC limitation: the treatment effect of low temperature and low turbidity water is poor.
● PAFC limit: iron content may slightly affect the color of effluent and is not suitable for drinking water.

Summarize recommendations

● Choose PAC: drinking water, low turbidity water or scenes that require strict control of aluminum.
● Choose PAFC: industrial wastewater, high turbidity or scenes that require rapid sedimentation.